Search Results

Search found 66801 results on 2673 pages for 'near real time'.

Page 462/2673 | < Previous Page | 458 459 460 461 462 463 464 465 466 467 468 469  | Next Page >

  • Controlling Brightness in Sony Vaio SVE151A11W |Not Working|

    - by Rabimba Karanjai
    Disclaimer First: I have gone thorugh these following threads here and followed all of their advice but none of them worked Brightness Control Problem on Sony VAIO with NVIDIA GT-320M unable to change brightness settings in sony vaio e series laptop Brightness doesn't change on Sony laptop Now the Problem I have installed Ubuntu 12.10 (64bit) in this Sony Vaio laptop. After vanilla isntallation the brightness keys are workinga nd I can see the brightness indictaor going up and down buit its isn't having any effect on the real brightness of the device. I have installer additional drivers too but that didn't solve the problem. I can't seem to be able to change the brightness. Anyone knows how I can fix this?

    Read the article

  • Soluto’s New Quick Question Button Makes Family Tech Support Simple

    - by Jason Fitzpatrick
    Soluto, a computer and boot management tool, now features a Quick Question button that allows the people you help out to easily click a button and send you both a short message and a screenshot of the problem. Any time your friend or family member presses F8, Soluto will take a screenshot of the screen, the Task Manager history, and a note from the user highlighting what issue they’re experiencing, and then email it all to you. After reviewing the email you can easily login to Soluto to remotely manage your friend’s computer and help with the problem. For more information about Soluto you can check out our previous reviews of the service here and here, or just hit up the link below to read more and take Soluto for a test drive. Soluto is a free service (for the first 5 computers), Windows only. Introducing Quick Question [The Soluto Blog] Java is Insecure and Awful, It’s Time to Disable It, and Here’s How What Are the Windows A: and B: Drives Used For? HTG Explains: What is DNS?

    Read the article

  • Week in Geek: Facebook Valentine’s Day Scams Edition

    - by Asian Angel
    This week we learned how to get started with the Linux command-line text editor Nano, “speed up Start Menu searching, halt auto-rotating Android screens, & set up Dropbox-powered torrenting”, change the default application for Android tasks, find great gift recommendations for Valentine’s Day using the How-To Geek Valentine’s Day gift guide, had fun decorating our desktops with TRON and TRON Legacy theme items, and more Latest Features How-To Geek ETC Internet Explorer 9 RC Now Available: Here’s the Most Interesting New Stuff Here’s a Super Simple Trick to Defeating Fake Anti-Virus Malware How to Change the Default Application for Android Tasks Stop Believing TV’s Lies: The Real Truth About "Enhancing" Images The How-To Geek Valentine’s Day Gift Guide Inspire Geek Love with These Hilarious Geek Valentines Four Awesome TRON Legacy Themes for Chrome and Iron Anger is Illogical – Old School Style Instructional Video [Star Trek Mashup] Get the Old Microsoft Paint UI Back in Windows 7 Relax and Sleep Is a Soothing Sleep Timer Google Rolls Out Two-Factor Authentication Peaceful Early Morning by the Riverside Wallpaper

    Read the article

  • What a Performance! MySQL 5.5 and InnoDB 1.1 running on Oracle Linux

    - by zeynep.koch(at)oracle.com
    The MySQL performance team in Oracle has recently completed a series of benchmarks comparing Read / Write and Read-Only performance of MySQL 5.5 with the InnoDB and MyISAM storage engines. Compared to MyISAM, InnoDB delivered 35x higher throughput on the Read / Write test and 5x higher throughput on the Read-Only test, with 90% scalability across 36 CPU cores. A full analysis of results and MySQL configuration parameters are documented in a new whitepaperIn addition to the benchmark, the new whitepaper, also includes:- A discussion of the use-cases for each storage engine- Best practices for users considering the migration of existing applications from MyISAM to InnoDB- A summary of the performance and scalability enhancements introduced with MySQL 5.5 and InnoDB 1.1.The benchmark itself was based on Sysbench, running on AMD Opteron "Magny-Cours" processors, and Oracle Linux with the Unbreakable Enterprise Kernel You can learn more about MySQL 5.5 and InnoDB 1.1 from here and download it from here to test whether you witness performance gains in your real-world applications.  By Mat Keep

    Read the article

  • Fix Windows Computer Problems with Microsoft Fix it Center

    - by Matthew Guay
    Fixing computer problems can often be difficult, but Microsoft is aiming to make it as simple as a couple clicks with.  Here’s how you can easily fix computer problems with Microsoft’s new Fix it Center Beta. Last year Microsoft began offering small Fix it scripts that you could download and run to help solve common computer problems automatically.  These were added to some of the most visited Windows help pages, and helped fix problems with things such as printing errors and Aero glass support.  Now, the Fix it scripts have been bundled together with the Fix it Center, making fixing your computer even easier.  This free tool works great on all editions of Windows XP, Vista, and Windows 7. Note: The Fix it Center is currently in beta, so only run if you are comfortable running beta software. Getting Started Download the Fix it Center installer (link below), and install as normal. The installer will download the remaining components, and then finish the installation. In Windows XP, if you have not yet installed .NET 2.0, you may see the following prompt.  Click Yes to go to the download site, and once you’ve installed .NET 2.0, run the Fix it Center setup again. Also, the Fix it Center uses PowerShell to automate its fixes, but if it is not installed yet the installer will automatically download and install it. Find Fixes for Your PC Once Fix it Center is installed, you can personalize it for your computer.  Select Now, and the click Next. It will scan your computer for problems with known solutions, and will offer to go ahead and install these troubleshooters.  If you choose to not install them, you can always download them from within the Fix it Center at a later time. While those troubleshooters are downloading, you can create a Fix it account.  This will give you additional help and support, and let you review Fix it solutions for all your computers from an online dashboard.  You need a Windows Live ID to create an account. Also, choose whether or not to send information to Microsoft about your hardware and software problems. Get Problems Fixed Now that the Fix it Center is installed and has identified issues on your computer, it’s time to get the problems fixed.  Here’s the default front screen in Windows 7, showing all of the available fixes. And here’s the Fix it Center running in Windows XP. Select one of the Troubleshooters to see more information about it, and click Run to start it. You can choose to either detect problems and have them fixed automatically, or you can choose for the Fix it Center to show you the solutions and let you choose whether to apply them or not.  The defaults usually work good, and only take a couple minutes to apply the fixes, but you can select your own fixes if you’d rather be in control. It will scan your computer for known problems in this area, and then will show you the results.  Here, Fix it determined that startup programs may be causing performance issues.  Select Start System Configuration, and uncheck any of the programs you do not usually use. Once you’ve run a troubleshooter, you can see the issues it checked for and any problems it discovered. If you created the online account, you can also choose to view the details online.  This will show all of your computers with Fix it Center and the fixes you’ve run on them.   Conclusion Whether you’re a power user or new to computers, sometimes it’s best to just get your problems fixed and go on with life instead of digging through the registry, forums, and hacking your way to a solution.  Remember the service is still in beta and may not work perfectly or solve your issues every time. But it’s something cool and worth a look. Links Download Microsoft Fix it Center Beta Fix additional problems with Microsoft’s Fix it Center Online Similar Articles Productive Geek Tips Disable Windows Mobility Center in Windows 7 or VistaMake Outlook Faster by Disabling Unnecessary Add-InsUsing Netflix Watchnow in Windows Vista Media Center (Gmedia)Disable Security Center Popup Notifications in Windows VistaHow To Manage Action Center in Windows 7 TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 Icelandic Volcano Webcams Open Multiple Links At One Go NachoFoto Searches Images in Real-time Office 2010 Product Guides Google Maps Place marks – Pizza, Guns or Strip Clubs Monitor Applications With Kiwi

    Read the article

  • How to Play FLAC Files in Windows 7 Media Center & Player

    - by Mysticgeek
    An annoyance for music lovers who enjoy FLAC format, is there’s no native support for WMP or WMC. If you’re a music enthusiast who prefers FLAC format, we’ll look at adding support to Windows 7 Media Center and Player. For the following article we are using Windows 7 Home Premium 32-bit edition. Download and Install madFLAC v1.8 The first thing we need to do is download and install the madFLAC v1.8 decoder (link below). Just unzip the file and run install.bat… You’ll get a message that it has been successfully registered, click Ok. To verify everything is working, open up one of your FLAC files with WMP, and you’ll get the following message. Check the box Don’t ask me again for this extension and click Yes. Now Media Player should play the track you’ve chosen.   Delete Current Music Library But what if you want to add your entire collection of FLAC files to the Library? If you already have it set up as your default music player, unfortunately we need to remove the current library and delete the database. The best way to manage the music library in Windows 7 is via WMP 12. Since we don’t want to delete songs from the computer we need to Open WMP, press “Alt+T” and navigate to Tools \ Options \ Library.   Now uncheck the box Delete files from computer when deleted from library and click Ok. Now in your Library click “Ctrl + A” to highlight all of the songs in the Library, then hit the “Delete” key. If you have a lot of songs in your library (like on our system) you’ll see the following dialog box while it collects all of the information.   After all of the data is collected, make sure the radio button next to Delete from library only is marked and click Ok. Again you’ll see the Working progress window while the songs are deleted. Deleting Current Database Now we need to make sure we’re starting out fresh. Close out of Media Player, then we’ll basically follow the same directions The Geek pointed out for fixing the WMP Library. Click on Start and type in services.msc into the search box and hit Enter. Now scroll down and stop the service named Windows Media Player Network Sharing Service. Now, navigate to the following directory and the main file to delete CurrentDatabase_372.wmdb %USERPROFILE%\Local Settings\Application Data\Microsoft\Media Player\ Again, the main file to delete is CurrentDatabase_372.wmdb, though if you want, you can delete them all. If you’re uneasy about deleting these files, make sure to back them up first. Now after you restart WMP you can begin adding your FLAC files. For those of us with large collections, it’s extremely annoying to see WMP try to pick up all of your media by default. To delete the other directories go to Organize \ Manage Libraries then open the directories you want to remove. For example here we’re removing the default libraries it tries to check for music. Remove the directories you don’t want it to gather contents from in each of the categories. We removed all of the other collections and only added the FLAC music directory from our home server. SoftPointer Tag Support Plugin Even though we were able to get FLAC files to play in WMP and WMC at this point, there’s another utility from SoftPointer to add. It enables FLAC (and other file formats) to be picked up in the library much easier. It has a long name but is effective –M4a/FLAC/Ogg/Ape/Mpc Tag Support Plugin for Media Player and Media Center (link below). Just install it by accepting the defaults, and you’ll be glad you did. After installing it, and re-launching Media Player, give it some time to collect all of the data from your FLAC directory…it can take a while. In fact, if your collection is huge, just walk away and let it do its thing. If you try to use it right away, WMP slows down considerably while updating the library.   Once the library is setup you’ll be able to play your FLAC tunes in Windows 7 Media Center as well and Windows Media Player 12.   Album Art One caveat is that some of our albums didn’t show any cover art. But we were usually able to get it by right-clicking the album and selecting Find album info.   Then confirming the album information is correct…   Conclusion Although this seems like several steps to go through to play FLAC files in Windows 7 Media Center and Player, it seems to work really well after it’s set up. We haven’t tried this with a 64-bit machine, but the process should be similar, but you might want to make sure the codecs you use are 64-bit. We’re sure there are other methods out there that some of you use, and if so leave us a comment and tell us about it. Download madFlac V1.8  M4a/FLAC/Ogg/Ape/Mpc Tag Support Plugin for Media Player and Media Center from SoftPointer Similar Articles Productive Geek Tips How to Play .OGM Video Files in Windows VistaFixing When Windows Media Player Library Won’t Let You Add FilesUsing Netflix Watchnow in Windows Vista Media Center (Gmedia)Kantaris is a Unique Media Player Based on VLCEasily Change Audio File Formats with XRECODE TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 PCmover Professional OutSync will Sync Photos of your Friends on Facebook and Outlook Windows 7 Easter Theme YoWindoW, a real time weather screensaver Optimize your computer the Microsoft way Stormpulse provides slick, real time weather data Geek Parents – Did you try Parental Controls in Windows 7?

    Read the article

  • Podcast: Advanced MVVM with Josh Smith

    - by craigshoemaker
    Author, Microsoft MVP and accomplished pianist Josh Smith, Sr. UX Developer at IdentityMine, joins the show to discuss some of Model View ViewModel’s more advanced scenarios. Full Speed: download Fast Version: download Josh shares is experience using MVVM gives some real-world advice on: Using modal dialogs Evils and virtues of code behind in views Use of attached behaviors Undo/redo strategies Working with animations Building a task based architecture for managing communication between View and ViewModel Frameworks in the MVVM space The Book Get first-hand experience implementing the solutions to the challenges discussed in the show by reading Josh’s new book ‘Advanced MVVM’. Resources The following resources are mentioned in the show: Laurent Bugnion's mix talk ‘Understanding the Model-View-ViewModel Pattern Josh Smith’s MVVM Foundation Laurent Bugnion’s MVVM Light framework Rob Eisenberg's Caliburn

    Read the article

  • ARM TechCon 2013: Oracle, ARM expand collaboration on servers, Internet of Things

    - by Henrik Stahl
    If you have been following Java news, you are already aware of the fact that there has been a lot of investment in Java for ARM-based devices and servers over the last couple of years (news, more news, even more, and lots more). We have released Java ME Embedded binaries for ARM Cortex-M micro controllers, Java SE Embedded for ARM application processors, and a port of the Oracle JDK for ARM-based servers. We have been making Java available to the Beagleboard, Raspberry Pi and Lego Mindstorms/LeJOS communities and worked with them and the Java User Groups to evangelize Java as a great development environment for IoT devices. We have announced commercial relationships with Freescale, Qualcomm, Gemalto M2M, SIMCom to name a few. ARM and Freescale on their side have joined the JCP, recently been voted in as members of the Executive Committee, and have worked with Oracle to evangelize Java in their ecosystem. It is with this background, Nandini Ramani, Vice President, Java Platform at Oracle, announced a expanded collaboration with ARM in a TechCon 2013 keynote titled "Enabling Compelling Services for IoT". To summarize the announcement: ARM and Oracle will work together on interoperability between the ARM Sensinode communications stack (based on CoAP, DTLS and 6LoWPAN) and Oracle's Java ME, Java SE and middleware products. ARM will donate the Sensinode CoAP protocol engine to OpenJDK to stimulate broad adoption of the CoAP protocol, and work with Oracle to extend the relevant Java specifications with CoAP support. CoAP (Constrained Application Protocol) is an IETF specification that provides a low-bandwidth request/response protocol suitable for IoT applications. ARM will work with Oracle and Freescale to enable the mbed Hardware Abstraction Layer (HAL) to act as a portability layer for Java ME Embedded. Oracle will enable mbed as a tier one platform for Java ME Embedded. Over time, this effort will allow any mbed-enabled platforms (mostly based on Cortex-M microcontrollers) to work with off the shelf Java ME Embedded binaries, extending the reach of Java ME into IoT edge nodes. In Nandini's keynote, Oracle showed a roadmap to port the Oracle JDK for Linux on 64-bit ARMv8 servers in the 2015 time frame, preceded by an extended early access program. We expect this binary to have full feature parity with Oracle JDK on other platforms, and be available under the same royalty-free license. This effort has been going on for some time, but is now accelerated due to availability of hardware from Applied Micro. Oracle will be working with Applied Micro on the ARMv8 port, and on optimizing Java for their X-Gene products. Oracle and ARM will work closely on IoT architecture, and on evangelizing Java on ARM for both servers and IoT devices. These announcements reinforce Java's position as a first-class citizen in the ARM ecosystem, and signal a commitment from us to collaborate on driving standards and open ecosystem for the Internet of Things. If you are active in this area and not already in touch with us, or interested in learning more - please reach out to us!

    Read the article

  • A Taxonomy of Numerical Methods v1

    - by JoshReuben
    Numerical Analysis – When, What, (but not how) Once you understand the Math & know C++, Numerical Methods are basically blocks of iterative & conditional math code. I found the real trick was seeing the forest for the trees – knowing which method to use for which situation. Its pretty easy to get lost in the details – so I’ve tried to organize these methods in a way that I can quickly look this up. I’ve included links to detailed explanations and to C++ code examples. I’ve tried to classify Numerical methods in the following broad categories: Solving Systems of Linear Equations Solving Non-Linear Equations Iteratively Interpolation Curve Fitting Optimization Numerical Differentiation & Integration Solving ODEs Boundary Problems Solving EigenValue problems Enjoy – I did ! Solving Systems of Linear Equations Overview Solve sets of algebraic equations with x unknowns The set is commonly in matrix form Gauss-Jordan Elimination http://en.wikipedia.org/wiki/Gauss%E2%80%93Jordan_elimination C++: http://www.codekeep.net/snippets/623f1923-e03c-4636-8c92-c9dc7aa0d3c0.aspx Produces solution of the equations & the coefficient matrix Efficient, stable 2 steps: · Forward Elimination – matrix decomposition: reduce set to triangular form (0s below the diagonal) or row echelon form. If degenerate, then there is no solution · Backward Elimination –write the original matrix as the product of ints inverse matrix & its reduced row-echelon matrix à reduce set to row canonical form & use back-substitution to find the solution to the set Elementary ops for matrix decomposition: · Row multiplication · Row switching · Add multiples of rows to other rows Use pivoting to ensure rows are ordered for achieving triangular form LU Decomposition http://en.wikipedia.org/wiki/LU_decomposition C++: http://ganeshtiwaridotcomdotnp.blogspot.co.il/2009/12/c-c-code-lu-decomposition-for-solving.html Represent the matrix as a product of lower & upper triangular matrices A modified version of GJ Elimination Advantage – can easily apply forward & backward elimination to solve triangular matrices Techniques: · Doolittle Method – sets the L matrix diagonal to unity · Crout Method - sets the U matrix diagonal to unity Note: both the L & U matrices share the same unity diagonal & can be stored compactly in the same matrix Gauss-Seidel Iteration http://en.wikipedia.org/wiki/Gauss%E2%80%93Seidel_method C++: http://www.nr.com/forum/showthread.php?t=722 Transform the linear set of equations into a single equation & then use numerical integration (as integration formulas have Sums, it is implemented iteratively). an optimization of Gauss-Jacobi: 1.5 times faster, requires 0.25 iterations to achieve the same tolerance Solving Non-Linear Equations Iteratively find roots of polynomials – there may be 0, 1 or n solutions for an n order polynomial use iterative techniques Iterative methods · used when there are no known analytical techniques · Requires set functions to be continuous & differentiable · Requires an initial seed value – choice is critical to convergence à conduct multiple runs with different starting points & then select best result · Systematic - iterate until diminishing returns, tolerance or max iteration conditions are met · bracketing techniques will always yield convergent solutions, non-bracketing methods may fail to converge Incremental method if a nonlinear function has opposite signs at 2 ends of a small interval x1 & x2, then there is likely to be a solution in their interval – solutions are detected by evaluating a function over interval steps, for a change in sign, adjusting the step size dynamically. Limitations – can miss closely spaced solutions in large intervals, cannot detect degenerate (coinciding) solutions, limited to functions that cross the x-axis, gives false positives for singularities Fixed point method http://en.wikipedia.org/wiki/Fixed-point_iteration C++: http://books.google.co.il/books?id=weYj75E_t6MC&pg=PA79&lpg=PA79&dq=fixed+point+method++c%2B%2B&source=bl&ots=LQ-5P_taoC&sig=lENUUIYBK53tZtTwNfHLy5PEWDk&hl=en&sa=X&ei=wezDUPW1J5DptQaMsIHQCw&redir_esc=y#v=onepage&q=fixed%20point%20method%20%20c%2B%2B&f=false Algebraically rearrange a solution to isolate a variable then apply incremental method Bisection method http://en.wikipedia.org/wiki/Bisection_method C++: http://numericalcomputing.wordpress.com/category/algorithms/ Bracketed - Select an initial interval, keep bisecting it ad midpoint into sub-intervals and then apply incremental method on smaller & smaller intervals – zoom in Adv: unaffected by function gradient à reliable Disadv: slow convergence False Position Method http://en.wikipedia.org/wiki/False_position_method C++: http://www.dreamincode.net/forums/topic/126100-bisection-and-false-position-methods/ Bracketed - Select an initial interval , & use the relative value of function at interval end points to select next sub-intervals (estimate how far between the end points the solution might be & subdivide based on this) Newton-Raphson method http://en.wikipedia.org/wiki/Newton's_method C++: http://www-users.cselabs.umn.edu/classes/Summer-2012/csci1113/index.php?page=./newt3 Also known as Newton's method Convenient, efficient Not bracketed – only a single initial guess is required to start iteration – requires an analytical expression for the first derivative of the function as input. Evaluates the function & its derivative at each step. Can be extended to the Newton MutiRoot method for solving multiple roots Can be easily applied to an of n-coupled set of non-linear equations – conduct a Taylor Series expansion of a function, dropping terms of order n, rewrite as a Jacobian matrix of PDs & convert to simultaneous linear equations !!! Secant Method http://en.wikipedia.org/wiki/Secant_method C++: http://forum.vcoderz.com/showthread.php?p=205230 Unlike N-R, can estimate first derivative from an initial interval (does not require root to be bracketed) instead of inputting it Since derivative is approximated, may converge slower. Is fast in practice as it does not have to evaluate the derivative at each step. Similar implementation to False Positive method Birge-Vieta Method http://mat.iitm.ac.in/home/sryedida/public_html/caimna/transcendental/polynomial%20methods/bv%20method.html C++: http://books.google.co.il/books?id=cL1boM2uyQwC&pg=SA3-PA51&lpg=SA3-PA51&dq=Birge-Vieta+Method+c%2B%2B&source=bl&ots=QZmnDTK3rC&sig=BPNcHHbpR_DKVoZXrLi4nVXD-gg&hl=en&sa=X&ei=R-_DUK2iNIjzsgbE5ID4Dg&redir_esc=y#v=onepage&q=Birge-Vieta%20Method%20c%2B%2B&f=false combines Horner's method of polynomial evaluation (transforming into lesser degree polynomials that are more computationally efficient to process) with Newton-Raphson to provide a computational speed-up Interpolation Overview Construct new data points for as close as possible fit within range of a discrete set of known points (that were obtained via sampling, experimentation) Use Taylor Series Expansion of a function f(x) around a specific value for x Linear Interpolation http://en.wikipedia.org/wiki/Linear_interpolation C++: http://www.hamaluik.com/?p=289 Straight line between 2 points à concatenate interpolants between each pair of data points Bilinear Interpolation http://en.wikipedia.org/wiki/Bilinear_interpolation C++: http://supercomputingblog.com/graphics/coding-bilinear-interpolation/2/ Extension of the linear function for interpolating functions of 2 variables – perform linear interpolation first in 1 direction, then in another. Used in image processing – e.g. texture mapping filter. Uses 4 vertices to interpolate a value within a unit cell. Lagrange Interpolation http://en.wikipedia.org/wiki/Lagrange_polynomial C++: http://www.codecogs.com/code/maths/approximation/interpolation/lagrange.php For polynomials Requires recomputation for all terms for each distinct x value – can only be applied for small number of nodes Numerically unstable Barycentric Interpolation http://epubs.siam.org/doi/pdf/10.1137/S0036144502417715 C++: http://www.gamedev.net/topic/621445-barycentric-coordinates-c-code-check/ Rearrange the terms in the equation of the Legrange interpolation by defining weight functions that are independent of the interpolated value of x Newton Divided Difference Interpolation http://en.wikipedia.org/wiki/Newton_polynomial C++: http://jee-appy.blogspot.co.il/2011/12/newton-divided-difference-interpolation.html Hermite Divided Differences: Interpolation polynomial approximation for a given set of data points in the NR form - divided differences are used to approximately calculate the various differences. For a given set of 3 data points , fit a quadratic interpolant through the data Bracketed functions allow Newton divided differences to be calculated recursively Difference table Cubic Spline Interpolation http://en.wikipedia.org/wiki/Spline_interpolation C++: https://www.marcusbannerman.co.uk/index.php/home/latestarticles/42-articles/96-cubic-spline-class.html Spline is a piecewise polynomial Provides smoothness – for interpolations with significantly varying data Use weighted coefficients to bend the function to be smooth & its 1st & 2nd derivatives are continuous through the edge points in the interval Curve Fitting A generalization of interpolating whereby given data points may contain noise à the curve does not necessarily pass through all the points Least Squares Fit http://en.wikipedia.org/wiki/Least_squares C++: http://www.ccas.ru/mmes/educat/lab04k/02/least-squares.c Residual – difference between observed value & expected value Model function is often chosen as a linear combination of the specified functions Determines: A) The model instance in which the sum of squared residuals has the least value B) param values for which model best fits data Straight Line Fit Linear correlation between independent variable and dependent variable Linear Regression http://en.wikipedia.org/wiki/Linear_regression C++: http://www.oocities.org/david_swaim/cpp/linregc.htm Special case of statistically exact extrapolation Leverage least squares Given a basis function, the sum of the residuals is determined and the corresponding gradient equation is expressed as a set of normal linear equations in matrix form that can be solved (e.g. using LU Decomposition) Can be weighted - Drop the assumption that all errors have the same significance –-> confidence of accuracy is different for each data point. Fit the function closer to points with higher weights Polynomial Fit - use a polynomial basis function Moving Average http://en.wikipedia.org/wiki/Moving_average C++: http://www.codeproject.com/Articles/17860/A-Simple-Moving-Average-Algorithm Used for smoothing (cancel fluctuations to highlight longer-term trends & cycles), time series data analysis, signal processing filters Replace each data point with average of neighbors. Can be simple (SMA), weighted (WMA), exponential (EMA). Lags behind latest data points – extra weight can be given to more recent data points. Weights can decrease arithmetically or exponentially according to distance from point. Parameters: smoothing factor, period, weight basis Optimization Overview Given function with multiple variables, find Min (or max by minimizing –f(x)) Iterative approach Efficient, but not necessarily reliable Conditions: noisy data, constraints, non-linear models Detection via sign of first derivative - Derivative of saddle points will be 0 Local minima Bisection method Similar method for finding a root for a non-linear equation Start with an interval that contains a minimum Golden Search method http://en.wikipedia.org/wiki/Golden_section_search C++: http://www.codecogs.com/code/maths/optimization/golden.php Bisect intervals according to golden ratio 0.618.. Achieves reduction by evaluating a single function instead of 2 Newton-Raphson Method Brent method http://en.wikipedia.org/wiki/Brent's_method C++: http://people.sc.fsu.edu/~jburkardt/cpp_src/brent/brent.cpp Based on quadratic or parabolic interpolation – if the function is smooth & parabolic near to the minimum, then a parabola fitted through any 3 points should approximate the minima – fails when the 3 points are collinear , in which case the denominator is 0 Simplex Method http://en.wikipedia.org/wiki/Simplex_algorithm C++: http://www.codeguru.com/cpp/article.php/c17505/Simplex-Optimization-Algorithm-and-Implemetation-in-C-Programming.htm Find the global minima of any multi-variable function Direct search – no derivatives required At each step it maintains a non-degenerative simplex – a convex hull of n+1 vertices. Obtains the minimum for a function with n variables by evaluating the function at n-1 points, iteratively replacing the point of worst result with the point of best result, shrinking the multidimensional simplex around the best point. Point replacement involves expanding & contracting the simplex near the worst value point to determine a better replacement point Oscillation can be avoided by choosing the 2nd worst result Restart if it gets stuck Parameters: contraction & expansion factors Simulated Annealing http://en.wikipedia.org/wiki/Simulated_annealing C++: http://code.google.com/p/cppsimulatedannealing/ Analogy to heating & cooling metal to strengthen its structure Stochastic method – apply random permutation search for global minima - Avoid entrapment in local minima via hill climbing Heating schedule - Annealing schedule params: temperature, iterations at each temp, temperature delta Cooling schedule – can be linear, step-wise or exponential Differential Evolution http://en.wikipedia.org/wiki/Differential_evolution C++: http://www.amichel.com/de/doc/html/ More advanced stochastic methods analogous to biological processes: Genetic algorithms, evolution strategies Parallel direct search method against multiple discrete or continuous variables Initial population of variable vectors chosen randomly – if weighted difference vector of 2 vectors yields a lower objective function value then it replaces the comparison vector Many params: #parents, #variables, step size, crossover constant etc Convergence is slow – many more function evaluations than simulated annealing Numerical Differentiation Overview 2 approaches to finite difference methods: · A) approximate function via polynomial interpolation then differentiate · B) Taylor series approximation – additionally provides error estimate Finite Difference methods http://en.wikipedia.org/wiki/Finite_difference_method C++: http://www.wpi.edu/Pubs/ETD/Available/etd-051807-164436/unrestricted/EAMPADU.pdf Find differences between high order derivative values - Approximate differential equations by finite differences at evenly spaced data points Based on forward & backward Taylor series expansion of f(x) about x plus or minus multiples of delta h. Forward / backward difference - the sums of the series contains even derivatives and the difference of the series contains odd derivatives – coupled equations that can be solved. Provide an approximation of the derivative within a O(h^2) accuracy There is also central difference & extended central difference which has a O(h^4) accuracy Richardson Extrapolation http://en.wikipedia.org/wiki/Richardson_extrapolation C++: http://mathscoding.blogspot.co.il/2012/02/introduction-richardson-extrapolation.html A sequence acceleration method applied to finite differences Fast convergence, high accuracy O(h^4) Derivatives via Interpolation Cannot apply Finite Difference method to discrete data points at uneven intervals – so need to approximate the derivative of f(x) using the derivative of the interpolant via 3 point Lagrange Interpolation Note: the higher the order of the derivative, the lower the approximation precision Numerical Integration Estimate finite & infinite integrals of functions More accurate procedure than numerical differentiation Use when it is not possible to obtain an integral of a function analytically or when the function is not given, only the data points are Newton Cotes Methods http://en.wikipedia.org/wiki/Newton%E2%80%93Cotes_formulas C++: http://www.siafoo.net/snippet/324 For equally spaced data points Computationally easy – based on local interpolation of n rectangular strip areas that is piecewise fitted to a polynomial to get the sum total area Evaluate the integrand at n+1 evenly spaced points – approximate definite integral by Sum Weights are derived from Lagrange Basis polynomials Leverage Trapezoidal Rule for default 2nd formulas, Simpson 1/3 Rule for substituting 3 point formulas, Simpson 3/8 Rule for 4 point formulas. For 4 point formulas use Bodes Rule. Higher orders obtain more accurate results Trapezoidal Rule uses simple area, Simpsons Rule replaces the integrand f(x) with a quadratic polynomial p(x) that uses the same values as f(x) for its end points, but adds a midpoint Romberg Integration http://en.wikipedia.org/wiki/Romberg's_method C++: http://code.google.com/p/romberg-integration/downloads/detail?name=romberg.cpp&can=2&q= Combines trapezoidal rule with Richardson Extrapolation Evaluates the integrand at equally spaced points The integrand must have continuous derivatives Each R(n,m) extrapolation uses a higher order integrand polynomial replacement rule (zeroth starts with trapezoidal) à a lower triangular matrix set of equation coefficients where the bottom right term has the most accurate approximation. The process continues until the difference between 2 successive diagonal terms becomes sufficiently small. Gaussian Quadrature http://en.wikipedia.org/wiki/Gaussian_quadrature C++: http://www.alglib.net/integration/gaussianquadratures.php Data points are chosen to yield best possible accuracy – requires fewer evaluations Ability to handle singularities, functions that are difficult to evaluate The integrand can include a weighting function determined by a set of orthogonal polynomials. Points & weights are selected so that the integrand yields the exact integral if f(x) is a polynomial of degree <= 2n+1 Techniques (basically different weighting functions): · Gauss-Legendre Integration w(x)=1 · Gauss-Laguerre Integration w(x)=e^-x · Gauss-Hermite Integration w(x)=e^-x^2 · Gauss-Chebyshev Integration w(x)= 1 / Sqrt(1-x^2) Solving ODEs Use when high order differential equations cannot be solved analytically Evaluated under boundary conditions RK for systems – a high order differential equation can always be transformed into a coupled first order system of equations Euler method http://en.wikipedia.org/wiki/Euler_method C++: http://rosettacode.org/wiki/Euler_method First order Runge–Kutta method. Simple recursive method – given an initial value, calculate derivative deltas. Unstable & not very accurate (O(h) error) – not used in practice A first-order method - the local error (truncation error per step) is proportional to the square of the step size, and the global error (error at a given time) is proportional to the step size In evolving solution between data points xn & xn+1, only evaluates derivatives at beginning of interval xn à asymmetric at boundaries Higher order Runge Kutta http://en.wikipedia.org/wiki/Runge%E2%80%93Kutta_methods C++: http://www.dreamincode.net/code/snippet1441.htm 2nd & 4th order RK - Introduces parameterized midpoints for more symmetric solutions à accuracy at higher computational cost Adaptive RK – RK-Fehlberg – estimate the truncation at each integration step & automatically adjust the step size to keep error within prescribed limits. At each step 2 approximations are compared – if in disagreement to a specific accuracy, the step size is reduced Boundary Value Problems Where solution of differential equations are located at 2 different values of the independent variable x à more difficult, because cannot just start at point of initial value – there may not be enough starting conditions available at the end points to produce a unique solution An n-order equation will require n boundary conditions – need to determine the missing n-1 conditions which cause the given conditions at the other boundary to be satisfied Shooting Method http://en.wikipedia.org/wiki/Shooting_method C++: http://ganeshtiwaridotcomdotnp.blogspot.co.il/2009/12/c-c-code-shooting-method-for-solving.html Iteratively guess the missing values for one end & integrate, then inspect the discrepancy with the boundary values of the other end to adjust the estimate Given the starting boundary values u1 & u2 which contain the root u, solve u given the false position method (solving the differential equation as an initial value problem via 4th order RK), then use u to solve the differential equations. Finite Difference Method For linear & non-linear systems Higher order derivatives require more computational steps – some combinations for boundary conditions may not work though Improve the accuracy by increasing the number of mesh points Solving EigenValue Problems An eigenvalue can substitute a matrix when doing matrix multiplication à convert matrix multiplication into a polynomial EigenValue For a given set of equations in matrix form, determine what are the solution eigenvalue & eigenvectors Similar Matrices - have same eigenvalues. Use orthogonal similarity transforms to reduce a matrix to diagonal form from which eigenvalue(s) & eigenvectors can be computed iteratively Jacobi method http://en.wikipedia.org/wiki/Jacobi_method C++: http://people.sc.fsu.edu/~jburkardt/classes/acs2_2008/openmp/jacobi/jacobi.html Robust but Computationally intense – use for small matrices < 10x10 Power Iteration http://en.wikipedia.org/wiki/Power_iteration For any given real symmetric matrix, generate the largest single eigenvalue & its eigenvectors Simplest method – does not compute matrix decomposition à suitable for large, sparse matrices Inverse Iteration Variation of power iteration method – generates the smallest eigenvalue from the inverse matrix Rayleigh Method http://en.wikipedia.org/wiki/Rayleigh's_method_of_dimensional_analysis Variation of power iteration method Rayleigh Quotient Method Variation of inverse iteration method Matrix Tri-diagonalization Method Use householder algorithm to reduce an NxN symmetric matrix to a tridiagonal real symmetric matrix vua N-2 orthogonal transforms     Whats Next Outside of Numerical Methods there are lots of different types of algorithms that I’ve learned over the decades: Data Mining – (I covered this briefly in a previous post: http://geekswithblogs.net/JoshReuben/archive/2007/12/31/ssas-dm-algorithms.aspx ) Search & Sort Routing Problem Solving Logical Theorem Proving Planning Probabilistic Reasoning Machine Learning Solvers (eg MIP) Bioinformatics (Sequence Alignment, Protein Folding) Quant Finance (I read Wilmott’s books – interesting) Sooner or later, I’ll cover the above topics as well.

    Read the article

  • Developer Training – Various Options for Maximum Benefit – Part 4

    - by pinaldave
    Developer Training - Importance and Significance - Part 1 Developer Training – Employee Morals and Ethics – Part 2 Developer Training – Difficult Questions and Alternative Perspective - Part 3 Developer Training – Various Options for Developer Training – Part 4 Developer Training – A Conclusive Summary- Part 5 If you have been reading this series, by now you are aware of all the pros and cons that can come along with training.  We’ve asked and answered hard questions, and investigated them “whys” and “hows” of training.  Now it is time to talk about all the different kinds of training that are out there! On Job Training The most common type of training is on the job training.  Everyone receives this kind of education – even experts who come in to consult have to be taught where the printer, pens, and copy machines are.  If you are thinking about more concrete topics, though, on the job training can be some of the easiest to come across.  Picture this: someone in the company whom you really admire is hard at work on a project.  You come up to them and ask to help them out – if they are a busy developer, the odds are that they will say “yes, please!”   If you phrase your question as an offer of help, you can receive training without ever putting someone in the awkward position of acting as a mentor.  However, some people may want the task of being a mentor.  It can never hurt to ask.  Most people will be more than willing to pass their knowledge along. Extreme Programming If your company and coworkers are willing, you can even investigate Extreme Programming.  This is a type of programming that allows small teams to quickly develop code and products that are released with almost immediate user feedback.  You can find more information at http://www.extremeprogramming.org/.  If this is something your company could use, suggest it to your supervisor.  Even if they say no, it will make it clear that you are a go-getter who is interested in new and exciting projects.  If the answer is yes, then you have the opportunity to get some of the best on the job training around. In Person Training Click on Image to Enlarge When you say the word “training,” most people’s minds go back to the classroom, an image they are familiar with.  While training doesn’t always have to be in a traditional setting, because it is so familiar it can also be the most valuable type of training.  There are many ways to get training through a live instructor.  Some companies may be willing to send a representative to you, where employees will get training, sometimes food and coffee, and a live instructor who can answer questions immediately.  Sometimes these trainers are also able to do consultations at the same time, which can invaluable to a company.  If you are the one to asks your supervisor for a training session that can also be turned into a consultation, you may stick in their minds as an incredibly dedicated employee.  If you can’t find a representative, local colleges can also be a good resource for free or cheap classes – or they may have representatives coming who are willing to take on a few more students. Benefits of On Demand Developer Training Of course, you can often get the best of all these types of training with online or On Demand training.  You can get the benefit of a live instructor who is willing to answer questions (although in this case, usually through e-mail or other online venues), there are often real-world examples to follow along – like on the job training – and best of all you can learn whenever you have the time or need.  Did a problem with your server come up at midnight when all your supervisors are safe at home and probably in bed?  No problem!  On Demand training is especially useful if you need to slow down, pause, or rewind a training session.  Not even a real-life instructor can do that! When I was writing this blog post, I felt that each of the subject, which I have covered can be blog posts of itself. However, I wanted to keep the the blog post concise and so touch based on three major training aspects 1) On Job Training 2) In Person Training and 3) Online training. Here is the question for you – is there any other kind of training methods available, which are effective and one should consider it? If yes, what are those, I may write a follow up blog post on the same subject next week. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Developer Training, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

    Read the article

  • Toorcon14

    - by danx
    Toorcon 2012 Information Security Conference San Diego, CA, http://www.toorcon.org/ Dan Anderson, October 2012 It's almost Halloween, and we all know what that means—yes, of course, it's time for another Toorcon Conference! Toorcon is an annual conference for people interested in computer security. This includes the whole range of hackers, computer hobbyists, professionals, security consultants, press, law enforcement, prosecutors, FBI, etc. We're at Toorcon 14—see earlier blogs for some of the previous Toorcon's I've attended (back to 2003). This year's "con" was held at the Westin on Broadway in downtown San Diego, California. The following are not necessarily my views—I'm just the messenger—although I could have misquoted or misparaphrased the speakers. Also, I only reviewed some of the talks, below, which I attended and interested me. MalAndroid—the Crux of Android Infections, Aditya K. Sood Programming Weird Machines with ELF Metadata, Rebecca "bx" Shapiro Privacy at the Handset: New FCC Rules?, Valkyrie Hacking Measured Boot and UEFI, Dan Griffin You Can't Buy Security: Building the Open Source InfoSec Program, Boris Sverdlik What Journalists Want: The Investigative Reporters' Perspective on Hacking, Dave Maas & Jason Leopold Accessibility and Security, Anna Shubina Stop Patching, for Stronger PCI Compliance, Adam Brand McAfee Secure & Trustmarks — a Hacker's Best Friend, Jay James & Shane MacDougall MalAndroid—the Crux of Android Infections Aditya K. Sood, IOActive, Michigan State PhD candidate Aditya talked about Android smartphone malware. There's a lot of old Android software out there—over 50% Gingerbread (2.3.x)—and most have unpatched vulnerabilities. Of 9 Android vulnerabilities, 8 have known exploits (such as the old Gingerbread Global Object Table exploit). Android protection includes sandboxing, security scanner, app permissions, and screened Android app market. The Android permission checker has fine-grain resource control, policy enforcement. Android static analysis also includes a static analysis app checker (bouncer), and a vulnerablity checker. What security problems does Android have? User-centric security, which depends on the user to grant permission and make smart decisions. But users don't care or think about malware (the're not aware, not paranoid). All they want is functionality, extensibility, mobility Android had no "proper" encryption before Android 3.0 No built-in protection against social engineering and web tricks Alternative Android app markets are unsafe. Simply visiting some markets can infect Android Aditya classified Android Malware types as: Type A—Apps. These interact with the Android app framework. For example, a fake Netflix app. Or Android Gold Dream (game), which uploads user files stealthy manner to a remote location. Type K—Kernel. Exploits underlying Linux libraries or kernel Type H—Hybrid. These use multiple layers (app framework, libraries, kernel). These are most commonly used by Android botnets, which are popular with Chinese botnet authors What are the threats from Android malware? These incude leak info (contacts), banking fraud, corporate network attacks, malware advertising, malware "Hackivism" (the promotion of social causes. For example, promiting specific leaders of the Tunisian or Iranian revolutions. Android malware is frequently "masquerated". That is, repackaged inside a legit app with malware. To avoid detection, the hidden malware is not unwrapped until runtime. The malware payload can be hidden in, for example, PNG files. Less common are Android bootkits—there's not many around. What they do is hijack the Android init framework—alteering system programs and daemons, then deletes itself. For example, the DKF Bootkit (China). Android App Problems: no code signing! all self-signed native code execution permission sandbox — all or none alternate market places no robust Android malware detection at network level delayed patch process Programming Weird Machines with ELF Metadata Rebecca "bx" Shapiro, Dartmouth College, NH https://github.com/bx/elf-bf-tools @bxsays on twitter Definitions. "ELF" is an executable file format used in linking and loading executables (on UNIX/Linux-class machines). "Weird machine" uses undocumented computation sources (I think of them as unintended virtual machines). Some examples of "weird machines" are those that: return to weird location, does SQL injection, corrupts the heap. Bx then talked about using ELF metadata as (an uintended) "weird machine". Some ELF background: A compiler takes source code and generates a ELF object file (hello.o). A static linker makes an ELF executable from the object file. A runtime linker and loader takes ELF executable and loads and relocates it in memory. The ELF file has symbols to relocate functions and variables. ELF has two relocation tables—one at link time and another one at loading time: .rela.dyn (link time) and .dynsym (dynamic table). GOT: Global Offset Table of addresses for dynamically-linked functions. PLT: Procedure Linkage Tables—works with GOT. The memory layout of a process (not the ELF file) is, in order: program (+ heap), dynamic libraries, libc, ld.so, stack (which includes the dynamic table loaded into memory) For ELF, the "weird machine" is found and exploited in the loader. ELF can be crafted for executing viruses, by tricking runtime into executing interpreted "code" in the ELF symbol table. One can inject parasitic "code" without modifying the actual ELF code portions. Think of the ELF symbol table as an "assembly language" interpreter. It has these elements: instructions: Add, move, jump if not 0 (jnz) Think of symbol table entries as "registers" symbol table value is "contents" immediate values are constants direct values are addresses (e.g., 0xdeadbeef) move instruction: is a relocation table entry add instruction: relocation table "addend" entry jnz instruction: takes multiple relocation table entries The ELF weird machine exploits the loader by relocating relocation table entries. The loader will go on forever until told to stop. It stores state on stack at "end" and uses IFUNC table entries (containing function pointer address). The ELF weird machine, called "Brainfu*k" (BF) has: 8 instructions: pointer inc, dec, inc indirect, dec indirect, jump forward, jump backward, print. Three registers - 3 registers Bx showed example BF source code that implemented a Turing machine printing "hello, world". More interesting was the next demo, where bx modified ping. Ping runs suid as root, but quickly drops privilege. BF modified the loader to disable the library function call dropping privilege, so it remained as root. Then BF modified the ping -t argument to execute the -t filename as root. It's best to show what this modified ping does with an example: $ whoami bx $ ping localhost -t backdoor.sh # executes backdoor $ whoami root $ The modified code increased from 285948 bytes to 290209 bytes. A BF tool compiles "executable" by modifying the symbol table in an existing ELF executable. The tool modifies .dynsym and .rela.dyn table, but not code or data. Privacy at the Handset: New FCC Rules? "Valkyrie" (Christie Dudley, Santa Clara Law JD candidate) Valkyrie talked about mobile handset privacy. Some background: Senator Franken (also a comedian) became alarmed about CarrierIQ, where the carriers track their customers. Franken asked the FCC to find out what obligations carriers think they have to protect privacy. The carriers' response was that they are doing just fine with self-regulation—no worries! Carriers need to collect data, such as missed calls, to maintain network quality. But carriers also sell data for marketing. Verizon sells customer data and enables this with a narrow privacy policy (only 1 month to opt out, with difficulties). The data sold is not individually identifiable and is aggregated. But Verizon recommends, as an aggregation workaround to "recollate" data to other databases to identify customers indirectly. The FCC has regulated telephone privacy since 1934 and mobile network privacy since 2007. Also, the carriers say mobile phone privacy is a FTC responsibility (not FCC). FTC is trying to improve mobile app privacy, but FTC has no authority over carrier / customer relationships. As a side note, Apple iPhones are unique as carriers have extra control over iPhones they don't have with other smartphones. As a result iPhones may be more regulated. Who are the consumer advocates? Everyone knows EFF, but EPIC (Electrnic Privacy Info Center), although more obsecure, is more relevant. What to do? Carriers must be accountable. Opt-in and opt-out at any time. Carriers need incentive to grant users control for those who want it, by holding them liable and responsible for breeches on their clock. Location information should be added current CPNI privacy protection, and require "Pen/trap" judicial order to obtain (and would still be a lower standard than 4th Amendment). Politics are on a pro-privacy swing now, with many senators and the Whitehouse. There will probably be new regulation soon, and enforcement will be a problem, but consumers will still have some benefit. Hacking Measured Boot and UEFI Dan Griffin, JWSecure, Inc., Seattle, @JWSdan Dan talked about hacking measured UEFI boot. First some terms: UEFI is a boot technology that is replacing BIOS (has whitelisting and blacklisting). UEFI protects devices against rootkits. TPM - hardware security device to store hashs and hardware-protected keys "secure boot" can control at firmware level what boot images can boot "measured boot" OS feature that tracks hashes (from BIOS, boot loader, krnel, early drivers). "remote attestation" allows remote validation and control based on policy on a remote attestation server. Microsoft pushing TPM (Windows 8 required), but Google is not. Intel TianoCore is the only open source for UEFI. Dan has Measured Boot Tool at http://mbt.codeplex.com/ with a demo where you can also view TPM data. TPM support already on enterprise-class machines. UEFI Weaknesses. UEFI toolkits are evolving rapidly, but UEFI has weaknesses: assume user is an ally trust TPM implicitly, and attached to computer hibernate file is unprotected (disk encryption protects against this) protection migrating from hardware to firmware delays in patching and whitelist updates will UEFI really be adopted by the mainstream (smartphone hardware support, bank support, apathetic consumer support) You Can't Buy Security: Building the Open Source InfoSec Program Boris Sverdlik, ISDPodcast.com co-host Boris talked about problems typical with current security audits. "IT Security" is an oxymoron—IT exists to enable buiness, uptime, utilization, reporting, but don't care about security—IT has conflict of interest. There's no Magic Bullet ("blinky box"), no one-size-fits-all solution (e.g., Intrusion Detection Systems (IDSs)). Regulations don't make you secure. The cloud is not secure (because of shared data and admin access). Defense and pen testing is not sexy. Auditors are not solution (security not a checklist)—what's needed is experience and adaptability—need soft skills. Step 1: First thing is to Google and learn the company end-to-end before you start. Get to know the management team (not IT team), meet as many people as you can. Don't use arbitrary values such as CISSP scores. Quantitive risk assessment is a myth (e.g. AV*EF-SLE). Learn different Business Units, legal/regulatory obligations, learn the business and where the money is made, verify company is protected from script kiddies (easy), learn sensitive information (IP, internal use only), and start with low-hanging fruit (customer service reps and social engineering). Step 2: Policies. Keep policies short and relevant. Generic SANS "security" boilerplate policies don't make sense and are not followed. Focus on acceptable use, data usage, communications, physical security. Step 3: Implementation: keep it simple stupid. Open source, although useful, is not free (implementation cost). Access controls with authentication & authorization for local and remote access. MS Windows has it, otherwise use OpenLDAP, OpenIAM, etc. Application security Everyone tries to reinvent the wheel—use existing static analysis tools. Review high-risk apps and major revisions. Don't run different risk level apps on same system. Assume host/client compromised and use app-level security control. Network security VLAN != segregated because there's too many workarounds. Use explicit firwall rules, active and passive network monitoring (snort is free), disallow end user access to production environment, have a proxy instead of direct Internet access. Also, SSL certificates are not good two-factor auth and SSL does not mean "safe." Operational Controls Have change, patch, asset, & vulnerability management (OSSI is free). For change management, always review code before pushing to production For logging, have centralized security logging for business-critical systems, separate security logging from administrative/IT logging, and lock down log (as it has everything). Monitor with OSSIM (open source). Use intrusion detection, but not just to fulfill a checkbox: build rules from a whitelist perspective (snort). OSSEC has 95% of what you need. Vulnerability management is a QA function when done right: OpenVas and Seccubus are free. Security awareness The reality is users will always click everything. Build real awareness, not compliance driven checkbox, and have it integrated into the culture. Pen test by crowd sourcing—test with logging COSSP http://www.cossp.org/ - Comprehensive Open Source Security Project What Journalists Want: The Investigative Reporters' Perspective on Hacking Dave Maas, San Diego CityBeat Jason Leopold, Truthout.org The difference between hackers and investigative journalists: For hackers, the motivation varies, but method is same, technological specialties. For investigative journalists, it's about one thing—The Story, and they need broad info-gathering skills. J-School in 60 Seconds: Generic formula: Person or issue of pubic interest, new info, or angle. Generic criteria: proximity, prominence, timeliness, human interest, oddity, or consequence. Media awareness of hackers and trends: journalists becoming extremely aware of hackers with congressional debates (privacy, data breaches), demand for data-mining Journalists, use of coding and web development for Journalists, and Journalists busted for hacking (Murdock). Info gathering by investigative journalists include Public records laws. Federal Freedom of Information Act (FOIA) is good, but slow. California Public Records Act is a lot stronger. FOIA takes forever because of foot-dragging—it helps to be specific. Often need to sue (especially FBI). CPRA is faster, and requests can be vague. Dumps and leaks (a la Wikileaks) Journalists want: leads, protecting ourselves, our sources, and adapting tools for news gathering (Google hacking). Anonomity is important to whistleblowers. They want no digital footprint left behind (e.g., email, web log). They don't trust encryption, want to feel safe and secure. Whistleblower laws are very weak—there's no upside for whistleblowers—they have to be very passionate to do it. Accessibility and Security or: How I Learned to Stop Worrying and Love the Halting Problem Anna Shubina, Dartmouth College Anna talked about how accessibility and security are related. Accessibility of digital content (not real world accessibility). mostly refers to blind users and screenreaders, for our purpose. Accessibility is about parsing documents, as are many security issues. "Rich" executable content causes accessibility to fail, and often causes security to fail. For example MS Word has executable format—it's not a document exchange format—more dangerous than PDF or HTML. Accessibility is often the first and maybe only sanity check with parsing. They have no choice because someone may want to read what you write. Google, for example, is very particular about web browser you use and are bad at supporting other browsers. Uses JavaScript instead of links, often requiring mouseover to display content. PDF is a security nightmare. Executible format, embedded flash, JavaScript, etc. 15 million lines of code. Google Chrome doesn't handle PDF correctly, causing several security bugs. PDF has an accessibility checker and PDF tagging, to help with accessibility. But no PDF checker checks for incorrect tags, untagged content, or validates lists or tables. None check executable content at all. The "Halting Problem" is: can one decide whether a program will ever stop? The answer, in general, is no (Rice's theorem). The same holds true for accessibility checkers. Language-theoretic Security says complicated data formats are hard to parse and cannot be solved due to the Halting Problem. W3C Web Accessibility Guidelines: "Perceivable, Operable, Understandable, Robust" Not much help though, except for "Robust", but here's some gems: * all information should be parsable (paraphrasing) * if not parsable, cannot be converted to alternate formats * maximize compatibility in new document formats Executible webpages are bad for security and accessibility. They say it's for a better web experience. But is it necessary to stuff web pages with JavaScript for a better experience? A good example is The Drudge Report—it has hand-written HTML with no JavaScript, yet drives a lot of web traffic due to good content. A bad example is Google News—hidden scrollbars, guessing user input. Solutions: Accessibility and security problems come from same source Expose "better user experience" myth Keep your corner of Internet parsable Remember "Halting Problem"—recognize false solutions (checking and verifying tools) Stop Patching, for Stronger PCI Compliance Adam Brand, protiviti @adamrbrand, http://www.picfun.com/ Adam talked about PCI compliance for retail sales. Take an example: for PCI compliance, 50% of Brian's time (a IT guy), 960 hours/year was spent patching POSs in 850 restaurants. Often applying some patches make no sense (like fixing a browser vulnerability on a server). "Scanner worship" is overuse of vulnerability scanners—it gives a warm and fuzzy and it's simple (red or green results—fix reds). Scanners give a false sense of security. In reality, breeches from missing patches are uncommon—more common problems are: default passwords, cleartext authentication, misconfiguration (firewall ports open). Patching Myths: Myth 1: install within 30 days of patch release (but PCI §6.1 allows a "risk-based approach" instead). Myth 2: vendor decides what's critical (also PCI §6.1). But §6.2 requires user ranking of vulnerabilities instead. Myth 3: scan and rescan until it passes. But PCI §11.2.1b says this applies only to high-risk vulnerabilities. Adam says good recommendations come from NIST 800-40. Instead use sane patching and focus on what's really important. From NIST 800-40: Proactive: Use a proactive vulnerability management process: use change control, configuration management, monitor file integrity. Monitor: start with NVD and other vulnerability alerts, not scanner results. Evaluate: public-facing system? workstation? internal server? (risk rank) Decide:on action and timeline Test: pre-test patches (stability, functionality, rollback) for change control Install: notify, change control, tickets McAfee Secure & Trustmarks — a Hacker's Best Friend Jay James, Shane MacDougall, Tactical Intelligence Inc., Canada "McAfee Secure Trustmark" is a website seal marketed by McAfee. A website gets this badge if they pass their remote scanning. The problem is a removal of trustmarks act as flags that you're vulnerable. Easy to view status change by viewing McAfee list on website or on Google. "Secure TrustGuard" is similar to McAfee. Jay and Shane wrote Perl scripts to gather sites from McAfee and search engines. If their certification image changes to a 1x1 pixel image, then they are longer certified. Their scripts take deltas of scans to see what changed daily. The bottom line is change in TrustGuard status is a flag for hackers to attack your site. Entire idea of seals is silly—you're raising a flag saying if you're vulnerable.

    Read the article

  • Screencasts introducing C++ AMP

    - by Daniel Moth
    It has been almost 2.5 years since I last recorded a screencast, and I had forgotten how time consuming they are to plan/record/edit/produce/publish, but at the same time so much fun to see the end result! So below are links to 4 screencasts to teach you C++ AMP basics from scratch (even if you class yourself as a .NET developer you'll be able to follow). Setup code - part 1 array_view, extent, index - part 2 parallel_for_each - part 3 accelerator - part 4 If you have comments/questions about what is shown in each video, please leave them at each video recoding. If you have generic questions about C++ AMP, please ask in the C++ AMP MSDN forum. Comments about this post by Daniel Moth welcome at the original blog.

    Read the article

  • The best terminal emulator for a heavy terminal user?

    - by Noah Goodrich
    I spend a lot of time at the command-line during the workday and at home too since I run Ubuntu exclusively. I've been using the default gnome terminal but I've reached a point where I'd really like to get my terminal tricked out so that my common tasks are as easy as possible. Specifically, I find that I spend of lot of time browsing code in the terminal and working in config files. On my wish list would be: Ability to have multiple screens, tabs, windows (I don't have a preference at this point) that I can easily switch between. Color coding for everything Easy to modify the aesthetics of the terminal (is it vain to want my terminal to look nice?) such as transparency, borders, etc.

    Read the article

  • Is there a website like this?

    - by Slawek
    Hi guys, because so much questions are closed here i was wondering if there is some website that's really about programmers< you know real programmers, that have a life not codemonkeys. For example i'd like to see what programmers around the world wear, maybe pictures. It's of course related to programming but i think community here is to strict to allow anything that has no "PHP" or "Java" in title. You know, some place where you can ask questions not only related to lines of code but to ... programmers :) For now this subsite feels more than .coding, not .programmers to be honest :) BTW: I saw there's life-style tag... maybe not all hope is lost...

    Read the article

  • New Rules of Retail

    - by David Dorf
    I've been on vacation and preparing for Crosstalk, so its been a while since I've posted. I've seen the agenda, and I can assure you Crosstalk will be lots of fun. In addition to hearing from lots of retailers, we'll also be doing a little bowling and racing on the track. I'll be around for the sessions, the ORUG meetings, and our Customer Advisory Board so please be sure to say hello. I also just completed a white paper based on a previous blog posting which in turn was based on learnings from reading What Would Google Do? For each of Jarvis' ten rules, I discuss the concept in the context of retail and provide real-world examples. No mention of products or sales pitches at all. You can download the paper here. It will put you in the right frame of mind for hearing Jeff Jarvis speak at Crosstalk. For those that can't make it, I'll post some highlights afterwards.

    Read the article

  • Non-Dom Element Event Binding with jQuery

    Yesterday I had a short discussion with Dave Reed on Twitter regarding setting up fake events on objects that are hookable. jQuery makes it real easy to bind events on DOM elements and with a little bit of extra work (that I didnt know about) you can also set up binding to non-DOM element event bindings. Assume for a second that you have a simple JavaScript object like this: var item = { sku: "wwhelp" , foo: function() { alert('orginal foo function'); } }; and...Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

    Read the article

  • Ubuntu 14.04:LTS , HPLIP loses USB connection to HP laserjet

    - by Gareth
    This is my first post, so please let me know if i have inadvertanly broken any rules. Problem There seems to be a problem with HPLIP and USB connections in ubuntu 14.04LTS. After upgrading i managed to get the printing to work but today it has broken. Initial Issue (Solved) After upgrading to unbutntu 14.04 LTS my printer lHP LaserJet 1018 stopped printing (code=12) Looking through the Forumsthere are several issues with printitng and HPLIP so I was able to troubleshoot this. The steps I took were : Reran HPdoctor Ran hp-check Un-installed and installed the latest version of HPLIP (3.14.4) Checked the USB connections lsusb and lsusb-v Re-ran hpcheck Removed the printer from HPLIP Re-ran hpcheck Manually configued HPLIP to the printer hp-setup-g <xxx:yyy> And this worked HPLIP was able to see the printer in the USB , test page printed and was happily working for a few weeks. Current Issue Printer Not working However today my wife complains the printer is not working and checking see that although HPLIP has the same error code and did not seem to be able to see the printer although running lsusb could see the printer. Initially thought this may be due to usb given a new bus/device after being turned on and off and went to repeat the steps above at the moment still seeing an error in that the HPLIP is complaining that it cannot see the device **error: Device not found. Please make sure your printer is properly connected and powered-on.** current Observations lsusb output ## Bus 002 Device 007: ID 03f0:4117 Hewlett-Packard LaserJet 1018 sudo hp-check output *> "duan@duan-Lenovo-B550:~$ sudo hp-check [sudo] password for duan: Saving output in log file: /home/duan/hp-check.log HP Linux Imaging and Printing System (ver. 3.14.4) Dependency/Version Check Utility ver. 15.1 Copyright (c) 2001-13 Hewlett-Packard Development Company, LP This software comes with ABSOLUTELY NO WARRANTY. This is free software, and you are welcome to distribute it under certain conditions. See COPYING file for more details. Note: hp-check can be run in three modes: 1. Compile-time check mode (-c or --compile): Use this mode before compiling the HPLIP supplied tarball (.tar.gz or .run) to determine if the proper dependencies are installed to successfully compile HPLIP. Run-time check mode (-r or --run): Use this mode to determine if a distro supplied package (.deb, .rpm, etc) or an already built HPLIP supplied tarball has the proper dependencies installed to successfully run. Both compile- and run-time check mode (-b or --both) (Default): This mode will check both of the above cases (both compile- and run-time dependencies). Full Output output of hp-setup -g 002:007 window box "device not found please make sure your printer is properly connected and powered on" duan@duan-Lenovo-B550:~$ sudo hp-setup -g 002:007 [sudo] password for duan: > HP Linux Imaging and Printing System (ver. 3.14.4) Printer/Fax Setup > Utility ver. 9.0 > > Copyright (c) 2001-13 Hewlett-Packard Development Company, LP This > software comes with ABSOLUTELY NO WARRANTY. This is free software, and > you are welcome to distribute it under certain conditions. See COPYING > file for more details. > > hp-setup[18461]: debug: param=002:007 hp-setup[18461]: debug: > selected_device_name=None Fontconfig error: > "/etc/fonts/conf.d/65-khmer.conf", line 14: out of memory Fontconfig > error: "/etc/fonts/conf.d/65-khmer.conf", line 23: out of memory > Fontconfig error: "/etc/fonts/conf.d/65-khmer.conf", line 32: out of > memory hp-setup[18461]: debug: Sys.argv=['/usr/bin/hp-setup', '-g', > '002:007'] printer_name=None param=002:007 jd_port=1 device_uri=None > remove=False Searching for device... hp-setup[18461]: debug: Trying > USB with bus=002 dev=007... hp-setup[18461]: debug: Not found. > hp-setup[18461]: debug: Trying serial number 002:007 hp-setup[18461]: > debug: Probing bus: usb hp-setup[18461]: debug: Probing bus: par > error: Device not found. Please make sure your printer is properly > connected and powered-on. hp-setup[18461]: debug: Starting GUI loop. .. USB lead Works with the Windows 7 laptop Printer Works with windows 7 laptop Questions Is this a Bug with HPLIP or an issue with laptop/printer? Supplementary question if it is a bug what information is needed and where should it be sent ? Any suggestions on how to get the printer to work correctly with Ubuntu 14.04LTS/HPLIP 13.4.3 so that it stays working ?

    Read the article

  • Form, function and complexity in rule processing

    - by Charles Young
    Tim Bass posted on ‘Orwellian Event Processing’. I was involved in a heated exchange in the comments, and he has more recently published a post entitled ‘Disadvantages of Rule-Based Systems (Part 1)’. Whatever the rights and wrongs of our exchange, it clearly failed to generate any agreement or understanding of our different positions. I don't particularly want to promote further argument of that kind, but I do want to take the opportunity of offering a different perspective on rule-processing and an explanation of my comments. For me, the ‘red rag’ lay in Tim’s claim that “...rules alone are highly inefficient for most classes of (not simple) problems” and a later paragraph that appears to equate the simplicity of form (‘IF-THEN-ELSE’) with simplicity of function.   It is not the first time Tim has expressed these views and not the first time I have responded to his assertions.   Indeed, Tim has a long history of commenting on the subject of complex event processing (CEP) and, less often, rule processing in ‘robust’ terms, often asserting that very many other people’s opinions on this subject are mistaken.   In turn, I am of the opinion that, certainly in terms of rule processing, which is an area in which I have a specific interest and knowledge, he is often mistaken. There is no simple answer to the fundamental question ‘what is a rule?’ We use the word in a very fluid fashion in English. Likewise, the term ‘rule processing’, as used widely in IT, is equally difficult to define simplistically. The best way to envisage the term is as a ‘centre of gravity’ within a wider domain. That domain contains many other ‘centres of gravity’, including CEP, statistical analytics, neural networks, natural language processing and so much more. Whole communities tend to gravitate towards and build themselves around some of these centres. The term 'rule processing' is associated with many different technology types, various software products, different architectural patterns, the functional capability of many applications and services, etc. There is considerable variation amongst these different technologies, techniques and products. Very broadly, a common theme is their ability to manage certain types of processing and problem solving through declarative, or semi-declarative, statements of propositional logic bound to action-based consequences. It is generally important to be able to decouple these statements from other parts of an overall system or architecture so that they can be managed and deployed independently.  As a centre of gravity, ‘rule processing’ is no island. It exists in the context of a domain of discourse that is, itself, highly interconnected and continuous.   Rule processing does not, for example, exist in splendid isolation to natural language processing.   On the contrary, an on-going theme of rule processing is to find better ways to express rules in natural language and map these to executable forms.   Rule processing does not exist in splendid isolation to CEP.   On the contrary, an event processing agent can reasonably be considered as a rule engine (a theme in ‘Power of Events’ by David Luckham).   Rule processing does not live in splendid isolation to statistical approaches such as Bayesian analytics. On the contrary, rule processing and statistical analytics are highly synergistic.   Rule processing does not even live in splendid isolation to neural networks. For example, significant research has centred on finding ways to translate trained nets into explicit rule sets in order to support forms of validation and facilitate insight into the knowledge stored in those nets. What about simplicity of form?   Many rule processing technologies do indeed use a very simple form (‘If...Then’, ‘When...Do’, etc.)   However, it is a fundamental mistake to equate simplicity of form with simplicity of function.   It is absolutely mistaken to suggest that simplicity of form is a barrier to the efficient handling of complexity.   There are countless real-world examples which serve to disprove that notion.   Indeed, simplicity of form is often the key to handling complexity. Does rule processing offer a ‘one size fits all’. No, of course not.   No serious commentator suggests it does.   Does the design and management of large knowledge bases, expressed as rules, become difficult?   Yes, it can do, but that is true of any large knowledge base, regardless of the form in which knowledge is expressed.   The measure of complexity is not a function of rule set size or rule form.  It tends to be correlated more strongly with the size of the ‘problem space’ (‘search space’) which is something quite different.   Analysis of the problem space and the algorithms we use to search through that space are, of course, the very things we use to derive objective measures of the complexity of a given problem. This is basic computer science and common practice. Sailing a Dreadnaught through the sea of information technology and lobbing shells at some of the islands we encounter along the way does no one any good.   Building bridges and causeways between islands so that the inhabitants can collaborate in open discourse offers hope of real progress.

    Read the article

  • ODI SDK: Retrieving Information From the Logs

    - by Christophe Dupupet
    It is fairly common to want to retrieve data from the ODI logs: statistics, execution status, even the generated code can be retrieved from the logs. The ODI SDK provides a robust set of APIs to parse the repository and retreve such information. To locate the information you are looking for, you have to keep in mind the structure of the logs: sessions contain steps; steps containt tasks. The session is the execution unit: basically, each time you execute something (interface, package, procedure, scenario) you create a new session. The steps are the individual entries found in a session: these will be the icons in your package for instance. Or if you are running an interface, you will have one single step: the interface itself. The tasks will represent the more atomic elements of the steps: the individual DDL, DML, scripts and so forth that are generated by ODI, along with all the detailed statistics for that task. All these details can be retrieved with the SDK. Because I had a question recently on the API ODIStepReport, I focus explicitly in this code on Scenario logs, but a lot more can be done with these APIs. Here is the code sample (you can just cut and paste that code in your ODI 11.1.1.6 Groovy console). Just save, adapt the code to your environment (in particular to connect to your repository) and hit "run" //Created by ODI Studioimport oracle.odi.core.OdiInstanceimport oracle.odi.core.config.OdiInstanceConfigimport oracle.odi.core.config.MasterRepositoryDbInfo import oracle.odi.core.config.WorkRepositoryDbInfo import oracle.odi.core.security.Authentication  import oracle.odi.core.config.PoolingAttributes import oracle.odi.domain.runtime.scenario.finder.IOdiScenarioFinder import oracle.odi.domain.runtime.scenario.OdiScenario import java.util.Collection import java.io.* /* ----------------------------------------------------------------------------------------- Simple sample code to list all executions of the last version of a scenario,along with detailed steps information----------------------------------------------------------------------------------------- */ /* update the following parameters to match your environment => */def url = "jdbc:oracle:thin:@myserver:1521:orcl"def driver = "oracle.jdbc.OracleDriver"def schema = "ODIM1116"def schemapwd = "ODIM1116PWD"def workrep = "WORKREP1116"def odiuser= "SUPERVISOR"def odiuserpwd = "SUNOPSIS" // Rather than hardcoding the project code and folder name, // a great improvement here would be to parse the entire repository def scenario_name = "LOAD_DWH" /*Scenario Name*/ /* <=End of the update section */ //--------------------------------------//Connection to the repository// Note for ODI 11.1.1.6: you could use predefined odiInstance variable if you are // running the script from a Studio that is already connected to the repository def masterInfo = new MasterRepositoryDbInfo(url, driver, schema, schemapwd.toCharArray(), new PoolingAttributes())def workInfo = new WorkRepositoryDbInfo(workrep, new PoolingAttributes())def odiInstance = OdiInstance.createInstance(new OdiInstanceConfig(masterInfo, workInfo)) //--------------------------------------// In all cases, we need to make sure we have authorized access to the repositorydef auth = odiInstance.getSecurityManager().createAuthentication(odiuser, odiuserpwd.toCharArray())odiInstance.getSecurityManager().setCurrentThreadAuthentication(auth) //--------------------------------------// Retrieve the scenario we are looking fordef odiScenario = ((IOdiScenarioFinder)odiInstance.getTransactionalEntityManager().getFinder(OdiScenario.class)).findLatestByName(scenario_name) if (odiScenario == null){    println("Error: cannot find scenario "+scenario_name);    return} //--------------------------------------// Retrieve all reports for the scenario def OdiScenarioReportsList = odiScenario.getScenarioReports() println("*** Listing all reports for Scenario \""+scenario_name+"\" ") //--------------------------------------// For each report, print the folowing:// - start time// - duration// - status// - step reports: selection of details for (s in OdiScenarioReportsList){        println("\tStart time: " + s.getSessionStartTime())        println("\tDuration: " + s.getSessionDuration())        println("\tStatus: " + s.getSessionStatus())                def OdiScenarioStepReportsList = s.getStepReports()        for (st in OdiScenarioStepReportsList){            println("\t\tStep Name: " + st.getStepName())            println("\t\tStep Resource Name: " + st.getStepResourceName())            println("\t\tStep Start time: " + st.getStepStartTime())            println("\t\tStep Duration: " + st.getStepDuration())            println("\t\tStep Status: " + st.getStepStatus())            println("\t\tStep # of inserts: " + st.getStepInsertCount())            println("\t\tStep # of updates: " + st.getStepUpdateCount()+'\n')      }      println("\t")}

    Read the article

  • SSAS Multithreaded sync with Windows 2008 R2

    - by ACALVETT
    We have been happily running some of our systems on WIndows 2003 and have had an upgrade to W2K8 R2 on the list for quite some time. The upgrade has now completed and we can start taking advantage of some of the new features which is the reason for this post. For a long time we have used the sample Robocopy script from the SQLCat team to synchronize some of our larger SSAS databases. If your wondering what i mean by large, around 5 TB with a good few thousand partitions. The script works like a dream...(read more)

    Read the article

  • Ask How-To Geek: How Can I Monitor My Bandwidth Usage?

    - by Jason Fitzpatrick
    If you’re lucky you enjoy wide open internet access with out restriction (or restrictions so high you would have to work all month to meet them). If you’re not so lucky, you’ve got an ISP with heavy caps. Today we help out a reader working under such a cap. Latest Features How-To Geek ETC Internet Explorer 9 RC Now Available: Here’s the Most Interesting New Stuff Here’s a Super Simple Trick to Defeating Fake Anti-Virus Malware How to Change the Default Application for Android Tasks Stop Believing TV’s Lies: The Real Truth About "Enhancing" Images The How-To Geek Valentine’s Day Gift Guide Inspire Geek Love with These Hilarious Geek Valentines Can the Birds and Pigs Really Be Friends in the End? [Angry Birds Video] Add the 2D Version of the New Unity Interface to Ubuntu 10.10 and 11.04 MightyMintyBoost Is a 3-in-1 Gadget Charger Watson Ties Against Human Jeopardy Opponents Peaceful Tropical Cavern Wallpaper SnapBird Supercharges Your Twitter Searches

    Read the article

  • SOLVED: Error 1 Ticks must be between DateTime.MinValue.Ticks and DateTime.MaxValue.Ticks

    This is a simple looking error message that is deceptively hard to track down. Thankfully if you're having this problem then this article should get you back on track without spending hours scratching your head. Scenario It was time to update an existing website so after synchronising my copy of the site with the server I was ready to make my changes. The only problem was that every time I tried to compile the site I was getting an error: Error 1 Ticks must be between DateTime.MinValue.Ticks...Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

    Read the article

  • SSAS Compare: an intern’s journey

    - by Red Gate Software BI Tools Team
    About a month ago, David mentioned an intern working in the BI Tools Team. That intern happens to be me! In five weeks’ time, I’ll start my second year of Computer Science at the University of Cambridge and be a full-time student again, but for the past eight weeks, I’ve been living a completely different life. As Jon mentioned before, the teams here at Red Gate are small and everyone (including the interns!) is responsible for the product as a whole. I’ve attended planning sessions, UX tests, daily meetings, and everything else a full-time member of the team would; I had as much say in where we would go next with the product as anyone; I was able to see that what I was doing was an important part of the product from the feedback we got in the UX tests. All these things almost made me forget that this is just an internship and not my full-time job. First steps at Red Gate Being based in Cambridge, Red Gate has many Cambridge university graduates working for them. They also hire some Cambridge undergraduates for internships each summer. With its popularity with university graduates and its great working environment, Red Gate has managed to build up a great reputation. When I thought of doing an internship here in Cambridge, Red Gate just seemed to be the obvious choice for my first real work experience. On my first day at Red Gate, David, the lead developer for SSAS Compare, helped me settle in and explained what I’d be doing. My task was to improve the user experience of displaying differences between MDX scripts by syntax highlighting, script formatting, and improving the difference identification in the first place. David suggested how I should approach the problem, but left all the details and design decisions to me. That was when I realised how much independence and responsibility I’d have. What I’ve done If you launch the latest version of SSAS Compare and drill down to an MDX script difference, you can see the changes that have been made. In earlier versions, you could only see the scripts in plain text on both sides — either in black or grey, depending on whether they were the same or not. However, you couldn’t see exactly where the scripts were different, which was especially annoying when the two scripts were large – as they often are. Furthermore, if parts of the two scripts were formatted differently, they seemed to be different but were actually the same, which caused even more confusion and made it difficult to see where the differences were. All these issues have been fixed now. The two scripts are automatically formatted by the tool so that if two things are syntactically equivalent, they look the same – including case differences in keywords! The actual difference is highlighted in grey, which makes them easy to spot. The difference identification has been improved as well, so two scripts aren’t identified as different if there’s just a difference in meaningless whitespace characters, or when you have “select” on one side and “SELECT” on the other. We also have syntax highlighting, which makes it easier to read the scripts. How I did it In order to do the formatting properly, we decided to parse the MDX scripts. After some investigation into parser builders, I decided to go with the GOLD Parser builder and the bsn-goldparser .NET engine. GOLD Parser builder provides a fairly nice GUI to write, build, and test grammar in. We also liked the idea of separating the grammar building from parsing a text. The bsn-goldparser is one of many .NET engines for GOLD, and although it doesn’t support the newest features of GOLD Parser, it has “the ability to map semantic action classes to terminals or reduction rules, so that a completely functional semantic AST can be created directly without intermediate token AST representation, and without the need for glue code.” That makes it much easier for us to change the implementation in our program when we change the grammar. As bsn-goldparser is open source, and I wanted some more features in it, I contributed two new features which have now been merged to the project. Unfortunately, there wasn’t an MDX grammar written for GOLD already, so I had to write it myself. I was referencing MSDN to get the formal grammar specification, but the specification was all over the place, so it wasn’t that easy to implement and find. We’re aware that we don’t yet fully support all valid MDX, so sometimes you’ll just see the MDX script difference displayed the old way. In that case, there is some grammar construct we don’t yet recognise. If you come across something SSAS Compare doesn’t recognise, we’d love to hear about it so we can add it to our grammar. When some MDX script gets parsed, a tree is produced. That tree can then be processed into a list of inlines which deal with the correct formatting and can be outputted to the screen. Doing all this has led me to many new technologies and projects I haven’t worked with before. This was my first experience with C# and Visual Studio, although I have done things in Java before. I have learnt how to unit test with NUnit, how to do dependency injection with Ninject, how to source-control code with SVN and Mercurial, how to build with TeamCity, how to use GOLD, and many other things. What’s coming next Sadly, my internship comes to an end this week, so there will be less development on MDX difference view for a while. But the team is going to work on marking the differences better and making it consistent with difference indication in the top part of comparison window, and will keep adding support for more MDX grammar so you can see the differences easily in every comparison you make. So long! And maybe I’ll see you next summer!

    Read the article

  • Umbraco Certified Developer - Level 2 - Chris Houston

    - by Vizioz Limited
    I just thought I'd create a quick blog post to say that I have now been on the Umbraco Level 2 course (which I would recommend!) and although it turned out that I pretty much new 95% of what was taught, the extra 5% and a chance to have a trip to Copenhagen made it worth it :)I am now officially Umbraco level 2 certified :)Hopefully over the next month I will have some time to start adding a few more useful blog posts to my blog. I know I've been a little slack on the posting in the last month, it's just been a busy time for me!

    Read the article

  • New Reference Configuration: Accelerate Deployment of Virtual Infrastructure

    - by monica.kumar
    Today, Oracle announced the availability of Oracle VM blade cluster reference configuration based on Sun servers, storage and Oracle VM software. Assembling and integrating software and hardware systems from different vendors can be a huge barrier to deploying virtualized infrastructures as it is often a complicated, time-consuming, risky and expensive process. Using this tested configuration can help reduce the time to configure and deploy a virtual infrastructure by up to 98% as compared to putting together multi-vendor configurations. Once ready, the infrastructure can be used to easily deploy enterprise applications in a matter of minutes to hours as opposed to days/weeks, by using Oracle VM Templates. Find out more: Press Release Business whitepaper Technical whitepaper

    Read the article

< Previous Page | 458 459 460 461 462 463 464 465 466 467 468 469  | Next Page >