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• Why does setting the margin on a div not affect the position of child content?

  - by DanM

  I'd like to understand a little more clearly how css margins work with divs and child content. If I try this... <div style="clear: both; margin-top: 2em;"> <input type="submit" value="Save" /> </div> ...the Save button is right up against the User Role (margin fail): If I change it to this... <div style="clear: both;"> <input style="margin-top: 2em;" type="submit" value="Save" /> </div> ...there is a gap between the Save button and the User Role (margin win): Questions: Can someone explain what I'm observing? Why doesn't putting a margin on the div cause the input to move down? Why must I put the margin on the input itself? There must be some fundamental law of css I am not grasping.

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• Python: need to get energies of charge pairs.

  - by Two786

  I am new to python. I have to make a program for a project that takes a PDB format file as input and returns a list of all the intra-chain and inter-chain charge pairs and their energies (using coulomb’s law assuming a dielectric constant of (?) of 40.0). For simplicity, the charged residues for this program are just Arg (CZ), Lys (NZ), Asp (CG) and Glu (CD) with the charge bearing atoms for each indicated in parentheses. The program should report any attractive or repulsive interactions within 8.0 Å. Here is some additional information needed for the program. Eij = energy of interaction between atoms i and j in kilocalories/mole (kcals/mol) qi = charge for atom i (+1 for Lys or Arg, -1 for Glu or Asp) rij = distance between atoms i and j in angstroms using the distance formula The output should adhere to the following format: First residue : Second residue Distance Energy Lys 10 Chain A: ASP 46 Chain A D= 4.76 ang E= -2.32 kcals/mol (For some reason I can't organize the top two rows, but the first row should be lables and below it the corresponding values.) I really have no idea how to tackle this problem, any and all help is greatly appreciated. I hope this is the right place to ask. Thank you in advance. Using python 2.5

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• c++ and visual studio 08, how to develop the following web extracting application. folloow up of las

  - by user287745

  the purpose is to use c++ in a useful way. i have just started programming and have made a few small applications in c and c#. my understanding is that programming for web and thing related to web is now a days a very easy task. please note this is for personnel learning not for rent a coder or any money making. an application which can run on any windows platform even win98. the application should start automatically at a scheduled time and do the following. connect to a site which displays stock prices summary (high low current open ). captures the data (excluding the other things in the site) and saves it to disk ( a sql database) please note:- internet connection is assumed to be there always. do not want to know how to make database schema or database. the stock exchange has no law prohibiting the use of the data provided on its site, but i do not want to mention the name in case i am wrong, but its for personnel private use only. the data of summary of pricing is arranged in a table such that when copied pasted to ms excel it automatically forms a table. guidance needed thank u.

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• Why does setting the margin on a div not affect the position of child content?

  - by DanM

  I'd like to understand a little more clearly how css margins work with divs and child content. If I try this... <div style="clear: both; margin-top: 2em;"> <input type="submit" value="Save" /> </div> ...the Save button is right up against the User Role (margin fail): If I change it to this... <div style="clear: both;"> <input style="margin-top: 2em;" type="submit" value="Save" /> </div> ...there is a gap between the Save button and the User Role (margin win): Questions: Can someone explain what I'm observing? Why doesn't putting a margin on the div cause the input to move down? Why must I put the margin on the input itself? There must be some fundamental law of css I am not grasping.

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• Interval arithmetic to correctly deal with end of month - Oracle SQL

  - by user2003974

  I need a function which will do interval arithmetic, dealing "correctly" with the different number of days in a month. For my version of "correctly" - see below! First try select to_date('31-May-2014') + interval '1' months from dual This returns an error, because there is no 31st June. I understand that this behaviour is expected due to the ANSI standard. Second try select add_months(to_date('31-May-2014'),1) from dual This correctly (in my use case) returns 30th June 2014, which is great. BUT select add_months(to_date('28-Feb-2014'),1) from dual returns 31st March 2014, when I want 28th March 2014. Background This has to do with legal deadlines. The deadlines are expressed in law as a number of months (say, 3) from a base date. If the base date is last day of the month and three months later the month is longer, then the deadline does NOT extend to the end of the longer month (as per the add_months function). However, if the base date is last day of the month and three months later the month is shorter, then the deadline expires on the last day of the shorter month. Question Is there a function that does what I need? I have intervals (year to month) stored in a table, so preferably the function would look like: add_interval_correctly(basedate DATE, intervaltoadd INTERVAL YEAR TO MONTH)

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• PSTN Trunk TDM400P Install on Asterisk / Trixbox

  - by Jona

  Hey All, I'm trying to get a TDM400P card with FXO module to connect to our PSTN line. The card is correctly detected by Linux: [trixbox1.localdomain asterisk]# lspci 00:09.0 Communication controller: Tiger Jet Network Inc. Tiger3XX Modem/ISDN interface And asterisk can see the channel: > trixbox1*CLI> dahdi show channel 1 > Channel: 1LI> File Descriptor: 14 > Span: 11*CLI> Extension: I> Dialing: > noI> Context: from-pstn Caller ID: I> > Calling TON: 0 Caller ID name: > Mailbox: none Destroy: 0LI> InAlarm: > 1LI> Signalling Type: FXS Kewlstart > Radio: 0*CLI> Owner: <None> Real: > <None>> Callwait: <None> Threeway: > <None> Confno: -1LI> Propagated > Conference: -1 Real in conference: 0 > DSP: no1*CLI> Busy Detection: no TDD: > no1*CLI> Relax DTMF: no > Dialing/CallwaitCAS: 0/0 Default law: > ulaw Fax Handled: no Pulse phone: no > DND: no1*CLI> Echo Cancellation: > trixbox1128 taps trixbox1(unless TDM > bridged) currently OFF Actual > Confinfo: Num/0, Mode/0x0000 Actual > Confmute: No > Hookstate (FXS only): Onhook I have configured a "ZAP Trunk (DAHDI compatibility Mode)" with the ZAP identifier 1 and an outbound route, but when ever I try to make an external call via it I get the "All Circuits are busy now, please try your call again later message". The FXO module is directly connected to our phone line from BT via a BT-RJ11 cable. I'm guessing I've missed a configuration step somewhere but no idea where, any help greatly appreciated.

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• Reviews Cheyney Group Marketing: What accounting softwares are available in the market for small businesses?

  - by user225556

  Accounting is the language of business, and good accounting software can save you hundreds of hours at the business equivalent of Berlitz. There's no substitute for an accounting pro who knows the ins and outs of tax law, but today's desktop packages can help you with everything from routine bookkeeping to payroll, taxes, and planning. Each package also produces files that you can hand off to an accountant as needed. Small-business managers have more accounting software options than ever, including subscription Web-based options that don't require their users to install or update software. Many businesses, however--including those that need to track large inventories or client databases, and those that prefer not to entrust their data to the cloud--may be happier with a desktop tool. We looked at three general-purpose, small-business accounting packages: Acclivity AccountEdgePro 2012 (both the product and the company were previously called MYOB), Intuit QuickBooks Premier 2012, and Sage's Sage 50 Complete 2013 (the successor to Peachtree Complete). All three packages offer a solid array of tools for tracking income and expenses, invoicing, managing payroll, and creating reports. These full-featured and highly mature programs don't come cheap. Acclivity AccountEdge Pro, at $299, is the least expensive; and prices climb if you opt to use common time-saving add-ons such as payroll services, or if you add licenses for multiple user accounts. All three are solid on the basics, but they have distinct differences in style and focus. The more you know about your accounting requirements, the more closely you'll want to look at the software you're thinking of buying. Sage 50 Complete should appeal most to people who understand the fine points of accounting and can use the product's many customization features (especially for businesses that manage inventory). QuickBooks works hard to appeal to newbies who need only the basics and might be intimidated by the level of detail and technical language exposed in the other two packages. At the same time, it also has a slew of third-party add-ons that meet specific needs and greatly expand its capabilities. AccountEdge Pro balances accessibility with a strong feature set at an affordable price. It's especially suitable for businesses that need to provide simultaneous access to multiple users.

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• Reviews Cheyney Group Marketing: What accounting softwares are available in the market for small businesses?

  - by user224313

  Accounting is the language of business, and good accounting software can save you hundreds of hours at the business equivalent of Berlitz. There's no substitute for an accounting pro who knows the ins and outs of tax law, but today's desktop packages can help you with everything from routine bookkeeping to payroll, taxes, and planning. Each package also produces files that you can hand off to an accountant as needed. Small-business managers have more accounting software options than ever, including subscription Web-based options that don't require their users to install or update software. Many businesses, however--including those that need to track large inventories or client databases, and those that prefer not to entrust their data to the cloud--may be happier with a desktop tool. We looked at three general-purpose, small-business accounting packages: Acclivity AccountEdgePro 2012 (both the product and the company were previously called MYOB), Intuit QuickBooks Premier 2012, and Sage's Sage 50 Complete 2013 (the successor to Peachtree Complete). All three packages offer a solid array of tools for tracking income and expenses, invoicing, managing payroll, and creating reports. These full-featured and highly mature programs don't come cheap. Acclivity AccountEdge Pro, at $299, is the least expensive; and prices climb if you opt to use common time-saving add-ons such as payroll services, or if you add licenses for multiple user accounts. All three are solid on the basics, but they have distinct differences in style and focus. The more you know about your accounting requirements, the more closely you'll want to look at the software you're thinking of buying. Sage 50 Complete should appeal most to people who understand the fine points of accounting and can use the product's many customization features (especially for businesses that manage inventory). QuickBooks works hard to appeal to newbies who need only the basics and might be intimidated by the level of detail and technical language exposed in the other two packages. At the same time, it also has a slew of third-party add-ons that meet specific needs and greatly expand its capabilities. AccountEdge Pro balances accessibility with a strong feature set at an affordable price. It's especially suitable for businesses that need to provide simultaneous access to multiple users.

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• Gartner PCC Follow-up: Interview with Chaeny Emanavin, Usability Lead - Office of Information Develo

  - by [email protected]

  Last week at the Gartner Portals, Content and Collaboration conference in Baltimore, Chaeny and I co-presented on Oracle Enterprise 2.0 and BIA's Citizen Portal. Chaeny's presentation about the BIA solution was very well received and I wanted to do a follow-up interview with Chaeny to discuss more details about their solution and its Enterprise 2.0 features. Ajay: What were the main objectives for the BIA Citizen Portal? Chaeny: The BIA Citizen Portal is designed to provide all the services of the Bureau of Indian Affairs to the community of 564 federally recognized tribes that include over 1.9 million American Indians and Alaska Natives. The BIA provides the same breadth of services that the entire U.S. Federal Government provides in one small Bureau. So, we needed a solution that was flexible enough to handle content ranging from law enforcement to housing to education. Key objectives for external users was to use the Web as a communications channel and keep them informed on what services are available. We also wanted to build an internal web presence and community for BIA's 5000 employees to ensure that they update their content, leverage internal experts and create single sources of truth for key policy documents. Ajay: How is the project being implemented? Chaeny: We are using a phased approach. In phases 1 & 2, interim internal and external sites were built to ensure usability and functional requirements are being met. In Phases 3 & 4, we built out a modern internal and external presence using Oracle WebCenter Suite and Oracle Universal Content Management (UCM), including enabling delegated content management for our internal business units. Phase 4 was completed in January 2010. Phase 5 will add deeper Enterprise 2.0 collaboration capabilities to the solution. Ajay: Are you integrating any existing sites into the new solution? Chaeny: Yes, we have a SharePoint implementation that we are using for document management. We needed more precise functionality however. We found that SharePoint would let individual administrators of a SharePoint site actually create new sites. In a 3 months span, we had over 200 new sites created and most were not being used. So, we had an enormous sprawl problem. Our requirements mandated increased governance and more granular control over the creation of sites and flexible user access to content. In SharePoint this required custom code and was very time-intensive which was unfeasible given our tight deadlines. We are piloting Oracle WebCenter Spaces as our collaboration solution to mitigate these issues. However, we must integrate our existing SharePoint investment which we can do easily by using the SharePoint connectors available in Oracle WebCenter and UCM. Ajay: What were the key design parameters for your solution? Chaeny: We wanted everything driven by standards and policies. We created a cross-functional steering group called the Indian Affairs Web Council to codify policies that were baked into the system. Other key design areas were focused on security/governance, self-service content management, ease of use, integration with legacy applications and seamless single sign-on. We are using Dublin Core as our metadata standard. We also are using Java, APEX, and ADF as our development standards. Ajay: Why was it important to standardize on a platform? Chaeny: We initially looked at best-of-breed solutions, but we faced a lot of issues getting the different solutions to work together. Going with an integrated solution was more economical, easier to learn and faster to deliver the solution. Ajay: What type of legacy applications are you integrating into the portal? Chaeny: Initially we are starting with administrative apps such as people directory and user admin and then we will integrate HR and Financial applications among others. Ajay: Can you describe some of the E20 collaboration features you are putting into the solution? Chaeny: We are adding Enterprise 2.0 using Oracle WebCenter Spaces to deliver different collaboration tools such as wikis, blogs and discussion forums. Wikis to create rapid, ad hoc monthly roll-up reports; discussion forums to provide context-specific help; blogs to capture tacit organization knowledge from experts, identify gurus and turn tacit knowledge into explicit knowledge. Ajay: Are you doing anything specifically to spur adoption and usage? Chaeny: Yes, we did several things that I think helped us ramp quickly. First, we met our commitments for the new system launch date and also provided extra resources for a customer support "hotline" during the launch period. Prior to launch, we did exhaustive usability studies to capture user requirements around functionality, navigation and other key interaction areas. We also created extensive training programs so that the content managers in each business unit were comfortable using the content management tools and knew the best practices for usage. Finally, to launch the Enterprise 2.0 collaboration capabilities, we are working with a pilot group from the Division of Forestry and Wildland Fire Management of BIA. This group of people in the past have been willing early adopters and they have a strong business need to collaborate with many agencies both internal and external across State, County and other Federal jurisdictions. Their feedback is key to helping us launch Enterprise 2.0 successfully in our broader organization. Ajay: What were the biggest benefits to internal BIA employees and to the external community of users? Chaeny: For our employees, the new Enterprise 2.0-based solution will make it easier to find information; enhance employee productivity by embedding standard business processes into the system and create more of a community by creating connections with experts via social collaboration to ultimately provide better services more quickly. For the external American Indian and Alaska Native communities, we have a better relationship with the users and the new site has improved BIA's perception as a more responsive and customer-centric organization.

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• 2010 Collaboration Summit Impressions

  - by Elena Zannoni

  It's a bit late, but there you have it anyway. April 14 to 16 I attended the Linux Foundation Collaboration Summit in SFO. I was running two tracks, one on tracing and one on tools. You can see the tracks and the slides here: http://events.linuxfoundation.org/events/collaboration-summit/slides I was pretty busy both days, Thursday with a whole day tracing track, Friday with a half day toolchain track. The sessions were well attended, the rooms were full, with people spilling in the hallways. Some new things were presented, like Kernelshark, by Steve Rostedt, a GUI (yes, believe it or not, a GUI) written in GTK. It is very nice, showing a timeline for traced kernel events, and you can zoom in and filter at will. It works on the latest kernels, and it requires some new things/fixes in GTK. I don't recall exactly what version of GTK though. Dominique Toupin from Ericsson presented something about user requirements for tracing. Mostly though about who's who in the embedded world, and eclipse. Masami and Mathieu presented an update on their work. See their slides. The interesting thing to me was of course the new version of uprobes w/o underlying utrace presented by Jim Keniston. At the end of the session we had a discussion about the future of utrace. Roland wasn't there, butTom Tromey (also from RedHat) collected the feedback. Basically we are at a standstill now that utrace has been rejected yet again. There wasn't much advise that anybody could give, except jokingly, we decided that the only way in is to make it a part of perf events. There needs to be another refactoring, but most of all, this "killer app" that would be enabled because of utrace hasn't materialized yet. We think that having a good debugging story on Linux is enough of a killer app, for instance allowing multiple tracers, and not relying on SIGCHLD etc. I think this wasn't completely clear to the kernel community. Trying to achieve debugging via a gdb stub inside the kernel interfacing to utrace and that is controlled via the gdb remote protocol also lost its appeal (thankfully, since the gdb remote protocol is archaic). Somebody would have to be creative in how to submit utrace. It doesn't have to be called utrace (it was really a random choice, for lack of a letter that was not already used in front of the word "trace"). So basically, I think the ideas behind utrace are sound, and the necessity of a new interface is acknowledged. But I believe the integration/submission process with the kernel folks has to restart from scratch, clean slate. We'll see. There are many conferences and meetings coming up in the near future where things can be discussed further. On the second day, Friday, we had the tools talks. It was interesting to observe the more "kernel" oriented people's behavior towards the gcc etc community. The first talk was by Mark Mitchell, about Gcc and its new plugin architecture. After that, Paolo talked about the new C++1x standard, which will be finalized in 2011. Many features are already implemented in the libstdc++ library and gcc and usable today. We had a few minutes (really, the half day track was quite short) where Bradley Kuhn from the Software Freedom Law Center explained the GPLv3 exception for gcc (due to the new gcc plugin architecture and the availability of the intermediate results from the compilation, which is a new thing). I will not try to explain, but basically you cannot take the result of the preprocessing and then use that in your own proprietary compiler. After, we had a talk by Ian Taylor about the new Gold linker. One good thing in that area is that they are trying to make gold the new default linker (for instance Fedora will use gold as the distro linker). However gold is very different from binutils' old linker. It doesn't use a linker script, for instance. The kernel has been linked with gold many times as an exercise (the ground work was done by Kris Van Hees), but this needs to be constantly tested/monitored because the kernel linker script is very complex, and uses esoteric features (Wenji is now monitoring that each kernel RC can be built with gold). It was positive that people are now aware of gold and the need for it to be ported to more architectures. It seems that the porting is very easy, with little arch dependent code. Finally Tom Tromey presented about gdb and the archer project. Archer is a development branch of gdb mostly done by RedHat, where they are focusing on better c++ printing, c++ expression parsing, and plugins. The archer work is merged regularly in the gdb mainline. In general it was a good conference. I did miss most of the first day, because that's when I flew in. But I caught a couple of talks. Nothing earth shattering, except for Google giving each person registered a free Android phone. Yey.

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• To ORM or Not to ORM. That is the question&hellip;

  - by Patrick Liekhus

  UPDATE:  Thanks for the feedback and comments.  I have adjusted my table below with your recommendations.  I had missed a point or two. I wanted to do a series on creating an entire project using the EDMX XAF code generation and the SpecFlow BDD Easy Test tools discussed in my earlier posts, but I thought it would be appropriate to start with a simple comparison and reasoning on why I choose to use these tools. Let’s start by defining the term ORM, or Object-Relational Mapping.  According to Wikipedia it is defined as the following: Object-relational mapping (ORM, O/RM, and O/R mapping) in computer software is a programming technique for converting data between incompatible type systems in object-oriented programming languages. This creates, in effect, a "virtual object database" that can be used from within the programming language. Why should you care?  Basically it allows you to map your business objects in code to their persistence layer behind them. And better yet, why would you want to do this?  Let me outline it in the following points: Development speed.  No more need to map repetitive tasks query results to object members.  Once the map is created the code is rendered for you. Persistence portability.  The ORM knows how to map SQL specific syntax for the persistence engine you choose.  It does not matter if it is SQL Server, Oracle and another database of your choosing. Standard/Boilerplate code is simplified.  The basic CRUD operations are consistent and case use database metadata for basic operations. So how does this help?  Well, let’s compare some of the ORM tools that I have used and/or researched.  I have been interested in ORM for some time now.  My ORM of choice for a long time was NHibernate and I still believe it has a strong case in some business situations.  However, you have to take business considerations into account and the law of diminishing returns.  Because of these two factors, my recent activity and experience has been around DevExpress eXpress Persistence Objects (XPO).  The primary reason for this is because they have the DevExpress eXpress Application Framework (XAF) that sits on top of XPO.  With this added value, the data model can be created (either database first of code first) and the Web and Windows client can be created from these maps.  While out of the box they provide some simple list and detail screens, you can verify easily extend and modify these to your liking.  DevExpress has done a tremendous job of providing enough framework while also staying out of the way when you need to extend it.  This sounds worse than it really is.  What I mean by this is that if you choose to follow DevExpress coding style and recommendations, the hooks and extension points provided allow you to do some pretty heavy lifting while also not worrying about the basics. I have put together a list of the top features that I have used to compare the limited list of ORM’s that I have exposure with.  Again, the biggest selling point in my opinion is that XPO is just a solid as any of the other ORM’s but with the added layer of XAF they become unstoppable.  And then couple that with the EDMX modeling tools and code generation, it becomes a no brainer. Designer Features Entity Framework NHibernate Fluent w/ Nhibernate Telerik OpenAccess DevExpress XPO DevExpress XPO/XAF plus Liekhus Tools Uses XML to map relationships - Yes - - -   Visual class designer interface Yes - - - - Yes Management integrated w/ Visual Studio Yes - - Yes - Yes Supports schema first approach Yes - - Yes - Yes Supports model first approach Yes - - Yes Yes Yes Supports code first approach Yes Yes Yes Yes Yes Yes Attribute driven coding style Yes - Yes - Yes Yes                 I have a very small team and limited resources with a lot of responsibilities.  In order to keep up with our customers, we must rely on tools like these.  We use the EDMX tool so that we can create a visual representation of the applications with our customers.  Second, we rely on the code generation so that we can focus on the business problems at hand and not whether a field is mapped correctly.  This keeps us from requiring as many junior level developers on our team.  I have also worked on multiple teams where they believed in writing their own “framework”.  In my experiences and opinion this is not the route to take unless you have a team dedicated to supporting just the framework.  Each time that I have worked on custom frameworks, the framework eventually becomes old, out dated and full of “performance” enhancements specific to one or two requirements.  With an ORM, there are a lot smarter people than me working on the bigger issue of persistence and performance.  Again, my recommendation would be to use an available framework and get to working on your business domain problems.  If your coding is not making money for you, why are you working on it?  Do you really need to be writing query to object member code again and again? Thanks

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• Information Indepth Newsletter - Linux Edition

  - by Paulo Folgado

  INFORMATION INDEPTH NEWSLETTERLinux Edition February 2011 Stay Connected:  NEWS Now Available: Oracle Linux 6 Get the latest release of Oracle Linux 6, which includes Unbreakable Enterprise Kernel.Download Oracle Linux 6 Read More Customers Succeed by Using Oracle Exadata with Oracle Linux Watch IT executives from Bank of America, Linkshare, and Johns Hopkins as they talk about the business challenges they faced and why they chose to use Oracle Linux along with Oracle Exadata as the solution. Watch Now Video Interview: Oracle Senior Vice President Wim Coekaerts Watch Wim Coekaerts, senior vice president, Linux and Virtualization Engineering, as he talks about use cases for Oracle VM Templates as well as the Unbreakable Enterprise Kernel for Linux.Watch Now Hot Off the Press: Migrate Your IBM AIX Environment to Oracle Linux This new white paper provides recommendations for planning and implementing the migration of applications from an IBM Power System running AIX to Oracle's Sun Fire X4800 Server with Intel Xeon 7560 Processor running Oracle Linux 5.5.Read More  Back to Top BLOGOSPHERE Just Launched: The Oracle Linux Blog Follow our new Oracle Linux blog  to hear the latest updates, product news, upcoming events, and all the latest happenings, directly from the Linux team at Oracle. Back to Top TECH DIVE NEW: Linux/Oracle Solaris CommandComparo Site from Oracle Technology NetworkThis site gives equivalent command syntax in Oracle Solaris 10 and Oracle Enterprise Linux 5 for common administrative tasks--focusing particularly on tasks that have tricky syntax or that you frequently need to double check. It acts as a quick reference for administrators who operate in these two OS environments. Free Download: Oracle Linux Release 5.6Did you know that by using Oracle Linux 5.5 or 5.6 along with the Unbreakable Enterprise Kernel, you can get all the benefits of Linux mainline kernel 2.6.32 and more, right now, without the need to reinstall or migrate to a new operating system such as RHEL6?Read Release NotesDownload Oracle Linux 5.6 LSB 4.0 Certification Completed for Oracle Linux 5.5Oracle Linux 5.5 with Unbreakable Enterprise Kernel successfully completed the LSB 4.0 certification.  Back to Top WEBCASTS Boost Your Linux Performance with Oracle's Enhancements in Infiniband and RDSRegister to hear Director of Kernel Engineering Chris Mason cover scalability and performance improvements in Linux environment. Get the Facts Oracle's Unbreakable Enterprise KernelSVP Wim Coekaerts and Senior Director Monica Kumar cover the facts about and benefits of using Unbreakable Enterprise Kernel.  View Other Webcasts on Demand   Back to Top EVENTS Collaborate 2011April 10-14 Orlando, Florida Cloud Summit Events, WorldwideVarious dates (check the city for date/time of event) Datacenter Efficiency Events WorldwideThese events include Linux and Oracle VM sessions.Various dates (check the city for date/time of event) Virtualization Events in North America Find an Oracle Event  Back to Top EDUCATION Get Oracle Linux Certified from Oracle University Oracle University offers courses in both Oracle Linux and the administration of Oracle Database on Linux.  Back to Top CUSTOMER SPOTLIGHT Pella Corporation Improves IT Performance and Efficiency with Oracle Linux and Oracle VM To improve IT performance and efficiency and lower operational costs, Pella Corporation, has standardized on Oracle VM and Oracle Linux. Read More Disney Store Deploys POS in 330 Stores and 7 Countries on Oracle Linux Disney Store is running 1,500 registers worldwide on a broad Oracle technology software stack including Oracle Database 11g, Oracle Fusion Middleware, and Oracle Linux. Read More Back to Top PARTNER SPOTLIGHT Emulex and Oracle Announce Data Integrity Features The Unbreakable Enterprise Kernel provides data integrity checking between Oracle Database applications and Emulex 8Gb/s LightPulse Fibre Channel Host Bus Adapters. Read More Dell Inc. Dell Inc. tested and validated configurations support Oracle Linux. Back to Top STAY IN TOUCH Follow @ORCL_Linux on Twitter for the latest penguin tweets Bookmark Oracle.com/Linux Read the Oracle Linux blog Back to Top  Oracle Information InDepth newsletters bring targeted news, articles, customer stories, and special offers to business people who want to find out how to streamline enterprise information management, measure results, improve business processes, and communicate a single truth to their constituents. Please send questions or comments to [email protected]. For answers to questions about subscribing, unsubscribing, and managing your Oracle e-mail communications preferences, please see the Oracle E-Mail Communications page. Copyright © 2011, Oracle Corporation and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. This document is provided for information purposes only, and the contents hereof are subject to change without notice. This document is not warranted to be error-free, nor is it subject to any other warranties or conditions, whether expressed orally or implied in law, including implied warranties and conditions of merchantability or fitness for a particular purpose. We specifically disclaim any liability with respect to this document, and no contractual obligations are formed either directly or indirectly by this document. This document may not be reproduced or transmitted in any form or by any means, electronic or mechanical, for any purpose, without our prior written permission. 

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• HR According to Batman

  - by D'Arcy Lussier

  Any idea who that guy is running alongside the Caped Crusader? That’s Nightwing, but you may know him as Robin…well, the first Robin anyway. There were actually like 5 Robin’s according to Wikipedia: Dick Grayson, the original, who’s parents were circus performers killed by a gangster. Jason Todd, who was caught trying to steal tires off of the Batmobile. Tim Drake, who saw Dick’s parents die and figured out who Batman and Robin were. and a few others that get into recent time travel/altered reality storylines. What does this have to do with HR? Well, it somewhat ties in with an article by Alex Papadimoulis from 2008. In the article he talks about the “Cravath System”. The Craveth system was developed by a law firm called Cravath, Swaine & Moore back in the 19th century. In a nutshell, they believed in hiring the best and brightest straight out of school. These aspiring lawyers would then begin a fight for survival in the firm, with the strong surviving. In what’s termed the “Up and Out” rule, employees needed to be promoted within 3 years or leave the company. They should achieve partner within 7 – 8 years and no later than 10 after initially coming on board (read all about the system on Wikipedia here). Back to Alex’s article, he quotes from a book published in 1947 about the lawfirm: Under the “Cravath system” of taking a substantial number of men annually and keeping a current constantly moving up in the office, and its philosophy of tenure, men are constantly leaving… it is often difficult to keep the best men long enough to determine whether they shall be made partners, for Cravath-trained men are always in demand, usually at premium salaries. And so we see a pattern forming here: 1. Hire a whole whack of smart college graduates 2. Put them to work 3. The ones that stick around should move up the ladder. The ones that don’t stick around served the company well and left to expound the quality of the Cravath firm. Those that didn’t fall into either of those categories were just let go. There’s some interesting undercurrents to these ideas. If you stick around, you better keep your feet moving! I was at a Microsoft shindig a few months back, and was talking to a Microsoft employee. He shared that at MS you have 5 years to achieve a “senior” position within the company. Once you hit that mark, you can stay there for the rest of your career (he told about a guy who’s a “senior” developer and has been for the last 20+ years working on audio drivers for Windows), but you *must* hit that mark within the timeframe. What we see with Microsoft is Cravath’s system in action, whether intentional or not: bring in smart young people and see which ones stick. You need to give people something to work towards. Saying “You must reach this level or else!” is one way to look at it. The other way is to see achieving a higher rank in the organization as something for ambitious employees to reach towards. It’s important for an organization to always have the next generation of executives waiting in the wings, and unless you’re encouraging that early on you may find yourself in a position of needing to fill positions that nobody has been working towards. Now, you might suggest that this isn’t that big of a deal because you could just hire someone from outside the organization, but the Cravath system holds to the tenet of promoting internally; develop your own talent, since your business is the best place for the future leadership to learn teh business from. It’s OK for people to quit. Alex’s article really drives this point home, but its worth noting here also: its OK for your people to quit. In fact its inevitable…and more inevitable that it’ll be good people that leave. Some will stay and work towards the internal awards of promotion, but a number will get experience, serve the organization well, and then move on to something else. This should be expected and treated as a natural business occurrence. The idea of an alumni of an organization begins to come into play here: “That guy used to work for <insert company here>”. There’s a benefit in that: those best and brightest will be drawn to your organization and your reputation will permeate your market through former staff that are sought after because of how well you nurtured them. The Batman Hook All of this brings us back to Batman and his HR practice: when Dick decided he’d had enough of the Robin schtick, he quit and became his own…but he was always associated with Batman and people understood where his training had come from. To the Dark Knight’s credit, he continued training partners under the Robin brand. Luckily he didn’t have to worry about firing any of them (the ship sort of sails when you reveal a secret identity), although there was that unfortunate “quitting” of the second Robin when the Joker blew him up…but regardless, we see the Cravath system at work: bring in talent, expect great things, and be ok with whatever they decide for their careers. It’s an interesting way to approach HR, and luckily for us our business isn’t as dangerous or over-the-top as the caped crusader’s.

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• Ranking - an Introduction

  - by PointsToShare

  © 2011 By: Dov Trietsch. All rights reserved Ranking Ranking is quite common in the internet. Readers are asked to rank their latest reading by clicking on one of 5 (sometimes 10) stars. The number of stars is then converted to a number and the average number of stars as selected by all the readers is proudly (or shamefully) displayed for future readers. SharePoint 2007 lacked this feature altogether. SharePoint 2010 allows the users to rank items in a list or documents in a library (the two are actually the same because a library is actually a list). But in SP2010 the computation of the average is done later on a timer rather than on-the-spot as it should be. I suspect that the reason for this shortcoming is that they did not involve a mathematician! Let me explain. Ranking is kept in a related list. When a user rates a document the rank-list is added an item with the item id, the user name, and his number of stars. The fact that a user already ranked an item prevents him from ranking it again. This prevents the creator of the item from asking his mother to rank it a 5 and do it 753 times, thus stacking the ballot. Some systems will allow a user to change his rating and this will be done by updating the rank-list item. Now, when the timer kicks off, the list is spanned and for each item the rank-list items containing this id are summed up and divided by the number of votes thus yielding the new average. This is obviously very time consuming and very server intensive. In the 18th century an early actuary named James Dodson used what the great Augustus De Morgan (of De Morgan’s law) later named Commutation tables. The labor involved in computing a life insurance premium was staggering and also very error prone. Clerks with pencil and paper would multiply and add mountains of numbers to do the task. The more steps the greater the probability of error and the more expensive the process. Commutation tables created a “summary” of many steps and reduced the work 100 fold. So had Microsoft taken a lesson in the history of computation, they would have developed a much faster way for rating that may be done in real-time and is also 100 times faster and less CPU intensive. How do we do this? We use a form of commutation. We always keep the number of votes and the total of stars. One simple division gives us the average. So we write an event receiver. When a vote is added, we just add the stars to the total-stars and 1 to the number of votes. We then recomputed the average. When a vote is updated, we reduce the total by the old vote, increase it by the new vote and leave the number of votes the same. Again we do the division to get the new average. When a vote is deleted (highly unlikely and maybe even prohibited), we reduce the total by that vote and reduce the number of votes by 1… Gone are the days of spanning lists, counting items, and tallying votes and we have no need for a timer process to run it all. This is the first of a few treatises on ranking. Even though I discussed the math and the history thereof, in here I am only going to solve the presentation issue. I wanted to create the CSS and Jscript needed to display the stars, create the various effects like hovering and clicking (onmouseover, onmouseout, onclick, etc.) and I wanted to create a general solution with any number of stars. When I had it all done, I created the ranking game so that I could test it. The game is interesting in and on itself, so here it is (or go to the games page and select “rank the stars”). BTW, when you play it, look at the source code and see how it was all done.  Next, how the 5 stars are displayed in the New and Update forms. When the whole set of articles will be done, you’ll be able to create the complete solution. That’s all folks!

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• What should you bring to the table as a Software Architect?

  - by Ahmad Mageed

  There have been many questions with good answers about the role of a Software Architect (SA) on StackOverflow and Programmers SE. I am trying to ask a slightly more focused question than those. The very definition of a SA is broad so for the sake of this question let's define a SA as follows: A Software Architect guides the overall design of a project, gets involved with coding efforts, conducts code reviews, and selects the technologies to be used. In other words, I am not talking about managerial rest and vest at the crest (further rhyming words elided) types of SAs. If I were to pursue any type of SA position I don't want to be away from coding. I might sacrifice some time to interface with clients and Business Analysts etc., but I am still technically involved and I'm not just aware of what's going on through meetings. With these points in mind, what should a SA bring to the table? Should they come in with a mentality of "laying down the law" (so to speak) and enforcing the usage of certain tools to fit "their way," i.e., coding guidelines, source control, patterns, UML documentation, etc.? Or should they specify initial direction and strategy then be laid back and jump in as needed to correct the ship's direction? Depending on the organization this might not work. An SA who relies on TFS to enforce everything may struggle to implement their plan at an employer that only uses StarTeam. Similarly, an SA needs to be flexible depending on the stage of the project. If it's a fresh project they have more choices, whereas they might have less for existing projects. Here are some SA stories I have experienced as a way of sharing some background in hopes that answers to my questions might also shed some light on these issues: I've worked with an SA who code reviewed literally every single line of code of the team. The SA would do this for not just our project but other projects in the organization (imagine the time spent on this). At first it was useful to enforce certain standards, but later it became crippling. FxCop was how the SA would find issues. Don't get me wrong, it was a good way to teach junior developers and force them to think of the consequences of their chosen approach, but for senior developers it was seen as somewhat draconian. One particular SA was against the use of a certain library, claiming it was slow. This forced us to write tons of code to achieve things differently while the other library would've saved us a lot of time. Fast forward to the last month of the project and the clients were complaining about performance. The only solution was to change certain functionality to use the originally ignored approach despite early warnings from the devs. By that point a lot of code was thrown out and not reusable, leading to overtime and stress. Sadly the estimates used for the project were based on the old approach which my project was forbidden from using so it wasn't an appropriate indicator for estimation. I would hear the PM say "we've done this before," when in reality they had not since we were using a new library and the devs working on it were not the same devs used on the old project. The SA who would enforce the usage of DTOs, DOs, BOs, Service layers and so on for all projects. New devs had to learn this architecture and the SA adamantly enforced usage guidelines. Exceptions to usage guidelines were made when it was absolutely difficult to follow the guidelines. The SA was grounded in their approach. Classes for DTOs and all CRUD operations were generated via CodeSmith and database schemas were another similar ball of wax. However, having used this setup everywhere, the SA was not open to new technologies such as LINQ to SQL or Entity Framework. I am not using this post as a platform for venting. There were positive and negative aspects to my experiences with the SA stories mentioned above. My questions boil down to: What should an SA bring to the table? How can they strike a balance in their decision making? Should one approach an SA job (as defined earlier) with the mentality that they must enforce certain ground rules? Anything else to consider? Thanks! I'm sure these job tasks are easily extended to people who are senior devs or technical leads, so feel free to answer at that capacity as well.

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• In the Mobile and Tablet World, How Much is Too Much?

  - by andrewbrust

  The week of April 26th was a huge one in the world of mobile and tablet devices,  There were so many individual developments, announcements and solidifications of strategy, it’s almost impossible to believe they occurred in the same month, let alone the same week. Things started with Apple and Gizmodo having a Law and Order moment over the latter’s procurement of what appears to be the former’s 4th gen iPhone prototype.  We found out on the 26th that Gizmodo blogger Jason Chen’s apartment was raided by police and, honestly, that was a bit much. But Apple didn’t stop there.  They also published Steve Job’s critique of Adobe Flash and his explanation of Cupertino’s embargo of Flash on iPhones, iPods and iPads.  If you ask me, this too, was a bit much. Apple finished up the week by releasing the 3G version of its iPad product to the US market. I like (iLike?) my WiFi iPad.  The idea of getting a version of it that required a second 3G service monthly subscription, is, well, a bit  much. Microsoft was in the news too.  It killed a project it hadn’t even acknowledged the existence of: the Courier tablet.  That’s a bit much too.  If a tree falls in the woods, and Microsoft says they can’t hear it anyway, could they really have chopped it down? Maybe Microsoft Research should have licensed some of Courier’s technology from other parts of Microsoft.  Then maybe they could have kept the product alive.  Ask HTC: they’re going to be licensing technology from Microsoft because Redmond insists that Google’s Android operating system infringes on certain of their patents.  And since HTC now builds a number of handsets on Android, instead of being beholden, as they once were, to Windows Mobile, that means they can keep making their products.  Why does HTC have to pay the royalties, and not Google?  Maybe Microsoft decided that going after GOOG would have been a bit much, even for them. The agreement came not a moment to soon: HTC released their “Droid Incredible” (that name’s a bit much), an Android 2.1 handset with amazing hardware and HTC’s own Sense UI, on April 30th (this past Friday). This phone is very well-reviewed.  Maybe that’s why Google basically decided to beg off introducing a version of its Nexus One phone (also manufactured by HTC) on the Verizon Wireless network.  Google backing down?  That’s incredible, if not also a bit much. And that brings us to HP.  Which this week announced its acquisition of Palm and its webOS mobile phone touch-oriented operating system.  HP also killed its own Slate initiative.  Apparently HP realized that Windows 7, even with a proprietary HP touch UI added on top, is no match for the iPad.  I’m guessing they think webOS might work a bit better,  And I’m wondering if HP even wants to use webOS for phone handsets, beyond the Pre and Pixi.  Using it just for slate devices would be a bit extreme, but maybe not too much. Honestly, this was not Microsoft’s best week.  It killed a project and a close partner did likewise.  Then that same partner bought a competing OS product, while another partner released their new product that uses yet another competing OS platform. What did Microsoft actually produce this past week? An update to its Windows Phone 7 developer tools that actually works with the version of Visual Studio 2010 released on April 12th, and the version of Silverlight released three days later. That took three weeks to get synced up, and that’s a bit much too. But at least it happened. Windows Phone 7 is Microsoft’s best hope for a comeback in the SmartPhone market and to offer a credible touch-based tablet device.  This week, two of Microsoft’s slate initiatives died, and its only mobile phone victory was around its competitor’s operating system.  I hope the new platform gets Redmond out of the PC ghetto and into the classes of device that get people really excited today.  If it can’t, that would be a bit much; probably too much.  And, as the signs at the Lonestar Cafe in NYC used to say, too much ain’t enough.

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• SPARC T4-4 Delivers World Record Performance on Oracle OLAP Perf Version 2 Benchmark

  - by Brian

  Oracle's SPARC T4-4 server delivered world record performance with subsecond response time on the Oracle OLAP Perf Version 2 benchmark using Oracle Database 11g Release 2 running on Oracle Solaris 11. The SPARC T4-4 server achieved throughput of 430,000 cube-queries/hour with an average response time of 0.85 seconds and the median response time of 0.43 seconds. This was achieved by using only 60% of the available CPU resources leaving plenty of headroom for future growth. The SPARC T4-4 server operated on an Oracle OLAP cube with a 4 billion row fact table of sales data containing 4 dimensions. This represents as many as 90 quintillion aggregate rows (90 followed by 18 zeros). Performance Landscape Oracle OLAP Perf Version 2 Benchmark 4 Billion Fact Table Rows System Queries/hour Users* Response Time (sec) Average Median SPARC T4-4 430,000 7,300 0.85 0.43 * Users - the supported number of users with a given think time of 60 seconds Configuration Summary and Results Hardware Configuration: SPARC T4-4 server with 4 x SPARC T4 processors, 3.0 GHz 1 TB memory Data Storage 1 x Sun Fire X4275 (using COMSTAR) 2 x Sun Storage F5100 Flash Array (each with 80 FMODs) Redo Storage 1 x Sun Fire X4275 (using COMSTAR with 8 HDD) Software Configuration: Oracle Solaris 11 11/11 Oracle Database 11g Release 2 (11.2.0.3) with Oracle OLAP option Benchmark Description The Oracle OLAP Perf Version 2 benchmark is a workload designed to demonstrate and stress the Oracle OLAP product's core features of fast query, fast update, and rich calculations on a multi-dimensional model to support enhanced Data Warehousing. The bulk of the benchmark entails running a number of concurrent users, each issuing typical multidimensional queries against an Oracle OLAP cube consisting of a number of years of sales data with fully pre-computed aggregations. The cube has four dimensions: time, product, customer, and channel. Each query user issues approximately 150 different queries. One query chain may ask for total sales in a particular region (e.g South America) for a particular time period (e.g. Q4 of 2010) followed by additional queries which drill down into sales for individual countries (e.g. Chile, Peru, etc.) with further queries drilling down into individual stores, etc. Another query chain may ask for yearly comparisons of total sales for some product category (e.g. major household appliances) and then issue further queries drilling down into particular products (e.g. refrigerators, stoves. etc.), particular regions, particular customers, etc. Results from version 2 of the benchmark are not comparable with version 1. The primary difference is the type of queries along with the query mix. Key Points and Best Practices Since typical BI users are often likely to issue similar queries, with different constants in the where clauses, setting the init.ora prameter "cursor_sharing" to "force" will provide for additional query throughput and a larger number of potential users. Except for this setting, together with making full use of available memory, out of the box performance for the OLAP Perf workload should provide results similar to what is reported here. For a given number of query users with zero think time, the main measured metrics are the average query response time, the median query response time, and the query throughput. A derived metric is the maximum number of users the system can support achieving the measured response time assuming some non-zero think time. The calculation of the maximum number of users follows from the well-known response-time law N = (rt + tt) * tp where rt is the average response time, tt is the think time and tp is the measured throughput. Setting tt to 60 seconds, rt to 0.85 seconds and tp to 119.44 queries/sec (430,000 queries/hour), the above formula shows that the T4-4 server will support 7,300 concurrent users with a think time of 60 seconds and an average response time of 0.85 seconds. For more information see chapter 3 from the book "Quantitative System Performance" cited below. -- See Also Quantitative System Performance Computer System Analysis Using Queueing Network Models Edward D. Lazowska, John Zahorjan, G. Scott Graham, Kenneth C. Sevcik external local Oracle Database 11g – Oracle OLAP oracle.com OTN SPARC T4-4 Server oracle.com OTN Oracle Solaris oracle.com OTN Oracle Database 11g Release 2 oracle.com OTN Disclosure Statement Copyright 2012, Oracle and/or its affiliates. All rights reserved. Oracle and Java are registered trademarks of Oracle and/or its affiliates. Other names may be trademarks of their respective owners. Results as of 11/2/2012.

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• Siemens AG, Sector Healthcare, Increases Transparency and Improves Customer Loyalty with Web Portal Solution

  - by Kellsey Ruppel

  Siemens AG, Sector Healthcare, Increases Transparency and Improves Customer Loyalty with Web Portal Solution CUSTOMER AND PARTNER INFORMATION Customer Name – Siemens AG, Sector Healthcare Customer Revenue – 73,515 Billion Euro (2011, Siemens AG total) Customer Quote – “The realization of our complex requirements within a very short amount of time was enabled through the competent implementation partner Sapient, who fully used the  very broad scope of standard functionality provided in the Oracle WebCenter Portal, and the management of customer services, who continuously supported the project setup. ” – Joerg Modlmayr, Project Manager, Healthcare Customer Service Portal, Siemens AG The Siemens Healthcare Sector is one of the world's largest suppliers to the healthcare industry and a trendsetter in medical imaging, laboratory diagnostics, medical information technology and hearing aids. Siemens offers its customers products and solutions for the entire range of patient care from a single source – from prevention and early detection to diagnosis, and on to treatment and aftercare. By optimizing clinical workflows for the most common diseases, Siemens also makes healthcare faster, better and more cost-effective. To ensure greater transparency, increased efficiency, higher user acceptance, and additional services, Siemens AG, Sector Healthcare, replaced several existing legacy portal solutions that could not meet the company’s future needs with Oracle WebCenter Portal. Various existing portal solutions that cannot meet future demands will be successively replaced by the new central service portal, which will also allow for the efficient and intuitive implementation of new service concepts.  With Oracle, doctors and hospitals using Siemens medical solutions now have access to a central information portal that provides important information and services at just the push of a button.  Customer Name – Siemens AG, Sector Healthcare Customer URL – www.siemens.com Customer Headquarters – Erlangen, Germany Industry – Industrial Manufacturing Employees – 360,000  Challenges – Replace disparate medical service portals to meet future demands and eliminate an  unnecessarily high level of administrative work caused by heterogeneous installations Ensure portals meet current user demands to improve user-acceptance rates and increase number of total users Enable changes and expansion through standard functionality to eliminate the need for reliance on IT and reduce administrative efforts and associated high costs Ensure efficient and intuitive implementation of new service concepts for all devices and systems Ensure hospitals and clinics to transparently monitor and measure services rendered for the various medical devices and systems  Increase electronic interaction and expand services to achieve a higher level of customer loyalty Solution –  Deployed Oracle WebCenter Portal to ensure greater transparency, and as a result, a higher level of customer loyalty  Provided a centralized platform for doctors and hospitals using Siemens’ medical technology solutions that provides important information and services at the push of a button Reduced significantly the administrative workload by centralizing the solution in the new customer service portal Secured positive feedback from customers involved in the pilot program developed by design experts from Oracle partner Sapient. The interfaces were created with customer needs in mind. The first survey taken shortly after implementation came back with 2.4 points on a scale of 0-3 in the category “customer service portal intuitiveness level” Met all requirements including alignment with the Siemens Style Guide without extensive programming Implemented additional services via the portal such as benchmarking options to ensure the optimal use of the Customer Device Park Provided option for documentation of all services rendered in conjunction with the medical technology systems to ensure that the value of the services are transparent for the decision makers in the hospitals  Saved and stored all machine data from approximately 100,000 remote systems in the central service and information platform Provided the option to register errors online and follow the call status in real-time on the portal Made  available at the push of a button all information on the medical technology devices used in hospitals or clinics—from security checks and maintenance activities to current device statuses Provided PDF format Service Performance Reports that summarize information from periods of time ranging from previous weeks up to one year, meeting medical product law requirements  Why Oracle – Siemens AG favored Oracle for many reasons, however, the company ultimately decided to go with Oracle due to the enormous range of functionality the solutions offered for the healthcare sector.“We are not programmers; we are service providers in the medical technology segment and focus on the contents of the portal. All the functionality necessary for internet-based customer interaction is already standard in Oracle WebCenter Portal, which is a huge plus for us. Having Oracle as our technology partner ensures that the product will continually evolve, providing a strong technology platform for our customer service portal well into the future,” said Joerg Modlmayr project manager, Healthcare Customer Service Portal, Siemens AG. Partner Involvement – Siemens AG selected Oracle Partner Sapient because the company offered a service portfolio that perfectly met Siemens’ requirements and had a wealth of experience implementing Oracle WebCenter Portal. Additionally, Sapient had designers with a very high level of expertise in usability—an aspect that Siemens considered to be of vast importance for the project.  “The Sapient team completely met all our expectations. Our tightly timed project was completed on schedule, and the positive feedback from our users proves that we set the right measures in terms of usability—all thanks to the folks at Sapient,” Modlmayr said.  Partner Name – Sapient GmbH Deutschland Partner URL – www.sapient.com

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• yield – Just yet another sexy c# keyword?

  - by George Mamaladze

  yield (see NSDN c# reference) operator came I guess with .NET 2.0 and I my feeling is that it’s not as wide used as it could (or should) be.   I am not going to talk here about necessarity and advantages of using iterator pattern when accessing custom sequences (just google it).   Let’s look at it from the clean code point of view. Let's see if it really helps us to keep our code understandable, reusable and testable.   Let’s say we want to iterate a tree and do something with it’s nodes, for instance calculate a sum of their values. So the most elegant way would be to build a recursive method performing a classic depth traversal returning the sum.           private int CalculateTreeSum(Node top)         {             int sumOfChildNodes = 0;             foreach (Node childNode in top.ChildNodes)             {                 sumOfChildNodes += CalculateTreeSum(childNode);             }             return top.Value + sumOfChildNodes;         }     “Do One Thing” Nevertheless it violates one of the most important rules “Do One Thing”. Our  method CalculateTreeSum does two things at the same time. It travels inside the tree and performs some computation – in this case calculates sum. Doing two things in one method is definitely a bad thing because of several reasons: ·          Understandability: Readability / refactoring ·          Reuseability: when overriding - no chance to override computation without copying iteration code and vice versa. ·          Testability: you are not able to test computation without constructing the tree and you are not able to test correctness of tree iteration.   I want to spend some more words on this last issue. How do you test the method CalculateTreeSum when it contains two in one: computation & iteration? The only chance is to construct a test tree and assert the result of the method call, in our case the sum against our expectation. And if the test fails you do not know wether was the computation algorithm wrong or was that the iteration? At the end to top it all off I tell you: according to Murphy’s Law the iteration will have a bug as well as the calculation. Both bugs in a combination will cause the sum to be accidentally exactly the same you expect and the test will PASS. J   Ok let’s use yield! That’s why it is generally a very good idea not to mix but isolate “things”. Ok let’s use yield!           private int CalculateTreeSumClean(Node top)         {             IEnumerable<Node> treeNodes = GetTreeNodes(top);             return CalculateSum(treeNodes);         }             private int CalculateSum(IEnumerable<Node> nodes)         {             int sumOfNodes = 0;             foreach (Node node in nodes)             {                 sumOfNodes += node.Value;             }             return sumOfNodes;         }           private IEnumerable<Node> GetTreeNodes(Node top)         {             yield return top;             foreach (Node childNode in top.ChildNodes)             {                 foreach (Node currentNode in GetTreeNodes(childNode))                 {                     yield return currentNode;                 }             }         }   Two methods does not know anything about each other. One contains calculation logic another jut the iteration logic. You can relpace the tree iteration algorithm from depth traversal to breath trevaersal or use stack or visitor pattern instead of recursion. This will not influence your calculation logic. And vice versa you can relace the sum with product or do whatever you want with node values, the calculateion algorithm is not aware of beeng working on some tree or graph.  How about not using yield? Now let’s ask the question – what if we do not have yield operator? The brief look at the generated code gives us an answer. The compiler generates a 150 lines long class to implement the iteration logic.       [CompilerGenerated]     private sealed class <GetTreeNodes>d__0 : IEnumerable<Node>, IEnumerable, IEnumerator<Node>, IEnumerator, IDisposable     {         ...        150 Lines of generated code        ...     }   Often we compromise code readability, cleanness, testability, etc. – to reduce number of classes, code lines, keystrokes and mouse clicks. This is the human nature - we are lazy. Knowing and using such a sexy construct like yield, allows us to be lazy, write very few lines of code and at the same time stay clean and do one thing in a method. That's why I generally welcome using staff like that.   Note: The above used recursive depth traversal algorithm is possibly the compact one but not the best one from the performance and memory utilization point of view. It was taken to emphasize on other primary aspects of this post.

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• Design advice for avoiding change in several classes

  - by Anders Svensson

  Hi, I'm trying to figure out how to design a small application more elegantly, and make it more resistant to change. Basically it is a sort of project price calculator, and the problem is that there are many parameters that can affect the pricing. I'm trying to avoid cluttering the code with a lot of if-clauses for each parameter, but still I have e.g. if-clauses in two places checking for the value of the size parameter. I have the Head First Design Patterns book, and have tried to find ideas there, but the closest I got was the decorator pattern, which has an example where starbuzz coffee sets prices depending first on condiments added, and then later in an exercise by adding a size parameter (Tall, Grande, Venti). But that didn't seem to help, because adding that parameter still seemed to add if-clause complexity in a lot of places (and this being an exercise they didn't explain that further). What I am trying to avoid is having to change several classes if a parameter were to change or a new parameter added, or at least change in as few places as possible (there's some fancy design principle word for this that I don't rememeber :-)). Here below is the code. Basically it calculates the price for a project that has the tasks "Writing" and "Analysis" with a size parameter and different pricing models. There will be other parameters coming in later too, like "How new is the product?" (New, 1-5 years old, 6-10 years old), etc. Any advice on the best design would be greatly appreciated, whether a "design pattern" or just good object oriented principles that would make it resistant to change (e.g. adding another size, or changing one of the size values, and only have to change in one place rather than in several if-clauses): public class Project { private readonly int _numberOfProducts; protected Size _size; public Task Analysis { get; set; } public Task Writing { get; set; } public Project(int numberOfProducts) { _numberOfProducts = numberOfProducts; _size = GetSize(); Analysis = new AnalysisTask(numberOfProducts, _size); Writing = new WritingTask(numberOfProducts, _size); } private Size GetSize() { if (_numberOfProducts <= 2) return Size.small; if (_numberOfProducts <= 8) return Size.medium; return Size.large; } public double GetPrice() { return Analysis.GetPrice() + Writing.GetPrice(); } } public abstract class Task { protected readonly int _numberOfProducts; protected Size _size; protected double _pricePerHour; protected Dictionary<Size, int> _hours; public abstract int TotalHours { get; } public double Price { get; set; } protected Task(int numberOfProducts, Size size) { _numberOfProducts = numberOfProducts; _size = size; } public double GetPrice() { return _pricePerHour * TotalHours; } } public class AnalysisTask : Task { public AnalysisTask(int numberOfProducts, Size size) : base(numberOfProducts, size) { _pricePerHour = 850; _hours = new Dictionary<Size, int>() { { Size.small, 56 }, { Size.medium, 104 }, { Size.large, 200 } }; } public override int TotalHours { get { return _hours[_size]; } } } public class WritingTask : Task { public WritingTask(int numberOfProducts, Size size) : base(numberOfProducts, size) { _pricePerHour = 650; _hours = new Dictionary<Size, int>() { { Size.small, 125 }, { Size.medium, 100 }, { Size.large, 60 } }; } public override int TotalHours { get { if (_size == Size.small) return _hours[_size] * _numberOfProducts; if (_size == Size.medium) return (_hours[Size.small] * 2) + (_hours[Size.medium] * (_numberOfProducts - 2)); return (_hours[Size.small] * 2) + (_hours[Size.medium] * (8 - 2)) + (_hours[Size.large] * (_numberOfProducts - 8)); } } } public enum Size { small, medium, large } public partial class Form1 : Form { public Form1() { InitializeComponent(); List<int> quantities = new List<int>(); for (int i = 0; i < 100; i++) { quantities.Add(i); } comboBoxNumberOfProducts.DataSource = quantities; } private void comboBoxNumberOfProducts_SelectedIndexChanged(object sender, EventArgs e) { Project project = new Project((int)comboBoxNumberOfProducts.SelectedItem); labelPrice.Text = project.GetPrice().ToString(); labelWriterHours.Text = project.Writing.TotalHours.ToString(); labelAnalysisHours.Text = project.Analysis.TotalHours.ToString(); } } At the end is a simple current calling code in the change event for a combobox that set size... (BTW, I don't like the fact that I have to use several dots to get to the TotalHours at the end here either, as far as I can recall, that violates the "principle of least knowledge" or "the law of demeter", so input on that would be appreciated too, but it's not the main point of the question) Regards, Anders

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• Download a file with DefaultHTTPClient and preemptive authentication

  - by Nils

  After I had a lot of problems with preemptive authentication , I got it finally working. Now the next problem. I want to get a file with it, but I don't know how. I thought the file data might be in the variable response, but it isn't. Any ideas how this might work? I'm trying it since days without success :( - Basically I'm trying to download an jpeg file, which is on a server protected by prem. auth. // BASIC AUTH /* * ==================================================================== * * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * ==================================================================== * * This software consists of voluntary contributions made by many * individuals on behalf of the Apache Software Foundation. For more * information on the Apache Software Foundation, please see * <http://www.apache.org/>. */ //http://svn.apache.org/repos/asf/httpcomponents/httpclient/branches/4.0.x/httpclient/src/examples/org/apache/http/examples/client/ClientPreemptiveBasicAuthentication.java httpclient = new DefaultHttpClient(); httpclient.getCredentialsProvider().setCredentials( new AuthScope(host, port), new UsernamePasswordCredentials(username, password)); // Generate BASIC scheme object and stick it to the local // execution context BasicHttpContext localcontext = new BasicHttpContext(); BasicScheme basicAuth = new BasicScheme(); localcontext.setAttribute("preemptive-auth", basicAuth); //first request interceptor httpclient.addRequestInterceptor(new PreemptiveAuth(), 0); HttpHost targetHost = new HttpHost(host, port, "http"); //HttpGet httpget = new HttpGet("/"); HttpGet httpget = new HttpGet(http.url); System.out.println("executing request" + httpget.getRequestLine()); /// !!! HttpResponse response = httpclient.execute(targetHost, httpget, localcontext); HttpEntity entity = response.getEntity(); System.out.println("----------------------------------------"); System.out.println("+"+response.getStatusLine()+"+"); ...

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• How to assess a job offer with stock options? [closed]

  - by seas

  Cannot help expressing my curiosity about this issue. First of all, Russia, a country, I live in, as far as I understand, is a virgin land on this matter. Motivation is purely developed here and options are not existed at all. So, I am absolutely not aware about this. I roughly understand the mechanism of options. And, as far as I understand, the major white spot in the whole that story, how much will a singe share cost. How much will I get from all those N x 1000 options? I see two ways one can get money from the business: 1. Business goes IPO !!! 2. Business is sold as a whole to another owner. Next way is rather questionable about getting money: 3. Business goes without IPO "forever" (a generation would rather die before it IPO). I am also interested some explanations about situation ?3. Situation ?1 is clear - market decides everything, you either wait for stock price you satisfied or sell everything now. But topic is rather about ?2 - business is sold to another business. I am considering the following model: I am well payed specialist with company X. Somebody, with a company Y makes me an offer. Y is a startup. They cannot offer me much money and cannot overbid my salary, but they grow fast and hope to be bought soon. Instead of money, they offer me N x 1000 options. My problem is "how to assess this offer against my current, stable and well-payed job"? Are there any average cost of virtual share during selling one company to another? Are there any average stock price companies prefer to go to IPO? Are there any barriers against spreading the value of sock before selling the company or IPO (hiring too much people with options package too fast will decrease each package value, I mean)? Are there any good articles with explanations? Is all that somehow written in the law?

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• Scared of Calculus - Required to pass Differential Calculus as part of my Computer science major

  - by ke3pup

  Hi guys I'm finishing my Computer science degree in university but my fear of maths (lack of background knowledge) made me to leave all my maths units til' the very end which is now. i either take them on and pass or have to give up. I've passed all my programming units easily but knowing my poor maths skills won't do i've been staying clear of the maths units. I have to pass Differential Calculus and Linear Algebra first. With a help of book named "Linear Algebra: A Modern Introduction" i'm finding myself on track and i think i can pass the Linear Algebra unit. But with differential calculus i can't find a book to help me. They're either too advanced or just too simple for what i have to learn. The things i'm required to know for this units are: Set notation, the real number line, Complex numbers in cartesian form. Complex plane, modulus. Complex numbers in polar form. De Moivre’s Theorem. Complex powers and nth roots. Definition of ei? and ez for z complex. Applications to trigonometry. Revision of domain and range of a function Working in R3. Curves and surfaces. Functions of 2 variables. Level curves.Partial derivatives and tangent planes. The derivative as a difference quotient. Geometric significance of the derivative. Discussion of limit. Higher order partial derivatives. Limits of f(x,y). Continuity. Maxima and minima of f(x,y). The chain rule. Implicit differentiation. Directional derivatives and the gradient. Limit laws, l’Hoˆpital’s rule, composition law. Definition of sinh and cosh and their inverses. Taylor polynomials. The remainder term. Taylor series. Is there a book to help me get on track with the above? Being a student i can't buy too many books hence why i'm looking for a book that covers topics I need to know. The University library has a fairly limited collection which i took as loan but didn't find useful as it was too complex.

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• Deleting a node in a family tree

  - by user559142

  Hi, I'm trying to calclulate the best way to delete a node in a family tree. First, a little description of how the app works. My app makes the following assumption: Any node can only have one partner. That means that any child a single node has, it will also be the partner nodes child too. Therefore, step relations, divorces etc aren't compensated for. A node always has two parents - A mother and father cannot be added seperately. If the user doesn't know the details - the nodes attributes are set to a default value. Also any node can add parents, siblings, children to itself. Therefore in law relationships can be added. I have the following classes: FamilyMember String fName; String lName; String dob; String gender; FamilyMember mother, father, partner; ArrayListchildren; int index; int generation; void linkParents(); void linkPartner(); void addChild(); //gets & sets for fields Family ArrayListfamily; void addMember(); void removeMember(); FamilyMember getFamilyMember(index); ArrayListgetFamilyMembers(); FamilyTree Family family; void removeMember(); //need help void displayFamilyMembers(); void addFamilyMember(); void enterDetails(); void displayAncestors(); void displayDescendants(); void printDescendants(); FamilyMember findRootNode(); void sortGenerations(); void getRootGeneration(); I am having trouble with identifying the logic for removing a member. All other functions work fine. Has anyone developed a family tree app before who knows how to deal with removing various different nodes in the family "tree"? e.g. removing a leaf removing a leaf with partner (what if partner has parents etc) removing a parent It seems to be another recursive property but my head is swelling from over thought.

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• Are there any modern GUI toolkits which implement a heirarchical menu buffer zone?

  - by scomar

  In Bruce Tognazzini's quiz on Fitt's Law, the question discussing the bottleneck in the hierarchical menu (as used in almost every modern desktop UI), talks about his design for the original Mac: The bottleneck is the passage between the first-level menu and the second-level menu. Users first slide the mouse pointer down to the category menu item. Then, they must carefully slide the mouse directly across (horizontally) in order to move the pointer into the secondary menu. The engineer who originally designed hierarchicals apparently had his forearm mounted on a track so that he could move it perfectly in a horizontal direction without any vertical component. Most of us, however, have our forarms mounted on a pivot we like to call our elbow. That means that moving our hand describes an arc, rather than a straight line. Demanding that pivoted people move a mouse pointer along in a straight line horizontally is just wrong. We are naturally going to slip downward even as we try to slide sideways. When we are not allowed to slip downward, the menu we're after is going to slam shut just before we get there. The Windows folks tried to overcome the pivot problem with a hack: If they see the user move down into range of the next item on the primary menu, they don't instantly close the second-level menu. Instead, they leave it open for around a half second, so, if users are really quick, they can be inaccurate but still get into the second-level menu before it slams shut. Unfortunately, people's reactions to heightened chance of error is to slow down, rather than speed up, a well-established phenomenon. Therefore, few users will ever figure out that moving faster could solve their problem. Microsoft's solution is exactly wrong. When I specified the Mac hierarchical menu algorthm in the mid-'80s, I called for a buffer zone shaped like a <, so that users could make an increasingly-greater error as they neared the hierarchical without fear of jumping to an unwanted menu. As long as the user's pointer was moving a few pixels over for every one down, on average, the menu stayed open, no matter how slow they moved. (Cancelling was still really easy; just deliberately move up or down.) This just blew me away! Such a simple idea which would result in a huge improvement in usability. I'm sure I'm not the only one who regularly has the next level of a menu slam shut because I don't move the mouse pointer in a perfectly horizontal line. So my question is: Are there any modern UI toolkits which implement this brilliant idea of a < shaped buffer zone in hierarchical menus? And if not, why not?!

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