Search Results

Search found 339 results on 14 pages for 'seed'.

Page 11/14 | < Previous Page | 7 8 9 10 11 12 13 14  | Next Page >

• Kickstarting an Ubuntu Server 10.04 installation (DHCP fails)

  - by William

  I'm trying to automate the network installation of Ubuntu 10.04 LTS with an anaconda kickstart and everything seems to running except for the initial DHCP autoconfiguration. The installer attempts to configure the install via DHCP but fails on its first attempt. This brings me to a prompt where I can retry DHCP and it seems to always work on the second attempt. My issue is that this is not really automated if I have to hit retry for DHCP. Is there something I can add to the kickstart file so that it will automatically retry or better yet not fail the first time? Thanks. Kickstart: # System language lang en_US # Language modules to install langsupport en_US # System keyboard keyboard us # System mouse mouse # System timezone timezone America/New_York # Root password rootpw --iscrypted $1$unrsWyF2$B0W.k2h1roBSSFmUDsW0r/ # Initial user user --disabled # Reboot after installation reboot # Use text mode install text # Install OS instead of upgrade install # Use Web installation url --url=http://10.16.0.1/cobbler/ks_mirror/ubuntu-10.04-x86_64/ # System bootloader configuration bootloader --location=mbr # Clear the Master Boot Record zerombr yes # Partition clearing information clearpart --all --initlabel # Disk partitioning information part swap --size 512 part / --fstype ext3 --size 1 --grow # System authorization infomation auth --useshadow --enablemd5 %include /tmp/pre_install_ubuntu_network_config # Always install the server kernel. preseed --owner d-i base-installer/kernel/override-image string linux-server # Install the Ubuntu Server seed. preseed --owner tasksel tasksel/force-tasks string server # Firewall configuration firewall --disabled # Do not configure the X Window System skipx %pre wget "http://10.16.0.1/cblr/svc/op/trig/mode/pre/system/Test-D" -O /dev/null # Network information # Start pre_install_network_config generated code # Start of code to match cobbler system interfaces to physical interfaces by their mac addresses # Start eth0 # Configuring eth0 (00:1A:64:36:B1:C8) if ip -o link show | grep -i 00:1A:64:36:B1:C8 then IFNAME=$(ip -o link show | grep -i 00:1A:64:36:B1:C8 | cut -d" " -f2 | tr -d :) echo "network --device=$IFNAME --bootproto=dhcp" >> /tmp/pre_install_ubuntu_network_config fi # End pre_install_network_config generated code %packages openssh-server

  Read the article

• zsh : How to list directory content with tab?

  - by Philippe CM

  I just switched from BASH to ZSH and thing are pretty good, but: when I start typing cd /usr/share/s and hit TAB, this is what I get : $ cd /usr/share/sane/ sane/ skype/ ssl-cert/ screen/ smplayer/ strigi/ seed-gtk3/ snmp/ synaptic/ sgml/ software-properties/ system-config-printer/ sgml-base/ soprano/ sysv-rc/ sgml-data/ sounds/ simple-scan/ splashy/ And this is ok. If I then hit TAB again, I get $ cd /usr/share/screen/, the next candidate, witch is also OK. (BTW, how do I cycle back to the previous candidate? Sorry, on to my question) Now what if I want to see the contents of /usr/share/screen/ now ? You now, BASH-style? The cursor is at the end of the line, will I have to ctrl-a (or home), then del del (to erase cd) then ls then ENTER? That seems like a lot of typing. (And it - possibly unnecessarily - enters the command in the history) Would not there be a key (maybe modifier-TAB? but the obvious candidates are already taken by the desktop... I digress) that would tell zsh to stop cycling through /usr/share/ and instead, just list the content /usr/share/screen/ ?

  Read the article

• OBIEE 11.1.1 - Introduction to OBIEE 11g Full Sample App

  - by user809526

  Isn't it nice to discover OBIEE 11g around a nice "How To" catalog of features? to observe OBI and Essbase relationships at work? to discover TimesTen? The OBIEE 11g Full Sample App (FSA) is a comprehensive collection of examples designed to demonstrate the latest Oracle BIEE 11g capabilities and design best practices: Enhanced visualizations as Geo-spacial maps and interactive dashboards, Action Framework,  BI Publisher, Scorecard and Strategy Management, Mobile style sheets, Semantic layer modeling, Multi-source federation, Integration with products such as Essbase, Oracle OLAP, ODM, TimesTen, ODI and more The FSA is intended to be comprehensive, it is big (see CAVEAT below). The FSA is not an Oracle product, it is a good will free deployment of OBIEE/Essbase designed to exemplify OBIEE features, infrastructure and security around the Fusion Middleware components. Its contents and code are distributed free for demonstrative purposes only. It is neither maintained nor supported by Oracle as a licensed product. The OBIEE Full Sample App is independent of the default Sample App that comes with the OBIEE product. BENEFITS The FSA helps as a demonstrator of OBIEE 11g best practices, a tutorial, an environment "Test & Scrap", a SR bench (regression, conflicts), a tuning bench, a quick ready made POC seed for projects, a security options environment, ... The FSA - Is organized around a catalog of functional features - Has been deployed over 1000 times, it should be stable RELEASE The Full Sample App (V107) is bound to OBIEE 11.1.1.5 and Essbase 11.1.2.1 (November 2011). The FSA release dates are independent of the Product GA date (OBIEE). In early December 2011, a new functional Patch (V110) is released. It is easily applied (in less than 15 mins) on top of OBIEE SampleApp 11.1.1.5 (V107). The patch (V110) includes additional functional examples:        1. Web Catalog Statistics Application: Provides detailed insight into your web catalog content, dormant catalog objects, webcat impact analysis for metadata changes and more        2. Data inflation Scripts: A set of simple SQL procedures to quickly inflate SampleApp Fact and Dimension data to millions of records in a few minutes        3. Public Content Extensions Framework: A patching framework for public examples and contributions leveraging SampleApp        4. Additional report examples (including bridge report, external chart integrations) and bug fixes DISTRIBUTION as VBox image (November 2011) The ready made VBox image is designed to run on Virtual Box. It can be converted to VMware (see another BLOG). 1/ http://www.oracle.com/technetwork/middleware/bi-foundation/obiee-samples-167534.html VBox Image Deployment Guide Sampleapp_v107_GA.ovf - VBox image key file The above http URL provides the user:password for the ftp URLs below. 2/ ftp://user:[email protected]/static/SampleAppV107/ 12 "7-zip" files Sampleapp_v107_GA_7_20.7z.001 -> .012 We recommend 7-zip file manager for unzipping (http://www.7-zip.org/). Select Unzip here option, it will create the contents under a directory named "SampleApp_10722". On Windows, it is important to download and save zip file under the root directory (e.g. C:\ or D:\) because of possible long pathnames. 3/ ftp://user:[email protected]/static/SampleAppV107/Unzipped_Version/ 4 files Sampleapp_v107_GA-disk[1234].vmdk Important note: Check the provided checksums (md5sum). Please do it! DISTRIBUTION as Installation files for existing OBI 11.1.1.5 (November 2011) http://www.oracle.com/technetwork/middleware/bi-foundation/obiee-samples-167534.html Install files Deployment Guide SampleApp_10722_1.zip - 198 MB CAVEAT Many computers have RAM chips problems that keep often silent ... until you manipulate big files. It is strongly advised you run some memory check program eg MEMTEST in GRUB boot manager. Running md5sum repeatedly onto the very same big file must be consistent [same result], else a hardware memory problem is suspected. For Virtual Box, you should most likely enable VT-X (Vanderpool) hardware virtualization in BIOS. A free disk space of 80 GB is required to perform safely the VBox image installation. A Virtual Machine of minimum 6 to 7 GB memory fits the needs of combining OBIEE and Essbase execution.

  Read the article

• NServiceBus Generic Host and mqsvc.exe high CPU

  - by Michael Stephenson

  We have been doing some work with NServiceBus recently and observed some unusual behaviour which was caused by our mistake and seemed worthy of a small post.   The Scenario In our solution we were doing some standard NServiceBus stuff by pushing a message to a queue using NServiceBus.  We had a direct send/receive scenario rather than a publish/subscribe one.   The background process which was meant to collect the message and then process it was a normal NServiceBus message handler.  We would run the NServiceBus.Host.exe which would find the handler and then do the usual NServiceBus magic.   The Problem In this solution we were creating some automated tests around this module of the integration process to ensure that it would work well.  We had two tests.   Test 1 This test would start NServiceBus.Host.exe using the Process object, then seed a message to the queue via our web service façade sitting above the queue which wrapped NServiceBus.  The background process would then process the message and the test would check the message had been processed fine.   If all was well then the NServiceBus.Host.exe process was stopped.   Test 2 In test 2 we would do a very similar thing except that instead of starting the process the test would install NServiceBus.Host.exe as a windows service and then start the service before the test and once the test was executed it would stop the test.   The Results of the Tests Test 1 worked really well, however in test 2 we found that it didn’t really work at all, instead of doing the background process we were finding that between mqsvc.exe and NServiceBus.Host.exe the CPU on the machine was maxed and nothing was really happening.   The Solution After trying a few things we found it was the permissions on the queue were not set correctly.  Once this was resolved it all worked fine and CPU was not excessive and ran just like the console application.   I think the couple of take aways from this are:   Make sure you set the windows service for NserviceBus Generic Host to the right credentials When you install the generic host as a windows service then by default it will use the default windows credentials.  For any production like scenario you should be using a domain account to run the process as via the windows service. Make sure you have the queue set with the right permissions For the credentials you have used to configure the generic host as a windows service you should ensure that this user has the appropriate permissions for any queues it will interact with. Make sure you turn on the right logging configuration in NServiceBus When this wasnt working correctly we didnt know there was an issue, we were just experiencing the high CPU condition.  I am a little surprised that there wasnt something logged and that the process didnt crash.  I guess this could be by design bearing in mind that the process could be monitoring many queues.  In this point Im just saying that originally we didnt have all of the log4net logging which is available from NServiceBus turned on.  Its probably a good idea to have this turned on and configured until you are happy your solution is working fine.   Thanks to Ahmed Hashmi on my team who got this working in the end.

  Read the article

• How can I back up my ubuntu system?

  - by Eloff

  I'm sure there's a lot of questions on here similar to this, and I've been reading them, but I still feel this warrants a new question. I want nightly, incremental backups (full disk images would waste a lot of space - unless compressed somehow.) Preferably rotating or deleting old backups when running out of space or after a fixed number of backups. I want to be able to quickly and painlessly restore my system from these backups. This is my first time running ubuntu as my main development machine and I know from my experience with it as a server and in virtual machines that I regularly manage to make it unbootable or damage it to the point of being unable to rescue it. So how would you recommend I do this? There are so many options out there I really don't know where to start. There seems to be a vocal school of thought that it's sufficient to backup your home directory and the list of installed packages from the package manager. I've already installed lots of things from source, or outside of the package manager (development tools, ides, compilers, graphics drivers, etc.) So at the very least, if I do not back up the operating system itself I need to grab all config files, all program binaries, all created but required files, etc. I'd rather backup too much than too little - an ubuntu install is tiny anyway. Also this drastically reduces the restore time, which would cost me more in my time than the extra storage space. I tried using Deja Dup to backup the root partition, excluding some things like /mnt /media /dev /proc etc. Although many websites assured me you can backup a running linux system this way - that seems to be false as it complained that it could not backup the following files: /boot/System.map-3.0.0-17-generic /boot/System.map-3.2.0-22-generic /boot/vmcoreinfo-3.0.0-17-generic /boot/vmlinuz-3.0.0-17-generic /boot/vmlinuz-3.2.0-22-generic /etc/.pwd.lock /etc/NetworkManager/system-connections/LAN Connection /etc/apparmor.d/cache/lightdm-guest-session /etc/apparmor.d/cache/sbin.dhclient /etc/apparmor.d/cache/usr.bin.evince /etc/apparmor.d/cache/usr.lib.telepathy /etc/apparmor.d/cache/usr.sbin.cupsd /etc/apparmor.d/cache/usr.sbin.tcpdump /etc/apt/trustdb.gpg /etc/at.deny /etc/ati/inst_path_default /etc/ati/inst_path_override /etc/chatscripts /etc/cups/ssl /etc/cups/subscriptions.conf /etc/cups/subscriptions.conf.O /etc/default/cacerts /etc/fuse.conf /etc/group- /etc/gshadow /etc/gshadow- /etc/mtab.fuselock /etc/passwd- /etc/ppp/chap-secrets /etc/ppp/pap-secrets /etc/ppp/peers /etc/security/opasswd /etc/shadow /etc/shadow- /etc/ssl/private /etc/sudoers /etc/sudoers.d/README /etc/ufw/after.rules /etc/ufw/after6.rules /etc/ufw/before.rules /etc/ufw/before6.rules /lib/ufw/user.rules /lib/ufw/user6.rules /lost+found /root /run/crond.reboot /run/cups/certs /run/lightdm /run/lock/whoopsie/lock /run/udisks /var/backups/group.bak /var/backups/gshadow.bak /var/backups/passwd.bak /var/backups/shadow.bak /var/cache/apt/archives/lock /var/cache/cups/job.cache /var/cache/cups/job.cache.O /var/cache/cups/ppds.dat /var/cache/debconf/passwords.dat /var/cache/ldconfig /var/cache/lightdm/dmrc /var/crash/_usr_lib_x86_64-linux-gnu_colord_colord.102.crash /var/lib/apt/lists/lock /var/lib/dpkg/lock /var/lib/dpkg/triggers/Lock /var/lib/lightdm /var/lib/mlocate/mlocate.db /var/lib/polkit-1 /var/lib/sudo /var/lib/urandom/random-seed /var/lib/ureadahead/pack /var/lib/ureadahead/run.pack /var/log/btmp /var/log/installer/casper.log /var/log/installer/debug /var/log/installer/partman /var/log/installer/syslog /var/log/installer/version /var/log/lightdm/lightdm.log /var/log/lightdm/x-0-greeter.log /var/log/lightdm/x-0.log /var/log/speech-dispatcher /var/log/upstart/alsa-restore.log /var/log/upstart/alsa-restore.log.1.gz /var/log/upstart/console-setup.log /var/log/upstart/console-setup.log.1.gz /var/log/upstart/container-detect.log /var/log/upstart/container-detect.log.1.gz /var/log/upstart/hybrid-gfx.log /var/log/upstart/hybrid-gfx.log.1.gz /var/log/upstart/modemmanager.log /var/log/upstart/modemmanager.log.1.gz /var/log/upstart/module-init-tools.log /var/log/upstart/module-init-tools.log.1.gz /var/log/upstart/procps-static-network-up.log /var/log/upstart/procps-static-network-up.log.1.gz /var/log/upstart/procps-virtual-filesystems.log /var/log/upstart/procps-virtual-filesystems.log.1.gz /var/log/upstart/rsyslog.log /var/log/upstart/rsyslog.log.1.gz /var/log/upstart/ureadahead.log /var/log/upstart/ureadahead.log.1.gz /var/spool/anacron/cron.daily /var/spool/anacron/cron.monthly /var/spool/anacron/cron.weekly /var/spool/cron/atjobs /var/spool/cron/atspool /var/spool/cron/crontabs /var/spool/cups

  Read the article

• Linq To SQL: Behaviour for table field which is NotNull and having Default value or binding

  - by kaushalparik27

  I found this something interesting while wandering over community which I would like to share. The post is whole about: DBML is not considering the table field's "Default value or Binding" setting which is a NotNull. I mean the field which can not be null but having default value set needs to be set IsDbGenerated = true in DBML file explicitly.Consider this situation: There is a simple tblEmployee table with below structure: The fields are simple. EmployeeID is a Primary Key with Identity Specification = True with Identity Seed = 1 to autogenerate numeric value for this field. EmployeeName and their EmailAddress to store in rest of 2 fields. And the last one is "DateAdded" with DateTime datatype which doesn't allow NULL but having Default Value/Binding with "GetDate()". That means if we don't pass any value to this field then SQL will insert current date in "DateAdded" field.So, I start with a new website, add a DBML file and dropped the said table to generate LINQ To SQL context class. Finally, I write a simple code snippet to insert data into the tblEmployee table; BUT, I am not passing any value to "DateAdded" field. Because I am considering SQL Server's "Default Value or Binding (GetDate())" setting to this field and understand that SQL will insert current date to this field.        using (TestDatabaseDataContext context = new TestDatabaseDataContext())        {            tblEmployee tblEmpObjet = new tblEmployee();            tblEmpObjet.EmployeeName = "KaushaL";            tblEmpObjet.EmployeeEmailAddress = "[email protected]";            context.tblEmployees.InsertOnSubmit(tblEmpObjet);            context.SubmitChanges();        }Here comes the twist when application give me below error:  This is something not expecting! From the error it clearly depicts that LINQ is passing NULL value to "DateAdded" Field while according to my understanding it should respect Sql Server's "Default value or Binding" setting for this field. A bit googling and I found very interesting related to this problem.When we set Primary Key to any field with "Identity Specification" Property set to true; DBML set one important property "IsDbGenerated=true" for this field. BUT, when we set "Default Value or Biding" property for some field; we need to explicitly tell the DBML/LINQ to let it know that this field is having default binding at DB side that needs to be respected if I don't pass any value. So, the solution is: You need to explicitly set "IsDbGenerated=true" for such field to tell the LINQ that the field is having default value or binding at Sql Server side so, please don't worry if i don't pass any value for it.You can select the field and set this property from property window in DBML Designer file or write the property in DBML.Designer.cs file directly. I have attached a working example with required table script with this post here. I hope this would be helpful for someone hunting for the same. Happy Discovery!

  Read the article

• How should I Test a Genetic Algorithm

  - by James Brooks

  I have made a quite few genetic algorithms; they work (they find a reasonable solution quickly). But I have now discovered TDD. Is there a way to write a genetic algorithm (which relies heavily on random numbers) in a TDD way? To pose the question more generally, How do you test a non-deterministic method/function. Here is what I have thought of: Use a specific seed. Which wont help if I make a mistake in the code in the first place but will help finding bugs when refactoring. Use a known list of numbers. Similar to the above but I could follow the code through by hand (which would be very tedious). Use a constant number. At least I know what to expect. It would be good to ensure that a dice always reads 6 when RandomFloat(0,1) always returns 1. Try to move as much of the non-deterministic code out of the GA as possible. which seems silly as that is the core of it's purpose. Links to very good books on testing would be appreciated too.

  Read the article

• Looking for a good world map generation algorithm

  - by FalconNL

  I'm working on a Civilization-like game and I'm looking for a good algorithm for generating Earth-like world maps. I've experimented with a few alternatives, but haven't hit on a real winner yet. One option is to generate a heightmap using perlin noise and add water at a level so that about 30% of the world is land. While perlin noise (or similar fractal-based techniques) are frequently used for terrain and is reasonably realistic, it doesn't offer much in the way of control over the number, size and position of the resulting continents, which I'd like to have from a gameplay perspective. See http://farm3.static.flickr.com/2792/4462870263_ff26c40365_o.jpg for an example (sorry, can't post pictures yet). A second option is to start with a randomly positioned one-tile seed (I'm working on a grid of tiles), determine the desired size for the continent and each turn add a tile that is horizontally or vertically adjacent to the existing continent until you've reached the desired size. Repeat for the other continents. This technique is part of the algorithm used in Civilization 4. The problem is that after placing the first few continents, it's possible to pick a starting location that's surrounded by other continents, and thus won't fit the new one. Also, it has a tendency to spawn continents too close together, resulting in something that looks more like a river than continents. See http://farm5.static.flickr.com/4069/4462870383_46e86b155c_o.jpg for an example. Does anyone happen to know a good algorithm for generating realistic continents on a grid-based map while keeping control over their number and relative sizes?

  Read the article

• How do you use asynchronous ORMs without huge callback chains?

  - by hornairs

  I'm using the relatively immature Joose Javascript ORM plugin (project page) to persist objects in an Appcelerator Titanium (company page) mobile project. Since it's client side storage, the application has to check to see if the database is initialized before starting up the ORM since it inspects the DB tables to construct the classes. My problem is that this sequence of operations (and if this one is like this, other things down the road) takes a lot of callbacks to complete. I have a lot of jumping around in the code that isn't apparent to a maintainer and results in some complex call graphs and whatnot. So, I ask these questions: How would you asynchronously initialize a database and populate it with seed data using an ORM that needs the schema to be correct to function? Do you have any general strategies or links for async/event driven programming and keeping the call graph simple and understandable? Do you have any suggestions for Javascript ORMs/meta object systems that work with HTML 5 as a storage engine and are hopefully framework agnostic? Am I just a big newb and should be able to work this out with ease? Thanks folks!

  Read the article

• Change find method in database search so that it isn't case sensitive in Rails app

  - by Ryan

  Hello, I am learning Rails and have created a work-in-progress app that does one-word searches on a database of shortcut keys for various programs (http://keyboardcuts.heroku.com/shortcuts/home). The search method in the Shortcut model is the following: def self.search(search) search_condition = "%" + search + "%" find(:all, :conditions => ['action LIKE ? OR application LIKE ?', search_condition, search_condition]) end ...where 'action' and 'application' are columns in a SQLite table. (source: https://we.riseup.net/rails/simple-search-tutorial) For some reason, the search seems to be case sensitive (you can see this by searching 'Paste' vs. 'paste'). Can anyone help me figure out why and what I can do to make it not case sensitive? If not, can you at least point me in the right direction? Database creation: I first copied shortcuts from various website into Excel and saved it as a CSV. Then I migrated the database and filled it with the data using db:seed and a small script I wrote (I viewed the database and it looked fine). To get the SQLite database to the server, I used Taps as outline by the Heroku website (http://blog.heroku.com/archives/2009/3/18/push_and_pull_databases_to_and_from_heroku/). I am using Ubuntu. Please let me know if you need more information. Thanks in advance for you help, very much appreciated! Ryan

  Read the article

• Subset a data.frame by list and apply function on each part, by rows

  - by aL3xa

  This may seem as a typical plyr problem, but I have something different in mind. Here's the function that I want to optimize (skip the for loop). # dummy data set.seed(1985) lst <- list(a=1:10, b=11:15, c=16:20) m <- matrix(round(runif(200, 1, 7)), 10) m <- as.data.frame(m) dfsub <- function(dt, lst, fun) { # check whether dt is `data.frame` stopifnot (is.data.frame(dt)) # check if vectors in lst are "whole" / integer # vector elements should be column indexes is.wholenumber <- function(x, tol = .Machine$double.eps^0.5) abs(x - round(x)) < tol # fall if any non-integers in list idx <- rapply(lst, is.wholenumber) stopifnot(idx) # check for list length stopifnot(ncol(dt) == length(idx)) # subset the data subs <- list() for (i in 1:length(lst)) { # apply function on each part, by row subs[[i]] <- apply(dt[ , lst[[i]]], 1, fun) } # preserve names names(subs) <- names(lst) # convert to data.frame subs <- as.data.frame(subs) # guess what =) return(subs) } And now a short demonstration... actually, I'm about to explain what I primarily intended to do. I wanted to subset a data.frame by vectors gathered in list object. Since this is a part of code from a function that accompanies data manipulation in psychological research, you can consider m as a results from personality questionnaire (10 subjects, 20 vars). Vectors in list hold column indexes that define questionnaire subscales (e.g. personality traits). Each subscale is defined by several items (columns in data.frame). If we presuppose that the score on each subscale is nothing more than sum (or some other function) of row values (results on that part of questionnaire for each subject), you could run: > dfsub(m, lst, sum) a b c 1 46 20 24 2 41 24 21 3 41 13 12 4 37 14 18 5 57 18 25 6 27 18 18 7 28 17 20 8 31 18 23 9 38 14 15 10 41 14 22 I took a glance at this function and I must admit that this little loop isn't spoiling the code at all... BUT, if there's an easier/efficient way of doing this, please, let me know!

  Read the article

• Collision Attacks, Message Digests and a Possible solution

  - by Dominar

  I've been doing some preliminary research in the area of message digests. Specifically collision attacks of cryptographic hash functions such as MD5 and SHA-1, such as the Postscript example and X.509 certificate duplicate. From what I can tell in the case of the postscript attack, specific data was generated and embedded within the header of the postscript (which is ignored during rendering) which brought about the internal state of the md5 to a state such that the modified wording of the document would lead to a final MD equivalent to the original. The X.509 took a similar approach where by data was injected within the comment/whitespace of the certificate. Ok so here is my question, and I can't seem to find anyone asking this question: Why isn't the length of ONLY the data being consumed added as a final block to the MD calculation? In the case of X.509 - Why is the whitespace and comments being taken into account as part of the MD? Wouldn't a simple processes such as one of the following be enough to resolve the proposed collision attacks: MD(M + |M|) = xyz MD(M + |M| + |M| * magicseed_0 +...+ |M| * magicseed_n) = xyz where : M : is the message |M| : size of the message MD : is the message digest function (eg: md5, sha, whirlpool etc) xyz : is the acutal message digest value for the message M magicseed_{i}: Is a set random values generated with seed based on the internal-state prior to the size being added. This technqiue should work, as to date all such collision attacks rely on adding more data to the original message. In short, the level of difficulty involved in generating a collision message such that: It not only generates the same MD But is also comprehensible/parsible/compliant and is also the same size as the original message, is immensely difficult if not near impossible. Has this approach ever been discussed? Any links to papers etc would be nice.

  Read the article

• Advice on optimzing speed for a Stored Procedure that uses Views

  - by Belliez

  Based on a previous question and with a lot of help from Damir Sudarevic (thanks) I have the following sql code which works great but is very slow. Can anyone suggest how I can speed this up and optimise for speed. I am now using SQL Server Express 2008 (not 2005 as per my original question). What this code does is retrieves parameters and their associated values from several tables and rotates the table in a form that can be easily compared. Its great for one of two rows of data but now I am testing with 100 rows and to run GetJobParameters takes over 7 minutes to complete? Any advice is gratefully accepted, thank you in advanced. /*********************************************************************************************** ** CREATE A VIEW (VIRTUAL TABLE) TO ALLOW EASIER RETREIVAL OF PARMETERS ************************************************************************************************/ CREATE VIEW dbo.vParameters AS SELECT m.MachineID AS [Machine ID] ,j.JobID AS [Job ID] ,p.ParamID AS [Param ID] ,t.ParamTypeID AS [Param Type ID] ,m.Name AS [Machine Name] ,j.Name AS [Job Name] ,t.Name AS [Param Type Name] ,t.JobDataType AS [Job DataType] ,x.Value AS [Measurement Value] ,x.Unit AS [Unit] ,y.Value AS [JobDataType] FROM dbo.Machines AS m JOIN dbo.JobFiles AS j ON j.MachineID = m.MachineID JOIN dbo.JobParams AS p ON p.JobFileID = j.JobID JOIN dbo.JobParamType AS t ON t.ParamTypeID = p.ParamTypeID LEFT JOIN dbo.JobMeasurement AS x ON x.ParamID = p.ParamID LEFT JOIN dbo.JobTrait AS y ON y.ParamID = p.ParamID GO -- Step 2 CREATE VIEW dbo.vJobValues AS SELECT [Job Name] ,[Param Type Name] ,COALESCE(cast([Measurement Value] AS varchar(50)), [JobDataType]) AS [Val] FROM dbo.vParameters GO /*********************************************************************************************** ** GET JOB PARMETERS FROM THE VIEW JUST CREATED ************************************************************************************************/ CREATE PROCEDURE GetJobParameters AS -- Step 3 DECLARE @Params TABLE ( id int IDENTITY (1,1) ,ParamName varchar(50) ); INSERT INTO @Params (ParamName) SELECT DISTINCT [Name] FROM dbo.JobParamType -- Step 4 DECLARE @qw TABLE( id int IDENTITY (1,1) , txt nchar(300) ) INSERT INTO @qw (txt) SELECT 'SELECT' UNION SELECT '[Job Name]' ; INSERT INTO @qw (txt) SELECT ',MAX(CASE [Param Type Name] WHEN ''' + ParamName + ''' THEN Val ELSE NULL END) AS [' + ParamName + ']' FROM @Params ORDER BY id; INSERT INTO @qw (txt) SELECT 'FROM dbo.vJobValues' UNION SELECT 'GROUP BY [Job Name]' UNION SELECT 'ORDER BY [Job Name]'; -- Step 5 --SELECT txt FROM @qw DECLARE @sql_output VARCHAR (MAX) SET @sql_output = '' -- NULL + '' = NULL, so we need to have a seed SELECT @sql_output = -- string to avoid losing the first line. COALESCE (@sql_output + txt + char (10), '') FROM @qw EXEC (@sql_output) GO

  Read the article

• Concat LPSTR in C++

  - by Cat Man Do

  Trying to use as basic C++ as I can to build a list of numbers from 1-52 in a random order (deck of cards). Unfortauntely, all my attempts to concat the strings and get a result end in failure. Any suggestions? NOTE: This is not homework it's something I'm using to create a game. // Locals char result[200] = ""; // Result int card[52]; // Array of cards srand(time(0)); // Initialize seed "randomly" // Build for (int i=0; i<52; i++) { card[i] = i; // fill the array in order } // Shuffle cards for (int i=0; i<(52-1); i++) { int r = i + (rand() % (52-i)); int temp = card[i]; card[i] = card[r]; card[r] = temp; } // Build result for (int c=0; c<52; c++) { // Build sprintf(result, "%d", card[c]); // Comma? if ( c < 51 ) { sprintf(result, "%s", ","); } } My end result is always garbled text. Thanks for the help.

  Read the article

• Pseudo random numbers in php

  - by pg

  I have a function that outputs items in a different order depending on a random number. for example 1/2 of the time Popeye's and its will be #1 on the list and Taco Bell and its logo will be #2 and half the time the it will be the other way around. The problem is that when a user reloads or comes back to the page, the order is re-randomized. $Range here is the number of items in the db, so it's using a random number between 1 and the $range. $random = mt_rand(1,$range); for ($i = 0 ; $i < count($variants); $i++) { $random -= $variants[$i]['weight']; if ($random <= 0) { $chosenoffers[$tag] = $variants[$i]; break; } } I went to the beginning of the session and set this: if (!isset($_SESSION['rannum'])){ $_SESSION['rannum']=rand(1,100); } With the idea that I could replace the mt_rand in the function with some sort of pseudo random generator that used the same 1-100 random number as a seed throughout the session. That way i won't have to rewrite all the code that was already written. Am I barking up the wrong tree or is this a good idea?

  Read the article

• How to use Common Table Expression and check no duplication in sqlserver

  - by vodkhang

  I have a table references to itself. User table: id, username, managerid and managerid links back to id Now, I want to get all the managers including direct manager, manager of direct manager, so on and so forth... The problem is that I do not want to have a unstop recursive sql. So, I want to check if an id alreay in a list, I will not include it anymore. Here is my sql for that: with --the relation for all the subparts of ozsolar including itself all_managers (id, username, managerid, idlist) as ( --seed that is the ozsola part select u1.id, u1.username, u1.managerid, ' ' from users u1, users u2 where u1.id = u2.managerid and u2.id = 6 UNION ALL select u.id, u.username, u.managerid, idlist + ' ' + u.id from all_managers a, users u where a.managerid = u.id and charindex(cast(u.id as nvarchar(5)), idlist) != 0 ) --select the total number of subparts and group by subpart select id, username from all_managers; The problem is that in this line: select u1.id, u1.username, u1.managerid, ' ' The sqlserver complains with me that I can not put ' ' as the initialized for idlist. nvarchar(40) does not work as well. I do not know how to declare it inside a common table expression like this one. Usually, in db2, I can just put varchar(40)

  Read the article

• Function within function in R

  - by frespider

  Can you please explain to me why th code complain saying that Samdat is not found? I am trying to switch between the models as you can see, so i declared a functions that contains these specific models and I just need to call these function as one of the argument in the get.f function where the resampling will change the structure for each design matrix in the model. the code complain the Samdat is not found when it is found. Also, is there a way I can make the condition statement as if(Model == M1()) instead I have to create another argument M to set if(M==1) Can you explain please? dat <- cbind(Y=rnorm(20),rnorm(20),runif(20),rexp(20),rnorm(20),runif(20), rexp(20),rnorm(20),runif(20),rexp(20)) nam <- paste("v",1:9,sep="") colnames(dat) <- c("Y",nam) M1 <- function(){ a1 = cbind(Samdat[,c(2:5,7,9)]) b1 = cbind(Samdat[,c(2:4,6,8,7)]) c1 = b1+a1 list(a1=a1,b1=b1,c1=c1)} M2 <- function(){ a1= cbind(Samdat[,c(2:5,7,9)])+2 b1= cbind(Samdat[,c(2:4,6,8,7)])+2 c1 = a1+b1 list(a1=a1,b1=b1,c1=c1)} M3 <- function(){ a1= cbind(Samdat[,c(2:5,7,9)])+8 b1= cbind(Samdat[,c(2:4,6,8,7)])+8 c1 = a1+b1 list(a1=a1,b1=b1,c1=c1)} ################################################################# get.f <- function(asim,Model,M){ sse <-c() for(i in 1:asim){ set.seed(i) Samdat <- dat[sample(1:nrow(dat),nrow(dat),replace=T),] Y <- Samdat[,1] if(M==1){ a2 <- Model$a1 b2 <- Model$b1 c2 <- Model$c1 s<- a2+b2+c2 fit <- lm(Y~s) cof <- sum(summary(fit)$coef[,1]) coff <-Model$cof sse <-c(sse,coff) } else if(M==2){ a2 <- Model$a1 b2 <- Model$b1 c2 <- Model$c1 s<- c2+12 fit <- lm(Y~s) cof <- sum(summary(fit)$coef[,1]) coff <-Model$cof sse <-c(sse,coff) } else { a2 <- Model$a1 b2 <- Model$b1 c2 <- Model$c1 s<- c2+a2 fit <- lm(Y~s) cof <- sum(summary(fit)$coef[,1]) coff <- Model$cof sse <-c(sse,coff) } } return(sse) } get.f(10,Model=M1(),M=1) get.f(10,Model=M2(),M=2) get.f(10,Model=M3(),M=3)

  Read the article

• Represent multiple Null/Generic objects in an ActiveRecord association?

  - by slothbear

  I have a Casefile model that belongs_to a Doctor. In additional to all the "real" doctors, there are several generic Doctors: "self-treated", "not specified", and "removed" (it used to have a real doctor, but no longer does). I suspect there will be even more generic values in the future. I started with special "doctors" in the database, generated from seed. The generic Doctors only need to respond to the "name" and "real_doctor?" methods. This worked with one, was strained with two, and now feels completely broken. I want to change the behavior and can't figure out how to test it, a bad sign. Creating all the generic objects for testing is also trouble, including fake values to pass validation of the required Doctor attributes. The Null Object pattern works well for one generic object. The "name" method could check casefile.doctor.nil? and return "self-treated", as demonstrated by Craig Ambrose. What pattern should I use when there are multiple generic objects with very limited state?

  Read the article

• How Can I: Generate 40/64 Bit WEP Key In Python?

  - by Aktariel

  So, I've been beating my head against the wall of this issue for several months now, partly because it's a side interest and partly because I suck at programming. I've searched and researched all across the web, but have not had any luck (except one small bit of success; see below), so I thought I might try asking the experts. What I am trying to do is, as the title suggests, generate a 40/64 bit WEP key from a passphrase, according to the "de facto" standard. (A site such as [http://www.powerdog.com/wepkey.cgi] produces the expected outputs.) I have already written portions of the script that take inputs and write them to a file; one of the inputs would be the passphrase, sanitized to lower case. For the longest time I had no idea what the defacto standard was, much less how to even go about implementing it. I finally stumbled across a paper (http://www.lava.net/~newsham/wlan/WEP_password_cracker.pdf) that sheds as much light as I've had yet on the issue (page 18 has the relevant bits). Apparently, the passphrase is "mapped to a 32-bit value with XOR," the result of which is then used as the seed for a "linear congruential PRNG (which one of the several PRNGs Python has would fit this description, I don't know), and then from that result several bits of the result are taken. I have no idea how to go about implementing this, since the description is rather vague. What I need is help in writing the generator in Python, and also in understanding how exactly the key is generated. I'm not much of a programmer, so explanations are appreciated as well. (Yes, I know that WEP isn't secure.)

  Read the article

• Is this a correct porting of java.util.Random in objectiveC

  - by dipu

  I have ported the code inside java.util.Random class in objectivec. I want to have an identical random number generator so that it synchs with the server app running on java. Now is this a safe porting and if not is there a way to mimic AtomicLong as it is found in java? Please see my code below. static long long multiplier = 0x5DEECE66DL; static long addend = 0xBL; static long long mask = (0x1000000000000001L << 48) - 1; -(void) initWithSeed:(long long) seed1 { [self setRandomSeed: 0L];// = new AtomicLong(0L); [self setSeed: seed1]; } -(int) next:(int)bits { long long oldseed, nextseed; long long seed1 = [self.randomSeed longLongValue]; //AtomicLong //do { oldseed = seed1; nextseed = (oldseed * multiplier + addend) & mask; //} while (!seed.compareAndSet(oldseed, nextseed)); [self setRandomSeed: [NSNumber numberWithLongLong:nextseed]]; ///int ret = (int)(nextseed >>> (48 - bits)); int ret = (unsigned int)(nextseed >> (48 - bits)); return ret; } -(void) setSeed:(long long) seed1 { seed1 = (seed1 ^ multiplier) & mask; [self setRandomSeed: [NSNumber numberWithLongLong:seed1]]; }

  Read the article

• Python multiprocessing doesn't play nicely with uuid.uuid4().

  - by yig

  I'm trying to generate a uuid for a filename, and I'm also using the multiprocessing module. Unpleasantly, all of my uuids end up exactly the same. Here is a small example: import multiprocessing import uuid def get_uuid( a ): ## Doesn't help to cycle through a bunch. #for i in xrange(10): uuid.uuid4() ## Doesn't help to reload the module. #reload( uuid ) ## Doesn't help to load it at the last minute. ## (I simultaneously comment out the module-level import). #import uuid ## uuid1() does work, but it differs only in the first 8 characters and includes identifying information about the computer. #return uuid.uuid1() return uuid.uuid4() def main(): pool = multiprocessing.Pool( 20 ) uuids = pool.map( get_uuid, range( 20 ) ) for id in uuids: print id if __name__ == '__main__': main() I peeked into uuid.py's code, and it seems to depending-on-the-platform use some OS-level routines for randomness, so I'm stumped as to a python-level solution (to do something like reload the uuid module or choose a new random seed). I could use uuid.uuid1(), but only 8 digits differ and I think there are derived exclusively from the time, which seems dangerous especially given that I'm multiprocessing (so the code could be executing at exactly the same time). Is there some Wisdom out there about this issue?

  Read the article

• How to use boost normal distribution classes?

  - by David Alfonso

  Hi all, I'm trying to use boost::normal_distribution in order to generate a normal distribution with mean 0 and sigma 1. The following code uses boost normal classes. Am I using them correctly? #include <boost/random.hpp> #include <boost/random/normal_distribution.hpp> int main() { boost::mt19937 rng; // I don't seed it on purpouse (it's not relevant) boost::normal_distribution<> nd(0.0, 1.0); boost::variate_generator<boost::mt19937&, boost::normal_distribution<> > var_nor(rng, nd); int i = 0; for (; i < 10; ++i) { double d = var_nor(); std::cout << d << std::endl; } } The result on my machine is: 0.213436 -0.49558 1.57538 -1.0592 1.83927 1.88577 0.604675 -0.365983 -0.578264 -0.634376 As you can see all values are not between -1 and 1. Thank you all in advance!

  Read the article

• How do I test is storage-conf is being loaded in Cassandra 0.7.3?

  - by user657253

  I have installed Cassandra and gotten it working on two machines. I have followed the instructions to hook them up to each other by configuring the storage-conf.xml files. Both machines respond well to thrift and to command line cassandra. This is tutorial I used to setup the storage-conf.xml files. The tutorial says that if I run netstat, I should NOT see Cassandra bound to 127.0.0.1 on my seed node. I should see it bound to my internal IP, which I have configured in the storage-conf.xml file. I have rebooted the servers and relaunched cassandra. Still, I see the localhost address insead of the correct internal IP address. Is it that my .yaml file is overriding the storage-conf.xml file? If so, how do I delete the appropriate things in the .yaml? Or how do I tell Cassandra to look for my storage-conf.xml file? A few things I have tried: renaming the cassandra.yaml file. What happens is that cassandra will not load. If i rename the storage-conf.xml, cassandra does load. When I installed Cassandra, it did not come with a storage-conf.xml file. I had to grab it off the apache wiki.

  Read the article

• authentication question (security code generation logic)

  - by Stick it to THE MAN

  I have a security number generator device, small enough to go on a key-ring, which has a six digit LCD display and a button. After I have entered my account name and password on an online form, I press the button on the security device and enter the security code number which is displayed. I get a different number every time I press the button and the number generator has a serial number on the back which I had to input during the account set-up procedure. I would like to incorporate similar functionality in my website. As far as I understand, these are the main components: Generate a unique N digit aplha-numeric sequence during registration and assign to user (permanently) Allow user to generate an N (or M?) digit aplha-numeric sequence remotely For now, I dont care about the hardware side, I am only interested in knowing how I may choose a suitable algorithm that will allow the user to generate an N (or M?) long aplha-numeric sequence - presumably, using his unique ID as a seed Identify the user from the number generated in step 2 (which decryption method is the most robust to do this?) I have the following questions: Have I identified all the steps required in such an authentication system?, if not please point out what I have missed and why it is important What are the most robust encryption/decryption algorithms I can use for steps 1 through 3 (preferably using 64bits)?

  Read the article

• EF 6 Code First Many to many With Payload and self referencing many to many

  - by lesley86

  I Have the problem where i have a many to many relationship and on one of the tables there will be a self referencing many to many. So basically a school have zero or many groups and many groups can have 0 or many schools. The groups table will contain a parent child many to many with itself because a group can be a child of another group or it can have no children and that child can have a child, one child can also have many parents or a entity can have no parents. I created a mapping table with Payload to solvethe first many to many problem. code snippet public class School { public virtual ICollection<SchoolGroupMap> SchoolGroupMaps } public class SchoolGroup { public virtual ICollection<SchoolGroupMap> SchoolGroupMaps } public class SchoolGroupMap { public virtual School School public virtual SchoolGroup SchoolGroup } i Then tried modifying the code the following way for the the self referencing many to many public class SchoolGroup { public virtual ICollection<SchoolGroupMap> SchoolGroupMaps public virtual ICollection<SchoolGroup> Parents public virtual ICollection<SchoolGroup> Children } I changed the context with has many and an auto mapping table (forgive me i have been trying so many things today i do not have the exact code). I received an error the properties on the classes must match. Can anyone help please. I want to do create navigation properties on the self referencing many to many. Also a seed example would be appreciated regards

  Read the article

< Previous Page | 7 8 9 10 11 12 13 14  | Next Page >