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• Prepared statement alternatives for this middle-man program?

  - by user2813274

  I have an program that is using a prepared statement to connect and write to a database working nicely, and now need to create a middle-man program to insert between this program and the database. This middle-man program will actually write to multiple databases and handle any errors and connection issues. I would like advice as to how to replicate the prepared statements such as to create minimal impact to the existing program, however I am not sure where to start. I have thought about creating a "SQL statement class" that mimics the prepared statement, only that seems silly. The existing program is in Java, although it's going to be networked anyways so I would be open to writing it in just about anything that would make sense. The databases are currently MySQL, although I would like to be open to changing the database type in the future. My main question is what should the interface for this program look like, and does doing this even make sense? A distributed DB would be the ideal solution, but they seem overly complex and expensive for my needs. I am hoping to replicate the main functionality of a distributed DB via this middle-man. I am not too familiar with sql-based servers distributing data (or database in general...) - perhaps I am fighting an uphill battle by trying to solve it via programming, but I would like to make an attempt at least.

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• Unable to use Maya animation with scripts when imported to Unity

  - by keshk

  I am testing to import Maya animation over to Unity. I set up a simple cylinder with 2 bones and an IK handle. Made a simple animation where the cylinder bends and goes back to straight position over 24 frames. Following that, I selected everything and baked, all bones,ik,(animation by selecting all at the graph editor) and even the cylinder. I saved the scene and then select all and export as FBX with animation and bake checked. In unity imported it and at the preview able to see the animation. When I load the model into scene and play (after assigning the controller), able to see animation too. But now when I try to script it and control the animation, nothing happens. Even to test, I tried the following under the Update method. if(animation.isPlaying) Debug.Log("Animation Works"); else Debug.Log("Animation not working"); The bool doesn't even return true nor false. My animation is called "bend", thus just for try I did the following and nothing happens. animation.Play("bend"); Can please advice based on my steps, am I missing something. Do I need to add the controller or is that an unnecessary step? Did I screw up on the Maya part or the Unity part. Thanks for help.

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• How to disable visual effects and compiz 100%

  - by oshirowanen

  UPDATE 1: The problem is not a monitor refresh rate flickering problem, as then the whole screen would be flickering. For me, only the application windows flicker in and out of view, then most of the time, when there do decide to show themselves, they only partly show themselves, like just top half, bottom half, left half, corner missing, window disappears when you try moving it or mouse over it even etc etc. I know it is a visual effect problem as I know my computer cannot handle visual effects and for some reason when the windows do appear partly, I can see the shadows behind the windows. Those shadows are part of the visual effects which are turned on by default for some reason. I get the same problem with 10.04, but can quickly turn off the visual effects by right clicking the desktop, selecting change background image, and in the visual effects tab, I can click on none, which stops all the visual problems. ORIGINAL QUESTION: I am having problems with 11.04 on my computer. For some reason it is enabling visual effects by default in the live cd when it should not be as my computer cannot support such effects. My computer cannot support Unity either, but it defaults to standard gnome with visual effects for some reason. It should be defaulting to standard gnome with no visual effects. THerefore, all I get is a very flickery live cd which makes it very difficult to see anything. So my question is, how do I disable the visual effects from the live cd? To put it simply, the live cd flickering is so bad, that I had to log back into my standard 10.04 install just to write this question, as I just couldn't see enough of the screen because of the flickering in 11.04 to even get to askubuntu.com...

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• Jenkins Paramerized Trigger + Copy Artifact

  - by Josh Kelley

  I'm working on setting up Jenkins to handle our release builds. A release build consists of a Windows installer that includes some binaries that must be built on Linux. Here's what I have so far: The Windows portion and Linux portion are set up as separate Jenkins projects. The Windows project is parameterized, taking the Subversion tag to build and release. As part of its build, the Windows project triggers a build of that same Subversion tag for the Linux project (using the Parameterized Trigger plugin) then copies the artifacts from the Linux project (using the Copy Artifact plugin) to the Windows project's workspace so that they can be included in the Windows installer. Where I'm stuck: Right now, Copy Artifact is set up to copy the last successful build. It seems more robust to configure Copy Artifact to copy from the exact build that Parameterized Trigger triggered, but I'm having trouble figuring out how to make that work. There's an option for a "build selector" parameter that I think is intended to help with this, but I can't figure out how it's supposed to be set up (and blindly experimenting with different possibilities is somewhat painful when the build takes an hour or two to find success or failure). How should I set this up? How does build selector work?

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• How to write constructors which might fail to properly instantiate an object

  - by whitman

  Sometimes you need to write a constructor which can fail. For instance, say I want to instantiate an object with a file path, something like obj = new Object("/home/user/foo_file") As long as the path points to an appropriate file everything's fine. But if the string is not a valid path things should break. But how? You could: 1. throw an exception 2. return null object (if your programming language allows constructors to return values) 3. return a valid object but with a flag indicating that its path wasn't set properly (ugh) 4. others? I assume that the "best practices" of various programming languages would implement this differently. For instance I think ObjC prefers (2). But (2) would be impossible to implement in C++ where constructors must have void as a return type. In that case I take it that (1) is used. In your programming language of choice can you show how you'd handle this problem and explain why?

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• Keeping files that are often changed in sync between desktop and laptop

  - by N.N.

  I'm looking for a way to keep a desktop and a laptop in sync. What I want to keep in sync are some folders, mainly ~/Documents, that are changed often when working on them. If it matters I can connect to my desktop from anywhere via an URL but my laptop is harder to access since it might be behind NAT and such. I have been looking at Ubuntu One but it seems to not go well with working on documents written in LaTeX. If I work on a .tex file in the Ubuntu One directory and compile it (with pdflatex) every now and then (as often as every 10 sec when working) it will create several new files including a pdf which are uploaded to Ubuntu One and this seems stupid since it will create continuous upload when working on .tex files. I also usually keep .tex documents version controlled by git and then every commit (which also can happen frequently) will cause upload (by changes in ./.git) so that it happens continuously when working. Another example is editing images that are saved often. What I think would be best is for sync to happen every tenth minute or at the end of every working session (but there might be some other way to handle this?).

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• Scheme vs Haskell for an Introduction to Functional Programming?

  - by haziz

  I am comfortable with programming in C and C#, and will explore C++ in the future. I may be interested in exploring functional programming as a different programming paradigm. I am doing this for fun, my job does not involve computer programming, and am somewhat inspired by the use of functional programming, taught fairly early, in computer science courses in college. Lambda calculus is certainly beyond my mathematical abilities, but I think I can handle functional programming. Which of Haskell or Scheme would serve as a good intro to functional programming? I use emacs as my text editor and would like to be able to configure it more easily in the future which would entail learning Emacs Lisp. My understanding, however, is that Emacs Lisp is fairly different from Scheme and is also more procedural as opposed to functional. I would likely be using "The Little Schemer" book, which I have already bought, if I pursue Scheme (seems to me a little weird from my limited leafing through it). Or would use the "Learn You a Haskell for Great Good" if I pursue Haskell. I would also watch the Intro to Haskell videos by Dr Erik Meijer on Channel 9. Any suggestions, feedback or input appreciated. Thanks. P.S. BTW I also have access to F# since I have Visual Studio 2010 which I use for C# development, but I don't think that should be my main criteria for selecting a language.

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• Strategy for backwards compatibility of persistent storage

  - by Baqueta

  In my experience, trying to ensure that new versions of an application retain compatibility with data storage from previous versions can often be a painful process. What I currently do is to save a version number for each 'unit' of data (be it a file, database row/table, or whatever) and ensure that the version number gets updated each time the data changes in some way. I also create methods to convert from v1 to v2, v2 to v3, and so on. That way, if I'm at v7 and I encounter a v3 file, I can do v3-v4-v5-v6-v7. So far this approach seems to be working out well, but I haven't had to make use of it extensively yet so there may be unforseen problems. I'm also concerned that if the objects I'm loading change significantly, I'll either have to keep around old versions of the classes or face updating all my conversion methods to handle the new class definition. Is my approach sound? Are there other/better approaches I could be using? Are there any design patterns applicable to this problem?

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• Scaling along an arbitrary axis (Dealing with non-uniform scale)

  - by Jon

  I'm trying to build my own little engine to get more familiar with the concepts of 3D programming. I have a transform class that on each frame it creates a Scaling Matrix (S), a Rotation Matrix from a Quaternion (R) and concatenates them together (S*R). Once i have SR, I insert the translation values into the bottom of the three columns. So i end up with a transformation matrix that looks like: [SR SR SR 0] [SR SR SR 0] [SR SR SR 0] [tx ty tz 1] This works perfectly in all cases except when rotating an object that has a non-uniform scale. For example a unit cube with ScaleX = 4, ScaleY = 2, ScaleZ = 1 will give me a rectangular box that is 4 times as wide as the depth and twice as high as the depth. If i then translate this around, the box stays the same and looks normal. The problem happens whenever I try to rotate this scaled box. The shape itself becomes distorted and it appears as though the Scale factors are affecting the object on the World X,Y,Z axis rather than the local X,Y,Z axis of the object. I've done some pretty extensive research through a variety of textbooks (Eberly, Moller/Hoffman, Phar etc) and there isn't a ton there to go off of. Online, most of the answers say to avoid non-uniform scaling which I understand the desire to avoid it, but I'd still like to figure out how to support it. The only thing I can think off is that when constructing a Scale Matrix: [sx 0 0 0] [0 sy 0 0] [0 0 sz 0] [0 0 0 1] This is scaling along the World Axis instead of the object's local Direction, Up and Right vectors or it's local Z, Y, X axis. Does anyone have any tips or ideas on how to handle construction a transformation matrix that allows for non-uniform scaling and rotation? Thanks!

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• Purpose oriented user accounts on a single desktop?

  - by dd_dent

  Starting point: I currently do development for Dynamics Ax, Android and an occasional dabble with Wordpress and Python. Soon, I'll start a project involving setting up WP on Google Apps Engine. Everything is, and should continue to, run from the same PC (running Linux Mint). Issue: I'm afraid of botching/bogging down my setup due to tinkering/installing multiple runtimes/IDE's/SDK's/Services, so I was thinking of using multiple users, each purposed to handle the task at hand (web, Android etc) and making each user as inert as possible to one another. What I need to know is the following: Is this a good/feasible practice? The second closest thing to this using remote desktops connections, either to computers or to VM's, which I'd rather avoid. What about switching users? Can it be made seamless? Anything else I should know? Update and clarification regarding VM's and whatnot: The reason I wish to avoid resorting to VM's is that I dislike the performance impact and sluggishness associated with it. I also suspect it might add a layer of complexity I wish to avoid. This answer by Wyatt is interesting but I think it's only partly suited for requirements (web development for example). Also, in reference to the point made about system wide installs, there is a level compromise I should accept as experessed by this for example. This option suggested by 9000 is also enticing (more than VM's actually) and by no means do I intend to "Juggle" JVMs and whatnot, partly due to the reason mentioned before. Regarding complexity, I agree and would consider what was said, only from my experience I tend to pollute my work environment with SDKs and runtimes I tried and discarded, which would occasionally leave leftovers which cause issues throught the session. What I really want is a set of well defined, non virtualized sessions from which I can choose at my leisure and be mostly (to a reasonable extent) safe from affecting each session from the other. And what I'm really asking is if and how can this be done using user accounts.

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• Architectural and Design Challenges with SOA

  With all of the hype about service oriented architecture (SOA) primarily through the use of web services, not much has been said about potential issues of using SOA in the design of an application. I am personally a fan of SOA, but it is not the solution for every application. Proper evaluation should be done on all requirements and use cases prior to deciding to go down the SOA road. It is important to consider how your application/service will handle the following perils as it executes. Example Challenges of SOA Network Connectivity Issues Handling Connectivity Issues Longer Processing/Transaction Times How many of us have had issues visiting our favorite web sites from time to time? The same issue will occur when using service based architecture especially if it is implemented using web services. Forcing applications to access services via a network connection introduces a lot of new failure points to the application. Potential failure points include: DNS issues, network hardware issues, remote server issues, and the lack of physical network connections. When network connectivity issues do occur, how are the service clients are implemented is very important. Should the client wait and poll the service until it is accessible again? If so what is the maximum wait time or number of attempts it should retry. Due to the fact of services being distributed across a network automatically increase the responsiveness of client applications due to the fact that processing time must now also include time to send and receive messages from called services. This could add nanoseconds to minutes per each request based on network load and server usage of the service provider. If speed highly desirable quality attribute then I would consider creating components that are hosted where the client application is located. References: Rader, Dave. (2002). Overcoming Web Services Challenges with Smart Design: http://soa.sys-con.com/node/39458

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• Implementing Circle Physics in Java

  - by Shijima

  I am working on a simple physics based game where 2 balls bounce off each other. I am following a tutorial, 2-Dimensional Elastic Collisions Without Trigonometry, for the collision reactions. I am using Vector2 from the LIBGDX library to handle vectors. I am a bit confused on how to implement step 6 in Java from the tutorial. Below is my current code, please note that the code strictly follows the tutorial and there are redundant pieces of code which I plan to refactor later. Note: refrences to this refer to ball 1, and ball refers to ball 2. /* * Step 1 * * Find the Normal, Unit Normal and Unit Tangential vectors */ Vector2 n = new Vector2(this.position[0] - ball.position[0], this.position[1] - ball.position[1]); Vector2 un = n.normalize(); Vector2 ut = new Vector2(-un.y, un.x); /* * Step 2 * * Create the initial (before collision) velocity vectors */ Vector2 v1 = this.velocity; Vector2 v2 = ball.velocity; /* * Step 3 * * Resolve the velocity vectors into normal and tangential components */ float v1n = un.dot(v1); float v1t = ut.dot(v1); float v2n = un.dot(v2); float v2t = ut.dot(v2); /* * Step 4 * * Find the new tangential Velocities after collision */ float v1tPrime = v1t; float v2tPrime = v2t; /* * Step 5 * * Find the new normal velocities */ float v1nPrime = v1n * (this.mass - ball.mass) + (2 * ball.mass * v2n) / (this.mass + ball.mass); float v2nPrime = v2n * (ball.mass - this.mass) + (2 * this.mass * v1n) / (this.mass + ball.mass); /* * Step 6 * * Convert the scalar normal and tangential velocities into vectors??? */

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• Need theoretical help, how to comprehend an if-else dependency net

  - by macbie

  I am going to face a following issue: I'm writing a program that manages some properties, some of them are general and some are specific. Each property is a pair of key and value, and for example: if it is given a general property and other specific property with exactly the same key and value has been existed before then the general property will swap the specific one in the register. If there are two the same general properties - both will remain in the register. And so on; it is like a net of dependencies. In my case I can handle with it intuitively and foresee all cases, but only because the system is not too vast. What if it would? I have met such problems a few times in many different programs and languages (i.e working with C semaphores) and my question is: How to approach this kind of problem? Is this connected with finite state machine, graph theory or something similar? How to be sure that I have considered the whole system and each possible case? Could you recommend some resources (books, sites) to learn from?

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• Design mode in Visual studio 2010 sp1 beta

  - by anirudha

  in MVC3 razor we found that their is no way to watch the design in Visual studio as well we can see aspx file by going to design mode. their is a little trick to solve this issue first is that if you have Expression web or Vs 2008 then open the file on them how see here in expression web 4 you need to add the extension .cshtml and open them as html as we open other. in Visual studio 2008 you need to add the extension .cshtml and set them open as html. well their is no big trouble if design not worked. but in some case when you need to get this issue solved this need to be work for configuration do this: Expression Web 4 > tools > application options > configure editor > click on new extension icon show in exact left put the cshtml in the window they show you and choose expression web [open as html] after that you can see the design in expression web. by default Expression web not have cshtml as known extension so you need to do that to add them because without it they never handle cshtml file and refer them to Visual studio. after setting this you  EW4 open the cshtml file as html and show you design in design mode. in Visual studio 2008 you can use same trick to solve this issue just follow this step > options > text editors > file extension put cshtml in textbox and set the option html editor from dropdown and click on add and ok this will open your cshtml file as html.

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• Going on 15 months for me...

  - by Ratman21

  About 5 face to face interviews, 4 telephone ones and except for the two weeks Census Job. But, after 15 months looking for work, I am still with out a JOB. What is wrong here or with me? Let’s see, hard worker (check), self motivated to do well on a Job (Check), Certified CompTIA A+, Security+  and Network+ Technician (Check), 20 + years experience in “IT” (CHECK), in good health, in 20 years of work only 15 days off due to health issues (Check), 18 years experience as technical Help Desk support (Check), can still work better than younger personal (Check), Strong trouble shooting skills for software, computer hard ware and circuit issues (Check) and Multiple software languages (Hey I have done some programming) Check. Hmm I don’t see any problem with me (of course I could have missed something, please let me know if you see what I am missing).    Now as to what have I been up to since I last blogged. The same things of course, Job hunting, job hunting and study.   I have set up sim of my home LAN and will be adding a wireless print server to the sim and in real life, soon.  I was able to pull up and copy the examples of Cisco router commands that I had on my old lap top, to my newer PC. Every time I used a new command while working the NOC on my last job.   I would cut and past a copy of the command on the router (and what it did) I was working on.  Along with notes on the problem and commands use for same router. I used these to make documentation for on how to handle these types of issues, for the other Operation Techs. My old notes are helping me in studying for the CCENT test.    As to Love Dare, I think it will take more like 40 weeks, than the 40 days of the book. Yes I am making progress, slow but, it is progress. I will have more on that in my next blog.

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• flat files vs. RDBMS database, few read/writes, few changes

  - by Bob Lapique

  I have to handle data from long term (years, decades) climate monitoring stations. The data flow usually starts with raw data (voltages, etc.) plus quality check information (pressure, temperature, flow rate, etc.) generally recorded @ 1Hz. Then, the data are assigned a quality flag (human and/or program), processed (apply calibration curves) and flagged. So, we basically end up with 2 datasets : raw and processed data. New data are typically added once a day (~500Ko/day/instrument). Simultaneous queries are not likely to ever happen. I wanted to go for a RDBMS (we have a MySQL server) and have some experience in database design, but the IT guy keeps telling me that flat files will to the job just as well. I suspect him to try to make his life easier when it comes to backup/upgrade the MySQL. There are not so many links between data, they don't change much, but the quality flags will change. A RDBMS is easier to compare data from different instruments on a "many days" scale, compared to daily text files. Well, what would you advise ? Thanks.

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• Are there plans for handwriting recognition?

  - by Patrick

  This is a big feature when it comes to putting Ubuntu onto tablets. Currently, Netbook edition works great for that purpose and the pen digitiser is perfect, but the handwriting would be a real dealmaker (especially for my business - we could actually move to Linux) to compete with the Windows one. CellWriter exists, but that only handles character and keyboard input (but I don't know about multitouch on the keyboard). It also needs to handle print and cursive, because character mode can be slow and uncomfortable (unless you're writing passwords). Lastly, CellWriter needs to have some default letter shapes rather than having to be trained from the start. There is a software package called MyScript (by Vision Objects) that handles all four modes (keyboard, character, print, cursive) plus calculator and fullscreen, but it's only free as a trial. Still, it would be nice to see it in the For Purchase section and the trial in the free section of the Software Centre. The only other ones are for Chinese/Japanese/Korean characters. What would really make a difference for us is the integration of some formal API with the OS that can automatically activate when running on a tablet to pass ink data to whatever recognition system is installed, and have something available (however rudimentary) to use it.

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• Looking for someone to point me in the right direction. I want to learn how to use hosted servers

  - by Leisure

  TL;DR: I want a Java program to run on a server, I want the server to forward a particular port from external to internal IP, I want store a few files on the server. Guides please. So I made a hack job Java program that acts as a server for my android application. It stores data in text files and HTML files, uploads them via FTP to my webhost, and manages socket connections (using port forwarding) with any phones connected. Right now I'm running it on NetBeans on my home computer. I know that it will probably slow down or crash once about 50 phones are connected at once. Is there any way I can run this program on a server with a high bandwidth? Can someone please find me a guide for that? I'm noob and don't know where to start looking. I seriously don't know anything about renting or using servers - I need a nice guide, and recommendations. My requirements for the server: Can handle about 2k socket connections at once Can run my Java code and store my txt files Can give me a port and an IP address so TCP/IP clients can be connected My budget: $50 CAD per month. Please someone set my ship sailing in the right direction, I really don't know where to look for resources.

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• Dual Boot Installing Ubuntu 12.04 with Windows 7 (64) on a non UEFI system

  - by Randnum

  I cannot seem to install the correct boot loader for a non-UEFI firmware system. I'm trying to install Ubuntu 12.04 and Windows 7 (64) which are technically compatible with GPT but for windows only if the firmware is UEFI enabled. My system uses the old BIOS system and does not support UEFI. Therefore, whenever I finish my Ubuntu install and try to install Windows I get a "cannot install to GPT partition type" error. Even if I use Gparted to format a special NTFS file format for windows it can't handle the GPT partition style because it doesn't have UEFI. But my ubuntu install always forces GPT during installation and never asks if I want to install the old BIOS style MBR instead. How do I resolve this? Both OS's will install fine on their own the problem is when I try to install the second OS it doesn't recognize any of the other's partitions and tries to rewrite it's own on top of the other. I've tried both OS's first and always run into the same problem. Since there is no way to make Windows recognize GPT without upgrading my Motherboard how do I tell Ubuntu to use the old BIOS MBR on install? Do I have to download a special Ubuntu with a specific grub version? or should I manaually configure my partition somehow to force it not to use GPT? Thank you,

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• How do you support your code post employment end?

  - by James

  What is the process for leaving a company (or even a group/division) in terms of code support? Is it best to handle all questions? Do you give the remaining developers access to yourself as a future resource? If so, is there a way to not give full access? I've experienced first hand where answers about the general software arthitecture from the initial developer would be invaluable. I understand that if serious assistance is needed, than it becomes a typical case of employment negotiation as a support contract. However, should serious assistance be required, what steps can you make to ease that process of contacting you? I was thinking of doing something like making a (YOUR_NAME)_codesupport @ (YOUR_FAVORITE_EMAIL_CLIENT).com address. My Situation Specifics: I'm a co-op student, and as such bounce around companies on 4-month stints. This means introducing myself to a lot of new code bases, as well as leaving a fair share of orphaned code behind when I leave a company. I feel bad if I leave junk code around.

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• Ubuntu Lenove OCZ Agility3 - No Grub after install

  - by Michael

  I've tried a dualboot (Win7 + Ubuntu) installation it on a Lenovo E330 with Agility3 240 Gigs... Conclusions: Ubuntu:: Ubuntu 12.04 x86_64 ( 21.06.2012 ) is not able to install grub in a bootable way. Grub will be installed and does update-grub during Installation, recognizes also the Win OS. But after a restart it boots directly to Windows.This is directly connected to the OCZ Agility3. On a good old fashion harddisk (those with the moving parts) Ubuntu is capable to install grub with no problem in a bootable manner. PinguyOS:: PinguyOS 12.04 LTS x86_64 (which is a Ubuntu based distro) is able to handle the Grub installation on OCZ Agility3. However they both use Grub 1.99... What i did:: Installed Windows. Installed Ubuntu. Installed PinguyOS. Grub Updates:: Grub updates are only through Pinguy OS possible, this means you have to edit the Ubuntu Grub entries manually after Kernelupdates on Ubuntu, in the PiguyOS sytem.. What i've already tried: Firmwareupgrade OCZ (livestick, successfull) Install Ubuntu Grub to sda Install Ubuntu Grub to sdc (Ubuntu Partion) Install Ubuntu Grub to /boot update-grub manually after install restore grub any ideas appreciated..

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• Alternative to nofollow: custom 302 url shortener?

  - by Dogweather

  Here's the scenario: lots of blogging platforms make it tedious to insert nofollow into links within the post content. I.e., you need to edit the html, format it correctly, etc. I have a client who posts lots of content with links that should be nofollow'ed, and I thought of a novel way to handle this, since the blogging platform they're using makes it hard: I install a URL shortener web app on the client's domain. The shortener works as normal, except it redirects via 302 instead of 301. The pagerank will therefore stay at the shortener's domain, and not flow on to the target site. Part 2: In order to get the pagerank to collect meaningfully, say on the site's home page, the shortened URLs would be generated like this: /link?12345 instead of /link/12345. And then, the path /link would 301 to the home page. This way, the id is a param, not a path element. And thus, all the incoming shortened links are going to one path, which transfers pagerank to the home page. So that's my idea. I wanted to see if anybody could find problems with it. Thanks!

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• Microeconomical simulation: coordination/planning between self-interested trading agents

  - by Milton Manfried

  In a typical perfect-information strategy game like Chess, an agent can calculate its best move by searching the state tree for the best possible move, while assuming that the opponent will also make the best possible move (i.e. Mini-max). I would like to use this approach in a "game" modeling economic activity, where the possible "moves" would be to buy or sell for a given price, and the goal, rather than a specific class of states (e.g. Checkmate), would be to maximize some function F of the agent's state (e.g. F(money, widget) = 10*money + widget). How to handle buy/sell actions that require coordination between both parties, at the very least agreement upon a price? The cheap way out would be to set the price beforehand, maybe based upon the current supply -- but the idea of this simulation is to examine how prices emerge when freely determined by "perfectly rational" agents. A great example of what I do not want is the trading algorithm in SugarScape -- paraphrasing from Growing Artificial Societies p101-102: when a pair of agents interact to trade, they each compute their internal valuations of the goods, then a bargaining process is conducted and a price is agreed to. If this price makes both agents better off, they complete the transaction The protocol itself is beautiful, but what it cannot capture (as far as I can tell) is the ability for an agent to pay more than it might otherwise for a good, because it knows that it can sell it for even more at a later date -- what appears to be called "strategic thinking" in this pape at Google Books Multi-Agent-Based Simulation III: 4th International Workshop, MABS 2003... to get realistic behavior like that, it seems one would either (1) have to build an outrageously-complex internal valuation system which could at best only cover situations that were planned for at compile-time, or otherwise (2) have some mechanism to search the state tree... which would require some way of planning future trades. Note: The chess analogy only works as far as the state-space search goes; the simulation isn't intended to be "zero sum", so a literal mini-max search wouldn't be appropriate -- and ideally, it should work with more than two agents.

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• Very Cool &ndash; Miami 311 System for tracking citizen service requests (Windows Azure, Silverlight

  - by Jim Duffy

  Having grown up in South Florida this short, but very enlightening, video explaining how the City of Miami has implemented a 311 citizen service request system using Windows Azure, Silverlight and Bing Maps definitely caught my attention. Miami311 The Miami311 System is a Windows Azure/Silverlight-based solution which enables City of Miami citizens report and track issues reported to city management. The system uses Bing Maps to plot the location and relevant information about each issue reported. Citizens now have the ability to easily see the status of the issue without having to call the city office. What I found interesting were a couple of benefits that a metropolitan area such as Miami can take advantage of in Windows Azure cloud-based solution. For the city of Miami, both benefits center around the weather. Of course the threat of a hurricane is a real issue in South Florida and what better way to make sure your site stays up during a hurricane then to have the site hosted far away from the eye of the storm. Using a Windows Azure cloud-based architecture the City of Miami is able to host the application within the Microsoft data centers safely away from any hurricane passing through South Florida. The second benefit is the inherent scalability of a Windows Azure based solution. During a severe weather event like thunderstorms or even worse, a hurricane, downed trees and power lines are a commonly reported problem. Being able to quickly scale up the computing resources required to handle the spike in citizens reporting these types of problems on the site is a huge benefit. Once the weather event has passed and downed tree reports begin to subside they can quickly reverse the process and scale the system back down to pre-storm levels. It’s kind of day-to-day kind of stuff but very cool stuff nonetheless. Have a day. :-|

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• How to minimize the usage of static variables and objects

  - by Peter Penzov

  I'm trying to implement this JavaFX code where I want to call remote Java class and pass boolean flag: final CheckMenuItem toolbarSubMenuNavigation = new CheckMenuItem("Navigation"); toolbarSubMenuNavigation.setOnAction(new EventHandler<ActionEvent>() { @Override public void handle(ActionEvent e) { //DataTabs.renderTab = toolbarSubMenuNavigation.isSelected(); DataTabs.setRenderTab(toolbarSubMenuNavigation.isSelected()); // call here the getter setter and send boolean flag System.out.println("subsystem1 #1 Enabled!"); } }); Java class which I want to call: public class DataTabs { private static boolean renderTab; // make members *private* private static TabPane tabPane; public static boolean isRenderTab() { return DataTabs.renderTab; } public static void setRenderTab(boolean renderTab) { DataTabs.renderTab = renderTab; tabPane.setVisible(renderTab); } // somewhere below // set visible the tab pane TabPane tabPane = DataTabs.tabPane = new TabPane(); tabPane.setVisible(renderTab); } This implementation works but I want to optimize it to use less static variables and objects. Can you tell me which sections of the code how can be optimized?

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