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• How to interview a natural scientist for a dev position?

  - by Silas

  I already did some interviews for my company, mostly computer scientists for dev positions but also some testers and project managers. Now I have to fill a vacancy in our research group within the R&D department (side note: “research” means that we try to solve problems in our professional domain/market niche using software in research projects together with universities, other companies, research centres and end user organisations. It’s not computer science research; we’re not going to solve the P=NP problem). Now we invited a guy holding an MSc in chemistry (with a lot of physics in his CV, too), who never had any computer science lesson. I already talked with him about half an hour at a local university’s career days and there’s no doubt the guy is smart. Also his marks are excellent and he graduated with distinction. For his BSc he needed to teach himself programming in Mathematica and told me believably that he liked programming a lot. Also he solved some physical chemistry problem that I probably don’t understand using his own software, implemented in Mathematica, for his MSc thesis. It includes a GUI and a notable size of 8,000 LoC. He seems to be very attracted by what we’re doing in our research group and to be honest it’s quite difficult for an SME like us to get good people. I also am very interested in hiring him since he could assist me in writing project proposals, reports, doing presentations and so on. He would probably fit to our team, too. The only question left is: How can I check if he will get the programming skills he needs to do software implementation in our projects since this will be a significant part of the job? Of course I will ask him what it is, that is fascinating him about programming. I’ll also ask how he proceeded to write his natural science software and how he structured it. I’ll ask about how he managed to obtain the skills and information about software development he needed. But is there something more I could ask? Something more concrete perhaps? Should I ask him to explain his Mathematica solution? To be clear: I’m not looking for knowledge in a particular language or technology stack. We’re a .NET shop in product development but I want to have a free choice for our research projects. So I’m interested in the meta-competence being able to learn whatever is actually needed. I hope this question is answerable and not open-ended since I really like to know if there is a default way to check for the ability to get further programming skills on the job. If something is not clear to you please give me some comments and let me improve my question.

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• Are closures with side-effects considered "functional style"?

  - by Giorgio

  Many modern programming languages support some concept of closure, i.e. of a piece of code (a block or a function) that Can be treated as a value, and therefore stored in a variable, passed around to different parts of the code, be defined in one part of a program and invoked in a totally different part of the same program. Can capture variables from the context in which it is defined, and access them when it is later invoked (possibly in a totally different context). Here is an example of a closure written in Scala: def filterList(xs: List[Int], lowerBound: Int): List[Int] = xs.filter(x => x >= lowerBound) The function literal x => x >= lowerBound contains the free variable lowerBound, which is closed (bound) by the argument of the function filterList that has the same name. The closure is passed to the library method filter, which can invoke it repeatedly as a normal function. I have been reading a lot of questions and answers on this site and, as far as I understand, the term closure is often automatically associated with functional programming and functional programming style. The definition of function programming on wikipedia reads: In computer science, functional programming is a programming paradigm that treats computation as the evaluation of mathematical functions and avoids state and mutable data. It emphasizes the application of functions, in contrast to the imperative programming style, which emphasizes changes in state. and further on [...] in functional code, the output value of a function depends only on the arguments that are input to the function [...]. Eliminating side effects can make it much easier to understand and predict the behavior of a program, which is one of the key motivations for the development of functional programming. On the other hand, many closure constructs provided by programming languages allow a closure to capture non-local variables and change them when the closure is invoked, thus producing a side effect on the environment in which they were defined. In this case, closures implement the first idea of functional programming (functions are first-class entities that can be moved around like other values) but neglect the second idea (avoiding side-effects). Is this use of closures with side effects considered functional style or are closures considered a more general construct that can be used both for a functional and a non-functional programming style? Is there any literature on this topic? IMPORTANT NOTE I am not questioning the usefulness of side-effects or of having closures with side effects. Also, I am not interested in a discussion about the advantages / disadvantages of closures with or without side effects. I am only interested to know if using such closures is still considered functional style by the proponent of functional programming or if, on the contrary, their use is discouraged when using a functional style.

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• Validate if aTextBox Value Start with a Specific Letter

  - by Vincent Maverick Durano

  In case you will be working on a page that needs to validate the first character of the TextBox entered by a user then here are two options that you can use: Option 1: Using an array   1: <asp:Content ID="Content1" ContentPlaceHolderID="HeadContent" runat="server"> 2: <script type="text/javascript"> 3: function CheckFirstChar(o) { 4: var arr = ['A', 'B', 'C', 'D']; 5: if (o.value.length > 0) { 6: for (var i = 0; i < arr.length; i++) { 7: if (o.value.charAt(0) == arr[i]) { 8: alert('Valid'); 9: return true; 10: } 11: else { 12: alert('InValid'); 13: return false; 14: } 15: } 16: } 17: } 18: </script> 19: </asp:Content> 20: <asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server"> 21: <asp:TextBox ID="TextBox1" runat="server" onblur="return CheckFirstChar(this);"></asp:TextBox> 22: </asp:Content>   The example above uses an array of string for storing the list of  characters that a TextBox value should start with. We then iterate to the array and compare the first character of TextBox value to see if it matches any characters from the array. Option 2: Using Regular Expression (Preferred way)   1: <asp:Content ID="Content1" ContentPlaceHolderID="HeadContent" runat="server"> 2: <script type="text/javascript"> 3: function CheckFirstChar(o) { 4: pattern = /^(A|B|C|D)/; 5: if (!pattern.test(o.value)) { 6: alert('InValid'); 7: return false; 8: } else { 9: alert('Valid'); 10: return true; 11: } 12: } 13: </script> 14: </asp:Content> 15: <asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server"> 16: <asp:TextBox ID="TextBox1" runat="server" onblur="return CheckFirstChar(this);"></asp:TextBox> 17: </asp:Content>   The example above uses regular expression with the pattern  /^(A|B|C|D)/. This will check if the TextBox value starts with A,B,C or D. Please note that it's case sensitive. If you want to allow lower case then you can alter the patter to this /^(A|B|C|D)/i. The i in the last part will cause a case-insensitive search.   That's it! I hope someone find this post useful!

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• Partial Shader Signatures HLSL D3D11 C++

  - by ThePhD

  I had been debugging a problem I was having in a single shader file with 2 functions in it. I'm using DirectX 11, vs_5_0 and ps_5_0. I have stripped it down to its basic components to understand what was going wrong with the shaders, because the different named components of the Pixel and Vertex shaders were swapping the data being input: void QuadVertex ( inout float4 position : SV_Position, inout float4 color : COLOR0, inout float2 tex : TEXCOORD0 ) { // ViewProject is a 4x4 matrix, // just included here to show the simple passthrough of the data position = mul(position, ViewProjection); } And a Pixel Shader: float4 QuadPixel ( float4 color : COLOR0, float2 tex : TEXCOORD0 ) : SV_Target0 { // Color is filled with position data and tex is // filled with color values from the Vertex Shader return color; } The ID3D11InputLayout and associated C++ code correctly compiles the shaders and sets them up with some simple primitive data: data[0].Position.x = 0.0f * 210; data[0].Position.y = 1.0f * 160; data[0].Position.z = 0.0f; data[1].Position.x = 0.0f * 210; data[1].Position.y = 0.0f * 160; data[1].Position.z = 0.0f; data[2].Position.x = 1.0f * 210; data[2].Position.y = 1.0f * 160; data[2].Position.z = 0.0f; data[0].Colour = Colors::Red; data[1].Colour = Colors::Red; data[2].Colour = Colors::Red; data[0].Texture = Vector2::Zero; data[1].Texture = Vector2::Zero; data[2].Texture = Vector2::Zero; When used with the shader, the float4 color always ended up with the position data, and the float2 tex always ended up with the color data. After a moment, I figured out that the shader's input and output signatures needed to be in the correct order and the correct format and be laid out in the exact order of the output from the Vertex Shader, regardless of the semantics: float4 QuadPixel ( float4 pos : SV_Position, float4 color : COLOR0, float2 tex : TEXCOORD0 ) : SV_Target0 { return color; } After finding this out, My question is: Why don't the semantics map the appropriate components when going from Vertex Shader to Pixel Shader? Is there any way that I can make it so certain semantics are always mapped to other semantics, or do I always have to follow the rigid Shader Signature (in this case, Position, Color, and Texture) ? As a side note for why I'm asking: I know that when using XNA, my shader signatures for functions could differ in position and even drop items from Vertex Shader to Pixel Shader function parameters, having only the COLOR0 and TEXCOORD0 components being used (and it would still match up correctly). However, I also know that XNA relied on DX9 (and maybe a little DX10) implementation, and that maybe this kind of flexibility no longer exists in DX11?

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• What is a good design model for my new class?

  - by user66662

  I am a beginning programmer who, after trying to manage over 2000 lines of procedural php code, now has discovered the value of OOP. I have read a few books to get me up to speed on the beginning theory, but would like some advice on practical application. So,for example, let's say there are two types of content objects - an ad and a calendar event. what my application does is scan different websites (a predefined list), and, when it finds an ad or an event, it extracts the data and saves it to a database. All of my objects will share a $title and $description. However, the Ad object will have a $price and the Event object will have $startDate. Should I have two separate classes, one for each object? Should I have a 'superclass' with the $title and $description with two other Ad and Event classes with their own properties? The latter is at least the direction I am on now. My second question about this design is how to handle the logic that extracts the data for $title, $description, $price, and $date. For each website in my predefined list, there is a specific regex that returns the desired value for each property. Currently, I have an extremely large switch statement in my constructor which determines what website I am own, sets the regex variables accordingly, and continues on. Not only that, but now I have to repeat the logic to determine what site I am on in the constructor of each class. This doesn't feel right. Should I create another class Algorithms and store the logic there for each site? Should the functions of to handle that logic be in this class? or specific to the classes whos properties they set? I want to take into account in my design two things: 1) I will add different content objects in the future that share $title and $description, but will have their own properties, so, I want to be able to easily grow these as needed. 2) I will add more websites constantly (each with their own algorithms for data extraction) so I would like to plan efficienty managing and working with these now. I thought about extending the Ad or Event class with 'websiteX' class and store its functions there. But, this didn't feel right either as now I have to manage 100s of little website specific class files. Note, I didn't know if this was the correct site or stackoverflow was the better choice. If so, let me know and I'll post there.

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• How to perform Cross Join with Linq

  - by berthin

  Cross join consists to perform a Cartesian product of two sets or sequences. The following example shows a simple Cartesian product of the sets A and B: A (a1, a2) B (b1, b2) => C (a1 b1,            a1 b2,            a2 b1,            a2, b2 ) is the Cartesian product's result. Linq to Sql allows using Cross join operations. Cross join is not equijoin, means that no predicate expression of equality in the Join clause of the query. To define a cross join query, you can use multiple from clauses. Note that there's no explicit operator for the cross join. In the following example, the query must join a sequence of Product with a sequence of Pricing Rules: 1: //Fill the data source 2: var products = new List<Product> 3: { 4: new Product{ProductID="P01",ProductName="Amaryl"}, 5: new Product {ProductID="P02", ProductName="acetaminophen"} 6: }; 7:  8: var pricingRules = new List<PricingRule> 9: { 10: new PricingRule {RuleID="R_1", RuleType="Free goods"}, 11: new PricingRule {RuleID="R_2", RuleType="Discount"}, 12: new PricingRule {RuleID="R_3", RuleType="Discount"} 13: }; 14: 15: //cross join query 16: var crossJoin = from p in products 17: from r in pricingRules 18: select new { ProductID = p.ProductID, RuleID = r.RuleID };   Below the definition of the two entities using in the above example.   1: public class Product 2: { 3: public string ProductID { get; set; } 4: public string ProductName { get; set; } 5: } 1: public class PricingRule 2: { 3: public string RuleID { get; set; } 4: public string RuleType { get; set; } 5: }   Doing this: 1: foreach (var result in crossJoin) 2: { 3: Console.WriteLine("({0} , {1})", result.ProductID, result.RuleID); 4: }   The output should be similar on this:   ( P01   -    R_1 )   ( P01   -    R_2 )   ( P01   -    R_3 )   ( P02   -    R_1 )   ( P02   -    R_2 )   ( P02   -    R_3) Conclusion Cross join operation is useful when performing a Cartesian product of two sequences object. However, it can produce very large result sets that may caused a problem of performance. So use with precautions :)

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• Remote Graphics Diagnostics with Windows RT 8.1 and Visual Studio 2013

  - by Michael B. McLaughlin

  Originally posted on: http://geekswithblogs.net/mikebmcl/archive/2013/11/12/remote-graphics-diagnostics-with-windows-rt-8.1-and-visual-studio.aspxThis blog post is a brief follow up to my What’s New in Graphics and Game Development in Visual Studio 2013 post on the MVP Award blog. While writing that post I was testing out various features to try to make sure everything worked as expected. I had some trouble getting Remote Graphics Diagnostics (a/k/a remote graphics debugging) working on my first generation Surface RT (upgraded to Windows RT 8.1). It was more strange since I could use remote debugging when doing CPU debugging; it was just graphics debugging that was causing trouble. After some discussions with the great folks who work on the graphics tools in Visual Studio, they were able to repro the problem and recommend a solution. My Surface RT needed the ARM Kits policy installed on it. Once I followed the instructions on the previous link, I could successfully use Remote Graphics Diagnostics on my Surface RT. Please note that this requires Windows RT 8.1 RTM (i.e. not Preview) and that Remote Graphics Diagnostics on ARM only works when you are using Visual Studio 2013 as it is a new feature (it should work just fine using the Express for Windows version). Also, when I installed the ARM Kits policy I needed to do two things to get it to work properly. First, when following the “How to install the Kits policy” instructions, I needed to copy the SecureBoot folder into Program Files on my Surface RT (specifically, I copied the SecureBoot folder to “C:\Program Files\Windows Kits\8.1\bin\arm\” on my Surface RT, creating any necessary directories). It may work if it’s in any system folder; I didn’t test any others after I got it working. I had initially put it in my Downloads folder and tried installing it from there. When the machine restarted it displayed a worrisome error message. I repeatedly pressed the button that would allow me to retry and eventually the machine rebooted and managed to recover itself to its previous state. Second, I needed to install it as an Administrator. The instructions say that this might be necessary. For me it was. This is a Remote Graphics Diagnostics is a great new feature in Visual Studio 2013 so I definitely encourage all of you to check it out!

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• The Softer Side of Customer Experience

  - by Christina McKeon

  It’s election season in the U.S., and you know what that means. It means I stop by the recycling bin in my garage before entering the house with the contents of my mailbox. A couple of weeks ago, I was doing my usual direct mail purge when I came across a piece from The Container Store®. This piece would have gone straight to the recycling bin, but the title stopped me: Learn what WE STAND FOR! Under full disclaimer, I’m probably a “frequent flier” at The Container Store. One can never be too organized! Now, back to the direct mail piece. I opened it to discover that The Container Store has taken their customer experience beyond “a shopping experience that makes you smile” to giving customers more insight and transparency into how they feel about their employees, the vendors they partner with, and the communities they live in. The direct mail piece included several employees showcasing a skill, hobby or talent with their photo and a personal note that used one word to describe what these employees believe The Container Store stands for. I do not recall the last time I read through an entire piece of direct mail. But this time, I pored over all the comments and photos.  Summer, a salesperson, believes that one word is PASSION. Thomas in distribution center inventory systems chooses the word ACTION. The list goes on to include MATCHLESS, FUN, FAMILY, LOVE, and EMPOWERMENT. The Container Store is running a contest asking you to tell them what nonprofit organization you stand for. Anyone can submit their favorite nonprofit to win cash, products and services from The Container Store. Don’t forget about the softer side of customer experience. With many organizations working feverishly to transform their business into being more customer-centric, it’s easy to get caught up in processes and technology. Focusing on people and social responsibility often falls behind and becomes a lower priority. Keeping people and social responsibility at the forefront is crucial. Your customers will use your processes and technology, but they will see or hear your people and feel their passion. The latter is what they will remember most about your brand. I’m sure there are many other great examples of the softer side of customer experience. Please share your examples in the comments section.

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• SQL Azure Security: DoS Part II

  - by Herve Roggero

  Ah!  When you shoot yourself in the foot... a few times... it hurts! That's what I did on Sunday, to learn more about the behavior of the SQL Azure Denial Of Service prevention feature. This article is a short follow up to my last post on this feature. In this post, I will outline some of the lessons learned that were the result of testing the behavior of SQL Azure from two machines. From the standpoint of SQL Azure, they look like one machine since they are behind a NAT. All logins affected The first thing to note is that all the logins are affected. If you lock yourself out to a specific database, none of the logins will work on that database. In fact the database size becomes "--" in the SQL Azure Portal.   Less than 100 sessions I was able to see 50+ sessions being made in SQL Azure (by looking at sys.dm_exec_sessions) before being locked out. The the DoS feature appears to be triggered in part by the number of open sessions. I could not determine if the lockout is triggered by the speed at which connection requests are made however.   Other Databases Unaffected This was interesting... the DoS feature works at the database level. Other databases were available for me to use.   Just Wait Initially I thought that going through SQL Azure and connecting from there would reset the database and allow me to connect again. Unfortunately this doesn't seem to be the case. You will have to wait. And the more you lock yourself out, the more you will have to wait... The first time the database became available again within 30 seconds or so; the second time within 2-3 minutes and the third time... within 2-3 hours...   Successful Logins The DoS feature appears to engage only for valid logins. If you have a login failure, it doesn't seem to count. I ran a test with over 100 login failures without being locked.

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• Running Built-In Test Simulator with SOA Suite Healthcare 11g in PS4 and PS5

  - by Shub Lahiri, A-Team

  Background SOA Suite for Healthcare Integration pack comes with a pre-installed simulator that can be used as an external endpoint to generate inbound and outbound HL7 traffic on specified MLLP ports. This is a command-line utility that can be very handy when trying to build a complete end-to-end demo within a standalone, closed environment. The ant-based utility accepts the name of a configuration file as the command-line input argument. The format of this configuration file has changed between PS4 and PS5. In PS4, the configuration file was XML based and in PS5, it is name-value property based. The rest of this note highlights these differences and provides samples that can be used to run the first scenario from the product samples set. PS4 - Configuration File The sample configuration file for PS4 is shown below. The configuration file contains information about the following items: Directory for incoming and outgoing files for the host running SOA Suite Healthcare Polling Interval for the directory External Endpoint Logical Names External Endpoint Server Host Name and Ports Message throughput to be simulated for generating outbound messages Documents to be handled by different endpoints A copy of this file can be downloaded from here. PS5 - Configuration File The corresponding sample configuration file for PS5 is shown below. The configuration file contains similar information about the sample scenario but is not in XML format. It has name-value pairs specified in the form of a properties file. This sample file can be downloaded from here. Simulator Configuration Before running the simulator, the environment has to be set by defining the proper ANT_HOME and JAVA_HOME. The following extract is taken from a working sample shell script to set the environment: Also, as a part of setting the environment, template jndi.properties and logging.properties can be generated by using the following ant command: ant -f ant-b2bsimulator-util.xml b2bsimulator-prop Sample jndi.properties and logging.properties are shown below and can be modified, as needed. The jndi.properties contains information about connectivity to the local Weblogic Managed Server instance and the logging.properties file controls the amount of logging that can be generated from the running simulator process. Simulator Usage - Start and Stop The command syntax to launch the simulator via ant is the same in PS4 and PS5. Only the appropriate configuration file has to be supplied as the command-line argument, for example: ant -f ant-b2bsimulator-util.xml b2bsimulatorstart -Dargs="simulator1.hl7-config.xml" This will start the simulator and will keep running to provide an active external endpoint for SOA Healthcare Integration engine. To stop the simulator, a similar ant command can be used, for example: ant -f ant-b2bsimulator-util.xml b2bsimulatorstop

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• Seven Accounting Changes for 2010

  - by Theresa Hickman

  I read a very interesting article called Seven Accounting Changes That Will Affect Your 2010 Annual Report from SmartPros that nicely summarized how 2010 annual financial statements will be impacted.  Here’s a Reader’s Digest version of the changes: 1.  Changes to revenue recognition if you sell bundled products with multiple deliverables: Old Rule: You needed to objectively establish the “fair value” of each bundled item. So if you sold a dishwasher plus installation and could not establish the fair value of the installation, you might have to delay recognizing revenue of the dishwasher days or weeks later until it was installed. New Rule (ASU 2009-13): “Objective” proof of each service or good is no longer required; you can simply estimate the selling price of the installation and warranty. So the dishwasher vendor can recognize the dishwasher revenue immediately at the point of sale without waiting a few weeks for the installation. Then they can recognize the estimated value of the installation after it is complete. 2.  Changes to revenue recognition for devices with embedded software: Old Rule: Hardware devices with embedded software, such as the iPhone, had to follow stringent software revrec rules. This forced Apple to recognize iPhone revenues over two years, the period of time that software updates were provided. New Rule (ASU 2009-14): Software revrec rules no longer apply to these devices with embedded software; these devices can now follow ASU 2009-13. This allows vendors, such as Apple, to recognize revenue sooner. 3.  Fair value disclosures: Companies (both public and private) now need to spend extra time gathering, summarizing, and disclosing information about items measured at fair value, such as significant transfers in and out of Level 1(quoted market price), Level 2 (valuation based on observable markets), and Level 3 (valuations based on internal information). 4.  Consolidation of variable interest entities (a.k.a special purpose entities): Consolidation rules for variable interest entities now require a qualitative, not quantitative, analysis to determine the primary beneficiary. Instead of simply looking at the percentage of voting interests, the primary beneficiary could have less than the majority interests as long as it has the power to direct the activities and absorb any losses.  5.  XBRL: Starting in June 2011, all U.S. public companies are required to file financial statements to the SEC using XBRL. Note: Oracle supports XBRL reporting. 6.  Non-GAAP financial disclosures: Companies that report non-GAAP measures of performance, such as EBITDA in SEC filings, have more flexibility.  The new interpretations can be found here: http://www.sec.gov/divisions/corpfin/guidance/nongaapinterp.htm.  7.  Loss contingencies disclosures: Companies should expect additional scrutiny of their loss disclosures, such as those from litigation losses, in their annual financial statements. The SEC wants more disclosures about loss contingencies sooner instead of after the cases are settled.

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• Ask the Readers: Which Browser is a Must-Have for You on Linux?

  - by Asian Angel

  Linux systems all come with their own particular set of default browsers, but those browsers may not be the ones you want or need. This week we would like to know which browser (or browsers) are considered “must-have” on your Linux systems. As a general rule many Linux distributions have Firefox and/or Konqueror as one of the default installation browsers. During this past year the open source browser Chromium has also been gaining a lot of traction as a default install for systems. For most people these browsers are the ones that they like best or feel work well enough to not make any changes. But there are other people who want more than what is available with a default system install. They may favor a particular browser for its’ extensibility or speed…others prefer a particular browser for its’ features or minimalist UI. Whatever your preferences may be, there is a browser out there to fit your style. Some people may even prefer to run only bleeding edge nightly releases or add them in with their current browsers. The important part is that you have choices when it comes to your Linux system. What we would like to know this week is which browser or browsers you make sure are always installed on your Linux systems. Does the Linux system you use already have your favorite browser installed as part of the default set? Maybe you are content with using the default set of browsers that come with the system. Or perhaps you prefer to rework the entire browser setup on your system by removing the defaults and adding your favorites. Let us know which browsers you consider “must have” and why in the comments! Note: You can make up to two selections on today’s poll since most people will likely have more than one browser that they make certain is always installed. How-To Geek Polls require Javascript. Please Click Here to View the Poll. Latest Features How-To Geek ETC How To Boot 10 Different Live CDs From 1 USB Flash Drive The 20 Best How-To Geek Linux Articles of 2010 The 50 Best How-To Geek Windows Articles of 2010 The 20 Best How-To Geek Explainer Topics for 2010 How to Disable Caps Lock Key in Windows 7 or Vista How to Use the Avira Rescue CD to Clean Your Infected PC BotSync Enables Secure FTP File Synchronization on Android Devices Enjoy Beautiful City Views with the Cityscape Theme for Windows 7 Luigi Installs Any OS on Google’s Cr-48 Notebook DIY iPad Stylus Offers Pen-Based Interaction on the Cheap Serene Blue Ubuntu Wallpaper for Your Desktop Enjoy Old School Style Video Game Fun with Chicken Invaders

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• Cheese won't start

  - by Anthony Hohenheim

  I can't start Cheese Webcam Booth. It starts loading and there is a brief moment when the window shows up but then it disappears, like it shuts itself down and it's not in system monitor. My webcam works perfectly in Skype video call. I installed and run Camorama and it gave me an error: Could not connect to video device (/dev/video0) Please check connection When I run the lsusb I get this line for my webcam: Bus 002 Device 002: ID 04f2:b210 Chicony Electronics Co., Ltd And for my graphic card, running lspci: VGA compatible controller: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller (rev 07) It's not a pressing matter, but it bugs my nerves, if it works on Skype, why does Cheese and other programs refuse to run. As I said, it's not a big deal but any help would be appreciated. Running Cheese in terminal: (cheese:11454): Gtk-WARNING **: Attempting to add a widget with type GtkImage to a GtkToggleButton, but as a GtkBin subclass a GtkToggleButton can only contain one widget at a time; it already contains a widget of type GtkLabel (cheese:11454): Gtk-WARNING **: Attempting to add a widget with type GtkImage to a GtkToggleButton, but as a GtkBin subclass a GtkToggleButton can only contain one widget at a time; it already contains a widget of type GtkLabel (cheese:11454): Gtk-WARNING **: Attempting to add a widget with type GtkImage to a GtkToggleButton, but as a GtkBin subclass a GtkToggleButton can only contain one widget at a time; it already contains a widget of type GtkLabel (cheese:11454): Gtk-WARNING **: Attempting to add a widget with type GtkHBox to a GtkButton, but as a GtkBin subclass a GtkButton can only contain one widget at a time; it already contains a widget of type GtkLabel (cheese:11454): Gtk-WARNING **: Attempting to add a widget with type GtkImage to a GtkButton, but as a GtkBin subclass a GtkButton can only contain one widget at a time; it already contains a widget of type GtkLabel (cheese:11454): Gtk-WARNING **: Attempting to add a widget with type GtkHBox to a GtkToggleButton, but as a GtkBin subclass a GtkToggleButton can only contain one widget at a time; it already contains a widget of type GtkLabel (cheese:11454): Gtk-WARNING **: Attempting to add a widget with type GtkImage to a GtkButton, but as a GtkBin subclass a GtkButton can only contain one widget at a time; it already contains a widget of type GtkLabel (cheese:11454): Gdk-WARNING **: The program 'cheese' received an X Window System error. This probably reflects a bug in the program. The error was 'BadDrawable (invalid Pixmap or Window parameter)'. (Details: serial 932 error_code 9 request_code 137 minor_code 9) (Note to programmers: normally, X errors are reported asynchronously; that is, you will receive the error a while after causing it. To debug your program, run it with the --sync command line option to change this behavior. You can then get a meaningful backtrace from your debugger if you break on the gdk_x_error() function.)

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• Business Analytics Oracle Partner Advisory Council 2013

  - by Mike.Hallett(at)Oracle-BI&EPM

  72 544x376 WHEN: Friday the 20th of September 2013 (just before OpenWorld) Register by: 1st of August 2013 WHERE: Sofitel San Francisco Bay 223 Twin Dolphin Drive, 94065 REDWOOD CITY, CA, USA Don’t miss this once a year opportunity to meet and drive a closer engagement with Oracle’s global Product Management Team: Oracle global Product Management will host this workshop. Target group: ACE Directors, Lead Consultants and key architects from our partners Topics: Product Development Roadmap, Partner project experience, your feedback, Q&A session For any inquiries please contact [email protected] As part of registering for the event, please note that you will need to complete the BI / EPM PAC-survey. Thank you for taking the time to provide this, your valuable input. The PAC (one for BI, and a separate track for Hyperion) is free of charge, but is only for OPN Specialised member partners, and is subject to availability. (Please do not attend unless you have received a confirmation from Oracle to do so.) Registration Link Coming Soon We do hope you will be able to join us - and I look forward to welcoming you in San Francisco. Normal 0 false false false EN-GB X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

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• What's about Java?

  - by Silviu Turuga

  What is Java? In very short words, Java is a programming language that let you make an application that can be run on different operating systems, no matter we are talking about Windows, Mac OS, Linux or even embedded devices, such as RaspberryPi. When you compile a Java program, instead of getting a binary output as you get on other programming languages, you'll get a Java intermediate code, called Java bytecode. This is interpreted at run time, by a virtual machine that is specifically for the hardware and operating system you are using. What Java do i need? There are 5 major versions of Java: Java SE(Standard Edition) - this is what I'll use on most of my tutorials. Most of the examples will run on Java 6, but for others you'll need Java 7. Java EE (Enterprise Edition) - used for enterprise development Java ME (Micro Edition) - for running Java on mobile and different embedded devices such as PDAs, TV set-top boxes, printers, etc. Java Embedded - for some embedded devices such as Raspberry Pi, where the resources are limited JavaFX - to develop rich content User Interfaces. This is also something that will use a lot. More detailed information can be found on Oracle's website If you just want to run java applications you'll need the JRE (Java Runtime Environment) installed. If you want to program and create new applications, then you'll need the JDK (Java Development Kit).  How to check if Java is already installed? From command line, if you are on Windows, or from Terminal on Mac enter the following: java -version You should get something like this, if you have java installed on your system: java version "1.6.0_37" Java(TM) SE Runtime Environment (build 1.6.0_37-b06-434-11M3909) Java HotSpot(TM) 64-Bit Server VM (build 20.12-b01-434, mixed mode) Note: your current Java version might be different from mine. More information https://www.java.com/en/download/faq/whatis_java.xml http://en.wikipedia.org/wiki/Java_(programming_language) Next steps Install Java SDK Chose an IDE. I recommend NetBeans as it is very easy to use and also let you quickly create the GUI of your application Alternatives are Eclipse, Komodo Edit (for Mac), etc. There are plenty of solutions both free or paid. Resources on web Oracle Tutorials - lot of tutorials and useful resources JavaRanch - forum about java

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• How to get around the Circular Reference issue with JSON and Entity

  - by DanScan

  I have been experimenting with creating a website that leverages MVC with JSON for my presentation layer and Entity framework for data model/database. My Issue comes into play with serializing my Model objects into JSON. I am using the code first method to create my database. When doing the code first method a one to many relationship (parent/child) requires the child to have a reference back to the parent. (Example code my be a typo but you get the picture) class parent { public List<child> Children{get;set;} public int Id{get;set;} } class child { public int ParentId{get;set;} [ForeignKey("ParentId")] public parent MyParent{get;set;} public string name{get;set;} } When returning a "parent" object via a JsonResult a circular reference error is thrown because "child" has a property of class parent. I have tried the ScriptIgnore attribute but I lose the ability to look at the child objects. I will need to display information in a parent child view at some point. I have tried to make base classes for both parent and child that do not have a circular reference. Unfortunately when I attempt to send the baseParent and baseChild these are read by the JSON Parser as their derived classes (I am pretty sure this concept is escaping me). Base.baseParent basep = (Base.baseParent)parent; return Json(basep, JsonRequestBehavior.AllowGet); The one solution I have come up with is to create "View" Models. I create simple versions of the database models that do not include the reference to the parent class. These view models each have method to return the Database Version and a constructor that takes the database model as a parameter (viewmodel.name = databasemodel.name). This method seems forced although it works. NOTE:I am posting here because I think this is more discussion worthy. I could leverage a different design pattern to over come this issue or it could be as simple as using a different attribute on my model. In my searching I have not seen a good method to overcome this problem. My end goal would be to have a nice MVC application that heavily leverages JSON for communicating with the server and displaying data. While maintaining a consistant model across layers (or as best as I can come up with).

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• What does path finding in internet routing do and how is it different from A*?

  - by alan2here

  Note: If you don't understand this question then feel free to ask clarification in the comments instead of voting down, it might be that this question needs some more work at the moment. I've been directed here from the Stack Excange chat room Root Access because my question didn't fit on Super User. In many aspects path finding algorithms like A star are very similar to internet routing. For example: A node in an A* path finding system can search for a path though edges between other nodes. A router that's part of the internet can search for a route though cables between other routers. In the case of A*, open and closed lists are kept by the system as a whole, sepratly from any individual node as well as each node being able to temporarily store a state involving several numbers. Routers on the internet seem to have remarkable properties, as I understand it: They are very performant. New nodes can be added at any time that use a free address from a finite (not tree like) address space. It's real routing, like A*, there's never any doubling back for example. Similar IP addresses don't have to be geographically nearby. The network reacts quickly to changes to the networks shape, for example if a line is down. Routers share information and it takes time for new IP's to be registered everywhere, but presumably every router doesn't have to store a list of all the addresses each of it's directions leads most directly to. I'm looking for a basic, general, high level description of the algorithms workings from the point of view of an individual router. Does anyone have one? I presume public internet routers don't use A* as the overheads would be to large, and scale to poorly. I also presume there is a single method worldwide because it seems as if must involve a lot of transferring data to update and communicate a reasonable amount of state between neighboring routers. For example, perhaps the amount of data that needs to be stored in each router scales logarithmically with the number of routers that exist worldwide, the detail and reliability of the routing is reduced over increasing distances, there is increasing backtracking involved in parts of the network that are less geographically uniform or maybe each router really does perform an A* style search, temporarily maintaining open and closed lists when a packet arrives.

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• Best Practices for High Volume CPA Import Operations with ebXML in B2B 11g

  - by Shub Lahiri, A-Team

  Background B2B 11g supports ebXML messaging protocol, where multiple CPAs can be imported via command-line utilities.  This note highlights one aspect of the best practices for import of CPA, when large numbers of CPAs in the excess of several hundreds are required to be maintained within the B2B repository. Symptoms The import of CPA usually is a 2-step process, namely creating a soa.zip file using b2bcpaimport utility based on a CPA properties file and then using b2bimport to import the b2b repository.  The commands are provided below: ant -f ant-b2b-util.xml b2bcpaimport -Dpropfile="<Path to cpp_cpa.properties>" -Dstandard=true ant -f ant-b2b-util.xml b2bimport -Dlocalfile=true -Dexportfile="<Path to soa.zip>" -Doverwrite=true Usually the first command completes fairly quickly regardless of the number of CPAs in the repository. However, as the number of trading partners within the repository goes up, the time to complete the second command could go up to ~30 secs per operation. So, this could add up to a significant amount, if there is a need to import hundreds of CPA in a production system within a limited downtime, maintenance window.  Remedy In situations, where there is a large number of entries to be imported, it is best to setup a staging environment and go through the import operation of each individual CPA in an empty repository. Since, this will be done in an empty repository, the time taken for completion should be reasonable.  After all the partner profiles have been imported, a full repository export can be taken to capture the metadata for all the entries in one file.  If this single file with all the partner entries is imported in a loaded repository, the total time taken for import of all the CPAs should see a dramatic reduction. Results Let us take a look at the numbers to see the benefit of this approach. With a pre-loaded repository of ~400 partners, the individual import time for each entry takes ~30 secs. So, if we had to import another 100 partners, the individual entries will take ~50 minutes (100 times ~30 secs). On the other hand, if we prepare the repository export file of the same 100 partners from a staging environment earlier, the import takes about ~5 mins. The total processing time for the loading of metadata, specially in a production environment, can thus be shortened by almost a factor of 10. Summary The following diagram summarizes the entire approach and process. Acknowledgements The material posted here has been compiled with the help from B2B Engineering and Product Management teams.

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• What actions does Ubuntu trigger when battery is low?

  - by blueyed

  When the battery is low, the screen gets dimmed after a few seconds already. This appears to be some special power-saving mode, and might be related to the time in org.gnome.settings-daemon.plugins.power.time-low (1200 seconds (20 minutes) the default). While this seems to get triggered by gnome-settings-daemon, I wonder what else Ubuntu does when this happens (e.g. via DBus listeners), or other event listeners that look for a "low battery" state. It seems like something in this regard causes Ubuntu / X / the system to behave more sluggish afterwards (when the laptop is on AC again), and I would like to look into what might be causing this. I could not find anything related via dconf-editor, e.g. in org.gnome.settings-daemon.plugins.power. It appears to get setup via idle_configure in plugins/power/gsd-power-manager.c, but it's probably something more related to something that listens on the DBus interface, which gets notified via e.g.: if (!g_dbus_connection_emit_signal (manager->priv->connection, NULL, GSD_POWER_DBUS_PATH, "org.freedesktop.DBus.Properties", "PropertiesChanged", props_changed, &error)) I could imagine that some "power saving" property gets set, but not unset when AC is available anymore and/or the battery is not low anymore. I have looked at the CPU governor setting (/sys/devices/system/cpu/cpu*/cpufreq/scaling_governor), but it was ondemand. I am using gnome-settings-daemon with awesomeWM on Ubuntu 14.04. gnome-settings-daemon=3.8.6.1-0ubuntu11.1 I've also compared gsd's plugins/power/gsd-power-manager.c with the one from Debian's gnome-settings-daemon-3.12.1, but could not find anything obvious that might have been fixed/changed in this regard. I have managed to trigger the gnome-power-manager's gnome-settings plugin (which dims the screen etc), by patching upower and use it after killing the system's upower daemon. (note that it's probably only energy that is being used by gpm to calculate it by itself). It does not make the system become sluggish.. OTOH I have not heard the speaker's beeping, which might come from the BIOS, which might be involved here, too - or other programs using the kernel's interface on /sys/class/power_supply/BAT0/. --- src/linux/up-device-supply.c.orig 2014-06-07 16:48:32.735920661 +0200 +++ src/linux/up-device-supply.c 2014-06-07 16:48:39.391920525 +0200 @@ -821,6 +821,9 @@ supply->priv->energy_old_first = 0; } + percentage = 3.1f; + time_to_empty = 3*60; + energy = 5; g_object_set (device, "energy", energy, "energy-full", energy_full,

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• How to Update Remote Diagnostic Agent (RDA) to Latest Version?

  - by Daniel Mortimer

  Remote Diagnostic Agent (RDA) 4.28 was released on 12th June. Full details can be found in this My Oracle Support documentRDA 4 Release Notes [ID 414970.1]From a Fusion Middleware Core Component, Install and Administration perspective this latest release does not offer any significant new features or changes. However, despite the lack of Fusion Middleware specific new features in version 4.28, Remote Diagnostic Agent still comes as highly recommended. It is incredibly useful problem solving / troubleshooting aid. Support engineers dealing with Service Requests often request RDA output as it collects just about everything you might need to get a view of the state and configuration of the host operating system, network setup and Fusion Middleware components. To find out more take a look at Running RDA Against Oracle Fusion Middleware 11g [ID 853437.1] Getting Started With Remote Diagnostic Agent: Case Study - Oracle WebLogic Server (Video) [ID 1262157.1] Note: While the latter document looks at RDA from the perspective of WebLogic Server, much of the advice given in the videos can be applied to other Fusion Middleware products.Ok, let's get back on track with the topic suggested by the title. If you are already familiar with Remote Diagnostic Agent you may ask the question - 'How do I keep my RDA at the latest version?' The answer is in "Running RDA Against Oracle Fusion Middleware 11g [ID 853437.1]". To quote: There are two methods: 1. Upgrade RDA via OCM (Oracle Configuration Manager) Refer to the advice given in: Remote Diagnostic Agent (RDA) Upgrade README [ID 1309034.1] OR 2. Manually download and upgrade to the latest version. To quote from Remote Diagnostic Agent (RDA) 4 - FAQ [ID 330363.1] +++++++++++++++++++++++++++++++++++++++++++++++++++++++ How do I upgrade my RDA 4.x installation from the prior release? The most simplest and reliable way to upgrade your RDA installation is delete or move your old installation to a new location. Then install the new release into the location you had the prior release installed. If you want to reuse you old setup.cfg file, you can place the older version into the new <rda> directory and it will try to upgrade your setup.cfg to the new features. A second approach is to install the latest RDA into another directory, then if needed copy the old setup.cfg file to the new RDA directory. When the new RDA is run for the first time, it will try to upgrade your setup.cfg to the new features. +++++++++++++++++++++++++++++++++++++++++++++++++++++++ The upgrade method via Oracle Configuration Manager is nice because it allows RDA to be auto updated whenever a new release of RDA is made available (which roughly speaking is every 3 months). However, it does require you to install and configure Oracle Configuration Manager in addition to RDA. A quick guide to Fusion Middleware 11g and OCM can be found in this support document.Configuring OCM in Oracle Fusion Middleware 11g? A Quick and Easy Guide [ID 1096871.1]

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• What to answer to a customer who asks which one of two equivalent technologies must be used?

  - by MainMa

  As a freelancer, I am often asked by my customers what they must choose between similar elements, neither of which being better than another. Examples: “Do I need my e-commerce website be in PHP or ASP.NET?” “Do I need to host this ordinary web service in Cloud or use an ordinary hosting service?” “Which one is better for my new website: MySQL or Oracle?” etc. There is maybe at most 1% of cases where the choice is relevant, and there is a real, objective reason to use one over another, based on the precise metrics and studies. In all other cases, it doesn't matter at all. It is totally, completely irrelevant, either because there are no implications¹, or because those implications are too small to be taken in account², or, finally, because it's impossible to predict those implications³. If you know one thing and not another one, the answer to those questions is easy: “You can either write the application in C# or Java, both being probably equivalent in your case. Note that I'm a C# developer, so if you choose Java, I would not be able to work on your project and you would need to find another freelancer.” When you know both technologies, you can't answer that. In this case, how to explain to the customer that the question he asks is subject to flamewar and has no real consequences on his project? In other words, how to explain that you've chosen to use one technology rather than an equivalent one for the reasons related to human resources, without giving the impression to be unprofessional or to not care about the project? ¹ Example: Is MySQL better (worse?), performance-wise, compared to Oracle, for a personal website which will be accessed by, oh, let's be optimistic, two people per day? ² Example: for a given project, I was asked to asset if Windows Azure hosting would be cheaper than the hosting of the same application on a well-known ASP.NET hosting provider. The cost revealed to be exactly the same. ³ Example: your customer have an idea of a future application (the idea itself being extremely vague). There is no business plan, no requirements, nothing at all. Just an idea. You are asked if Java is better than C# for this app. What do you answer?

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• Update in Certification Exam Score Report Access Process!

  - by Richard Lefebvre

  Please note that exam results for all Oracle Certification exams will be accessed through CertView, starting October 30th, 2012. Exam results will no longer be available at the test center, or on the Pearson VUE website. Candidates will receive an email from Oracle within 30 minutes of completing the exam to let them know that their exam results are available on CertView. Candidates must have an Oracle Web Account to access CertView. This new process applies to exam results for all Oracle Certification exams - proctored and non-proctored as well beta exams. CertView, Oracle's self-service certification portal will be the partners’ one stop source for all their certification and exam history! Other benefits of this change include: driving all candidates to have an Oracle Web Account which will lead to tighter integration with Oracle University records in the future, increased security around data privacy and a higher validity rate for candidate email addresses. Existing benefits of CertView include, self-service access to exam and certification records and logos, and access to Oracle's self service certification verification. Accessing Exam Results  Returning CertView Users ·         Click the link in the email sent by Oracle or go to certview.oracle.com ·         Select the See My New Exam Results Now link to view exam results ·         Select the Print My New Exam Results Now link to print exam results  New CertView Users - Who Have An Oracle Web Account ·         First time Users must authenticate their CertView account ·         Account Authentication requires the Oracle Testing ID and email address from your Pearson VUE profile ·         Click the link in the email sent by Oracle or go to certview.oracle.com and follow the Authenticate My CertView Account link.  New CertView Users - Who Do Not Have An Oracle Web Account ·         CertView users are required to have an Oracle Web Account ·         To create an Oracle Web Account, go to certview.oracle.com and select theCreate My Oracle Web Account Now link. Then follow the remaining instructions under I do not have an Oracle Web Account on that page.

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• Is OOP hard because it is not natural?

  - by zvrba

  One can often hear that OOP naturally corresponds to the way people think about the world. But I would strongly disagree with this statement: We (or at least I) conceptualize the world in terms of relationships between things we encounter, but the focus of OOP is designing individual classes and their hierarchies. Note that, in everyday life, relationships and actions exist mostly between objects that would have been instances of unrelated classes in OOP. Examples of such relationships are: "my screen is on top of the table"; "I (a human being) am sitting on a chair"; "a car is on the road"; "I am typing on the keyboard"; "the coffee machine boils water", "the text is shown in the terminal window." We think in terms of bivalent (sometimes trivalent, as, for example in, "I gave you flowers") verbs where the verb is the action (relation) that operates on two objects to produce some result/action. The focus is on action, and the two (or three) [grammatical] objects have equal importance. Contrast that with OOP where you first have to find one object (noun) and tell it to perform some action on another object. The way of thinking is shifted from actions/verbs operating on nouns to nouns operating on nouns -- it is as if everything is being said in passive or reflexive voice, e.g., "the text is being shown by the terminal window". Or maybe "the text draws itself on the terminal window". Not only is the focus shifted to nouns, but one of the nouns (let's call it grammatical subject) is given higher "importance" than the other (grammatical object). Thus one must decide whether one will say terminalWindow.show(someText) or someText.show(terminalWindow). But why burden people with such trivial decisions with no operational consequences when one really means show(terminalWindow, someText)? [Consequences are operationally insignificant -- in both cases the text is shown on the terminal window -- but can be very serious in the design of class hierarchies and a "wrong" choice can lead to convoluted and hard to maintain code.] I would therefore argue that the mainstream way of doing OOP (class-based, single-dispatch) is hard because it IS UNNATURAL and does not correspond to how humans think about the world. Generic methods from CLOS are closer to my way of thinking, but, alas, this is not widespread approach. Given these problems, how/why did it happen that the currently mainstream way of doing OOP became so popular? And what, if anything, can be done to dethrone it?

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• Big-name School for Undergrad Students

  - by itaiferber

  As a soon-to-be graduating high school senior in the U.S., I'm going to be facing a tough decision in a few months: which college should I go to? Will it be worth it to go to Cornell or Stanford or Carnegie Mellon (assuming I get in, of course) to get a big-name computer science degree, internships, and connections with professors, while taking on massive debt; or am I better off going to SUNY Binghamton (probably the best state school in New York) and still get a pretty decent education while saving myself from over a hundred-thousand dollars worth of debt? Yes, I know questions like this has been asked before (namely here and here), but please bear with me because I haven't found an answer that fits my particular situation. I've read the two linked questions above in depth, but they haven't answered what I want to know: Yes, I understand that going to a big-name college can potentially get me connected with some wonderful professors and leaders in the field, but on average, how does that translate financially? I mean, will good connections pay off so well that I'd be easily getting rid of over a hundred-thousand dollars of debt? And how does the fact that I can get a fifth-years master's degree at Carnegie Mellon play into the equation? Will the higher degree right off the bat help me get a better-paying job just out of college, or will the extra year only put me further into debt? Not having to go to graduate school to get a comparable degree will, of course, be a great financial relief, but will getting it so early give it any greater worth? And if I go to SUNY Binghamton, which is far lesser-known than what I've considered (although if there are any alumni out there who want to share their experience, I would greatly appreciate it), would I be closing off doors that would potentially offset my short-term economic gain with long-term benefits? Essentially, is the short-term benefit overweighed by a potential long-term loss? The answers to these questions all tie in to my final college decision (again, permitting I make it to these schools), so I hope that asking the skilled and knowledgeable people of the field will help me make the right choice (if there is such a thing). Also, please note: I'm in a rather peculiar situation where I can't pay for college without taking out a bunch of loans, but will be getting little to no financial aid (likely federal or otherwise). I don't want to elaborate on this too much (so take it at face value), but this is mainly the reason I'm asking the question. Thanks a lot! It means a lot to me.

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• How to get lookahead symbol when constructing LR(1) NFA for parser?

  - by greenoldman

  I am reading an explanation (awesome "Parsing Techniques" by D.Grune and C.J.H.Jacobs; p.292 in the 2nd edition) about how to construct an LR(1) parser, and I am at the stage of building the initial NFA. What I don't understand is how to get/compute a lookahead symbol. Here is the example from the book, the grammar: S -> E E -> E - T E -> T T -> ( E ) T -> n n is terminal. The "weird" transitions for me are is the sequence: 1) S -> . E eof 2) E -> . E - T eof 3) E -> . E - T - 4) E -> E . - T - 5) E -> E - . T - (Note: In the above table, the state numbers are in front and the lookahead symbol is at the end.) What puzzles me is that transition from (4) to (5) means reading - token, right? So how is it that - is still a lookahead symbol and even more important why is it that eof is no longer a lookahead symbol? After all in an input such as n - n eof there is only one - symbol. My naive thinking tells me (5) should be written as: 5) E -> E - . T - eof And another thing -- n is terminal. Why it is not used at all as a lookahead symbol? I mean -- we expect to see - or (, it is ok, but lack of n means we are sure it won't appear in input? Update: after more reading I am only more confused ;-) I.e. what is really a lookahead? Because I see such state as (p.292, 2nd column, 2nd row): E -> E . - T eof Lookahead says eof but the incoming input says -. Isn't it a contradiction? And it is not only in this book.

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