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• Layout of mathematical views (iOS)

  - by William Jockusch

  I am trying to figure out the right way to encapsulate graphical information about mathematical objects. It is not simple. For example, a matrix can include square brackets around its entries, or not. Some things carry down to sub-objects -- for example, a matrix might track the font size to be used by its entries. Similarly, the font color and the background color would carry down to the entries. Other things do not carry down. For example, the entries of the matrix do not need to know whether or not the matrix has those square brackets. Based on all of the above, I need to calculate sizes for everything, then frames. All of this can depend on the properties stored above. The size of a matrix depends on the sizes of its entries, and also on whether or not it has those brackets. What I am having a hard time with is not the individual ways to calculate sensible frames for this or that. It is the overall organizational structure of the whole thing. How can I keep track of it all without going crazy. One particular obstacle is worth mentioning -- for reasons I don't want to go into here, I need to calculate the sizes and frames for everything before I instantiate any actual views. So, for example, if I have a Matrix object, I need to calculate its size before I make a MatrixView. If I have an equation, I need to calculate the size of the view for the equation before I create the actual view. So I clearly need separate objects for those calculations. But I can't figure out a sensible class structure for those objects. If I put them all into a single class, I get some advantages because copying then becomes easy. But I also end up with a bloated class that contains info that is irrelevant for some objects -- such as whether or not to include those brackets around the matrix. But if I use a lot of different classes, copying properties becomes a real pain. If it matters, this is all in Objective C, for an iOS environment. Any pointers would be greatly appreciated.

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• Any ideas on reducing lag in terrain generation?

  - by l5p4ngl312

  Ok so here's the deal. I've written an isometric engine that generates terrain based on camera values using 2D perlin noise. I planned on doing 3D but first I need to work out the lag issues I'm having. I will try to explain how I am doing this so that maybe someone can spot where I am going wrong. I know it should not be this laggy. There is the abstract class Block which right now just contains render(). BlockGrass, etc. extend this class and each has code in the render function to create a textured quad at the given position. Then there is the class Chunk which has the function Generate() and setBlocksInArea(). Generate uses 2D perlin noise to make a height map and stores the heights in a 2D array. It stores the positions of each block it generates in blockarray[x][y][z]. The chunks are 8x8x128. In the main game class there is a 3D array called blocksInArea. The blocks in this array are what gets rendered. When a chunk generates, it adds its blocks to this array at the correct index. It is like this so chunks can be saved to the hard drive (even though they aren't yet) but there can still be optimization with the rendering that you wouldn't have if you rendered each chunk separately. Here's where the laggy part comes in: When the camera moves to a new chunk, a row of chunks generates on the end of the axis that the camera moved on. But it still has to move the other chunks up/down in the blocksInArea (render) array. It does this by calculating the new position in the array and doing the Chunk.setBlocksInArea(): for(int x = 0; x < 8; x++){ for(int y = 0; y < 8; y++){ nx = x+(coordX - camCoordX)*8 ny = y+(coordY - camCoordY)*8 for(int z = 0; z < height[x][y]; z++){ blockarray[x][y][z] = Game.blocksInArea[nx][ny][z]; } } } My reasoning was that this would be much faster than doing the perlin noise all over again, but there are still little spikes of lag when you move in between chunks. Edit: Would it be possible to create a 3 dimensional array list so that shifting of chunks within the array would not be neccessary?

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• 6 Ways to Modernize Your Customer Experience

  - by Mike Stiles

  If customers have changed, if the way they research and shop have changed, if their expectations have changed, if their ability to act on dissatisfaction has changed, but your customer experience has NOT changed, what was once “good enough” may now be crippling. Well, the customer has changed, and why wouldn’t they? You’ve probably changed too in your role as consumer. There’s more info available, it’s easier to get, there’s more choice, you’re more mobile, you’re more connected, it’s easier to buy, and yes, it’s easier to switch brands if experiences don’t meet your now higher expectations. Thanks to technological advances, we as marketers can increasingly work borderline miracles. But if we’re still not adamantly adopting customer centricity, and if we aren’t making the customer experience paramount amongst business goals, the tech is wasted. A far more modern customer experience is called for. Here are 6 ways to get there: 1. Modern Marketing: Marketing data is aggregated and targeted to the right customers, who are getting personal, relevant communications. In return, you’re getting insight that finally properly attributes revenue to your marketing efforts. 2. Modern Selling: Demand is being driven across all channels with modern selling tools. Productivity is up thanks to coordinated communication and selling, and performance is ever optimized using powerful analytics. 3. Modern CPQ: You’re cross-selling and upselling more effectively since reps and channel partners have been empowered with the ability to quickly, automatically generate 100% accurate, customer-friendly quotes complete with price controls and automated approvals. 4. Modern Commerce: You’re leveraging data and delivering personalized, targeted digital experiences to everyone. You’re attracting more visitors, and you’re able to scale and keep up with the market and control the experience. 5. Modern Service: You’re better serving your customers by making it easier for them to engage with your brand, plus you’re lowering your costs by increasing agent and tech support efficiencies. 6. Modern Social: You’re getting faster, deeper, more accurate insights from social and turning content around faster, which then goes out to the right people at the right time in the right place. You’ve also gotten proactive in your service, and customers love that. For far too many brands, the buying journey of Need, Research, Select, Buy, Use, Recommend across the multiple connect points of Social, Mobile, Store, Call Center, Site, Ecommerce is a disconnected mess. Oracle’s approach to CX is to connect every interaction your customer has with your brand, avoiding the revenue losses lousy customer experiences bring. How important is the experience to customers? 94% are willing to pay more of their hard-earned money to have better ones, while a meager 1% say they get the good, consistent experiences they expect. Brands, your words aren’t as loud anymore, so your actions as they relate to customer experience are going to have to do the talking. @mikestiles @oraclesocialPhoto: Julien Tromeur, freeimages.com

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• Give a session on C++ AMP – here is how

  - by Daniel Moth

  Ever since presenting on C++ AMP at the AMD Fusion conference in June, then the Gamefest conference in August, and the BUILD conference in September, I've had numerous requests about my material from folks that want to re-deliver the same session. The C++ AMP session I put together has evolved over the 3 presentations to its final form that I used at BUILD, so that is the one I recommend you base yours on. Please get the slides and the recording from channel9 (I'll refer to slide numbers below). This is how I've been presenting the C++ AMP session: Context (slide 3, 04:18-08:18) Start with a demo, on my dual-GPU machine. I've been using the N-Body sample (for VS 11 Developer Preview). (slide 4) Use an nvidia slide that has additional examples of performance improvements that customers enjoy with heterogeneous computing. (slide 5) Talk a bit about the differences today between CPU and GPU hardware, leading to the fact that these will continue to co-exist and that GPUs are great for data parallel algorithms, but not much else today. One is a jack of all trades and the other is a number cruncher. (slide 6) Use the APU example from amd, as one indication that the hardware space is still in motion, emphasizing that the C++ AMP solution is a data parallel API, not a GPU API. It has a future proof design for hardware we have yet to see. (slide 7) Provide more meta-data, as blogged about when I first introduced C++ AMP. Code (slide 9-11) Introduce C++ AMP coding with a simplistic array-addition algorithm – the slides speak for themselves. (slide 12-13) index<N>, extent<N>, and grid<N>. (Slide 14-16) array<T,N>, array_view<T,N> and comparison between them. (Slide 17) parallel_for_each. (slide 18, 21) restrict. (slide 19-20) actual restrictions of restrict(direct3d) – the slides speak for themselves. (slide 22) bring it altogether with a matrix multiplication example. (slide 23-24) accelerator, and accelerator_view. (slide 26-29) Introduce tiling incl. tiled matrix multiplication [tiling probably deserves a whole session instead of 6 minutes!]. IDE (slide 34,37) Briefly touch on the concurrency visualizer. It supports GPU profiling, but enhancements specific to C++ AMP we hope will come at the Beta timeframe, which is when I'll be spending more time talking about it. (slide 35-36, 51:54-59:16) Demonstrate the GPU debugging experience in VS 11. Summary (slide 39) Re-iterate some of the points of slide 7, and add the point that the C++ AMP spec will be open for other compiler vendors to implement, even on other platforms (in fact, Microsoft is actively working on that). (slide 40) Links to content – see slide – including where all your questions should go: http://social.msdn.microsoft.com/Forums/en/parallelcppnative/threads.   "But I don't have time for a full blown session, I only need 2 (or just 1, or 3) C++ AMP slides to use in my session on related topic X" If all you want is a small number of slides, you can take some from the session above and customize them. But because I am so nice, I have created some slides for you, including talking points in the notes section. Download them here. Comments about this post by Daniel Moth welcome at the original blog.

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• SQL: empty string vs NULL value

  - by Jacek Prucia

  I know this subject is a bit controversial and there are a lot of various articles/opinions floating around the internet. Unfortunatelly, most of them assume the person doesn't know what the difference between NULL and empty string is. So they tell stories about surprising results with joins/aggregates and generally do a bit more advanced SQL lessons. By doing this, they absolutely miss the whole point and are therefore useless for me. So hopefully this question and all answers will move subject a bit forward. Let's suppose I have a table with personal information (name, birth, etc) where one of the columns is an email address with varchar type. We assume that for some reason some people might not want to provide an email address. When inserting such data (without email) into the table, there are two available choices: set cell to NULL or set it to empty string (''). Let's assume that I'm aware of all the technical implications of choosing one solution over another and I can create correct SQL queries for either scenario. The problem is even when both values differ on the technical level, they are exactly the same on logical level. After looking at NULL and '' I came to a single conclusion: I don't know email address of the guy. Also no matter how hard i tried, I was not able to sent an e-mail using either NULL or empty string, so apparently most SMTP servers out there agree with my logic. So i tend to use NULL where i don't know the value and consider empty string a bad thing. After some intense discussions with colleagues i came with two questions: am I right in assuming that using empty string for an unknown value is causing a database to "lie" about the facts? To be more precise: using SQL's idea of what is value and what is not, I might come to conclusion: we have e-mail address, just by finding out it is not null. But then later on, when trying to send e-mail I'll come to contradictory conclusion: no, we don't have e-mail address, that @!#$ Database must have been lying! Is there any logical scenario in which an empty string '' could be such a good carrier of important information (besides value and no value), which would be troublesome/inefficient to store by any other way (like additional column). I've seen many posts claiming that sometimes it's good to use empty string along with real values and NULLs, but so far haven't seen a scenario that would be logical (in terms of SQL/DB design). P.S. Some people will be tempted to answer, that it is just a matter of personal taste. I don't agree. To me it is a design decision with important consequences. So i'd like to see answers where opion about this is backed by some logical and/or technical reasons.

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• How do you handle objects that need custom behavior, and need to exist as an entity in the database?

  - by Scott Whitlock

  For a simple example, assume your application sends out notifications to users when various events happen. So in the database I might have the following tables: TABLE Event EventId uniqueidentifier EventName varchar TABLE User UserId uniqueidentifier Name varchar TABLE EventSubscription EventUserId EventId UserId The events themselves are generated by the program. So there are hard-coded points in the application where an event instance is generated, and it needs to notify all the subscribed users. So, the application itself doesn't edit the Event table, except during initial installation, and during an update where a new Event might be created. At some point, when an event is generated, the application needs to lookup the Event and get a list of Users. What's the best way to link the event in the source code to the event in the database? Option 1: Store the EventName in the program as a fixed constant, and look it up by name. Option 2: Store the EventId in the program as a static Guid, and look it up by ID. Extra Credit In other similar circumstances I may want to include custom behavior with the event type. That is, I'll want subclasses of my Event entity class with different behaviors, and when I lookup an event, I want it to return an instance of my subclass. For instance: class Event { public Guid Id { get; } public Guid EventName { get; } public ReadOnlyCollection<EventSubscription> EventSubscriptions { get; } public void NotifySubscribers() { foreach(var eventSubscription in EventSubscriptions) { eventSubscription.Notify(); } this.OnSubscribersNotified(); } public virtual void OnSubscribersNotified() {} } class WakingEvent : Event { private readonly IWaker waker; public WakingEvent(IWaker waker) { if(waker == null) throw new ArgumentNullException("waker"); this.waker = waker; } public override void OnSubscribersNotified() { this.waker.Wake(); base.OnSubscribersNotified(); } } So, that means I need to map WakingEvent to whatever key I'm using to look it up in the database. Let's say that's the EventId. Where do I store this relationship? Does it go in the event repository class? Should the WakingEvent know declare its own ID in a static member or method? ...and then, is this all backwards? If all events have a subclass, then instead of retrieving events by ID, should I be asking my repository for the WakingEvent like this: public T GetEvent<T>() where T : Event { ... // what goes here? ... } I can't be the first one to tackle this. What's the best practice?

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• Using HBase or Cassandra for a token server

  - by crippy

  I've been trying to figure out how to use HBase/Cassandra for a token system we're re-implementing. I can probably squeeze quite a lot more from MySQL, but it just seems it has come to clinging on to the wrong tool for the task just because we know it well. Eventually will hit a wall (like happened to us in other areas). Naturally I started looking into possible NoSQL solutions. The prominent ones (at least in terms of buzz) are HBase and Cassandra. The story is more or less like this: A user can send a gift other users. Each gift has a list of recipients or is public in which case limited by number or expiration date For each gift sent we generate some token that uniquely identifies that gift. For each gift we track the list of potential recipients and their current status relating to that gift (accepted, declinded etc). A user can request to see all his currently pending gifts A can request a list of users he has sent a gift to today (used to limit number of gifts sent) Required the ability to "dump" or "ignore" expired gifts (x day old gifts are considered expired) There are some other requirements but I believe the above covers the essentials. How would I go and model that using HBase or Cassandra? Well, the wall was performance. A few 10s of millions of records per day over 2 tables kept for 2 weeks (wish I could have kept it for more but there was no way). The response times kept getting slower and slower until eventually we had to start cutting down number of days we kept data. Caching helps here but it's not an ideal solution since a big part of the ops are updates. Also, as I hinted in my original post. We use MySQL extensively. We know exactly what it can and can't do both in naive implementations followed by native partitioning and finally by horizontally sharding our dataset on the application level to reside on multiple DB nodes. It can be done, but that's not really what I'm trying to get from this. I asked a very specific question about designing a solution using a NoSQL solution since it's very hard to find examples for designs out there. Brainlag, not trying to come off as rude. I actually appreciate it a lot that you are the only one who even bothered to respond. but I see it over and over again. People ask questions and others assume they have no idea what they're talking about and give an irrelevant answer. Ignore RDBMS please. The question is about nosql.

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• iwlwifi on lenovo z570 disabled by hardware switch

  - by Kevin Gallagher

  It was working fine with windows 7. The hardware switch is not disabled. I've toggled it back and forth dozens of times. The wifi light never turns on and it always lists as hardware disabled. I have the latest updates installed. I've been searching for solutions, but none of them seem to work for me. I've tried removing acer-wmi. I've tried setting 11n_disable=1. I've tried resetting the bios. I've tried using rfkill to unblock (only removes soft block). I've rebooted dozens of times. The wifi light turns off as soon as grub loads. Edit: I have a usb edimax wireless nic. It shows hardware disabled as well (although rfkill lists as unblocked). If I unload iwlwifi the usb nic works fine. uname -a `Linux xxx-Ideapad-Z570 3.2.0-55-generic #85-Ubuntu SMP Wed Oct 2 12:29:27 UTC 2013 x86_64 x86_64 x86_64 GNU/Linu`x rfkill list 19: phy18: Wireless LAN Soft blocked: no Hard blocked: yes dmesg [43463.022996] Intel(R) Wireless WiFi Link AGN driver for Linux, in-tree: [43463.023002] Copyright(c) 2003-2011 Intel Corporation [43463.023107] iwlwifi 0000:03:00.0: PCI INT A -> GSI 17 (level, low) -> IRQ 17 [43463.023190] iwlwifi 0000:03:00.0: setting latency timer to 64 [43463.023253] iwlwifi 0000:03:00.0: pci_resource_len = 0x00002000 [43463.023257] iwlwifi 0000:03:00.0: pci_resource_base = ffffc900057c8000 [43463.023261] iwlwifi 0000:03:00.0: HW Revision ID = 0x0 [43463.023797] iwlwifi 0000:03:00.0: irq 43 for MSI/MSI-X [43463.024013] iwlwifi 0000:03:00.0: Detected Intel(R) Centrino(R) Wireless-N 1000 BGN, REV=0x6C [43463.024250] iwlwifi 0000:03:00.0: L1 Enabled; Disabling L0S [43463.045496] iwlwifi 0000:03:00.0: device EEPROM VER=0x15d, CALIB=0x6 [43463.045501] iwlwifi 0000:03:00.0: Device SKU: 0X50 [43463.045504] iwlwifi 0000:03:00.0: Valid Tx ant: 0X1, Valid Rx ant: 0X3 [43463.045542] iwlwifi 0000:03:00.0: Tunable channels: 13 802.11bg, 0 802.11a channels [43463.045744] iwlwifi 0000:03:00.0: RF_KILL bit toggled to disable radio. [43463.047652] iwlwifi 0000:03:00.0: loaded firmware version 39.31.5.1 build 35138 [43463.047823] Registered led device: phy18-led [43463.047895] cfg80211: Ignoring regulatory request Set by core since the driver uses its own custom regulatory domain [43463.048037] ieee80211 phy18: Selected rate control algorithm 'iwl-agn-rs' [43463.055533] ADDRCONF(NETDEV_UP): wlan0: link is not ready nm-tool State: connected (global) - Device: wlan0 ---------------------------------------------------------------- Type: 802.11 WiFi Driver: iwlwifi State: unavailable Default: no HW Address: 74:E5:0B:4A:9F:C2 Capabilities: Wireless Properties WEP Encryption: yes WPA Encryption: yes WPA2 Encryption: yes Wireless Access Points lshw -C network *-network DISABLED description: Wireless interface product: Centrino Wireless-N 1000 [Condor Peak] vendor: Intel Corporation physical id: 0 bus info: pci@0000:03:00.0 logical name: wlan0 version: 00 serial: 74:e5:0b:4a:9f:c2 width: 64 bits clock: 33MHz capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless configuration: broadcast=yes driver=iwlwifi driverversion=3.2.0-55-generic firmware=39.31.5.1 build 35138 latency=0 link=no multicast=yes wireless=IEEE 802.11bg resources: irq:43 memory:f1500000-f1501fff lspci 03:00.0 Network controller: Intel Corporation Centrino Wireless-N 1000 [Condor Peak]

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• Bullet Physics - Casting a ray straight down from a rigid body (first person camera)

  - by Hydrocity

  I've implemented a first person camera using Bullet--it's a rigid body with a capsule shape. I've only been using Bullet for a few days and physics engines are new to me. I use btRigidBody::setLinearVelocity() to move it and it collides perfectly with the world. The only problem is the Y-value moves freely, which I temporarily solved by setting the Y-value of the translation vector to zero before the body is moved. This works for all cases except when falling from a height. When the body drops off a tall object, you can still glide around since the translate vector's Y-value is being set to zero, until you stop moving and fall to the ground (the velocity is only set when moving). So to solve this I would like to try casting a ray down from the body to determine the Y-value of the world, and checking the difference between that value and the Y-value of the camera body, and disable or slow down movement if the difference is large enough. I'm a bit stuck on simply casting a ray and determining the Y-value of the world where it struck. I've implemented this callback: struct AllRayResultCallback : public btCollisionWorld::RayResultCallback{ AllRayResultCallback(const btVector3& rayFromWorld, const btVector3& rayToWorld) : m_rayFromWorld(rayFromWorld), m_rayToWorld(rayToWorld), m_closestHitFraction(1.0){} btVector3 m_rayFromWorld; btVector3 m_rayToWorld; btVector3 m_hitNormalWorld; btVector3 m_hitPointWorld; float m_closestHitFraction; virtual btScalar addSingleResult(btCollisionWorld::LocalRayResult& rayResult, bool normalInWorldSpace) { if(rayResult.m_hitFraction < m_closestHitFraction) m_closestHitFraction = rayResult.m_hitFraction; m_collisionObject = rayResult.m_collisionObject; if(normalInWorldSpace){ m_hitNormalWorld = rayResult.m_hitNormalLocal; } else{ m_hitNormalWorld = m_collisionObject->getWorldTransform().getBasis() * rayResult.m_hitNormalLocal; } m_hitPointWorld.setInterpolate3(m_rayFromWorld, m_rayToWorld, m_closestHitFraction); return 1.0f; } }; And in the movement function, I have this code: btVector3 from(pos.x, pos.y + 1000, pos.z); // pos is the camera's rigid body position btVector3 to(pos.x, 0, pos.z); // not sure if 0 is correct for Y AllRayResultCallback callback(from, to); Base::getSingletonPtr()->m_btWorld->rayTest(from, to, callback); So I have the callback.m_hitPointWorld vector, which seems to just show the position of the camera each frame. I've searched Google for examples of casting rays, as well as the Bullet documentation, and it's been hard to just find an example. An example is really all I need. Or perhaps there is some method in Bullet to keep the rigid body on the ground? I'm using Ogre3D as a rendering engine, and casting a ray down is quite straightforward with that, however I want to keep all the ray casting within Bullet for simplicity. Could anyone point me in the right direction? Thanks.

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• What do you do when practical problems get in the way of practical goals?

  - by P.Brian.Mackey

  UPDATE Source control is good to use. Sometimes, real world issues make it impractical to use. For example: If the team is not used to using source control, training problems can arise If a team member directly modifies code on the server, various issues can arise. Merge problems, lack of history, etc Let's say there's a project that is way out of sync. The physical files on the server differ in unknown ways over ~100 files. Merging would take not only a great knowledge of the project, but is also well beyond the ability to complete in the given time. Other projects are falling out of sync. Developers continue to have a distrust of source control and therefore compound the issue by not using source control. Developers argue that using source control is wasteful because merging is error prone and difficult. This is a difficult point to argue, because when source control is being so badly mis-used and source control continually bypassed, it is error prone indeed. Therefore, the evidence "speaks for itself" in their view. Developers argue that directly modifying source control saves time. This is also difficult to argue. Because the merge required to synchronize the code to start with is time consuming, across ~10 projects. Permanent files are often stored in the same directory as the web project. So publishing (full publish) erases these files that are not in source control. This also drives distrust for source control. Because "publishing breaks the project". Fixing this (moving stored files out of the solution subfolders) takes a great deal of time and debugging as these locations are not set in web.config and often exist across multiple code points. So, the culture persists itself. Bad practice begets more bad practice. Bad solutions drive new hacks to "fix" much deeper, much more time consuming problems. Servers, hard drive space are extremly difficult to come by. Yet, user expectations are rising. What can be done in this situation?

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• Why is multithreading often preferred for improving performance?

  - by user1849534

  I have a question, it's about why programmers seems to love concurrency and multi-threaded programs in general. I'm considering 2 main approaches here: an async approach basically based on signals, or just an async approach as called by many papers and languages like the new C# 5.0 for example, and a "companion thread" that manages the policy of your pipeline a concurrent approach or multi-threading approach I will just say that I'm thinking about the hardware here and the worst case scenario, and I have tested this 2 paradigms myself, the async paradigm is a winner at the point that I don't get why people 90% of the time talk about multi-threading when they want to speed up things or make a good use of their resources. I have tested multi-threaded programs and async program on an old machine with an Intel quad-core that doesn't offer a memory controller inside the CPU, the memory is managed entirely by the motherboard, well in this case performances are horrible with a multi-threaded application, even a relatively low number of threads like 3-4-5 can be a problem, the application is unresponsive and is just slow and unpleasant. A good async approach is, on the other hand, probably not faster but it's not worst either, my application just waits for the result and doesn't hangs, it's responsive and there is a much better scaling going on. I have also discovered that a context change in the threading world it's not that cheap in real world scenario, it's in fact quite expensive especially when you have more than 2 threads that need to cycle and swap among each other to be computed. On modern CPUs the situation it's not really that different, the memory controller it's integrated but my point is that an x86 CPUs is basically a serial machine and the memory controller works the same way as with the old machine with an external memory controller on the motherboard. The context switch is still a relevant cost in my application and the fact that the memory controller it's integrated or that the newer CPU have more than 2 core it's not bargain for me. For what i have experienced the concurrent approach is good in theory but not that good in practice, with the memory model imposed by the hardware, it's hard to make a good use of this paradigm, also it introduces a lot of issues ranging from the use of my data structures to the join of multiple threads. Also both paradigms do not offer any security abut when the task or the job will be done in a certain point in time, making them really similar from a functional point of view. According to the X86 memory model, why the majority of people suggest to use concurrency with C++ and not just an async approach ? Also why not considering the worst case scenario of a computer where the context switch is probably more expensive than the computation itself ?

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• Why should I not do a masters degree

  - by aurel

  I have left university on July 2010 where I studied web design (as we all know you learn more by your self but that’s not the issue at the moment). Since then I have not managed to find a job (apart from a one month work experience), from the way things are going, and by taking into account the fact that all my university friends are in the same situation, I don’t think that I am going to find a job soon (within the industry) Now as we all do, even though I don’t have a job, I am still working on personal projects and try to keep up to date (I don’t need a job or uni to do this) – but I am thinking, because there is not work available, would it be worth going back to uni for a master degree? I know I don’t need it and I know that is unlikely that I will learn anything important, as I believe in self learning, and in most cases it is a lot more effective (but I have to say I don’t mind going back to school) The only reason I am thinking of doing the master is, (and this is where I need your help): If it takes me a year to get a job, then on the interview, would the employer think “what the hell did this guy do since he left university” – now if I go to university that would solve this problem. Or I’m I making up a problem that does not exist Plus, I know that employers need examples of sites that I have been working on, at the moment I only have 3 (as when working on personal projects, where their is not time limit I tend drag things in order to get them perfect, and they never get perfect) – so by going back to uni, then this problem maybe solved I said all this as I have read a lot about the fact that you don’t need to have a masters degree to work on web design market (and I totally agree) but considering my concern, the question is should I do a masters course to avoid just spending hours in my room working and learning in my own (but that it would be hard to convince employers that I was really learning in my room) Maybe because I’m still young age 22 not that old anyway :), but I don’t have the “dream” of being rich, so if I were to tell the truth I don’t really care of the fact that I don’t have a job (at the moment), because regardless, I am working on what I love every day, but I know that in the future when I will need the job I may find it harder to get one, if I neglect doing so now Every time I ask a question that I’m not sure about, I keep going on and on, but I really hope you get what I am trying to get across. By the way the course that I am looking at for a masters says that it would teach me how to do these: e-commerce e-government e-science e-learning I don’t know any of them, a part from e-commerce Thanks

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• Learn Many Languages

  - by Jeff Foster

  My previous blog, Deliberate Practice, discussed the need for developers to “sharpen their pencil” continually, by setting aside time to learn how to tackle problems in different ways. However, the Sapir-Whorf hypothesis, a contested and somewhat-controversial concept from language theory, seems to hold reasonably true when applied to programming languages. It states that: “The structure of a language affects the ways in which its speakers conceptualize their world.” If you’re constrained by a single programming language, the one that dominates your day job, then you only have the tools of that language at your disposal to think about and solve a problem. For example, if you’ve only ever worked with Java, you would never think of passing a function to a method. A good developer needs to learn many languages. You may never deploy them in production, you may never ship code with them, but by learning a new language, you’ll have new ideas that will transfer to your current “day-job” language. With the abundant choices in programming languages, how does one choose which to learn? Alan Perlis sums it up best. “A language that doesn‘t affect the way you think about programming is not worth knowing“ With that in mind, here’s a selection of languages that I think are worth learning and that have certainly changed the way I think about tackling programming problems. Clojure Clojure is a Lisp-based language running on the Java Virtual Machine. The unique property of Lisp is homoiconicity, which means that a Lisp program is a Lisp data structure, and vice-versa. Since we can treat Lisp programs as Lisp data structures, we can write our code generation in the same style as our code. This gives Lisp a uniquely powerful macro system, and makes it ideal for implementing domain specific languages. Clojure also makes software transactional memory a first-class citizen, giving us a new approach to concurrency and dealing with the problems of shared state. Haskell Haskell is a strongly typed, functional programming language. Haskell’s type system is far richer than C# or Java, and allows us to push more of our application logic to compile-time safety. If it compiles, it usually works! Haskell is also a lazy language – we can work with infinite data structures. For example, in a board game we can generate the complete game tree, even if there are billions of possibilities, because the values are computed only as they are needed. Erlang Erlang is a functional language with a strong emphasis on reliability. Erlang’s approach to concurrency uses message passing instead of shared variables, with strong support from both the language itself and the virtual machine. Processes are extremely lightweight, and garbage collection doesn’t require all processes to be paused at the same time, making it feasible for a single program to use millions of processes at once, all without the mental overhead of managing shared state. The Benefits of Multilingualism By studying new languages, even if you won’t ever get the chance to use them in production, you will find yourself open to new ideas and ways of coding in your main language. For example, studying Haskell has taught me that you can do so much more with types and has changed my programming style in C#. A type represents some state a program should have, and a type should not be able to represent an invalid state. I often find myself refactoring methods like this… void SomeMethod(bool doThis, bool doThat) { if (!(doThis ^ doThat)) throw new ArgumentException(“At least one arg should be true”); if (doThis) DoThis(); if (doThat) DoThat(); } …into a type-based solution, like this: enum Action { DoThis, DoThat, Both }; void SomeMethod(Action action) { if (action == Action.DoThis || action == Action.Both) DoThis(); if (action == Action.DoThat || action == Action.Both) DoThat(); } At this point, I’ve removed the runtime exception in favor of a compile-time check. This is a trivial example, but is just one of many ideas that I’ve taken from one language and implemented in another.

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• Can't install alternate CD from USB?

  - by mattias

  Hi im trying to install ubuntu 12.04 with full hard disk encryption. After downloading and installing the Ubuntu live CD, I learned that truecrypt doesnt support full disk encryption on linux. I also learned that the best way to get "nearly full disk encryption" on ubuntu is by installing it from the alternate install CD. I tried that, but something is wrong with my CD reader/burner so it doesnt boot up when i insert the cd. My thought here was to take the .iso that I downloaded on my unencrypted Ubuntu system, use Unetbootin to make the usb drive. The usb drive used for this is exactly the same brand as one that I know has worked with a previous ubuntu live system on the same computer. I also used unetbootin for that usb, but I created it from windows that time. The usb stick boots up fine and i get through the first couple of steps in the installation process. However, After a while I get a "box" with the following error message "Load Installer components from CD" There was a problem reading data from the CD-ROM. Please make sure it is in the drive. If retrying does not work, you should check the integrity of your CD-ROM. "Failed to copy file from CD-ROM. Retry? " Then I cant get any further. I googled a lot and found this page which seems to tackle this very problem: http://www.dotkam.com/2010/11/29/ins...mage-from-usb/ I tried to do what it said. After pressing TAB, I wrote : cdrom-detect/try-usb=true without quotes because that's what i think is right. When I press TAB, there already is a text saying : /ubnkern initrd=/ubninit vga=788 -- quiet which can be removed. I have tried to both delete the text before the "--" and just inserting cdrom-detect/try-usb=true before it. Any idea of what can be wrong? I would like to do a full system encryption, or as full as it is possible. I dont want to just encrypt my /home folder. Maybe this isn't the easiest way. I use SanDisk usb sticks. I know there is a problem with U3 launcher on some SanDisks, but I never had to remove U3 before from similar disks, and the alternate install does boot up, so I dont think using U3 removal would help me. Any help or indication to an easier way to do this would be appreciated

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• AI to move custom-shaped spaceships (shape affecting movement behaviour)

  - by kaoD

  I'm designing a networked turn based 3D-6DOF space fleet combat strategy game which relies heavily on ship customization. Let me explain the game a bit, since you need to know a bit about it to set the question. What I aim for is the ability to create your own fleet of ships with custom shapes and attached modules (propellers, tractor beams...) which would give advantages and disadvantages to each ship, so you have lots of different fleet distributions. E.g., long ship with two propellers at the side would let the ship spin around that plane easily, bigger ships would move slowly unless you place lots of propellers at the back (therefore spending more "construction" points and energy when moving, and it will only move fast towards that direction.) I plan to balance all the game around this feature. The game would revolve around two phases: orders and combat phase. During the orders phase, you command the different ships. When all players finish the order phase, the combat phase begins and the ship orders get resolved in real-time for some time, then the action pauses and there's a new orders phase. The problem comes when I think about player input. To move a ship, you need to turn on or off different propellers if you want to steer, travel forward, brake, rotate in place... These propellers don't have to work at their whole power, so you can achieve more movement combinations with less propellers. I think this approach is a bit boring. The player doesn't want to fiddle with motors or anything, you just want to MOVE and KILL. The way I intend the player to give orders to these ships is by a destination and a rotation, and then the AI would calculate the correct propeller power to achive that movement and rotation. Propulsion doesn't have to be the same throught the entire turn calculation (after the orders have been given) so it would be cool if the ships reacted as they move, adjusting the power of the propellers for their needs dynamically, but it may be too hard to implement and it's not really needed for the game to work. In both cases, how would that AI decide which propellers to activate for the best (or at least not worst) trajectory to be achieved? I though about some approaches: Learning AI: The ship types would learn about their movement by trial and error, adjusting their behaviour with more uses, and finally becoming "smart". I don't want to get involved THAT far in AI coding, and I think it can be frustrating for the player (even if you can let it learn without playing.) Pre-calculated timestep movement: Upon ship creation, ALL possible movements are calculated for each propeller configuration and power for a given delta-time. Memory intensive, ugly, bad. Pre-calculated trajectories: The same as above but not for each delta-time but the whole trajectory, which would then be fitted as much as possible. Requires a fixed propeller configuration for the whole combat phase and is still memory intensive, ugly and bad. Continuous brute forcing: The AI continously checks ALL possible propeller configurations throughout the entire combat phase, precalculates a few time steps and decides which is the best one based on that. Con: what's good now might not be that good later, and it's too CPU intensive, ugly, and bad too. Single brute forcing: Same as above, but only brute forcing at the beginning of the simulation, so it needs constant propeller configuration throughout the entire combat phase. Coninuous angle check: This is not a full movement method, but maybe a way to discard "stupid" propeller configurations. Given the current propeller's normal vector and the final one, you can approximate the power needed for the propeller based on the angle. You must do this continuously throughout the whole combat phase. I figured this one out recently so I didn't put in too much thought. A priori, it has the "what's good now might not be that good later" drawback too, and it doesn't care about the other propellers which may act together to make a better propelling configuration. I'm really stuck here. Any ideas?

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• Memories about Tadeusz Golonka

  - by Damian

  Today at 10:55 AM, Tadeusz Golonka - my greatest  Mentor and Teacher  passed away. I had te opportunity to met Tadek in person several times last years. It was always a great experience to see how he shared his energy and passion. I was always impressed and had a lot of new ideas after such meeting or lecture. I can remember the meeting  in early 2009 and his briliant speech he did for us, the MVP community in Poland. We spent two days together and he talked to us all the time. He gave us examples how to share IT passion to other people and how to be better person for others. He was the greates Mentor I have ever met - I realized this during that meeting. My greates dream was and still is to be "like Tadek". Many Times I just went to events to see / hear him on stage ("in action"). I always wanted to have his energy, empathy and passion. Now I have to live without his good words and advices....Let me put here the words that Adam Cogan wrote on Tadek's profile on Facebook. I just can't write about that fatal accident. "The circumstances of Tadeusz Golonka death are too tragic. Tad stood up to offer his seat to an elderly lady, he lost his balance and then he slipped and hit the tram door hard. He then fell out of the tram and hit the metal barriers that separate the tram rails from the street. It was a severe accident...... So horrible.  At first it was a miracle is that he survived... he fought for several days.  My thoughts are with his lovely family. The family have asked for blood donations as a symbolic gift. Tad received a lot of blood.  Thank you Tad, you were a wonderful person. I will remember you as a kind man, a gentleman. "RIP Tadeusz- You will never ever be forgotten. You are with us all the time  

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• Monitor the Weather from Your Windows 7 Taskbar

  - by Asian Angel

  Keeping up with the weather forecast can be hard when you are extra busy with work. If you need a simple but nice looking way to integrate weather monitoring into your Taskbar then join us as we look at WeatherBar. Setting Up & Using WeatherBar To get started unzip the following files, place them in an appropriate “Program Files Folder”, and create a shortcut. When you start WeatherBar for the first time you will be presented with the following window and a random/default location. To get WeatherBar set up for your location there are only two settings to adjust (using the “Pencil & Gear Buttons”). Clicking on the “Pencil Button” will open up this small window…enter the name of your location and click “OK”. Next click on the “Gear Button” where you can choose the “Update Interval” and “Measurement Format” that best suits your needs. Click “OK” when finished and WeatherBar will be ready to go. That definitely looks nice. When you are finished viewing this window minimize it to the “Taskbar Icon” instead of clicking on the “Close Button”…otherwise the entire app will close. Left click on the “Taskbar Icon” to bring the window back up… Hovering the mouse over the “Taskbar Icon” provides a nice thumbnail of the weather forecast. Right clicking on the “Taskbar Icon” will display a nice mini forecast. Conclusion While WeatherBar may not be for everyone it does provide a nice easy way to monitor the weather from your “Taskbar” without taking up a lot of room. Links Download WeatherBar Similar Articles Productive Geek Tips Monitor the Weather for Your Location in ChromeCheck Weather Conditions in Real-time with Weather WatcherMonitor CPU, Memory, and Disk IO In Windows 7 with Taskbar MetersTaskbar Eliminator Does What the Name Implies: Hides Your Windows TaskbarBring Misplaced Off-Screen Windows Back to Your Desktop (Keyboard Trick) TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 Home Networks – How do they look like & the problems they cause Check Your IMAP Mail Offline In Thunderbird Follow Finder Finds You Twitter Users To Follow Combine MP3 Files Easily QuicklyCode Provides Cheatsheets & Other Programming Stuff Download Free MP3s from Amazon

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• What could be the best way to generalize data from Facebook and Twitter?

  - by Sjaak van der Heide

  I am not sure if this is the best subsite to ask this question, but I'm pretty sure it doesn't fit on the normal or facebook SO page... I've been asked to make a general API for connecting to several Social Media platforms (at the moment Facebook and Twitter). I have already realised both of them seperately. Meaning I retrieve the data I need from both Facebook and Twitter and hold the data in it's own dataclass. In my case a list of FacebookTimelineItems and a list of TwitterTimelineItems. now the hard part is taking the parts that are used in both (username, id, message and such) and make 1 general class that is eventually passed on to who/whatever sent the call to my API. these are two pics of the data classes I have: http://imageshack.us/photo/my-images/703/facebookdata.png/ http://imageshack.us/photo/my-images/204/twitterdata.png/ probably not 100% correct but it gives an idea what it looks like. Now I've been having several idea about how to go about and generalize the two, which is harder then I thought at first. Create an interface (TimelineItem) and let the other classes extend that one. this way I'll always be sure I have a class that contains at least the basic info I need. downside is that deserializing the JSON seems to be a nightmare. Use the two dataclasses I have and combine them into a new class afterwards, then pass that one back to whoever requested it. This would probably work but I get the idea it's not the best way to tackle this problem, and is pretty dodgy IF I get it working. Or, in case of the other two being nearly impossible. Keep the two seperated in the front end, and go sit in the corner crying because I've just figured out you can't lump together facebook and twitter... Note: I don't have to make the front end part (view), I just make sure the Model is nicely filled with data :) I hope I placed this in the right section, if I didn't I apologise and would like to know where I should go with my question. Thanks in advance for any replied/ideas/opinions on this.

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• Achieving decoupling in Model classes

  - by Guven

  I am trying to test-drive (or at least write unit tests) my Model classes but I noticed that my classes end up being too coupled. Since I can't break this coupling, writing unit tests is becoming harder and harder. To be more specific: Model Classes: These are the classes that hold the data in my application. They resemble pretty much the POJO (plain old Java objects), but they also have some methods. The application is not too big so I have around 15 model classes. Coupling: Just to give an example, think of a simple case of Order Header - Order Item. The header knows the item and the item knows the header (needs some information from the header for performing certain operations). Then, let's say there is the relationship between Order Item - Item Report. The item report needs the item as well. At this point, imagine writing tests for Item Report; you need have a Order Header to carry out the tests. This is a simple case with 3 classes; things get more complicated with more classes. I can come up with decoupled classes when I design algorithms, persistence layers, UI interactions, etc... but with model classes, I can't think of a way to separate them. They currently sit as one big chunk of classes that depend on each other. Here are some workarounds that I can think of: Data Generators: I have a package that generates sample data for my model classes. For example, the OrderHeaderGenerator class creates OrderHeaders with some basic data in it. I use the OrderHeaderGenerator from my ItemReport unit-tests so that I get an instance to OrderHeader class. The problem is these generators get complicated pretty fast and then I also need to test these generators; defeating the purpose a little bit. Interfaces instead of dependencies: I can come up with interfaces to get rid of the hard dependencies. For example, the OrderItem class would depend on the IOrderHeader interface. So, in my unit tests, I can easily mock the behaviour of an OrderHeader with a FakeOrderHeader class that implements the IOrderHeader interface. The problem with this approach is the complexity that the Model classes would end up having. Would you have other ideas on how to break this coupling in the model classes? Or, how to make it easier to unit-test the model classes?

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• In a multidisciplicary team, how much should each member's skills overlap?

  - by spade78

  I've been working in embedded software development for this small startup and our team is pretty small: about 3-4 people. We're responsible for all engineering which involves an RF device controlled by an embedded microcontroller that connects to a PC host which runs some sort of data collection and analysis software. I have come to develop these two guidelines when I work with my colleagues: Define a clear separation of responsibilities and make sure each person's contribution to the final product doesn't overlap. Don't assume your colleagues know everything about their responsibilities. I assume there is some sort of technology that I will need to be competent at to properly interface with the work of my colleagues. The first point is pretty easy for us. I do firmware, one guy does the RF, another does the PC software, and the last does the DSP work. Nothing overlaps in terms of two people's work being mixed into the final product. For that to happen, one guy has to hand off work to another guy who will vet it and integrate it himself. The second point is the heart of my question. I've learned the hard way not to trust the knowledge of my colleagues absolutley no matter how many years experience they claim to have. At least not until they've demonstrated it to me a couple of times. So given that whenever I develop a piece of firmware, if it interfaces with some technology that I don't know then I'll try to learn it and develop a piece of test code that helps me understand what they're doing. That way if my piece of the product comes into conflict with another piece then I have some knowledge about possible causes. For example, the PC guy has started implementing his GUI's in .NET WPF (C#) and using LibUSBdotNET for USB access. So I've been learning C# and the .NET USB library that he uses and I build a little console app to help me understand how that USB library works. Now all this takes extra time and energy but I feel it's justified as it gives me a foothold to confront integration problems. Also I like learning this new stuff so I don't mind. On the other hand I can see how this can turn into a time synch for work that won't make it into the final product and may never turn into a problem. So how much experience/skills overlap do you expect in your teammates relative to your own skills? Does this issue go away as the teams get bigger and more diverse?

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• Asynchrony in C# 5 (Part I)

  - by javarg

  I’ve been playing around with the new Async CTP preview available for download from Microsoft. It’s amazing how language trends are influencing the evolution of Microsoft’s developing platform. Much effort is being done at language level today than previous versions of .NET. In these post series I’ll review some major features contained in this release: Asynchronous functions TPL Dataflow Task based asynchronous Pattern Part I: Asynchronous Functions This is a mean of expressing asynchronous operations. This kind of functions must return void or Task/Task<> (functions returning void let us implement Fire & Forget asynchronous operations). The two new keywords introduced are async and await. async: marks a function as asynchronous, indicating that some part of its execution may take place some time later (after the method call has returned). Thus, all async functions must include some kind of asynchronous operations. This keyword on its own does not make a function asynchronous thought, its nature depends on its implementation. await: allows us to define operations inside a function that will be awaited for continuation (more on this later). Async function sample: Async/Await Sample async void ShowDateTimeAsync() {     while (true)     {         var client = new ServiceReference1.Service1Client();         var dt = await client.GetDateTimeTaskAsync();         Console.WriteLine("Current DateTime is: {0}", dt);         await TaskEx.Delay(1000);     } } The previous sample is a typical usage scenario for these new features. Suppose we query some external Web Service to get data (in this case the current DateTime) and we do so at regular intervals in order to refresh user’s UI. Note the async and await functions working together. The ShowDateTimeAsync method indicate its asynchronous nature to the caller using the keyword async (that it may complete after returning control to its caller). The await keyword indicates the flow control of the method will continue executing asynchronously after client.GetDateTimeTaskAsync returns. The latter is the most important thing to understand about the behavior of this method and how this actually works. The flow control of the method will be reconstructed after any asynchronous operation completes (specified with the keyword await). This reconstruction of flow control is the real magic behind the scene and it is done by C#/VB compilers. Note how we didn’t use any of the regular existing async patterns and we’ve defined the method very much like a synchronous one. Now, compare the following code snippet  in contrast to the previuous async/await: Traditional UI Async void ComplicatedShowDateTime() {     var client = new ServiceReference1.Service1Client();     client.GetDateTimeCompleted += (s, e) =>     {         Console.WriteLine("Current DateTime is: {0}", e.Result);         client.GetDateTimeAsync();     };     client.GetDateTimeAsync(); } The previous implementation is somehow similar to the first shown, but more complicated. Note how the while loop is implemented as a chained callback to the same method (client.GetDateTimeAsync) inside the event handler (please, do not do this in your own application, this is just an example).  How it works? Using an state workflow (or jump table actually), the compiler expands our code and create the necessary steps to execute it, resuming pending operations after any asynchronous one. The intention of the new Async/Await pattern is to let us think and code as we normally do when designing and algorithm. It also allows us to preserve the logical flow control of the program (without using any tricky coding patterns to accomplish this). The compiler will then create the necessary workflow to execute operations as the happen in time.

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• Games at Work Part 1: Introduction to Gamification and Applications

  - by ultan o'broin

  Games Are Everywhere How many of you (will admit to) remember playing Pong? OK then, do you play Angry Birds on your phone during work hours? Thought about why we keep playing online, video, and mobile games and what this "gamification" business we're hearing about means for the enterprise applications user experience? In Reality Is Broken: Why Games Make Us Better and How They Can Change the World, Jane McGonigal says that playing computer and online games now provides more rewards for people than their real lives do. Games offer intrinsic rewards and happiness to the players as they pursue more satisfying work and the success, social connection, and meaning that goes with it. Yep, Gran Turismo, Dungeons & Dragons, Guitar Hero, Mario Kart, Wii Boxing, and the rest are all forms of work it seems. Games are, in fact, work taken so seriously that governments now move to limit the impact of virtual gaming currencies on the real financial system. Anyone who spends hours harvesting crops on FarmVille realizes it’s hard work too. Yet games evoke a positive emotion in players who voluntarily stay engaged with games for hours, day after day. Some 183 million active gamers in the United States play on average 13 hours per week. Weekly, 5 million of those gamers play for longer than a working week (45 hours). So why not harness the work put into games to solve real-world problems? Or, in the case of our applications users, real-world work problems? What’s a Game? Jane explains that all games have four defining traits: a goal, rules, a feedback system, and voluntary participation. We need to look at what motivational ideas behind the dynamics of the game—what we call gamification—are appropriate for our users. Typically, these motivators are achievement, altruism, competition, reward, self-expression, and status). Common game techniques for leveraging these motivations include: Badging and avatars Points and awards Leader boards Progress charts Virtual currencies or goods Gifting and giving Challenges and quests Some technology commentators argue for a game layer on top of everything, but this layer is already part of our daily lives in many instances. We see gamification working around us already: the badging and kudos offered on My Oracle Support or other Oracle community forums, becoming a Dragon Slayer implementor of Atlassian applications, being made duke of your favorite coffee shop on Yelp, sharing your workout details with Nike+, or donating to Japanese earthquake relief through FarmVille, for example. And what does all this mean for the applications that you use in your work? Read on in part two...

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• With AMD style modules in JavaScript is there any benefit to namespaces?

  - by gman

  Coming from C++ originally and seeing lots of Java programmers doing the same we brought namespaces to JavaScript. See Google's closure library as an example where they have a main namespace, goog and under that many more namespaces like goog.async, goog.graphics But now, having learned the AMD style of requiring modules it seems like namespaces are kind of pointless in JavaScript. Not only pointless but even arguably an anti-pattern. What is AMD? It's a way of defining and including modules that removes all direct dependencies. Effectively you do this // some/module.js define([ 'name/of/needed/module', 'name/of/someother/needed/module', ], function( RefToNeededModule, RefToSomeOtherNeededModule) { ...code... return object or function }); This format lets the AMD support code know that this module needs name/of/needed/module.js and name/of/someother/needed/module.js loaded. The AMD code can load all the modules and then, assuming no circular dependencies, call the define function on each module in the correct order, record the object/function returned by the module as it calls them, and then call any other modules' define function with references to those modules. This seems to remove any need for namespaces. In your own code you can call the reference to any other module anything you want. For example if you had 2 string libraries, even if they define similar functions, as long as they follow the AMD pattern you can easily use both in the same module. No need for namespaces to solve that. It also means there's no hard coded dependencies. For example in Google's closure any module could directly reference another module with something like var value = goog.math.someMathFunc(otherValue) and if you're unlucky it will magically work where as with AMD style you'd have to explicitly include the math library otherwise the module wouldn't have a reference to it since there are no globals with AMD. On top of that dependency injection for testing becomes easy. None of the code in the AMD module references things by namespace so there is no hardcoded namespace paths, you can easily mock classes at testing time. Is there any other point to namespaces or is that something that C++ / Java programmers are bringing to JavaScript that arguably doesn't really belong?

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• How to handle encryption key conflicts when synchronizing data?

  - by Rafael

  Assume that there is data that gets synchronized between several devices. The data is protected with a symmetric encryption algorithm and a key. The key is stored on each device and encrypted with a password. When a user changes the password only the key gets re-encrypted. Under normal circumstances, when there is a good network connection to other peers, the current key gets synchronized and all data on the new device gets encrypted with the same key. But how to handle situations where a new device doesn’t have a network connection and e.g. creates its own new, but incompatible key? How to keep the usability as high as possible under such circumstances? The application could detect that there is no network and hence refuse to start. That’s very bad usability in my opinion, because the application isn’t functional at all in this case. I don’t consider this a solution. The application could ignore the missing network connection and create a new key. But what to do when the application gains a network connection? There will be several incompatible keys and some parts of the underlying data could only be encrypted with one key and other parts with another key. The situation would get worse if there would be more keys than just two and the application would’ve to ask every time for a password when another object that should get decrypted with another key would be needed. It is very messy and time consuming to try to re-encrypt all data that is encrypted with another key with a main key. What should be the main key at all in this case? The oldest key? The key with the most encrypted objects? What if the key got synchronized but not all objects that got encrypted with this particular key? How should the user know for which particular password the application asks and why it takes probably very long to re-encrypt the data? It’s very hard to describe encryption “issues” to users. So far I didn’t find an acceptable solution, nor some kind of generic strategy. Do you have some hints about a concrete strategy or some books / papers that describe synchronization of symmetrically encrypted data with keys that could cause conflicts?

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• Saddling your mountain lion with JDeveloper

  - by Blueberry Coder

  Last October, Apple released Java Update 2012-006. This patch brought the Apple-provided JDK for OS X Lion v10.7 and OS X Mountain Lion v10.8 to version 1.6.0_37. At the same time, it disabled the Apple Java plugins and removed the Java Preferences panel that enabled users to manage the various Java releases on their computer. On the Windows and Linux platforms, JDeveloper 11g R1 has been certified  to run on Java 7 since patch set 5. This is not the case on OS X.   ( The above is not a typo. Apple's OS for personal computer is now known as OS X; the « Mac » prefix has been dropped with the 10.8 release. And it's pronounced « Oh-Ess-Ten », by the way. Yes, I am a nitpicker. I know... ) Please note JDeveloper 11g R2 is not certified either. On any platform. It will generally work, but there are known issues with ADF Mobile. Personally, I would recommend to wait for 12c before going to JDK 7.  Now, suppose you have installed Oracle's JDK 7 on your Mac. JDeveloper will not run on it. It will even not install. Susan and I discovered this the hard way while setting up the ADF Mobile hands-on lab we ran at the UKOUG 2012 conference. The lab was a great success nevertheless, attracting nearly a hundred delegates. It was great to see the interest ADF Mobile already generates, especially among PL/SQL Developers and DBAs. But what did we do to make it work?  While Java Update 2012-006 removed the Java Preferences panel, it leaved in place OS X's command-line Java infrastructure. Thus, it is possible to invoke the Apple JDK 6 to start the JDeveloper installer. Suppose your user is named « Fred », and that the JDeveloper installer is on your desktop. You can execute the following command in a terminal window (on a single line) to start the installer:  /usr/libexec/java_home --version 1.6.0  --exec java -jar /Users/Fred/Desktop/jdevstudio11116install.jar  The JDeveloper installer, being provided a valid JDK reference, will set up the IDE and embedded WebLogic Server instance accordingly. Clever engineering at its finest!

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