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• Atheros Wireless card shows up as two different models?

  - by geermc4

  Hi I've been fighting these wireless drivers for a few days and just recently i noticed that the model the Wireless controller appears in lspci is different sometimes. This is the data i have after installing Ubuntu Server 64 bit ~# lspci -k .... 04:00.0 Network controller: Atheros Communications Inc. AR9285 Wireless Network Adapter (PCI-Express) (rev 01) Subsystem: AzureWave Device 1d89 Kernel driver in use: ath9k Kernel modules: ath9k ran some updates, restarted, all was good, all though it did say that linux-headers-server linux-image-server linux-server where beeing kept back. After that i installed ubuntu-desktop (aptitude install ubuntu-desktop --without-recommends) restarted and not only is the wireless not working anymore, but the hardware is listed as a different card ~# lspci -k .... 04:00.0 Ethernet controller: Atheros Communications Inc. AR5008 Wireless Network Adapter (rev 01) has no available drivers for it, still i tried to modprobe ath9k, they show up in lsmod as loaded, but still iw list shows nothing. this is what it looked like before the ubuntu-desktop instalation Wiphy phy0 Band 1: Capabilities: 0x11ce HT20/HT40 SM Power Save disabled RX HT40 SGI TX STBC RX STBC 1-stream Max AMSDU length: 3839 bytes DSSS/CCK HT40 Maximum RX AMPDU length 65535 bytes (exponent: 0x003) Minimum RX AMPDU time spacing: 8 usec (0x06) HT TX/RX MCS rate indexes supported: 0-7 Frequencies: * 2412 MHz [1] (14.0 dBm) * 2417 MHz [2] (15.0 dBm) * 2422 MHz [3] (15.0 dBm) * 2427 MHz [4] (15.0 dBm) * 2432 MHz [5] (15.0 dBm) * 2437 MHz [6] (15.0 dBm) * 2442 MHz [7] (15.0 dBm) * 2447 MHz [8] (15.0 dBm) * 2452 MHz [9] (15.0 dBm) * 2457 MHz [10] (15.0 dBm) * 2462 MHz [11] (15.0 dBm) * 2467 MHz [12] (15.0 dBm) (passive scanning) * 2472 MHz [13] (14.0 dBm) (passive scanning) * 2484 MHz [14] (17.0 dBm) (passive scanning) Bitrates (non-HT): * 1.0 Mbps * 2.0 Mbps (short preamble supported) * 5.5 Mbps (short preamble supported) * 11.0 Mbps (short preamble supported) * 6.0 Mbps * 9.0 Mbps * 12.0 Mbps * 18.0 Mbps * 24.0 Mbps * 36.0 Mbps * 48.0 Mbps * 54.0 Mbps max # scan SSIDs: 4 max scan IEs length: 2257 bytes Coverage class: 0 (up to 0m) Supported Ciphers: * WEP40 (00-0f-ac:1) * WEP104 (00-0f-ac:5) * TKIP (00-0f-ac:2) * CCMP (00-0f-ac:4) * CMAC (00-0f-ac:6) Available Antennas: TX 0x1 RX 0x3 Configured Antennas: TX 0x1 RX 0x3 Supported interface modes: * IBSS * managed * AP * AP/VLAN * WDS * monitor * mesh point * P2P-client * P2P-GO software interface modes (can always be added): * AP/VLAN * monitor interface combinations are not supported Supported commands: * new_interface * set_interface * new_key * new_beacon * new_station * new_mpath * set_mesh_params * set_bss * authenticate * associate * deauthenticate * disassociate * join_ibss * join_mesh * remain_on_channel * set_tx_bitrate_mask * action * frame_wait_cancel * set_wiphy_netns * set_channel * set_wds_peer * connect * disconnect Supported TX frame types: * IBSS: 0x0000 0x0010 0x0020 0x0030 0x0040 0x0050 0x0060 0x0070 0x0080 0x0090 0x00a0 0x00b0 0x00c0 0x00d0 0x00e0 0x00f0 * managed: 0x0000 0x0010 0x0020 0x0030 0x0040 0x0050 0x0060 0x0070 0x0080 0x0090 0x00a0 0x00b0 0x00c0 0x00d0 0x00e0 0x00f0 * AP: 0x0000 0x0010 0x0020 0x0030 0x0040 0x0050 0x0060 0x0070 0x0080 0x0090 0x00a0 0x00b0 0x00c0 0x00d0 0x00e0 0x00f0 * AP/VLAN: 0x0000 0x0010 0x0020 0x0030 0x0040 0x0050 0x0060 0x0070 0x0080 0x0090 0x00a0 0x00b0 0x00c0 0x00d0 0x00e0 0x00f0 * mesh point: 0x0000 0x0010 0x0020 0x0030 0x0040 0x0050 0x0060 0x0070 0x0080 0x0090 0x00a0 0x00b0 0x00c0 0x00d0 0x00e0 0x00f0 * P2P-client: 0x0000 0x0010 0x0020 0x0030 0x0040 0x0050 0x0060 0x0070 0x0080 0x0090 0x00a0 0x00b0 0x00c0 0x00d0 0x00e0 0x00f0 * P2P-GO: 0x0000 0x0010 0x0020 0x0030 0x0040 0x0050 0x0060 0x0070 0x0080 0x0090 0x00a0 0x00b0 0x00c0 0x00d0 0x00e0 0x00f0 Supported RX frame types: * IBSS: 0x00d0 * managed: 0x0040 0x00d0 * AP: 0x0000 0x0020 0x0040 0x00a0 0x00b0 0x00c0 0x00d0 * AP/VLAN: 0x0000 0x0020 0x0040 0x00a0 0x00b0 0x00c0 0x00d0 * mesh point: 0x00b0 0x00c0 0x00d0 * P2P-client: 0x0040 0x00d0 * P2P-GO: 0x0000 0x0020 0x0040 0x00a0 0x00b0 0x00c0 0x00d0 Device supports RSN-IBSS. What's with the hardware change? If it has 2, how can i make the AR9285 always load and disable AR5008, or, is it the same and it's just showing it different? :| Oh and I've tried this on Ubuntu 10.04 server, xubuntu 12.04, ubuntu 12.04 desktop and server. Thanks in advanced. -- Here's some more info, i have it setup in 2 hard drives, 1 works and the other one i'm using to figure it out The one that works... # lshw -class network *-network description: Ethernet interface product: RTL8111/8168B PCI Express Gigabit Ethernet controller vendor: Realtek Semiconductor Co., Ltd. physical id: 0 bus info: pci@0000:03:00.0 logical name: eth0 version: 06 serial: 54:04:a6:a3:3b:96 size: 1Gbit/s capacity: 1Gbit/s width: 64 bits clock: 33MHz capabilities: pm msi pciexpress msix vpd bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=full firmware=rtl_nic/rtl8168e-2.fw ip=192.168.2.147 latency=0 link=yes multicast=yes port=MII speed=1Gbit/s resources: irq:43 ioport:e000(size=256) memory:d0004000-d0004fff memory:d0000000-d0003fff *-network description: Wireless interface product: AR9285 Wireless Network Adapter (PCI-Express) vendor: Atheros Communications Inc. physical id: 0 bus info: pci@0000:04:00.0 logical name: wlan0 version: 01 serial: 74:2f:68:4a:26:73 width: 64 bits clock: 33MHz capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless configuration: broadcast=yes driver=ath9k driverversion=3.2.0-18-generic-pae firmware=N/A latency=0 link=no multicast=yes wireless=IEEE 802.11bgn resources: irq:18 memory:fea00000-fea0ffff Here's where it doesn't # lshw -class network *-network description: Ethernet interface product: RTL8111/8168B PCI Express Gigabit Ethernet controller vendor: Realtek Semiconductor Co., Ltd. physical id: 0 bus info: pci@0000:03:00.0 logical name: eth0 version: 06 serial: 54:04:a6:a3:3b:96 size: 1Gbit/s capacity: 1Gbit/s width: 64 bits clock: 33MHz capabilities: pm msi pciexpress msix vpd bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=full firmware=rtl_nic/rtl8168e-2.fw ip=192.168.2.160 latency=0 link=yes multicast=yes port=MII speed=1Gbit/s resources: irq:43 ioport:e000(size=256) memory:d0004000-d0004fff memory:d0000000-d0003fff *-network UNCLAIMED description: Ethernet controller product: AR5008 Wireless Network Adapter vendor: Atheros Communications Inc. physical id: 0 bus info: pci@0000:04:00.0 version: 01 width: 64 bits clock: 33MHz capabilities: pm msi pciexpress bus_master cap_list configuration: latency=0 resources: memory:fea00000-fea0ffff Update I've noticed that if i blacklist the ath9k and ath9k_common modules lspci gives me the AR9285, but then I need to modprobe ath9k for it to work, does this make any sense? If so, why?

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• What's the best game engine to use for my PC game project? [closed]

  - by user19860

  I'm in the planning phase of creating an action-rpg for the PC, and I'd like to create a League of Legends style look for the game (animated/cartoony). Any idea which engine best replicates this look? I ask because when I look at a lot of the UDk/Unreal games, they've all got the more realistic 3-D look that I'd like to avoid, so I was wondering if an alternate look was possible on that type of engine. Source SDK and Unity also look very interesting, I just don't know what types of visual capabilities these engines have. Thanks in advance.

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• Predicate delegate in C#

  - by Jalpesh P. Vadgama

  I am writing few post on different type of delegates and and this post also will be part of it. In this post I am going to write about Predicate delegate which is available from C# 2.0. Following is list of post that I have written about delegates. Delegates in C#. Multicast delegates in C#. Func delegate in C#. Action delegate in C#. Predicate delegate in C#: As per MSDN predicate delegate is a pointer to a function that returns true or false and takes generics types as argument. It contains following signature. Predicate<T> – where T is any generic type and this delegate will always return Boolean value. The most common use of a predicate delegate is to searching items in array or list. So let’s take a simple example. Following is code for that. Read More

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• JavaOne San Francisco 2013 Content Catalog Live!

  - by Yolande Poirier

  There will be over 500 technical sessions, BOFs, tutorials, and hands-on labs offered. Note that "Securing Java" is a new track this year. The tracks are:  Client and Embedded Development with JavaFX Core Java Platform Edge Computing with Java in Embedded, Smart Card, and IoT Applications Emerging Languages on the Java Virtual Machine Securing Java Java Development Tools and Techniques Java EE Web Profile and Platform Technologies Java Web Services and the Cloud In the Content Catalog you can search on tracks, session types, session categories, keywords, and tags. Or, you can search for your favorite speakers to see what they’re presenting this year. And, directly from the catalog, you can share sessions you’re interested in with friends and colleagues through a broad array of social media channels. Start checking out JavaOne content now to plan your week at the conference. Then, you’ll be ready to sign up for all of your sessions when the scheduling tool goes live.

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• Why would one overload the && and & operator?

  - by acidzombie24

  The same question goes for | and ||. Why would one overload or 'use' the & and && operator? The only use i thought of are Bitwise Ands for int base types (but not float/decimals) using & logical short circuit for bools/functions that return bool. Using the && operator usually. I cant think of any classes that use those operators. Absolutely none. I know a class might support + (and not '-') which combine two strings together. I seen an object such as datetime overload '-' so two dates can be subtracted to make a timespan (obviously you cant add two dates) but i never seen &, &&, | and || used. Does anyone know of a use? In any language?

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• Mise en oeuvre de composants web via le framework Ellipse, par l'équipe Ellipse

  L'objectif de ce nouveau tutoriel est de vous montrer comment créer des composants web réutilisables via le framework Ellipse. Deux types de composants web peuvent être envisagés : un composant web définit dans une simple classe Java, ou bien un composant web à base d'un modèle XML (TemplatedComponent) afin d'y stocker la mise en page pour le rendu HTML. Bien entendu, nous allons utiliser le plugin Ellipse afin de nous simplifier la construction de ces éléments. Ce tutoriel est accessible à partir de l'adresse suivante : http://ellipse.developpez.com/tutori...s-web-ellipse/ Si vous avez des commentaires ou des questions, n'hésitez pas à compléter cette discussion.

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• What algorithm(s) can be used to achieve reasonably good next word prediction?

  - by yati sagade

  What is a good way of implementing "next-word prediction"? For example, the user types "I am" and the system suggests "a" and "not" (or possibly others) as the next word. I am aware of a method that uses Markov Chains and some training text(obviously) to more or less achieve this. But I read somewhere that this method is very restrictive and applies to very simple cases. I understand basics of neural networks and genetic algorithms(though have never used them in a serious project) and maybe they could be of some help. I wonder if there are any algorithms that, given appropriate training text(e.g., newspaper articles, and the user's own typing) can come up with reasonably appropriate suggestions for the next word. If not (links to)algorithms, general high-level methods to attack this problem are welcome.

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• Strategies for Indexing Custom Fields in RavenDB

  - by Adrian Thompson Phillips

  In the relational database world, if I was developing a CRM system and wanted to have the user add their own custom fields that are searchable, I could have tables that store the name of the new column, the data type and the value, etc. (which would be less inefficient to index) or I could use the less elegant (but more searchable) solution that software like Dynamics and SharePoint use, whereas I create a load of columns on my aggregate root called CustomInt1, CustomInt2, etc. (which looks dirty and has a limit of how many custom fields a user can have, but has indexing advantages). But my questions is this, in NoSQL databases, what would be the best way of achieving the same thing? My priority would be for searchability. So what would be the best way to store this data? If I used a predefined set of properties (i.e. CustomData1, CustomData2, etc.), because these are all stored as JSON (i.e. strings) in the database, does this make it simpler because I don't have to worry about data types?

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• New Endeca Commerce 3.1 Specialization Launched!

  - by Roxana Babiciu

  We’ve just launched the Endeca Commerce 3.1 Specialization! This is your chance to be recognized as a proficient Oracle partner in selling, implementing and/or developing Endeca Commerce 3.1 solutions.  Check the specialization criteria to make sure you qualify! Oracle partners who achieve this Specialization are differentiated in the marketplace through proven expertise in Oracle Endeca Commerce 3.1. Are you a member of the Endeca Community?  If not, this is the place to be for exchanging ideas and questions regarding Endeca Commerce use. Do check it out! Topics covered in the Specialization include: Application Configuration Record Design Pipeline Development Working with Search Features Experience Manager Concepts Overview of Query Types Application development with the Assembler API

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• Can I create a hybrid software-RAID array with disks of different sizes?

  - by stueng

  Products such as Synology offer something called Synology Hybrid RAID http://www.synology.com/us/products/features/RAID.php This RAID type allows you to make best use of your disks available by using all the disk space available as long as at least two disks share the same increased size where a typical RAID setup would simply "throw away" the extra space I would like to build a NAS with 4 disks available. I will begin by populating it with 3 X 3TB to give me 6TB usable. By the time I have filled this 6TB I imagine that 4TB disks will have come down in price, so at this stage I would add a 4th 4TB disk to give me an additional 3TB of space. When I next run out of space I will change one of the original 3TB disks with a 4TB disk giving me an additional 1TB of space. This is not possible with a typical RAID configuration, only with these "hybrid RAID" types I am wondering if I can acheive a similar "hybrid RAID" with Ubuntu? or another linux distro?

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• Securing Mobile Apps in a Bring Your Own Device World

  - by Naresh Persaud

  As more and more business users begin using their personal devices to access corporate information and resources, the number of network access requests has risen dramatically.  Access Management products and strategies that were based on an employee accessing network resources from a single desktop PC were never designed to monitor and manage an employee that is using a desktop and a laptop, a tablet, and a smartphone all from outside the corporate network, and possibly from an unsecured wireless public network. A new approach is needed to manage the types and frequency of mobile app access requests - an integrated Platform Approach to Identity and Access Management that is location and device aware, that can warn you of unusual or high risk access.  A platform that provides standard APIs so you can manage your mobile apps the same way that you manage your enterprise apps. View the slideshow below to see how the Oracle Identity Management platform can help you secure your mobile applications and data in a Bring Your Own Device World. Securing access inabyod-world-final-ext View more PowerPoint from OracleIDM

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• EISK&ndash;Employee Info Starter Kit 5.0

  - by Tiago Salgado

  Employee Info Starter Kit is an open source project that is highly influenced by the concept ‘Pareto Principle’ or 80-20 rule, where it is targeted to enable a web developer to gain 80% productivity with 20% of effort with respect to learning curve and production. It is intended to address different types of real world challenges faced by web application developers when performing common CRUD operations. Using a single database table ‘Employee’, the current release illustrates how to utilize Microsoft ASP.NET 4.0 Web Form Data Controls, Entity Framework 4.0 and Visual Studio 2010 effectively in that context.   More information on codeplex project site.

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• Keyboard Layouts Plugin forgets settings, unable find workaround

  - by Honza Javorek

  I use Xubuntu. As everyone knows, Keyboard Layouts Plugin is very, very buggy and it still forgets my settings. It drives me crazy - I have to set them again and again every time I wake up or turn on my laptop. So I found a solution - put into my .bashrc this: setxkbmap -option '' -option grp:alt_shift_toggle cz,us -variant querty That should set my toggle to Alt+shift and my layouts to Czech QUERTY and plain US English as a second one. Voilà, that seems to work! I could use Keyboard Layouts Plugin only as an indicator, that's okay. However, it doesn't work well. The problem is that it ignores -variant setting. More or less. In Keyboard Layouts Plugin I actually see Czech QUERTY selected, but in reality my keyboard types QUERTZ. That's insane :-( Could anyone help, please?

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• How do I include Implementation and Usage Documentation in one file

  - by Angelo.Hannes

  There are two types of documentation. One type, the Implementation Documentation, contains information about specific implementation of a construct (eg. Class, Method, etc.). It is targeted to the future me, maintainer, debugger and so on. And there is Usage Documentation, containing information how to use a provided api. It does not contain information about specific implementation and is targeted to users of the api. How do I include both of them in one file? (Or do I include both of them in one file? And if not, what type belongs into the source file?) Are there special techniques, using java-doc and/or best practices?

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• Markup format or script for data files?

  - by Aaron

  The game I'm designing will be mainly written in a high level scripting language (leaning towards either Lua or Squirrel) with a C++ core. In addition to scripts I'm also going to need different data files. Many data files will be for static information such as graphical assets and monster types. I'd also want to create and update data files at runtime for user information like option settings and game saves. Can I get away with using plain script files (i.e. .lua or .nut files) for my data files, or is it better to use dedicated markup formats like XML or YAML? If I use script files, loaded separately from my true scripts, then I wouldn't need an extra library to read those files. Scripting languages like Lua also have table syntax that lend themselves towards data definition. On the other hand I'd have to write my own schema check code. These languages also don't seem to support serialization "out of the box" like the markup format libraries do.

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• What options are there for integrating with payment gateways?

  - by Rowland Shaw

  It seems that there are only two types of payment gateway service out there at the moment; Either that the entire cart logic is handled offsite (with something like Paypal's Standard option) or the other option being that you need to go through the certification for handling credit card numbers and doing pretty much everything yourself. Ideally, for the project I'm working on, I'm after a bit of middle ground such that I can handle the cart on-site, and only pass over to a payment gateway (with an order amount, billing & delivery details, and order ref) for them to handle the card details, before passing back. I'm sure that I've used e-commerce sites using this pattern before, but I cannot find any payment providers out there that offer this sort of option, so are there any? The only over requirement we have at present is that it must accept orders in Sterling.

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• Why the overhead when allocating objects/arrays in Java?

  - by Gnijuohz

  How many bytes an array occupies in Java? Assume It's a 64bit machine and also assume there are N elements in an array, so all these elements would take up 2*N, 4*N or 8*N bytes for different types of array. And a lecture in Coursera says that it would occupy 2*N+24, 4*N+24 or 8*N+24 bytes for a N element array and the 24 bytes is called overhead, but didn't explain why the overhead is needed. Also objects have overheads, which is 16 bytes. What exactly are these overheads? What are these 24/16 bytes composed of? Also, do these overheads only exist in Java? How about C, C++ and Python?

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• What is the ideal self hosted search engine?

  - by Tim Post

  I have an internal (intranet) site that is comprised of several blogs and forums, hundreds of static pages, lots of PDF files and several other document types. Its been glued together loosely over the last couple of years and now its my job to maintain it. I'm looking for a search engine that I can host myself that ideally: Allows for searching the Blog / Forum databases directly if given the database information and tables to search. Handles most text documents (PDF/DOC/ODF) Is open source, or allows access to the source code once purchased It doesn't matter to me what language or platform it is written in. Normally, I'd just use Google site search, but that's not an option for an intranet.

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• Replace your SKY+ HD Hard drive

  - by BizTalk Visionary

  As there are a number of different unit types there are a number of links provided here: If you wish to upgrade the Amstrad HD Box, please use this guide. How to upgrade the Hard Drive of your Amstrad HD box If you wish to upgrade the Thomson HD Box, please use this guide. How to upgrade the Hard Drive in your Thomson HD Box. If you wish to upgrade the Pace HD Box, please use this guide. How to upgrade the Hard Drive in your Pace HD Box If you wish to upgrade the Samsung HD Box, please use this guide. How to upgrade the Hard Drive in your Samsung HD Box I recommend you use a Hitachi DeskStar 1TB Hard Drive SATAII 7200rpm 16MB Cache

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• Brand New Oracle WebLogic 12c Online Launch Event, December 1, 10am PT

  - by B Shashikumar

  The brand new WebLogic 12c will be launched on December 1st with a 2-hour global webcast highlighting salient capabilities and benefits and featuring Hasan Rizvi, SVP, Oracle Fusion Middleware and Java. For the more techie types, the 2nd hour will be a developer focused discussion including multiple demos and live Q&A. Please join us, with your fellow IT managers, architects, and developers, to hear how the new release of Oracle WebLogic Server is: Designed to help you seamlessly move into the public or private cloud with an open, standards-based platform Built to drive higher value for your current infrastructure and significantly reduce development time and cost Enhanced with transformational platforms and technologies such as Java EE 6, Oracle’s Active GridLink for RAC, Oracle Traffic Director, and Oracle Virtual Assembly Builder   

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• Newton Game Dynamics: Making an object not affect another object

  - by Boreal

  I'm going to be using Newton in my networked action game with Mogre. There will be two "types" of physics object: global and local. Global objects will be kept in sync for everybody; these include the players, projectiles, and other gameplay-related objects. Local objects are purely for effect, like ragdolls, debris, and particles. Is there a way to make the global objects affect the local objects without actually getting affected themselves? I'd like debris to bounce off of a tank, but I don't want the tank to respond in any way.

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• JavaOne Content Catalog Live!

  - by programmarketingOTN

  The JavaOne Content Catalog—the central repository for information on sessions, demos, labs, user groups, exhibitors, and more for San Francisco 2012—is live!In the Content Catalog you can search on tracks, session types, session categories, keywords, and tags. Or, you can search for your favorite speakers to see what they’re presenting this year. And, directly from the catalog, you can share sessions you’re interested in with friends and colleagues through a broad array of social media channels.Start checking out JavaOne content now to plan your week at the conference. Then you’ll be ready to sign up for all of your sessions in mid-July when the scheduling tool goes live. Happy browsing! 

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• How to make local apache server public/visible ? [closed]

  - by George

  Hello. I am running an Apache2 server on a Fedora 13. I'd like to make it publicly accessible(visible).For example I'd like when somebody types http://my.ip.numbes/ that they would see what I have in my document root folder. Just for a presentation of a course work at university. Permissions are set to 755. User owning the document root is apache. SELinux is temporarily disabled. But port 80 is closed. I tried to open it by adding an entry to iptables and restarting them, no change. I guess I am missing something big here. Help would be greatly appreciated.

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• Computer Networks UNISA - Chap 8 &ndash; Wireless Networking

  - by MarkPearl

  After reading this section you should be able to Explain how nodes exchange wireless signals Identify potential obstacles to successful transmission and their repercussions, such as interference and reflection Understand WLAN architecture Specify the characteristics of popular WLAN transmission methods including 802.11 a/b/g/n Install and configure wireless access points and their clients Describe wireless MAN and WAN technologies, including 802.16 and satellite communications The Wireless Spectrum All wireless signals are carried through the air by electromagnetic waves. The wireless spectrum is a continuum of the electromagnetic waves used for data and voice communication. The wireless spectrum falls between 9KHZ and 300 GHZ. Characteristics of Wireless Transmission Antennas Each type of wireless service requires an antenna specifically designed for that service. The service’s specification determine the antenna’s power output, frequency, and radiation pattern. A directional antenna issues wireless signals along a single direction. An omnidirectional antenna issues and receives wireless signals with equal strength and clarity in all directions The geographical area that an antenna or wireless system can reach is known as its range Signal Propagation LOS (line of sight) uses the least amount of energy and results in the reception of the clearest possible signal. When there is an obstacle in the way, the signal may… pass through the object or be obsrobed by the object or may be subject to reflection, diffraction or scattering. Reflection – waves encounter an object and bounces off it. Diffraction – signal splits into secondary waves when it encounters an obstruction Scattering – is the diffusion or the reflection in multiple different directions of a signal Signal Degradation Fading occurs as a signal hits various objects. Because of fading, the strength of the signal that reaches the receiver is lower than the transmitted signal strength. The further a signal moves from its source, the weaker it gets (this is called attenuation) Signals are also affected by noise – the electromagnetic interference) Interference can distort and weaken a wireless signal in the same way that noise distorts and weakens a wired signal. Frequency Ranges Older wireless devices used the 2.4 GHZ band to send and receive signals. This had 11 communication channels that are unlicensed. Newer wireless devices can also use the 5 GHZ band which has 24 unlicensed bands Narrowband, Broadband, and Spread Spectrum Signals Narrowband – a transmitter concentrates the signal energy at a single frequency or in a very small range of frequencies Broadband – uses a relatively wide band of the wireless spectrum and offers higher throughputs than narrowband technologies The use of multiple frequencies to transmit a signal is known as spread-spectrum technology. In other words a signal never stays continuously within one frequency range during its transmission. One specific implementation of spread spectrum is FHSS (frequency hoping spread spectrum). Another type is known as DSS (direct sequence spread spectrum) Fixed vs. Mobile Each type of wireless communication falls into one of two categories Fixed – the location of the transmitted and receiver do not move (results in energy saved because weaker signal strength is possible with directional antennas) Mobile – the location can change WLAN (Wireless LAN) Architecture There are two main types of arrangements Adhoc – data is sent directly between devices – good for small local devices Infrastructure mode – a wireless access point is placed centrally, that all devices connect with 802.11 WLANs The most popular wireless standards used on contemporary LANs are those developed by IEEE’s 802.11 committee. Over the years several distinct standards related to wireless networking have been released. Four of the best known standards are also referred to as Wi-Fi. They are…. 802.11b 802.11a 802.11g 802.11n These four standards share many characteristics. i.e. All 4 use half duplex signalling Follow the same access method Access Method 802.11 standards specify the use of CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) to access a shared medium. Using CSMA/CA before a station begins to send data on an 802.11 network, it checks for existing wireless transmissions. If the source node detects no transmission activity on the network, it waits a brief period of time and then sends its transmission. If the source does detect activity, it waits a brief period of time before checking again. The destination node receives the transmission and, after verifying its accuracy, issues an acknowledgement (ACT) packet to the source. If the source receives the ACK it assumes the transmission was successful, – if it does not receive an ACK it assumes the transmission failed and sends it again. Association Two types of scanning… Active – station transmits a special frame, known as a prove, on all available channels within its frequency range. When an access point finds the probe frame, it issues a probe response. Passive – wireless station listens on all channels within its frequency range for a special signal, known as a beacon frame, issued from an access point – the beacon frame contains information necessary to connect to the point. Re-association occurs when a mobile user moves out of one access point’s range and into the range of another. Frames Read page 378 – 381 about frames and specific 802.11 protocols Bluetooth Networks Sony Ericson originally invented the Bluetooth technology in the early 1990s. In 1998 other manufacturers joined Ericsson in the Special Interest Group (SIG) whose aim was to refine and standardize the technology. Bluetooth was designed to be used on small networks composed of personal communications devices. It has become popular wireless technology for communicating among cellular telephones, phone headsets, etc. Wireless WANs and Internet Access Refer to pages 396 – 402 of the textbook for details.

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• Formula for three competing heroes, each has one they can beat and one they're beaten by

  - by Georgiadis Abraam

  I am trying to design a game for a project I have, The main idea is: 3 Types of heroes 3 Stats per hero There are no levels involved so the differences must be located on stats. Fight logic - The logic of fight is that type1hero has good chances winning type2hero, type2hero has good chances type3hero and type3hero has good chances winning type1hero. For over a week I am trying to find a stats based formula that will allow me to fix this but I can't, I was meddling with numbers yesterday and it was decent but I can't extract the formula out of it. Could you please guide me or give me hints on how should I start creating formulas on a Non lvl game that fulfills the fight logic?

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