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• Does the method of adjustment matter, or just the final calibration?

  - by Steve

  A company produces software (and hardware) that is used to both perform automatic adjustments on electronic test equipment as well as perform calibrations of the same equipment. The results of the calibrations are put onto a certificate of calibration that is sent to the customer along with the equipment. This calibration certificate states various conditions of the calibration, such as what hardware (models/serial numbers) and software (version) was used to perform the calibration, as well as things like environmental conditions, etc. Making the assumption that the software used to produce the data (and listed on the calibration certificate) used on the certificate of calibration must have gone through a "test/release" process and must be considered "released" software - does this also mean that the software used for adjustment must also be released? I believe that the method (software/environmental conditions/etc) used or present during adjustment doesn't matter, all that really matters is the end result of the calibration, the conditions present during the calibration, and whether or not the equipment was within the specifications. The real question I'm hoping to get answered: Is there a reputable source (e.g. NIST or somewhere similar) that addresses this question? (I have searched...) The thinking is that during high volume production runs, the "unreleased" system can be used to perform adjustments, as long as a released system is used to perform the calibrations, since the time required to perform the adjustments is much longer than the calibration. This unreleased system will eventually become released for use, but currently is not. Also, please not that there is a distinction between "adjustment" and "calibration". The definition from BIPM International vocabulary of metrology, 2.39: Operation that, under specified conditions, in a first step, establishes a relation between the quantity values with measurement uncertainties provided by measurement standards and corresponding indications with associated measurement uncertainties (of the calibrated instrument or secondary standard) and, in a second step, uses this information to establish a relation for obtaining a measurement result from an indication. Followed by NOTE 2 (emphasis in original text): Calibration should not be confused with adjustment of a measuring system, often mistakenly called "self-calibration", nor with verification of calibration As a side note, I'm not sure why this got down voted. It's regarding software and it's use before and after release for use. I believe there is a best practice that can be applied and this is (hopefully) not primarily opinion based.

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• SQL Saturday 43 (Redmond, WA) Review

  - by BuckWoody

  Last Saturday (June 12th) we held a “SQL Saturday” (more about those here) event in Redmond, Washington. The event was held at the Microsoft campus, at the Mixer in our new location called the “Commons”. This is a mall-like area that we have on campus, and the Mixer is a large building with lots of meeting rooms, so it made a perfect location for the event. There was a sign to find the parking, and once there they had a sign to show how to get to the building. Since it’s a secure facility, Greg Larsen and crew had a person manning the door so that even late arrivals could get in. We had about 400 sign up for the event, and a little over 300 attend (official numbers later). I think we would have had a lot more, but the sun was out – and you just can’t underestimate the effect of that here in the Pacific Northwest. We joke a lot about not seeing the sun much, but when a day like what we had on Saturday comes around, and on a weekend at that, you’d cancel your wedding to go outside to play in the sun. And your spouse would agree with you for doing it. We had some top-notch speakers, including Clifford Dibble and Kalen Delany. The food was great, we had multiple sponsors (including Confio who seems to be at all of these) and the attendees were from all over the professional spectrum, from developers to BI to DBA’s. Everyone I saw was very engaged, and when I visited room-to-room I saw almost no one in the halls – everyone was in the sessions. I also saw a much larger Microsoft presence this year, especially from Dan Jones’ team. I had a great turnout at my session, and yes, I was wearing an Oracle staff shirt. I did that because I wanted to show that the session I gave on “SQL Server for the Oracle DBA” was non-marketing – I couldn’t exactly bash Oracle wearing their colors! These events are amazing. I can’t emphasize enough how much I appreciate the volunteers and how much work they put into these events, and to you for coming. If you’re reading this and you haven’t attended one yet, definitely find out if there is one in your area – and if not, start one. It’s a lot of work, but it’s totally worth it.       Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

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• Best Frameworks/libraries/engines for 2D multiplayer C# Webbased RPG

  - by Thirlan

  Title is a mouthful but important because I'm looking to meet a specific criteria and it's complex enough that I need a lot of help in finding what I'm looking for. I really want people's suggestions because I trust it a lot more than anything else, so I just need to clearly define what it is I want heh : P Game is a 2D RPG. Think of Secret of Mana. Game is online multiplayer, but not MMO sized. Game must be webbased! I'm looking to the future and want to hit as many platforms as possible. I'm leaning to Webgl because of this, but still looking around. Since the users are seeing the game through the webbrowser the front-end should be mainly responsible for drawing, taking input and some basic checking such as preliminary collision detection. This is important because it means the game engine is NOT on the client's machine. The server should be responsible for the game engine and all the calculations. This means the server is doing all the work and the client is mostly a dumb terminal. Server language is c# I'm looking for fast project execution so I want to use as many pre-existing tools as possible. This would make sense because I'm making a game here, not an engine. I'm not creating some new revolutionary graphics or pushing the physics engines to the next level. Preference for commercially supported tools. For game mechanics reasons and for reasons 4 and 5, don't think I can use existing 2D rpg engines. I've seen them out there and I fear that if I try and use them they will have too many restrictions, but will be happy to hear out suggestions. So all this means I need a game engine on the server, or maybe just a physics engine, and then I need another engine/library to draw everything that the server is sending to the client on the webbrowser. Maybe this is how 50% of games work on the web and there are plenty of frameworks that support this! I wouldn't actually don't know : ( but my gut is telling me that most webgames are single player and 90% of the game is running on the client. So... any suggestions?

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• Impatient Customers Make Flawless Service Mission Critical for Midsize Companies

  - by Richard Lefebvre

  At times, I can be an impatient customer. But I’m not alone. Research by The Social Habit shows that among customers who contact a brand, product, or company through social media for support, 32% expect a response within 30 minutes and 42% expect a response within 60 minutes! 70% of respondents to another study expected their complaints to be addressed within 24 hours, irrespective of how they contacted the company. I was intrigued when I read a recent blog post by David Vap, Group Vice President of Product Development for Oracle Service Cloud. It’s about “Three Secrets to Innovation” in customer service. In David’s words: 1) Focus on making what’s hard simple 2) Solve real problems for real people 3) Don’t just spin a good vision. Do something about it  I believe midsize companies have a leg up in delivering on these three points, mainly because they have no other choice. How can you grow a business without listening to your customers and providing flawless service? Big companies are often weighed down by customer service practices that have been churning in bureaucracy for years or even decades. When the all-in-one printer/fax/scanner I bought my wife for Christmas (call me a romantic) failed after sixty days, I wasted hours of my time navigating the big brand manufacturer’s complex support and contact policies only to be offered a refurbished replacement after I shipped mine back to them. There was not a happy ending. Let's just say my wife still doesn't have a printer.  Young midsize companies need to innovate to grow. Established midsize company brands need to innovate to survive and reach the next level. Midsize Customer Case Study: The Boston Globe The Boston Globe, established in 1872 and the winner of 22 Pulitzer Prizes, is fighting the prevailing decline in the newspaper industry. Businessman John Henry invested in the Globe in 2013 because he, “…believes deeply in the future of this great community, and the Globe should play a vital role in determining that future”. How well the paper executes on its bold new strategy is truly mission critical—a matter of life or death for an industry icon. This customer case study tells how Oracle’s Service Cloud is helping The Boston Globe “do something about” and not just “spin” it’s strategy and vision via improved customer service. For example, Oracle RightNow Chat Cloud Service is now the preferred support channel for its online environments. The average e-mail or phone call can take three to four minutes to complete while the average chat is only 30 to 40 seconds. It’s a great example of one company leveraging technology to make things simpler to solve real problems for real people. Related: Oracle Cloud Service a leader in The Forrester Wave™: Customer Service Solutions For Small And Midsize Teams, Q2 2014

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• Can working exclusively with niche apps or tech hurt your career in software development? How to get out of the cycle? [closed]

  - by Keoma

  I'm finding myself in a bit of a pickle. I've been at a pretty comfortable IT group for almost a decade. I got my start here working on web development, mostly CRUD, but have demonstrated the ability to figure out more complex problems. I'm not a rock star, but I have received many compliments on my programming aptitude, and technologists and architects have commented on my ability to pick things up (for example, I recently learned a very popular web framework that shall remain nameless since I don’t want to be identified). My problem is that, over time, my responsibilities have been shifting towards work such as support or ‘development’ with some rather niche products (afraid to mention here due to potential for being identified). Some of this work, if it includes anything resembling coding, is very menial scripting in languages such as Powershell or VBScript. The vast majority of the time, however, a typical day consists of going back and forth with the product’s vendor support to send them logs and apply configuration changes or patches they recommend. I’m basically starved for some actual software development. However, even though I’m more than capable of doing that development work (and actually do a much better job at it than anything else), our boss is more interested in the kind of work I mentioned above, her reasoning being that since no one else in the organization wants to do it, it must mean job security. This has been going on for close to 3 years, and the only reason I have held on is on the promise that we would eventually get more development projects assigned to us. Well, that turned out not to be true at all. A recent talk with the boss has just made it more explicitly clear, as she told me in no uncertain terms that it’s very likely that development work (web or otherwise) would go to another group. The reason given to me is that our we don’t have enough resources in our group to handle that. So now I find myself in the position that I either have to stay in what has essentially become a dead end IT job that is tied to the fortunes of a niche stack of apps, or try to find a position that will be better for my long term career. My problem (is it a problem?), however, is that compared to others, my development projects in the last three years are very sparse in number. To compound things, projects using the latest and most popular frameworks, amount to the big fat number of just one—with no work of that kind in the foreseeable future. I am very concerned that this sparseness in my resume is a deficit, and that it will hurt my chances of landing a different job. I’m also wondering how much it will hurt me, and whether that can be ameliorated with hobby projects of my own. I guess I’m looking for opinions. Thank you very much for reading.

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• prism and multiple screens

  - by Avi

  OK - I am studying Prism a little because of a "free weekend" offer on Pluralsight. As this is proving too complex for me, I went to the Prism book and looked at the forward, and this is what it said: What comes after “Hello, World?” WPF and Silverlight developers are blessed with an abundance of excellent books... There’s no lack of tutorials on Model-View-ViewModel ... But they stop short of the guidance you need to deliver a non-trivial application in full. Your first screen goes well. You add a second screen and a third. Because you started your solution with the built-in “Navigation Application Template,” adding new screens feels like hanging shirts on a closet rod. You are on a roll. Until the harsh reality of real application requirements sets in. As it happens, your application has 30 screens not three. There’s no room on that closet rod for 30 screens. Some screens are modal pop-ups; you don’t navigate to a pop-up. Screens become interdependent such that user activity in one screen triggers changes that propagate throughout the UI. Some screens are optional; others are visible only to authorized users. Some screens are permanent, while other screens can be opened and closed at will. You discover that navigating back to a previously displayed screen creates a new instance. That’s not what you expected and, to your horror, the prior instance is gone along with the user’s unsaved changes. Now the issue is, I don't relate to this description. I've never been a UI programmer, but same as everyone else I'm using Windows apps such as MS-Office, and web sites such as Amazon, Facebook and StackExchange. And I look at these and I don't see many "so many screens" issues! Indeed, the only applications having many windows I can think of is Visual Studio. Maybe also Visio, a little. But take Word - You have a ribbon and a main window. Or take Facebook: You have those lists on the left (Favorites, Lists, Groups etc.), the status middle, the adds and then the Contacts sidebar. But it's only one page. Of course, I understand that in enterprise scenarios there are dashboad applications where multiple segments of the screen are updated from multiple non-related services. This I dig. But other scenarios? So - What am I missing? What is the "multiple screens" monster Pirsm is supposed to be the silver bullet solution for? Shoud I invest in studying Prism in addition to learning WPF or ASP.NET MVC?

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• Will Online Learning Save Higher Education (and does it need saving)?

  - by user739873

  A lot (an awful lot) of education industry rag real estate has been devoted to the topics of online learning, MOOC’s, Udacity, edX, etc., etc. and to the uninitiated you’d think that the education equivalent of the cure for cancer had been discovered. There are certainly skeptics (whose voice is usually swiftly trampled upon by the masses) who feel we could over steer and damage or destroy something vital to teaching and learning (i.e. the classroom experience and direct interaction with human beings known as instructors), but for the most part prevailing opinion seems to be that online learning will take over the world and that higher education will never be the same. Now I’m sure that since you all know I work for a technology company you think I’m going to come down hard on the side of online learning proselytizers. Yes, I do believe that this revolution can and will provide access to massive numbers of individuals that either couldn’t afford (from a fiscal or time perspective) a traditional education, and that in some cases the online modality will actually be an improvement over certain traditional forms (such as courses taught by an adjunct or teaching assistant that has no business being a teacher). But I think several things need immediate attention or we’re likely to get so caught up in the delivery that we miss some of the real issues (and opportunities) around online learning. First and foremost, we’ve got to give some thought to how traditional information systems are going to accommodate thousands (possibly hundreds of thousands) of individual students each taking courses from many, many different “deliverers” with an expectation that successful completion of these courses will result in credit at many or most institutions. There’s also a huge opportunity to refine the delivery platform (no, LMS is not a commodity when you are talking about online delivery being your sole mode of operation) as well as the course itself by mining all kinds of data from the interactions that the students have with the material each time they take it. Social data analytics tools will be key in achieving this goal. What about accreditation (badging or competencies vs. traditional degrees)? And again, will the information systems in place today adapt to changes in this area fast enough? The type of scale that this shift in learning could drive has the potential to abruptly overwhelm just about every system in place today in higher education. I would like to (with a not so gentle reminder) refer you back to a blog entry I wrote when I first stepped into my current role at Oracle in which I talked about how higher ed needs an “Oracle” more than at any other time in it’s evolution (despite the somewhat mercantilist reputation it has in some circles). There just aren’t that many organizations that can deliver the kinds of solutions “at scale” that this brave new world of online education will demand. The future may be closer than we think. Cole

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• Issue 56 - Super Stylesheets Skinning in DotNetNuke 5

  May 2010 Welcome to Issue 56 of DNN Creative Magazine In this issue we show you how to use the powerful new Super Stylesheets skinning feature in DotNetNuke 5. Super Stylesheets are ideal for both beginner and experienced skin designers, they provide skin layouts using CSS. The advantage of Super Stylesheets is that you can easily create a skin layout which works in all browsers without the need to learn complex CSS techniques. They are also very quick to build and you can change a skin layout in a matter of minutes rather than hours. We show you how to build a skin from the very beginning using Super Stylesheets, we show you how to create various skin layouts, as well as multi-layouts. We also show you how to style the skin, how to add tokens such as the logo, menu, login links etc. and walk you through how to create a fully working skin from scratch. Following this we continue the Open Web Studio tutorials, this month we demonstrate how to create an installable DotNetNuke PA module using OWS. This is an essential technique which allows you to package up the OWS applications that you have created and build them into an installable zip package. The zip file is then installable as a standard DotNetNuke module which means you can easily install your OWS applications on other DotNetNuke installations by simply installing them as a standard DotNetNuke module. To finish, we have part six of the "How to Build a News Application with DotNetMushroom Rapid Application Developer (RAD)" article, where we demonstrate how to create a News Carousel using RAD, JQuery and the JCarousel plugin. This issue comes complete with 15 videos. Skinning: Super Stylesheets Skinning in DotNetNuke 5 - DNN Layouts (12 videos - 98mins) Module Development Series: How to Create an Installable DotNetNuke PA Module Using OWS (3 videos - 23mins) How to Implement a News Carousel Using DotNetMushroom RAD and JQuery View issue 56 to download all of the videos in one zip file DNN Creative Magazine for DotNetNuke Web Designers Covering DotNetNuke module video reviews, video tutorials, mp3 interviews, resources and web design tips for working with DotNetNuke. In 56 issues we have created 578 videos!Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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• Getting started with object detection - Image segmentation algorithm

  - by Dev Kanchen

  Just getting started on a hobby object-detection project. My aim is to understand the underlying algorithms and to this end the overall accuracy of the results is (currently) more important than actual run-time. I'm starting with trying to find a good image segmentation algorithm that provide a good jump-off point for the object detection phase. The target images would be "real-world" scenes. I found two techniques which mirrored my thoughts on how to go about this: Graph-based Image Segmentation: http://www.cs.cornell.edu/~dph/papers/seg-ijcv.pdf Contour and Texture Analysis for Image Segmentation: http://www.eng.utah.edu/~bresee/compvision/files/MalikBLS.pdf The first one was really intuitive to understand and seems simple enough to implement, while the second was closer to my initial thoughts on how to go about this (combine color/intensity and texture information to find regions). But it's an order of magnitude more complex (at least for me). My question is - are there any other algorithms I should be looking at that provide the kind of results that these two, specific papers have arrived at. Are there updated versions of these techniques already floating around. Like I mentioned earlier, the goal is relative accuracy of image segmentation (with an eventual aim to achieve a degree of accuracy of object detection) over runtime, with the algorithm being able to segment an image into "naturally" or perceptually important components, as these two algorithms do (each to varying extents). Thanks! P.S.1: I found these two papers after a couple of days of refining my search terms and learning new ones relevant to the exact kind of techniques I was looking for. :) I have just about reached the end of my personal Google creativity, which is why I am finally here! Thanks for the help. P.S.2: I couldn't find good tags for this question. If some relevant ones exist, @mods please add them. P.S.3: I do not know if this is a better fit for cstheory.stackexchange (or even cs.stackexchange). I looked but cstheory seems more appropriate for intricate algorithmic discussions than a broad question like this. Also, I couldn't find any relevant tags there either! But please do move if appropriate.

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• What economic books would you suggest for learning about economic valuation of goods and simulations thereof?

  - by Rushyo

  I'm looking to create an economic model for a game based on goods created procedurally. Every natural resource and produced good would be procedurally generated, with certain goods being assigned certain uses. Fakesium might be used for the production of Weapon A and produced from Fakesium factories which use Dilithium and Widgets as reagents, where Widgets are also the product of Foo and Bar The problem is not creating the resources and their various production utlities - but getting the game's AI empires and merchants to (Addendum: somewhat) correctly value the goods according to their scarcity, utility and production costs. I need to create a simulation of goods which allows the various game factions to assign a common value denominator (credits) to each resource, depending on how much its worth to that empire. I see the simulation being something like: "I have a high requirement for Weapon A. Since I don't have much of Fakesium, which is needed for Weapon A - I must have a high demand for Fakesium. If I can acquire Fakesium, devalue it. If not, increase its value - and also increase demand for Dilithium and Widgets too." This is very naive - because it may be much much cheaper for the empire to simply purchase Dilithium and Widgets directly rather than purchasing Fakesium, for example. Another example is two resources might allow the creation of Weapon A (Fakesium and Lieron), so we'd need to consider that. I've been scratching my head over the problem and it keeps growing. By the time the player joins the world, I'd expect enough iterations of this process to have occurred that prices would have largely normalised - and would then only trigger rarely to compensate for major changes (eg. if the player blows up the world's only Foo mine!) Could anyone suggest resources (books, largely) which outline this style of modelling, preferably in the context of simulations? Since this problem would never occur outside fantasy worlds, I figured this is probably the most likely place to find people who have encountered similar problems and I'm sure there's people who know of good places for Games Developers to start looking at less specific economic theory too. Additionally, does anyone know of any developers with blogs whose games or research applications perform similar modelling? EDIT: I think I should underline that I'm not looking for optimal solutions. I'm looking to make the actors impulsive - making rudimentary decisions based on fuzzy inputs about what they care about or don't. I'm aiming to understand the problem area better not derive answers. All the textbooks I've found seem to be about real-world economics or how to solve complex theoretical problems, neither of which are terribly relevant to the actor's decision making.

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• Profiling Startup Of VS2012 &ndash; Ants Profiler

  - by Alois Kraus

  I just downloaded ANTS Profiler 7.4 to check how fast it is and how deep I can analyze the startup of Visual Studio 2012. The Pro version which is useful does cost 445€ which is ok. To measure a complex system I decided to simply profile VS2012 (Update 1) on my older Intel 6600 2,4GHz with 3 GB RAM and a 32 bit Windows 7. Ants Profiler is really easy to use. So lets try it out. The Ants Profiler does want to start the profiled application by its own which seems to be rather common. I did choose Method Level timing of all managed methods. In the configuration menu I did want to get all call stacks to get full details. Once this is configured you are ready to go.   After that you can select the Method Grid to view Wall Clock Time in ms. I hate percentages which are on by default because I do want to look where absolute time is spent and not something else.   From the Method Grid I can drill down to see where time is spent in a nice and I can look at the decompiled methods where the time is spent. This does really look nice. But did you see the size of the scroll bar in the method grid? Although I wanted all call stacks I do get only about 4 pages of methods to drill down. From the scroll bar count I would guess that the profiler does show me about 150 methods for the complete VS startup. This is nonsense. I will never find a bottleneck in VS when I am presented only a fraction of the methods that were actually executed. I have also tried in the configuration window to also profile the extremely trivial functions but there was no noticeable difference. It seems that the Ants Profiler does filter away way too many details to be useful for bigger systems. If you want to optimize a CPU bound operation inside NUnit then Ants Profiler is with its line level timings a very nice tool to work with. But for bigger stuff it is certainly not usable. I also do not like that I must start the profiled application from the profiler UI. This makes it hard to profile processes which are started by some other process. Next: JetBrains dotTrace

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• Still prompted for a password after adding SSH public key to a server

  - by Nathan Arthur

  I'm attempting to setup a git repository on my Dreamhost web server by following the "Setup: For the Impatient" instructions here. I'm having difficulty setting up public key access to the server. After successfully creating my public key, I ran the following command: cat ~/.ssh/[MY KEY].pub | ssh [USER]@[MACHINE] "mkdir ~/.ssh; cat >> ~/.ssh/authorized_keys" ...replacing the appropriate placeholders with the correct values. Everything seemed to go through fine. The server asked for my password, and, as far as I can tell, executed the command. There is indeed a ~/.ssh/authorized_keys file on the server. The problem: When I try to SSH into the server, it still asks for my password. My understanding is that it shouldn't be asking for my password anymore. What am I missing? EDIT: SSH -v Log: Macbook:~ michaeleckert$ ssh -v [USER]@[SERVER URL] OpenSSH_6.2p2, OSSLShim 0.9.8r 8 Dec 2011 debug1: Reading configuration data /etc/ssh_config debug1: /etc/ssh_config line 20: Applying options for * debug1: /etc/ssh_config line 53: Applying options for * debug1: Connecting to [SERVER URL] [[SERVER IP]] port 22. debug1: Connection established. debug1: identity file /Users/michaeleckert/.ssh/id_rsa type -1 debug1: identity file /Users/michaeleckert/.ssh/id_rsa-cert type -1 debug1: identity file /Users/michaeleckert/.ssh/id_dsa type -1 debug1: identity file /Users/michaeleckert/.ssh/id_dsa-cert type -1 debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_6.2 debug1: Remote protocol version 2.0, remote software version OpenSSH_5.5p1 Debian-6+squeeze3 debug1: match: OpenSSH_5.5p1 Debian-6+squeeze3 pat OpenSSH_5* debug1: SSH2_MSG_KEXINIT sent debug1: SSH2_MSG_KEXINIT received debug1: kex: server->client aes128-ctr hmac-md5 none debug1: kex: client->server aes128-ctr hmac-md5 none debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP debug1: SSH2_MSG_KEX_DH_GEX_INIT sent debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY debug1: Server host key: RSA [STRING OF NUMBERS AND LETTERS SEPARATED BY SEMI-COLONS] debug1: Host ‘[SERVER URL]' is known and matches the RSA host key. debug1: Found key in /Users/michaeleckert/.ssh/known_hosts:2 debug1: ssh_rsa_verify: signature correct debug1: SSH2_MSG_NEWKEYS sent debug1: expecting SSH2_MSG_NEWKEYS debug1: SSH2_MSG_NEWKEYS received debug1: Roaming not allowed by server debug1: SSH2_MSG_SERVICE_REQUEST sent debug1: SSH2_MSG_SERVICE_ACCEPT received debug1: Authentications that can continue: publickey,password debug1: Next authentication method: publickey debug1: Trying private key: /Users/michaeleckert/.ssh/id_rsa debug1: Trying private key: /Users/michaeleckert/.ssh/id_dsa debug1: Next authentication method: password [USER]@[SERVER URL]'s password: debug1: Authentication succeeded (password). Authenticated to [SERVER URL] ([[SERVER IP]]:22). debug1: channel 0: new [client-session] debug1: Requesting [email protected] debug1: Entering interactive session. debug1: Sending environment. debug1: Sending env LANG = en_US.UTF-8 Welcome to [SERVER URL] Any malicious and/or unauthorized activity is strictly forbidden. All activity may be logged by DreamHost Web Hosting. Last login: Sun Nov 3 12:04:21 2013 from [MY IP] [[SERVER NAME]]$

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

  - by greenoldman

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

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• Lenovo W520 back usb port not working

  - by jaudette

  The usb port in the back of my laptop (on the right side when viewed from using perspective) is not working. Does anybody know if we can get this port working, and what the port number is. Here is my lsusb, if it can help. % lsusb Bus 001 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub Bus 002 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub Bus 003 Device 002: ID 046d:c01e Logitech, Inc. MX518 Optical Mouse Bus 003 Device 003: ID 046d:c318 Logitech, Inc. Illuminated Keyboard Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 001 Device 003: ID 0765:5001 X-Rite, Inc. Huey PRO Colorimeter Bus 001 Device 004: ID 147e:2016 Upek Biometric Touchchip/Touchstrip Fingerprint Sensor Bus 001 Device 005: ID 0a5c:217f Broadcom Corp. Bluetooth Controller Bus 001 Device 006: ID 04f2:b217 Chicony Electronics Co., Ltd Lenovo Integrated Camera (0.3MP) Bus 002 Device 003: ID 17ef:1003 Lenovo Integrated Smart Card Reader I am running 12.10, upgraded from 12.04 but it did not work either in 12.04. The two usb ports on the left work just fine. EDIT: I just updated my bios from 1.32 to 1.39, no change in behaviour. The port does not even power up my devices. EDIT 2: Booted up windows, and the port is working. I went into the device manager and looked at the USB settings. I found my USB drive on Port 2, Hub 3, i just don't know how that relates to the Bus and Device numbers of linux. In windows, Smart card reader was on USB hub located at port 1 hub 2, fingerprint and bluetooth were on USB hub located at port 1 hub 1 EDIT 3: Went and looked at this SO post. Tried to look at my kern.log file with tail -f /var/log/kern.log. Got some activity when plugging/removing devices in other ports, but nothing happens when connecting a device into that port. It really looks disabled. Looked at my usb1-4 sys/bus/usb/devices/usb1/power/control and they are all set on auto. As expected, usb4 have version 3.00, the others (usb1-usb3) are 2.00.

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• Switch from back-end to front-end programming: I'm out of my comfort zone, should I switch back?

  - by ripper234

  I've been a backend developer for a long time, and I really swim in that field. C++/C#/Java, databases, NoSql, caching - I feel very much at ease around these platforms/concepts. In the past few years, I started to taste end-to-end web programming, and recently I decided to take a job offer in a front end team developing a large, complex product. I wanted to break out of my comfort zone and become more of an "all around developer". Problem is, I'm getting more and more convinced I don't like it. Things I like about backend programming, and missing in frontend stuff: More interesting problems - When I compare designing a server that handle massive data, to adding another form to a page or changing the validation logic, I find the former a lot more interesting. Refactoring refactoring refactoring - I am addicted to Visual Studio with Resharper, or IntelliJ. I feel very comfortable writing code as it goes without investing too much thought, because I know that with a few clicks I can refactor it into beautiful code. To my knowledge, this doesn't exist at all in javascript. Intellisense and navigation - I hate looking at a bunch of JS code without instantly being able to know what it does. In VS/IntelliJ I can summon the documentation, navigate to the code, climb up inheritance hiererchies ... life is sweet. Auto-completion - Just hit Ctrl-Space on an object to see what you can do with it. Easier to test - With almost any backend feature, I can use TDD to capture the requirements, see a bunch of failing tests, then implement, knowing that if the tests pass I did my job well. With frontend, while tests can help a bit, I find that most of the testing is still manual - fire up that browser and verify the site didn't break. I miss that feeling of "A green CI means everything is well with the world." Now, I've only seriously practiced frontend development for about two months now, so this might seem premature ... but I'm getting a nagging feeling that I should abandon this quest and return to my comfort zone, because, well, it's so comfy and fun. Another point worth mentioning in this context is that while I am learning some frontend tools, a lot of what I'm learning is our company's specific infrastructure, which I'm not sure will be very useful later on in my career. Any suggestions or tips? Do you think I should give frontend programming "a proper chance" of at least six to twelve months before calling it quits? Could all my pains be growing pains, and will they magically disappear as I get more experienced? Or is gaining this perspective is valuable enough, even if plan to do more "backend stuff" later on, that it's worth grinding my teeth and continuing with my learning?

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• So, I though I wanted to learn frontend/web development and break out of my comfort zone...

  - by ripper234

  I've been a backend developer for a long time, and I really swim in that field. C++/C#/Java, databases, NoSql, caching - I feel very much at ease around these platforms/concepts. In the past few years, I started to taste end-to-end web programming, and recently I decided to take a job offer in a front end team developing a large, complex product. I wanted to break out of my comfort zone and become more of an "all around developer". Problem is, I'm getting more and more convinced I don't like it. Things I like about backend programming, and missing in frontend stuff: More interesting problems - When I compare designing a server that handle massive data, to adding another form to a page or changing the validation logic, I find the former a lot more interesting. Refactoring refactoring refactoring - I am addicted to Visual Studio with Resharper, or IntelliJ. I feel very comfortable writing code as it goes without investing too much thought, because I know that with a few clicks I can refactor it into beautiful code. To my knowledge, this doesn't exist at all in javascript. Intellisense and navigation - I hate looking at a bunch of JS code without instantly being able to know what it does. In VS/IntelliJ I can summon the documentation, navigate to the code, climb up inheritance hiererchies ... life is sweet. Auto-completion - Just hit Ctrl-Space on an object to see what you can do with it. Easier to test - With almost any backend feature, I can use TDD to capture the requirements, see a bunch of failing tests, then implement, knowing that if the tests pass I did my job well. With frontend, while tests can help a bit, I find that most of the testing is still manual - fire up that browser and verify the site didn't break. I miss that feeling of "A green CI means everything is well with the world." Now, I've only seriously practiced frontend development for about two months now, so this might seem premature ... but I'm getting a nagging feeling that I should abandon this quest and return to my comfort zone, because, well, it's so comfy and fun. Another point worth mentioning in this context is that while I am learning some frontend tools, a lot of what I'm learning is our company's specific infrastructure, which I'm not sure will be very useful later on in my career. Any suggestions or tips? Do you think I should give frontend programming "a proper chance" of at least six to twelve months before calling it quits? Could all my pains be growing pains, and will they magically disappear as I get more experienced? Or is gaining this perspective is valuable enough, even if plan to do more "backend stuff" later on, that it's worth grinding my teeth and continuing with my learning?

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• Learning by doing (and programming by trial and error)

  - by AlexBottoni

  How do you learn a new platform/toolkit while producing working code and keeping your codebase clean? When I know what I can do with the underlying platform and toolkit, I usually do this: I create a new branch (with GIT, in my case) I write a few unit tests (with JUnit, for example) I write my code until it passes my tests So far, so good. The problem is that very often I do not know what I can do with the toolkit because it is brand new to me. I work as a consulant so I cannot have my preferred language/platform/toolkit. I have to cope with whatever the customer uses for the task at hand. Most often, I have to deal (often in a hurry) with a large toolkit that I know very little so I'm forced to "learn by doing" (actually, programming by "trial and error") and this makes me anxious. Please note that, at some point in the learning process, usually I already have: read one or more five-stars books followed one or more web tutorials (writing working code a line at a time) created a couple of small experimental projects with my IDE (IntelliJ IDEA, at the moment. I use Eclipse, Netbeans and others, as well.) Despite all my efforts, at this point usually I can just have a coarse understanding of the platform/toolkit I have to use. I cannot yet grasp each and every detail. This means that each and every new feature that involves some data preparation and some non-trivial algorithm is a pain to implement and requires a lot of trial-and-error. Unfortunately, working by trial-and-error is neither safe nor easy. Actually, this is the phase that makes me most anxious: experimenting with a new toolkit while producing working code and keeping my codebase clean. Usually, at this stage I cannot use the Eclipse Scrapbook because the code I have to write is already too large and complex for this small tool. In the same way, I cannot use any more an indipendent small project for my experiments because I need to try the new code in place. I can just write my code in place and rely on GIT for a safe bail-out. This makes me anxious because this kind of intertwined, half-ripe code can rapidly become incredibly hard to manage. How do you face this phase of the development process? How do you learn-by-doing without making a mess of your codebase? Any tips&tricks, best practice or something like that?

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• DTLoggedExec 1.1.2008.4 Released!

  - by Davide Mauri

  Today I've relased the latest version of my DTExec replacement tool, DTLoggedExec. The main changes are the following: Used a new strategy for version numbers. Now it will follow the following pattern Major.Minor.TargetSQLServerVersion.Revision Added support for Auto Configurations Fixed a bug that reported incorrect number of errors and warnings to Log Providers Fixed a buf that prevented correct casting of values when using /Set and /Param options Errors and Warnings are now counted more precisely. Updated database and log import scripts to categorize logs by projects and sections. E.g.: Project: MyBIProject; Sections: Staging, Datawarehouse Removed unused report stored procedures from database Updated Samples: 12 samples are now available to show ALL DTLoggedExec features From this version only SSIS 2008 will be supported http://dtloggedexec.codeplex.com/releases/view/62218  It useful to say something more on a couple of specific points: From this version only SSIS 2008 will be supportedYes, Integration Services 2005 are not supported anymore. The latest version capable of running SSIS 2005 Packages is the 1.0.0.2. Updated database and log import scripts to categorize logs by projects and sectionsWhen you import a log file, you can now assign it to a Project and to a Section of that project. In this way it's easier to gather statistical information for an entire project or a subsection of it. This also allows to store logged data of package belonging to different projects in the same database. For example:  Updated SamplesA complete set of samples that shows how to use all DTLoggedExec features are now shipped with the product. Enjoy! Added support for Auto ConfigurationsThis point will have a post on its own, since it's quite important and is by far the biggest new feature introduced in this release. To explain it in a few words, I can just say that you don't need to waste time with complex DTS configuration files or options, since a package will configure itself automatically. You just need to write a single statement as a parameter for DTLoggedExec. This feature can simplify deployment *a lot* :)   I the next days I'll write the mentioned post on Auto-Configurations and i'll update the documentation available on theDTLoggedExec website:   http://dtloggedexec.davidemauri.it/MainPage.ashx

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• IPS Package Groups

  - by Alan_Solaris_RE

  IPS group packages consist solely of dependencies on other packages that make up a logical grouping of software. These are similar to, but not the equivalent of, Solaris 10 metaclusters. The main difference is that metaclusters are nested subsets ranging from a minimal install to nearly all packages on the media. Group packages have no such hierarchy. They can overlap other groups, or be completely disjoint sets. A group dependency is set this way in an IPS package manifest file: depend fmri=full/pkg/name type=group Current Solaris Groups Solaris currently has 4 system groups defined. These are used for different types of installation, and are included in the xml manifest files used by the various Solaris installers: Package Name Summary Description Default Installation For:  group/system/solaris-desktop Oracle Solaris Desktop Provides an Oracle Solaris desktop environment Live Media  group/system/solaris-large-server Oracle Solaris Large Server Provides an Oracle Solaris large server environment Text Installer  group/system/solaris-small-server Oracle Solaris Small Server Provides a useful command-line Oracle Solaris environment  Zones  group/system/solaris-auto-install  Oracle Solaris Automated Installer Client  Provides an Oracle Solaris Automated Installer client  Automated Installer There are also several "feature" groups such as AMP and GNU Developer Tools. These are provided for convenience, but are not used directly by any installers. Retrieving Group Package Information A listing of all current groups can be found with the command: pkg info -r group/* A listing of all the packages in a group can be obtained with: pkg contents -o fmri -H -rt depend -a type=group groupname An example: $ pkg contents -o fmri -H -rt depend -a type=group solaris-desktop archiver/gnu-tar audio/audio-utilities codec/flac codec/libtheora codec/ogg-vorbis codec/speex communication/im/pidgin etc. You can determine which package group is currently installed on your system: $ pkg list group/system/\* Output would look like: NAME (PUBLISHER) VERSION IFO group/system/solaris-desktop 0.5.11-0.175.0.0.0.0.0 i-- Note that there are not version numbers associated with a group package dependency. The package version that best fits the system will be used, based on other dependencies such as what is listed in incorporation files. Installing a Group To Install a group, simple use the group package name as you would any other package: $ pkg install solaris-small-server  If you want to exclude a package from installing, you can use the --reject flag: $ pkg install --reject audio/audio-utilities solaris-desktop Creating Your Own Group To create your own group package, you can follow the pkg(5) documentation on how to create a package, and use this action for each package that is part of your group:   depend fmri=full/pkg/name type=group

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• ATG Live Webcast Dec. 6th: Minimizing EBS Maintenance Downtimes

  - by Bill Sawyer

  This webcast provides an overview of the plans and decisions you can make, and the actions you can take, that will help you minimize maintenance downtimes for your E-Business Suite instances. It is targeted to system administrators, DBAs, developers, and implementers. This session, led by Elke Phelps, Senior Principal Product Manager, and Santiago Bastidas, Principal Product Manager, will cover best practices, tools, utilities, and tasks to minimize your maintenance downtimes during the four key maintenance phases. Topics will include: Pre-Patching: Reviewing the list of patches and analyzing their impact Patching Trials: Testing the patch prior to actual production deployment Patch Deployment: Applying patching to your system Post Patching Analysis: Validating the patch application Date:                Thursday, December 6, 2012Time:               8:00 AM - 9:00 AM Pacific Standard TimePresenters:   Elke Phelps, Senior Principal Product Manager                         Santiago Bastidas, Principal Product Manager Webcast Registration Link (Preregistration is optional but encouraged) To hear the audio feed:    Domestic Participant Dial-In Number:           877-697-8128    International Participant Dial-In Number:      706-634-9568    Additional International Dial-In Numbers Link:    Dial-In Passcode:                                              103200To see the presentation:    The Direct Access Web Conference details are:    Website URL: https://ouweb.webex.com    Meeting Number:  595757500 If you miss the webcast, or you have missed any webcast, don't worry -- we'll post links to the recording as soon as it's available from Oracle University.  You can monitor this blog for pointers to the replay. And, you can find our archive of our past webcasts and training here. If you have any questions or comments, feel free to email Bill Sawyer (Senior Manager, Applications Technology Curriculum) at BilldotSawyer-AT-Oracle-DOT-com.

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• More elegant way to avoid hard coding the format of a a CSV file?

  - by dsollen

  I know this is trivial issue, but I just feel this can be more elegant. So I need to write/read data files for my program, lets say they are CSV for now. I can implement the format as I see fit, but I may have need to change that format later. The simply thing to do is something like out.write(For.getValue()+","+bar.getMinValue()+","+fi.toString()); This is easy to write, but obviously is guilty of hard coding and the general 'magic number' issue. The format is hard-coded, requires parsing of the code to figure out the file format, and changing the format requires changing multiple methods. I could instead have my constants specifying the location that I want each variable to be saved in the CSV file to remove some of the 'magic numbers'; then save/load into the an array at the location specified by the constants: int FOO_LOCATION=0; int BAR_MIN_VAL_LOCATION=1; int FI_LOCATION=2 int NUM_ARGUMENTS=3; String[] outputArguments=new String[NUM_ARGUMENTS]; outputArguments[FOO_LOCATION] = foo.getValue(); outputArgumetns[BAR_MIN_VAL_LOCATION] = bar.getMinValue(); outptArguments[FI_LOCATOIN==fi.toString(); writeAsCSV(outputArguments); But this is...extremely verbose and still a bit ugly. It makes it easy to see the format of existing CSV and to swap the location of variables within the file easily. However, if I decide to add an extra value to the csv I need to not only add a new constant, but also modify the read and write methods to add the logic that actually saves/reads the argument from the array; I still have to hunt down every method using these variables and change them by hand! If I use Java enums I can clean this up slightly, but the real issue is still present. Short of some sort of functional programming (and java's inner classes are too ugly to be considered functional) I still have no obvious way of clearly expressing what variable is associated with each constant short of writing (and maintaining) it in the read/write methods. For instance I still need to write somewhere that the FOO_LOCATION specifies the location of foo.getValue(). It seems as if there should be a prettier, easier to maintain, manner for approaching this? Incidentally, I'm working in java at the moment, however, I am interested conceptually about the design approach regardless of language. Some library in java that does all the work for me is definitely welcome (though it may prove more hassle to get permission to add it to the codebase then to just write something by hand quickly), but what I'm really asking is more about how to write elegant code if you had to do this by hand.

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• Your Cinnamon Roll & Morning Coffee: Powered by Oracle Enterprise Manager

  - by Ruma Sanyal

  1024x768 Truth be told, as I was getting my morning coffee today, I was pondering the recent election results more than Oracle [there, I said it]. But then an email from Glen Hawkins from the Enterprise Management team hit my Inbox and I started viewing this video. It was about the world’s largest convenience store chain, 7-Eleven, focusing on creating the best Digital Guest Experience (DGE) for their customers. Turns out that Oracle Enterprise Manager (OEM) powers 7-Eleven’s DGE Middleware Platform as a Service solution that consists of Oracle SOA Suite, Exalogic, and Exadata. “We need to present a consistent view of 7-Eleven across all our endpoints: 10,000 stores & various digital entities like our websites and apps”, said Ronald Clanton, the DGE Program Director for 7-Eleven. As 7-Eleven was rolling out a loyalty program with mobile support across multiple geos, it had many complex business & technical requirements, including supporting a wide variety of different apps, 10M guests in NA alone, ability to support high speed transactions, and very aggressive timelines. A key requirement was shortening the cycle for provisioning new environments. Whereas with other vendors this would take a few weeks, Oracle consulting showed them how with OEM provisioning new environments would take half a day, which was quite impressive. 7-Eleven has started to roll out this new program and are delighted to report that some provisioning cycles are as low as 10 minutes which includes provisioning the full Oracle SOA suite, Exalogic and more. They are delighted with OEM’s reporting capabilities and customization thereof. Watch the video to see for yourself. Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";}

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• Nvidia driver overscan issue second monitor via dvi-d cable

  - by benmichael

  Ok, I know that I have a bit of a bizarre setup, but here goes. I have an old laptop, HP Pavilion 6000. The graphics card in there is a GeForce 7150M. The monitor connection is an old 18pin. The external monitor I use is a Samsung SyncMaster 2333. Don't ask me why, but this monitor only has a dvi-d connection (yes, i have searched it). So I have the monitor plugged into the laptop. If I use any of the Nvidia propriety drivers and try to set the resolution up to 1920x1080 (the monitor's native resolution), I get a massive overscan issue. Over the years I have tried to get this to work, tinkering with my xorg.conf to death. I have also tried this on every Ubuntu since 10.04, on all the corresponding LUbuntus, and on all the Linux Mints since Lisa. Exact same issue. I have even tried it in WinDoze and it works perfectly there (although I did get the error once, but was unable to reproduce it). Using the Open Source drivers it works perfectly iff I switch off the laptop monitor (this makes no difference with the Nvidia drivers). I would have happily gone on using the Open Source drivers, except that since upgrading to LUbuntu 12.10, the Open Source drivers make my monitor completely hazy and have the same overscan issue until I (through the haze, only because I know where things are) go to the monitor settings, activate the laptop's monitor, then deactivate it, and suddenly it comes right. I have to do this every time. So I have to find a way to fix one of them, so I may as well tackle the propriety drivers, hence this overlong question. Amidst other things, I have tried the nvidia-settings, but because it is connected to an 18pin, it detects the monitor as a vga monitor and does not give me overscan correction options. I have tried custom modlines (although there are always more of those try), I have tried using xrandr, and I have tried all the FlatPanelOptions. What I have not tried is a Gentoo build, as I don't have time any more to do that installation, but up to about three years ago when I ran Gentoo exclusively I did not have this issue. Below is an link to an image with a red highlight around the portion of the screen visible to me, the numbers around it are the number of pixels which are cut off. This does seem to drift a few pixels every now and then. Thanks in advance. Nvidia driver issue image

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• Looking for recommendations for a server-side newsletter program

  - by Sparky672

  Hello- I'm currently using a server-side SQL based mailing list program called Php-List on multiple sites and it works fairly well. But installation and setup is quite cumbersome, quirky and the interface is not well organized... neither is the code... with pieces all over the place in random fashion. Customizing the "look & feel" and full site integration are both tedious and painful. Upgrading the version is made more complex since multiple edits need to be manually transferred each time. Also, probably due to a poor English translation, descriptions and instructions within certain areas of the user interface are contradictory and unclear. You just have to play with it and remember what you did last time it worked. It's supposed to be so my customers can send out their own newsletters... after supplying a written tutorial, about half of them seem to stumble through it okay and the other half just hire me to do it for them. So not quite easy enough for most average people to use. I'm looking for something that's as easy for them as using a blog or discussion forum. It also must be easier to set up and integrate into a site than Php-List. I have no problem getting dirty and writing CSS or HTML by hand. Nor do I have any problem editing the program code. Perhaps what I'm looking for is a solution that is more organized, a better GUI, and template or "skin" based. Therefore, if I spend many hours customizing a skin, I can simply update the program and re-use my custom skin without having to reproduce the tedious setup over and over. (I currently maintain a list of about 25 things I must manually edit or add to multiple files in multiple directories each time I install or upgrade Php-List) A great example of what I'm looking for is very much like WordPress or phpBB. They're both easy to install and customize yet powerful and packed full of features. They're also VERY well organized making customization less painful. So enough yammering for now... anyone know of something, besides Php-List, with many of the same features as Php-List; maintaining a mailing list with a server-side database, custom sign-up pages, automatic opt-in opt-out, allowing custom HTML newsletter templates, etc? Thank-you!

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

  - by alan2here

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

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