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• Looking for recommendations on OCR problem - tabular numeric data

  - by ldigas

  I have 20 pages of experiment measurement data which I need to digitalize. The results are in tabular form, scanned in 600 dpi resolution, and as far as scans go, they came up pretty clean and readable. For an example of how it looks see here (but beware: it is a rather big scan; about 5Mb; no problem for any broadband connection, but dialups should approach with caution!) ... and I need it finished by sunday afternoon (:-o) <-- smiley in a state of panic (then why did't you start sooner?)... yea, yeah ... I know ... but, it came up late, and I wasn't thinking I was gonna need this data also. So, I'm looking for recommendations. I haven't much experience with OCR programs, save scanning a page or two of pure text, but just to mention, I haven't the wish also to test out every OCR program out there. So this isn't a "name your OCR favourite". What I'm looking is advice from someone who's done something like that, and his/hers experience on what would be the best way to undertake. I need the data in txt form but since it will have to be checked (by drawing it, and just simply watching whether some points "jump out") I'll probably be entering it in Excel at first.

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• Western Digitial My Book: Can't access the data on the drive

  - by Bryan Denny

  My girlfriend has this external hard drive by Western Digital called a My Book. When the external drive is connected, it does not show it as an accessible disk drive on the computer. However, it shows up fine in Device Manager: I can also see it in Disk Management, but the volume is not mapped to a drive letter, nor can I change the drive letter: It only gives me access to Delete Volume: I would rather not lose the data on the drive if possible. What can I do from here to get to the data? Things I've tried/know: Uninstall drivers and re-install them Device does the same thing when attach to either her Win7 laptop or my Win8 laptop I don't think there's an issue with the HDD itself. No clicking noises, etc. I ran Western Digital Data LifeGuard Diangostics (DLGDIAG) and the SMART Status was a "PASS", all of the SMART Disk Information looked fine. I haven't had the time to run the diag tests yet but I do not believe it's a mechanical issue. The hard drive is inside of an enclosure, I have not attempted to pry the drive out yet. How can I get Windows to properly detect this drive?

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• How to I access "Deny" message from a Lidgren client?

  - by TJ Mott

  I'm using the Lidgren v3 network for a UDP client/server networking model. On the server end, I'm initializing a NetServer object with the NetIncomingMessage.ConnectionApproval message type enabled. So the client is able to successfully connect and the first packet it sends is a login packet, containing a username and password supplied by the user. The server is receiving that and doing some black magic to authenticate, and everything works up to that point. If the login fails, the server calling NetIncomingMessage.SenderConnection.Deny("Invalid Login Credentials"). I want to know how to properly receive this deny message on the client. I'm getting the message, it shows up with a message type of NetIncomingMessage.StatusChanged. If I call ReadString on that message, I get a corrupted version of the string I passed to the Deny method on the server. The type of corruption varies, I've seen odd characters in there but in every case it's truncated and is way shorter than the string I entered. Any ideas? The official documentation is sparse on this topic. I could use pointers from anyone who has successfully used the Lidgren library and uses the Accept or Deny methods. Also, if I don't do any authentication and just Approve() the connection every time, stuff actually works just fine and I'm getting reliable two-way UDP traffic. (And lastly, Stack Exchange said I don't have enough reputation to use the "Lidgren" tag....???)

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• Divide pivot table data by an arbitrary column in another table

  - by rsavu

  Hello all, I have this data from a pivot table: Countries P1 P2 Total Country 1 10 69 Country 2 36 2 92 Country 3 21 24 100 Country 4 22 77 Country 5 13 79 Country 6 12 1 48 Country 7 14 29 Country 8 22 1 46 Country 9 4 1 31 Country 10 16 7 120 Country 11 25 2 114 Country 12 8 11 68 Country 13 5 27 Country 14 11 3 23 Country 15 6 19 Country 16 33 79 Where: 1st column is the country name 2nd and 3rd column are the tickets introduced in the system 4th column is the total (disregard the data - total is not accurate) Additionally, I have another table that looks like this: Country P1 P2 Country 1 2 3 Country 2 2 2 Country 3 0 2 Country 4 0 3 Country 5 1 1 Country 6 2 2 Country 7 1 2 Country 8 3 3 Country 9 1 4 Country 10 2 1 Country 11 4 2 Country 12 2 1 Country 13 3 2 Country 14 3 3 Country 15 1 2 Country 16 2 2 Where the data represents the number of users of the application in each country. I want to be able to show the number of tickets submitted divided by the number of users in each country. Any ideeas how to do that? Thank you very much, Razvan

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• How To Replace Laptop HDD Without Losing Data?

  - by Ishan

  Hello, I recently went to Dell Service center and they tell that HDD is faulty and needs to be replaced. I have a Studio 1457 laptop with 500 GB HDD and don't want to lose the data(purchased in May 2010, still under warranty). I have searched a bit and I think it may be best to use a disk imaging software for this task. However, I don't know about a good software. I have following steps in mind: Get a 1 TB External HDD. Make an image of existing 500 GB HDD and store data on external disk. Install new HDD and install a brand new Windows copy and then install the software on it. Using the same software I used to make image, restore the old HDD image on new one. However, I have some questions in mind. First, is this possible? Second, I live in a country where piracy is a big issue and I am sure the support executive who will come to change HDD will have a pirated copy. But I have genuine Windows 7 Pro and don't want to lose it. Now, Dell does not supply and OS disks, so I can't install it on new HDD! If I follow above steps, which version of Windows 7 will be retained? One in the image(authentic) or one in the new HDD(pirated). I am ready to purchase a good software for this task and my budget is $50-60. Since laptop is under warranty, new HDD will be free. One last thing, I have created a Windows Migration file whose size is 70 GB. Can it be used to move from Windows 7 Pro to Windows 7 Pro?(In case I get a genuine copy of Windows 7!) Any other method to save all the data? Thanks in advance.

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• SQL Error (1064) when importing data from SQL file

  - by mejpark

  I have a MySQL database, which was originally set up with the default latin1 character set and latin1_swedish_ci collation. I was using the database like this for sometime, until I noticed strange characters on my production web site, which is powered by a database exported from my development machine. At this point, I changed the default character set of the database and tables to utf8 and the collation to utf8_unicode_ci, converted the latin1 data inside each table to utf8 (using the 'convert data' option) and exported the database as a single SQL file using HeidiSQL. When the resulting SQL file is opened in Notepad++, several characters are rendered incorrectly. For example, en dashes (-) are displayed as – and e with accent (é) are displayed as é. I changed the encoding of the file from ANSI to UTF-8 (using the encoding menu option in Notepad++) and the offending characters are rendered correctly. I saved the new utf8-encoded SQL file and attempted to import the contents into the MySQL database on my production server. The import process fails with following error: /* SQL Error (1064): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '?# -------------------------------------------------------- # Host: ' at line 1 */ /* Error with snippets directory: The specified path was not found */ The head of the SQL file: # -------------------------------------------------------- # Host: 127.0.0.1 # Server version: 5.1.33-community # Server OS: Win32 # HeidiSQL version: 6.0.0.3773 # Date/time: 2011-04-20 09:48:36 # -------------------------------------------------------- It chokes on the first line of the file, which is commented out. Why is this happening? I didn't have a problem loading data from SQL files until I changed the character set and collation of the database. I came up with an ugly workaround to this problem by performing following steps: Export database as single SQL file using HeidiSQL Open resulting file in Notepad++ and convert from ANSI to UTF-8 encoding Create new empty file in Notepad++, paste in UTF-8 and save file normally What am I missing here?

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• What's the best practice to do SOA exception handling?

  - by sun1991

  Here's some interesting debate going on between me and my colleague when coming to handle SOA exceptions: On one side, I support what Juval Lowy said in Programming WCF Services 3rd Edition: As stated at the beginning of this chapter, it is a common illusion that clients care about errors or have anything meaningful to do when they occur. Any attempt to bake such capabilities into the client creates an inordinate degree of coupling between the client and the object, raising serious design questions. How could the client possibly know more about the error than the service, unless it is tightly coupled to it? What if the error originated several layers below the service—should the client be coupled to those lowlevel layers? Should the client try the call again? How often and how frequently? Should the client inform the user of the error? Is there a user? By having all service exceptions be indistinguishable from one another, WCF decouples the client from the service. The less the client knows about what happened on the service side, the more decoupled the interaction will be. On the other side, here's what my colleague suggest: I believe it’s simply incorrect, as it does not align with best practices in building a service oriented architecture and it ignores the general idea that there are problems that users are able to recover from, such as not keying a value correctly. If we considered only systems exceptions, perhaps this idea holds, but systems exceptions are only part of the exception domain. User recoverable exceptions are the other part of the domain and are likely to happen on a regular basis. I believe the correct way to build a service oriented architecture is to map user recoverable situations to checked exceptions, then to marshall each checked exception back to the client as a unique exception that client application programmers are able to handle appropriately. Marshall all runtime exceptions back to the client as a system exception, along with the stack trace so that it is easy to troubleshoot the root cause. I'd like to know what you think about this? Thank you.

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• Should a project start with the client or the server?

  - by MadBurn

  Pretty simple question with a complex answer. Should a project start with the client or the server, and why? Where should a single programmer start a client/server project? What are the best practices and what are the reasons behind them? If you can't think of any, what reasons do you use to justify why you would choose to start one before the other? Personally, I'm asking this question because I'm finishing up specs for a project I will be doing for myself on the side for fun. But now that I'm finishing this phase, I'm wondering "ok, now where do I begin?" Since I've never done a project like this by myself, I'm not sure where I should start. In this project, my server will be doing all the heavy lifting and the client will just be sending updates, getting information from the server, and displaying it. But, I don't want that to sway the answer as I'm looking for more of an in depth and less specific answer that would apply to any project I begin in the future.

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• How to configure ubuntu ldap client to get password policies from server?

  - by Rafaeldv

  I have a ldap server on CentOS, 389-ds. I configured the client, ubuntu 12.04, to authenticate on that base and it works very well. But it don't gets the password policies from server. For example, if i set the policy to force user to change the password on first login, ubuntu ignores it and logs him in, always. How can i setup the client to get the policies? Here are the client files: /etc/nsswitch.conf passwd: files ldap group: files ldap shadow: files ldap hosts: files mdns4_minimal [NOTFOUND=return] dns mdns4 networks: files protocols: db files services: db files ethers: db files rpc: db files netgroup: nis sudoers: ldap files common-auth auth [success=2 default=ignore] pam_unix.so nullok_secure auth [success=1 default=ignore] pam_ldap.so use_first_pass auth requisite pam_deny.so auth required pam_permit.so auth optional pam_cap.so common-account account [success=2 new_authtok_reqd=done default=ignore] pam_unix.so account [success=1 default=ignore] pam_ldap.so account requisite pam_deny.so account required pam_permit.so common-password password requisite pam_cracklib.so retry=3 minlen=8 difok=3 password [success=2 default=ignore] pam_unix.so obscure use_authtok try_first_pass sha512 password [success=1 user_unknown=ignore default=die] pam_ldap.so use_authtok try_first_pass password requisite pam_deny.so password required pam_permit.so password optional pam_gnome_keyring.so common-session session [default=1] pam_permit.so session requisite pam_deny.so session required pam_permit.so session optional pam_umask.so session required pam_unix.so session optional pam_ldap.so session optional pam_ck_connector.so nox11 session optional pam_mkhomedir.so skel=/etc/skel umask=0022 /etc/ldap.conf base dc=a,dc=b,dc=c uri ldaps://a.b.c/ ldap_version 3 rootbinddn cn=directory manager pam_password md5 sudoers_base ou=SUDOers,dc=a,dc=b,dc=c pam_lookup_policy yes pam_check_host_attr yes nss_initgroups_ignoreusers avahi,avahi-autoipd,backup,bin,colord,daemon,games,gnats,hplip,irc,kernoops,libuuid,lightdm,list,lp,mail,man,messagebus,news,proxy,pulse,root,rtkit,saned,speech-dispatcher,sshd,sync,sys,syslog,usbmux,uucp,whoopsie,www-data /etc/ldap/ldap.conf BASE dc=a,dc=b,dc=c URI ldaps://a.b.c/ ssl on use_sasl no tls_checkpeer no sudoers_base ou=SUDOers,dc=a,dc=b,dc=c sudoers_debug 2 pam_lookup_policy yes pam_check_host_attr yes pam_lookup_policy yes pam_check_host_attr yes TLS_CACERT /etc/ssl/certs/ca-certificates.crt TLS_REQCERT never

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• Dropped WD External Harddisk, now it's shown as "Not initialized"

  - by Phelios

  So, the WD my passport external harddisk is dropped, and after that, the computer is unable to read it anymore. I was hopping if I can just find another case to try if the harddisk is still readable, but looks like the hard drive itself is not a normal SATA or PATA drive. I think it's modified. So, I can't find another case that I can try on. In the computer, I still can see the drive in the "Disk Management", but it's shown as Uninitialized, no size, and no drive letter. I've also tried a couple of recovery tools. Some can't detect at all, there is one (find and mount software) that can detect but shows 0 size. None of them can recover the data. WD is willing to replace it with a new one, but I still need to recover the data. Any way I can recover the data? UPDATE: I tried initialized it from the windows Disk Manager, but it give error "The request could not be performed because of an I/O device error."

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• Can MySQL use multiple data directories on different physical storage devices

  - by sirlark

  I am running MySQL with its data dir on a 128Gb SSD. I am dealing with large datasets (~20Gb) that are loaded and processed weekly, each stored in a separate DB for the purposes of time point comparisons. Putting all the data into a single database in unfeasible because the performance on such large databases is already a problem. However, I cannot keep more than 6 datasets on the SSD at a time. Right now I am manually dumping the oldest to much larger 2Tb spinning disk every week, and dropping the database to make space for the new one. But if I need one of the 'archived' databases (a semi regular occurrence) I have to drop a current one (after dumping), reload it, do what I need to, then reverse the results. Is there a way to configure MySQL to use multiple data directories, say one on the SSD and one on the 2Tb spinning disk, and 'merge' them transparently? If I could do this, then archiving would no longer mean "moved out of the database entirely", but instead would mean "moved onto the slow physical device". The time taken to do my queries on a spinning disk would be less than that taken to completely dump, drop, load, drop, reload two entire databases, so this is a win. I thought of using something like unionfs but I can't think of a way to control which database gets stored on which physical drive, because it works by merging on a directory level (from what I understand) so I'm still stuck with using multiple directories. Any help appreciated, thanks in advance

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• Find slow network nodes between two data centers

  - by 2called-chaos

  I've got a problem with syncing big amount of data between two data centers. Both machines have got a gigabit connection and are not fully occupied but the fastest that I am able to get is something between 6 and 10 Mbit = not acceptable! Yesterday I made some traceroute which indicates huge load on a LEVEL3 router but the problem exists for weeks now and the high response time is gone (20ms instead of 300ms). How can I trace this to find the actual slow node? Thought about a traceroute with bigger packages but will this work? In addition this problem might not be related to one of our servers as there are much higher transmission rates to other servers or clients. Actually office = server is faster than server <= server! Any idea is appreciated ;) Update We actually use rsync over ssh to copy the files. As encryption tends to have more bottlenecks I tried a HTTP request but unfortunately it is just as slow. We have a SLA with one of the data centers. They said they already tried to change the routing because they say this is related to a cheap network where the traffic gets routed through. It is true that it will route through a "cheapnet" but only the other way around. Our direction goes through LEVEL3 and the other way goes through lambdanet (which they said is not a good network). If I got it right (I'm a network intermediate) they simulated a longer path to force routing through LEVEL3 and they announce LEVEL3 in the AS path. I basically want to know if they're right or they're just trying to abdicate their responsibility. The thing is that the problem exists in both directions (while different routes), so I think it is in the responsibility of our hoster. And honestly, I don't believe that there is a DC2DC connection which only can handle 600kb/s - 1,5 MB/s for weeks! The question is how to detect WHERE this bottleneck is

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• Syncing two sheets, while being able to hide different data

  - by Joshua

  I'm pretty new to excel- so please bear with me. I have created a spreadsheet to organize gear by serial numbers and by who has it. This list is getting updated multiple times daily as gear shuffles regularly. I have gear that is assigned and unassigned. On the main sheet I have all the data, the way I want it to be organized. What I'm trying to do is duplicate this sheet, so that both sheets automatically keep the same data at all times, but on the first sheet I can hide all the unassigned gear, and view only the assigned gear, and then be able to narrow it down in groups using the hide function heavily. On the second sheet I want to be able to hide all of the assigned gear, and all the columns of gear that have no unassigned gear. End result will be that as gear is moved between individuals or is unassigned entirely, I make that adjustment on one sheet and the data stays the same on both, but the way I view that same sheet is different on both. If I'm making no sense just let me know and I'll try to explain again more clearly. Thanks

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• What are differences between sell side platforms (Admeld) and self-serve platform (AdReady)?

  - by Rick Chin

  I was confused with sell side platforms (e.g. Admeld) and self-serve platforms (e.g. AdReady) as both are serving services to publishers. I would like to know the differences in order to get the answer of "which platform is suitable for a medium size website publisher, and why?" references: http://en.wikipedia.org/wiki/Sell_Side_Platform. http://www.masternewmedia.org/self-serve-advertising-services-guide-to-the-best-do-it-yourself-ad-management-platforms/.

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• Best way to solve tile drawing in 2D side scroller?

  - by TheCompBoy

  What i still can't figure out is which would be the more sane way / easier and faster way to draw the map on the screen.. I mean i will use many tiles for my maps in my side scroller.. But problem is should i make the maps in whole images like one .png file for each map (Example) or should i draw the tiles by code like a for loop in c++.. Which way is most recomended or where can i read about which way is the best.

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• Is my client correct that I cannot take a vacation as a subcontractor? [closed]

  - by Rae Ann

  I have 2 clients who I do ongoing work for as a subcontractor. Both are sporadic and part-time. Company A sent me to a 3 day certification course out of state. The following week I was scheduled for a 3 day vacation. I warned company B three weeks prior to these events. During my training that Company A was paying for, Company B asked me to leave the training to workon something for them that needed immediate attention. I declined. However I made arrangements to work on it in the evening and in the early mornings after they threatened to take the work and all subsequent work for this client to someone else. I lost all networking and fun from that trip... The following week I was in Florida and was again asked to do more work on the project after the feedback from the client. The integrated product personnel would not cooperate/return any of our calls so I did the best I could. I turned in the work, explained the issue and then was gone for 3 hours. When I returned, all my access to the project had been revoked and after a week of my calls and emails I found out they replaced me. I sent an invoice 3 weeks ago and they tell me they owe me nothing because I did not do the whole project and they cannot bill the client for what I did, because they are billing for the second contractor who started over. I was told that they realize I was on vacation but as a subcontractor I lose the ability to just disappear. I was gone 3 hours! Is this normal, correct, legal?? Not only did they ruin my class and my vacation, but now they expect me to not demand payment? They ended our relationship and I was in the middle of another project of theirs too. They told me to immediately cease all work for them. How do I get paid for the work I have yet to invoice this month?

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• SQL SERVER What is MDS? Master Data Services in Microsoft SQL Server 2008 R2

  What is MDS?Master Data Services helps enterprises standardize the data people rely on to make critical business decisions. With Master Data Services, IT organizations can centrally manage critical data assets company wide and across diverse systems, enable more people to securely manage master data directly, and ensure the integrity of information [...]...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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• Where in the filesystem should I store shared data?

  - by misterben

  Where in the unix filesystem is the conventional location to save non-user specific data, for example data shared via nfs or ftp, or backups? I could obviously create and use any arbitrary folder (such as /home/shared, /data or /var/data), but I'm really wondering if there are any "best" or "common" practice guidelines. The Filesystem Hierarchy Standard doesn't specify a location for shared data. For backups, I tend to use /var/backups, but as several cronjobs write to it should it really be left for their use?

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• What is a good IDE for client side JavaScript development? [closed]

  - by Isuru

  I recently started learning JavaScript and am looking for a good JavaScript Editor/IDE. I found dozens of them in a Google search but I would appreciate if users who have experience with using such an IDE could recommend one. I want an IDE with syntax highlighting, possibly IntelliSense and debugging support for JavaScipt code. I'm a Windows 7 user and do just client-side JavaScript development. Any suggestions??

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• Where in the filesystem should I store shared data?

  - by misterben

  Where in the unix filesystem is the conventional location to save non-user specific data, for example data shared via nfs or ftp, or backups? I could obviously create and use any arbitrary folder (such as /home/shared, /data or /var/data), but I'm really wondering if there are any "best" or "common" practice guidelines. The Filesystem Hierarchy Standard doesn't specify a location for shared data. For backups, I tend to use /var/backups, but as several cronjobs write to it should it really be left for their use?

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• Client/Server game even in solo: any big problem?

  - by Klaim

  I'm making a game which have strong basic design based on multiplayer but also should provide a really interesting and self-sufficient solo game. A bit like a real-time strategy game. The events and actions taken shouldn't be as massive and immediate as in a FPS, so you can also think the networking like for an RTS. It's a PC game, targetting Windows, MacOSX and Linux (Ubuntu & Fedora). It's programmed in C++, using a variety of open source libraries, so I have great (potential) control over the performances. So far I always considered that just making the game work with two applications, client & server, even in solo mode was ok. However, as I'm in the process of starting the network code I'm having doubts about if it's a good idea. I'm not a specialist so I might be missing something in my analysis. I see these pros and cons: Pros: The game works only one way so if I fix a bug it should apply on all game modes, whatever the distance with the server is; Basic networking issues would be detected early, including behaviour with the protection softwares (firewall) installed (i am not specialist so this might be wrong); Cons: I suppose that even if it should be really fast enough, networking client and server on the same computer would still be slower than no networking and message passing in (one) process memory. Maybe debugging would be more difficult? I don't have experience in this case but so far I assume that debugging with Visual Studio allows me to debug multiple process so it shouldn't be really different. Also, remote debugging. My question is: is there a big disadvantage that I missed? Or maybe there are advantages that I missed and that should encourage me to just continue with only client-server game sessions?

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• Oracle 11g Data Guard over a WAN

  - by Dave LeJeune

  Hi - We are in process of looking at using Oracle's Data Guard to replicate our 11g instance from a colo facility in Washington DC to Chicago. To give some basics we have approximately 25TB of storage and a healthy transaction rate in the 1-2K/sec range. Also, because we are processing data in real-time we have a 24x7x365 requirement for processing data. We don't have any respites as far as volume except for system upgrades (once every few months) where we take the system offline but then course experience a spike in transactions when we bring the system back on-line. Ideally we would want the second instance in the DG configuration semi-online in a read-only fashion for reports/etc. We evaluated DG in 10g and were not overly impressed and research seemed to show that earlier versions had issues with replication over a WAN but I have heard good things about modifications the product has gone through w/ 11g. Can anyone confirm an instance of this size and transaction rate being replicated over a WAN and if so what is the general latency? An information or experiences with a DG implementation that is of this size and scope would really be helpful (or larger - I also realize we are still relatively small compared to many others out there). Many thanks in advance.

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• How to find collision detection side between two objects?

  - by user2362369

  I am using box2D and I have two objects, one is bouncy ball and the other one is block. I'd like to find which side of the block is collided with, so I can only make the ball bounce when it hits the top. I tried to implement many things like fixture data and by detecting position, using manifold but not get the accurate result. I also tried to calculate distance between two object but all went wrong.

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• Are You Aware of the Darker Side of SEO?

  SEO has even a darker side that should be taken care off. Few tips that could be pin pointed while optimizing the websites for the search engine.

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• Recommended integration mechanism for bi-directional, authenticated, encrypted connection in C clien

  - by rcampbell

  Let me first give an example. Imagine you have a single server running a JVM application. This server keeps a collection of N equations, once for each client: Client #1: 2x Client #2: 1 + y Client #3: z/4 This server includes an HTTP interface so that random visitors can type https://www.acme.com/client/3 int their browsers and see the latest evaluated result of z/4. The tricky part is that either the client or the server may change the variable value at any time, informing the other party immediately. More specifically, Client #3 - a C app - can initially tell the server that z = 20. An hour later that same client informs the server that z = 23. Likewise the server can later inform the client that z = 28. As caf pointed out in the comments, there can be a race condition when values are changed by the client and server simultaneously. The solution would be for both client and server to send the operation performed in their message, which would need to be executed by the other party. To keep things simple, let's limit the operations to (commutative) addition, allowing us to disregard message ordering. For example, the client seeds the server with z = 20: server:z=20, client:z=20 server sends {+3} message (so z=23 locally) & client sends {-2} message (so z=18 locally) at the exact same time server receives {-2} message at some point, adds to his local copy so z=21 client receives {+3} message at some point, adds to his local copy so z=21 As long as all messages are eventually evaluated by both parties, the correct answer will eventually be given to the users of the client and server since we limited ourselves to commutative operations (addition of 3 and -2). This does mean that both client and server can be returning incorrect answers in the time it takes for messages to be exchanged and processed. While undesirable, I believe this is unavoidable. Some possible implementations of this idea include: Open an encrypted, always on TCP socket connection for communication Pros: no additional infrastructure needed, client and server know immediately if there is a problem (disconnect) with the other party, fairly straightforward (except the the encryption), native support from both JVM and C platforms Cons: pretty low-level so you end up writing a lot yourself (protocol, delivery verification, retry-on-failure logic), probably have a lot of firewall headaches during client app installation Asynchronous messaging (ex: ActiveMQ) Pros: transactional, both C & Java integration, free up the client and server apps from needing retry logic or delivery verification, pretty straightforward encryption, easy extensibility via message filters/routers/etc Cons: need additional infrastructure (message server) which must never fail, Database or file system as asynchronous integration point Same pros/cons as above but messier RESTful Web Service Pros: simple, possible reuse of the server's existing REST API, SSL figures out the encryption problem for you (maybe use RSA key a la GitHub for authentication?) Cons: Client now needs to run a C HTTP REST server w/SSL, client and server need retry logic. Axis2 has both a Java and C version, but you may be limited to SOAP. What other techniques should I be evaluating? What real world experiences have you had with these mechanisms? Which do you recommend for this problem and why?

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