Chen J.-Y.,Zhejiang University |
Wang H.-D.,No800 Institute Of The Shanghai Aerospace Bureau |
Zhou J.-C.,Econ Technologies |
He H.-N.,Zhejiang University |
Chen Z.-W.,Zhejiang University
Zhendong yu Chongji/Journal of Vibration and Shock | Year: 2011
More and more people have paid attention to the multi-exciter vibration testing system since it can simulate the vibration environment more really, and now it has become a development tendency of environmental vibration test. The basic control principle of multi-exciters vibration testing system was presented and the key technologies, namely, the time-domain waveform replication, which includes iterative algorithm and overlap connection of driving signal, and the frequency spectrum replication, which includes feedback correcting logorithm and time randomization were introduced. A summary of control technologies for multi-exciters vibration testing was given with its prospect discussed.
Chen J.-Y.,Zhejiang University |
Zhou J.-C.,Econ Technologies |
Chen Z.-W.,Zhejiang University |
He H.-N.,Zhejiang University
Xi Tong Gong Cheng Yu Dian Zi Ji Shu/Systems Engineering and Electronics | Year: 2010
It is difficult to achieve the uniformity of vibration and stress distribution for slender specimens such as missiles. In order to complete the vibration test requirements, a multiple shaker is needed to excite them synchronously, and a multi-exciter synchronization vibration control system is implemented. A system equilibrium synthesis is presented to make up for deficiencies of different methods for random vibration test control algorithm. A control system is implemented with a hardware architecture of multiple digital signal processor (DSP) and peripheral component interconnect extensions for instrumentation (PXI) bus and a software architecture of multi-level modular. The related experiment result shows that the proposed control algorithm is effective and the system structure has a good expansibility. The control system can meet the vibration test requirements and has a certain practical value.
Chen Z.-W.,Zhejiang University |
Wen X.,Zhejiang University |
Zhou J.-C.,Econ Technologies |
He H.-N.,Zhejiang University
Zhendong yu Chongji/Journal of Vibration and Shock | Year: 2013
Traditional vibration tests based on acceleration response control are intended to control the acceleration of shaker platform according to specified acceleration specification. This kind of control may sometimes lead to over testing phenomenon at the natural frequency of testing article. Force limited vibration test is able to mitigate that tendency. Detailed calculations for force limitation specification were presented on the basis of the model of simple two-degree-of-freedom system (TDFS). Furthermore, the spectra of force and acceleration between spacecraft bracket and shaker platform were derived. Then the force limited random vibration test and force limited sine vibration test were carried out for spacecraft bracket. Experimental results indicate that the force limited vibration test in terms of force spectrum derived from the simple TDFS model can simulate the realistic dynamic environment better than the conventional acceleration response control vibration test, and the over testing tendency can be alleviated effectively. Thus those results offer a good verification for spacecraft vibration test.
Tian P.,Zhejiang University |
Tian P.,Zhenjiang College |
Chen Z.-W.,Zhejiang University |
Jing W.,Econ Technologies
Zhendong yu Chongji/Journal of Vibration and Shock | Year: 2012
To overcome the poor control precision of iterative learning control (ILC) which is generally used in earthquake simulation test, an adaptive control method was proposed. Adaptive control can obtain high simulation precision for seismic wave, by continuously identifying the transfer function of shaking table to overcome the time-variation of hydraulic system. On the basis of analyzing the disadvantage of pre-test step, the test method was so improved that the earthquake simulation test can be completed without conventional pre-test step, and the correlation coefficient between reference signal and control signal in time domain can reach a high level. Several typical earthquake wave experimental results, got on Zhejiang University shaking table, indicate that by the improved test method, the first frame correlation coefficient between reference signal and control signal in time domain can reach above 75% without pre-test step, while the experimental time is shortened; and after several frames of earthquake simulation test, the correlation coefficient can reach 95% through identifying the transfer function continuously.
Econ Technologies | Date: 2013-08-27
Computer application software for mobile phones, tablet computers, laptop computers and desktop computers, namely, software for the electronic storage, sharing and exchange of data files between devices.
Econ Technologies | Date: 2013-02-26
Vibration data acquisition and signal analysis systems comprised of network interfaces and input/output modules for industrial test and measurement.
News Article | February 10, 2005
Portraits & Prints from Econ Technologies is an application much like those you will find at many portrait studios. It features quick and easy touch-up and picture printing functions with easy to use templates for printing multiple images in different sizes on the same sheet of paper. Being a photography major I was the natural choice for reviewing this software, and this is actually a product I have been meaning to try out. I am an almost daily user of Adobe Photoshop so I wasn’t quite sure whether or not I would like this application at first. It didn’t take me long to realized that it was actually a very handy application. Where might you use this application instead of Photoshop, which has a very similar Picture Package feature? When you need to do it fast and easy is the first thing that comes to my mind. I was recently part of a very small team that was taking photographs at a formal dance and providing people with digital prints a few minutes later. I was manning my iBook and using Photoshop to manually crop the images to 5×7 and then using the picture package feature to setup and print two images per 8.5×11 inch sheet of paper. At first this was working fine but eventually I started to get overwhelmed and the wait for the pictures went from ten minutes to over thirty minutes. Portraits & Prints would have allowed me to streamline the workflow and save time. In my testing of Portraits & Prints I haven’t gone lightly on the application. I decided to throw a folder of 36 300 DPI 11×14 inch TIFF’s, all of which were around 25 megabytes each, onto it to see what would happen. Portraits & Prints managed to handle all 938 megabytes without flinching. I would even go so far as to say that it generated the thumbnails of each image as fast as Photoshop CS’s File Browser would have if not faster. Changing between images did take a few seconds but this is to be expected on a 1 GHz iBook. Portraits & Prints has some fast and easy to use image enhancement features. They offer you adjustments for Saturation, Brightness, Contrast, and Sharpness. These are presented as easy to use sliders but they lack a level of fine control since they can only be adjusted in increments of plus or minus ten percent. I am impressed with how well the Sharpness enhancing feature works though. Econ Technologies appears to be using a method more akin to Photoshop’s Unsharp Mask filter than convention sharpen methods, which often cause a higher level of noise. One of the problems though is that there doesn’t seem to be a way to view an image at actual size so it can be hard to judge if you have over sharpened or not. It also has a Red Eye eliminating feature, a standard crop feature, and a feature that allows you to add dialog bubbles like in comic books to the photos. Portraits & Prints Pro has a template editor, which allows you to create and edit templates to your liking. You can add image zones of whatever size you feel like as well as graphics, shapes, text, and dialog bubbles to the templates. The application also has a Template Exchange feature that lets you download and use new templates from the Internet. There is even a handy selection of Avery templates available through the Exchange. One thing that is an annoyance with Portraits & Prints is that it doesn’t take the orientation of the source photo versus that of the image zones in the template into account. Say you want to print two 5×7 inch prints from source files that are portrait oriented (taller than they are wide). Portraits & Prints will place these images into the template in their original orientation even though the 5×7 inch template has spaces for photos that are in the landscape orientation (wider than they are tall). It is a simple matter to fix this manually but it would be nice not to have to worry about it. When deciding on the area of the image you want printed there are some handy move and zoom tools that you use. This lets you quickly crop and position the image without having to resort to using the standard crop tool on the individual photos. It is a small feature that might not make that big of a difference if you are only working with a few images, but when you are working with a large number the small bit of time saved on each image will add up quickly. Portraits & Prints includes a number of export options including JPEG, TIFF, PNG, SGI, Photoshop, and Jpeg2000. Jpeg2000 isn’t a format to get too excited about now but hopefully within a few years it will be a more supported and useable format. The Print To File feature has an option to adjust the DPI of an image, which is very nice. If you are saving it to print later you want a higher resolution of at least 300 DPI but if it is for posting on the Internet you want to use 72 DPI since anything larger will just take longer to upload and download without actually effecting the image quality any. The annoying thing about this feature is that it only exports the selected image not the whole layout. If you want the whole layout you have to work around it by choosing the Print To Printer option and then using the Save As PDF option in the printer dialog. The Print To Email feature allows you to send an email featuring all the images in your layout. It allows you to set the pixel dimensions from a popup menu with many common sizes in it, and you can select the image quality from a similar popup menu. The images are then exported as JPEG’s at the settings you selected and placed into a new message in Mail. One thing that struck me as odd about this feature is that it doesn’t resample the images down to 72 DPI yet it didn’t leave them at 300 DPI like they started out as. Instead it adjusts the DPI and the pixel dimensions so that you end up with a print size equal to that in your layout and yet with the pixel dimensions you choose in the dialog. I think it would be better to include the DPI selection popup menu like in the Print To File feature that way you could send a higher quality printable version or a version with a smaller file size for viewing on-screen. As is you get a larger file that isn’t as good for printing. How does Portraits & Prints compare to iPhoto ’04? It is hard to compare these two to each other because they are different in scope. iPhoto ’04 is more of a photo organizing tool than a photo printing tool. iPhoto ’04 does have options for printing multiple photo’s per page but there is very little control in how and what sizes the prints end up as. The software for nearly every printer I am familiar with can do basically the same as iPhoto ’04 if not better. In the image adjustments category I give the edge to Portraits & Prints for its very nice Sharpness adjustment. Unfortunately I don’t have iLife ’05 yet so I can’t make a comparison to the new version of iPhoto’s image editing and printing abilities, which are supposed to be greatly improved. I didn’t expect much of Portraits & Prints going into this review so I am pleasantly surprised with it and even see how it could be very a useful addition to my workflow. There are two editions available from Econ Technologies. The standard edition will run you $30 US, while the Pro edition with the extra template editing and creation features will run you $50 US. The pricing seems just about right to me, and I am generally picky over pricing. Also there is a free demo of Portraits & Prints available. If you do a lot of printing of digital photographs then I definitely recommend that you give this application a try.
News Article | November 27, 2006
Over the past couple of years of running The Apple Blog, I’ve tried out literally thousands of applications. A lot have been great apps that I still use today, but infinitely more have just been plain bad. I know I’m not the only one who’s experienced this. So to help you weed through the clutter, here are 10 applications that I’ve stumbled across that you really should get your hands on…in alphabetical order. Econ Technologies’ ChronoSync has been one of my favorite apps for quite some time. It’s a backup/disk syncing tool that’s much more full-featured than something like SuperDuper. It’ll set you back $30. For the little chef in all of us, there’s The Little App Factory’s Connoisseur! It’s packed with super useful features like the Cooking View that gives a huge fullscreen view of the recipe and will even speak out the directions for you! It’s also got a solid number of recipes that are downloadable from their recipe community. It’s well worth the $20 price tag. I know a lot of people who subscribe to hundreds of blogs and podcasts but not many people who subscribe to vidcasts. There are hundreds (if not thousands) of great vidcasts and short films available for free out there. What Democracy does is allow you to aggregate everything into one place. It’s basically an RSS feed reader for videos. The player is fantastic, their directory of videos is growing every day, and best of all…it won’t cost you a penny! I’m a bit of a neat freak. It bothers me when stuff is all over the place in no real order or if there are an unnecessary number of things in a small space (ie. tons of icons/files on my desktop). MacRabbit has released a super dandy little app called DeskShade that lets you hide/show everything on your desktop with the simple press of a hotkey! It is $12.95 and comes with quote a few other features that are useful. I’ve been using GarageSale for over a year now and haven’t touched eBay’s listing submission form in just as long. GarageSale is a “slick, full-featured client application for the eBay online auction system.” Not only does it come with countless templates to use, but really makes posting auctions a breeze. You can easily preview your listing, upload photos from iPhoto, message buyers, track listings, and tons more. This has got to be one my favorite apps to come out in a long time. The $29.99 price tag really is a steal. Whether your boiling an egg or timing your 48 minute intervals, Minuteur really is the perfect timer for the mac. It’s got a smooth and simple interface that makes it incredibly intuitive to use. It’s not equipped with bells and whistles because it shouldn’t be. It does what it should…and does it with excellence. It’s completely free. I frequently need to take full screenshots of an entire website (as opposed to just what is visible on the screen). Paparazzi! gives me that ability. All you do is drop in the URL of the site you’re wanting to take a screenshot of and moments later you have a full screen of the entire length of the page! It’s also free…which is an obvious plus. Spam is an unfortunate fact of life…or is it? It hasn’t been for me in almost a year. I’ve abandoned the junk filter in Apple’s Mail app in favor of Michael Tsai’s SpamSieve. It’s incredibly accurate and really is the best spam filter I’ve ever used. No mac should be without this! It’s got a low $30 price tag for so much power. From passwords to serial numbers to credit cards…our lives are full of numbers. And while you could try to store them all in a text file, that’s an extremely risky move that’s just asking to get stolen. What you should be using is Waterfall Software’s Wallet. It offers military-strength 448-bit encryption to store everything from login information to credit cards to serial numbers…and everything in between. Quit trying to memorize so many numbers and start storing them in a safe place. They’re practically giving this away at $14.95. WebDesktop does exactly that. It lets you embed websites in your desktop. It ultimately acts like Safari (it uses WebKit) except when the app isn’t in focus it embeds directly into your desktop and won’t interfere with your clicking and what not. It’s useful for things like monitoring servers, staying on top of stocks, tracking sports score, and tons more. It’s free to the masses.
News Article | December 24, 2009
The good folks at Econ Technologies recently began offering some of its software for free, in order to allow it the time to focus on its flagship products. Earlier this week, Portraits & Prints, ImageCaster, and DayChaser specifically, went from paid software to freeware. Recognizing the mounting difficulty in competing with cloud-based services such as Google Calendars (which is free to use) was a contributing factor in the early Christmas present that Econ has provided for everyone. Portraits & Prints is a print shop sort of application allowing you to print off photos in customizable and out-of-the-ordinary ways. From the Econ web site: ImageCaster allows you to share your webcam’s view to webpages, turn it into a security camera, and more. It even gives you the option to schedule postings if you so choose. From the Econ web site: DayChaser can essentially be likened to iCal. I’ve used it in a limited capacity before, and it has functioned well. Though I’d agree with Econ that competing with the likes of Google Calendar et al., is a losing battle. From the Econ web site: All of the above applications have been updated to be Snow Leopard compatible prior to being made freely available. At this point in time, Econ Techologies will be turning all of its attention to improving the already solid ChronoSync and ChronoAgent programs. Both represent robust options for system backups, synchronization, and remote administration. In fact, I’ve found ChronoSync to be invaluable in backing up my work MacBook Pro to a remote SAN. Everyone’s gotta love free programs (I personally have a problem because I download them all and my Applications folder is atrocious!) right? If any of these sound interesting, why not give them a shot? However, be forewarned that because they are now free, support will likely be negligible, and updates are no longer in the cards.
News Article | November 23, 2011
While it's easier to manage a single Mac, it's still possible to have control over multiple Macs within your home. Not only can you remotely configure parental controls on another computer, you can also monitor what your kids do with their Macs, limit the hours they have Internet access, and share media between the computers within your home. You're familiar with what you can do with a parental-controlled account. What you may not know is that once you've created such an account, you can change its options from another Mac. When you first launch the Parental Controls system preference on a Mac you're managing you see a Manage Parental Controls From Another Computer option. Enable this option and proceed to configure the parental controls for that account. When you move to your Mac and launch Parental Controls, under the Other Computers heading within the Parental Controls window, you'll spy the names of any Macs for which you've configured controlled accounts and enabled remote management. Click the Lock icon at the bottom of the window and enter your administrator's password. Then select a computer whose controls you wish to configure. You'll be prompted for an administrator's name and password for that Mac (not for your own Mac). Enter each and click OK. All the controlled accounts on that remote Mac will appear. Select an account and you'll find that you can adjust the account's controls just as if you were sitting in front of that Mac. Additionally you can view that account's log files. The advantages of this remote control should be obvious. First, it allows you to modify a Mac's limitations even when a pouting minor has locked himself in his room. And you can do it very remotely. While on the road you could, for example, screen share to your Mac using Back To My Mac, open Parental Controls on your home computer, and then adjust another Mac's controls. This needn't be to "punish" your child. You may need to allow a particular application or website so your kid can get her homework done. Another operation you can perform remotely is approving the people your child communicates with. You can configure the People tab within Parental Controls so that whenever the user of the account attempts to send an email message or chat with someone not on the approved list, an email notification is sent to an account of your choosing. As long as you open that notification message with Apple's Mail (it doesn't work with other email clients) you can click an Always Allow button that then adds that address to the list of approved correspondents. If you and your child have separate Macs, you can watch his screen via OS X's Screen Sharing feature. First, while sitting down in front of his Mac, log on to that Mac as an administrator and switch on Screen Sharing in the Sharing preference pane. In Allow Access For, select Only These Users, click on the plus-sign button, and choose Administrators. To observe, go back to your Mac, open a Finder window, locate the Shared entry in the sidebar, and look for the Mac your child is using. Select it and click the Share Screen button.You can now see what he's doing on his Mac - and even control it. Your child can try to cut you off (by choosing Disconnect, and then your Mac's IP address, from the Screen Sharing menu in the menu bar), but your Mac will immediately reconnect. Screen Sharing with a child can be a delicate matter. No one likes to be spied on, but it can help keep your kid on the up-and-up if he or she understands that you have the option, at any time, to see what they're doing. Parental Controls can do only so much. While you can employ it to keep your kids from using the computer at all during certain hours, it can't be configured to block only their Internet access. For this kind of thing you must turn to your router and limit access via MAC address (the unique identifier address that all computers and iOS devices have). It's done this way with anAirPort Extreme Base Station: Launch AirPort Utility, select your base station, and click the Manual Setup button. Select the AirPort tab at the top of the window and click the Access Control tab. From the MAC Address Access Control pop-up menu choose Timed Access. This is where you begin setting up limits. Click the Plus button at the bottom of the pane, and in the sheet that appears enter the MAC address for the devices you want to limit (see "Blocking via MAC Address"). On an iOS device you'll find this address by choosing Settings -> General -> About and locating the Wi-Fi Address Entry. On a Mac, hold down the Option key and select System Profiler (Snow Leopard) or System Information (Lion) from the Apple menu. When System Profiler appears, select Network and then in the Active Services column to the right, select the device used to connect to the Internet (AirPort or Ethernet). Search for the MAC Address entry in the results below. Once you've entered the MAC Address, type in a description (Curt's iPhone, for example). Now configure the pop-up menus below. Here you can choose limits of No Access, Mondays, Tuesdays, Wednesdays, Thursdays, Fridays, Saturdays, Sundays, Weekdays, and Weekends. Click the Plus (+) button in this sheet and you can add more entries - you can, for example, include two entries for each weekday. Click Done and update the AirPort Extreme and the router will block access except during those hours allowed. Social networking sites such as Facebook are attractive for kids. It's a place where they can establish an identity and hang out with their friends. But there's the much-touted dark side: Kids often share too much, come in contact with strangers, and don't know how to configure deliberately-opaque privacy settings. Parental Controls can help by allowing you to completely block Facebook and similar sites, but that's a tough call with older kids. This is one situation where your best bet is parental involvement. If you're going to let your kids have a Facebook account (Facebook's rules require that users be 13 or older to have an account), learn how to configure its privacy settings so the least amount of information is shared (this includes blocking photos that your child appears in). Demand that your child "friends" you on Facebook so that you can keep an eye on their wall. And, without scaring them, let them know why they should be careful about sharing. You should also be very careful about providing a child with the means for spending money on the Internet. They should absolutely not have your credit card number or an iTunes ID tied to a credit card. If you want to allow your child to spend money on iTunes, set up an iTunes allowance within the iTunes Store or give them a gift card. Thanks to the file sharing capabilities built into OS X and Lion's new AirDrop technology, it's not difficult to move files between Macs on a local network. It is, however, trickier to create a single repository for music, video, and image files that can be shared between these same Macs. Apple's solution is the sharing options found in iTunes and iPhoto. To switch sharing on in iTunes, open the application's preferences, click on the Sharing tab, and enable the Share My Library On My Local Network option (see "Legal Music Sharing"). Do this and you can choose to share your entire music library or just selected playlists. To share your iTunes library with iOS devices, choose Turn On Home Sharing in iTunes' Advanced menu. When you do you'll be prompted for your Apple ID and password. Your iTunes library will now be playable from an iOS device that is connected to your local network. iPhoto has a similar sharing feature. From its preferences window, choose Sharing and enable both Look For Shared Photos and Share My Photos. Similar to iTunes, you can share all your photos or just select albums. Once you've switched on iPhoto sharing, others will be able to see your shared albums under iPhoto's Shared heading on their Macs. Apple's solution doesn't solve the central repository problem, however, as each Mac has its own iPhoto and iTunes library - the family's collection of media isn't located in just one place. There are options for making it available, however. One option is to set up a Mac as a media server - a Mac mini, for example, or an older Mac you're no longer using. When you want to add media to the family collection, you place it on this computer and then access that media via iTunes' and iPhoto's sharing areas. If a dedicated Mac is unavailable or too much for the family budget, you could obtain a Network Attached Storage (NAS) device. Many of today's NAS devices include features for sharing an iTunes and iPhoto library. Simply attach the NAS to your network, copy your media to its drive, and access that media from iTunes and iPhoto much as you'd access any other shared media in these applications. It's also possible that you already own the means for sharing iTunes media over the network - a recent AirPort Extreme Base Station or Time Capsule. Start by copying media to a hard drive attached to your AirPort Extreme (or the Time Capsule's internal hard drive). For each computer you want to share media with open iTunes' preferences, choose the Advanced tab, and disable the Copy Files To iTunes Media Folder When Adding To Library option. Within iTunes choose File -> Add To Library and navigate to the folder on the drive shared from your base station or Time Capsule. iTunes will add the names of the audio and video files it finds to the Mac's iTunes library without actually copying the files to each Mac. Each connected Mac will be able to play media within that folder and more than one Mac can play that folder's media at the same time. (Playing different movies simultaneously on multiple Macs will be challenging unless you use a wired gigabit ethernet network.) You've heard it before and you'll hear it again: It's not a question of if your hard drive will die, but when. Each Mac in your home must be backed up if you care about your data. With Time Machine, individual Macs can be easily backed up to hard drives attached to those Macs. But that could mean purchasing multiple hard drives to outfit your herd of computers. The better solution is this instance is a network backup - a scheme where each Mac is backed up to a single device. Apple's Time Capsule was built with exactly this in mind. Available in capacities of 2TB and 3TB (priced at £249 and £399 respectively), a Time Capsule is an easy-to-set-up solution, though not ideal if you have a lot of data to back up. Another, more flexible option is an old Mac configured as a backup server (perhaps the same one you'll use to store and stream your iTunes content). With an old Mac you can not only add exactly as much storage as you need in the form of internal and external hard drives, but you can choose to use software other than Time Machine - a program such as Econ Technologies' $40 ChronoSync (available from their US site), for example. When used in league with the $10 ChronoAgent (also only available from their US site) on each Mac, backing up multiple computers to a single Mac is a relative snap. Online backup is another option. Though slow-going due to the time it takes to upload a lot of data, storing your most important files online offers the protection of an off-site backup. Although each user can upload files to a service such as Dropbox or a MobileMe iDisk (at least until June 2012, when MobileMe and iDisk cease to exist), dedicated services such as CrashPlan provide automatic in-the-background backup and can provide plans that allow you to upload an unlimited amount of data from up to 10 computers for as little a $6 a month (about £4), depending on the plan you commit to. At one time managing multiple accounts or, worse yet, multiple computers took the patience of a saint and the smarts and experience of an IT professional. That's no longer the case. While it's not yet the kind of thing you can do with your eyes closed, with some familiarity with the Mac OS and the hints you now have in hand, you too can control a home full of Macs.