Kovitz J.M.,University of California at Los Angeles |
Rajagopalan H.,University of California at Los Angeles |
Rajagopalan H.,Apple USA |
Rahmat-Samii Y.,University of California at Los Angeles
IEEE Antennas and Wireless Propagation Letters | Year: 2012
Bias lines form an integral part of the reconfigurable antenna design process. Current methodologies for bias lines are either too narrowband or require a relatively large amount of real-estate that may not be available. Also, metallic lines are unsuitable for designs with strong fields in the bias line location. Bias lines using resistive materials are often prototyped using microfabrication facilities, but these facilities might not always be accessible. This letter investigates a novel, practical, and cost-effective bias line solution using conductive adhesives. These resistive lines effectively attenuate the RF signals providing good isolation between the RF and the dc signals while still passing a dc voltage to activate the switches. The reconfigurable E-shaped patch antenna is used as a case study in this letter, and some issues when using metallic lines in this type of antenna are also presented. The newly proposed bias line aims to minimize those issues shown hereafter. The fabrication process is also enumerated for those interested in repeating these designs for other applications. Overall, the S11 and pattern measurements show good agreement with the simulations and prove their effectiveness experimentally. © 2002-2011 IEEE.
Khan A.,ETH Zurich |
Singh V.,Apple USA
ACM International Conference Proceeding Series | Year: 2015
Given a collection of binary constraints that categorize whether a data object is relevant or not, we consider the problem of online retrieval of the top-k objects that best represent all other relevant objects in the underlying dataset. Such top-k representative queries naturally arise in a wide range of complex data analytic applications including advertisement, search, and recommendation. In this paper, we aim at identifying the top-k representative objects that are high-scoring, satisfy diverse subsets of given binary constraints, as well as representative of various other relevant objects in the dataset. We formulate our problem with the well-established notion of the top-k representative skylines, and we show that the problem is NP-hard. Hence, we design efficient techniques to solve our problem with theoretical performance guarantees. As a sideproduct of our algorithm, we also improve the asymptotic timecomplexity of skyline computation to log-linear time in the number of data points when all dimensions except one are binary in nature. Our empirical results attest that the proposed method efficiently finds high-quality top-k representative objects, while our technique is one order of magnitude faster than state-of-The-Art methods for finding the top-k skylines with binary constraints. © 2015 Copyright held by the owner/author(s).
Raguram R.,Apple USA |
Chum O.,Czech Technical University |
Pollefeys M.,ETH Zurich |
Matas J.,Czech Technical University |
Frahm J.-M.,University of North Carolina at Chapel Hill
IEEE Transactions on Pattern Analysis and Machine Intelligence | Year: 2013
A computational problem that arises frequently in computer vision is that of estimating the parameters of a model from data that have been contaminated by noise and outliers. More generally, any practical system that seeks to estimate quantities from noisy data measurements must have at its core some means of dealing with data contamination. The random sample consensus (RANSAC) algorithm is one of the most popular tools for robust estimation. Recent years have seen an explosion of activity in this area, leading to the development of a number of techniques that improve upon the efficiency and robustness of the basic RANSAC algorithm. In this paper, we present a comprehensive overview of recent research in RANSAC-based robust estimation by analyzing and comparing various approaches that have been explored over the years. We provide a common context for this analysis by introducing a new framework for robust estimation, which we call Universal RANSAC (USAC). USAC extends the simple hypothesize-and-verify structure of standard RANSAC to incorporate a number of important practical and computational considerations. In addition, we provide a general-purpose C++ software library that implements the USAC framework by leveraging state-of-the-art algorithms for the various modules. This implementation thus addresses many of the limitations of standard RANSAC within a single unified package. We benchmark the performance of the algorithm on a large collection of estimation problems. The implementation we provide can be used by researchers either as a stand-alone tool for robust estimation or as a benchmark for evaluating new techniques. © 1979-2012 IEEE.
Matolak D.W.,University of South Carolina |
Zhang Q.,InterDigital Corporation |
Wu Q.,Apple USA
IEEE Wireless Communications Letters | Year: 2013
We provide path loss data and models for a peer-to-peer wireless channel for an urban environment in six public safety bands, for simultaneous transmission to five spatially separated receiving sites. Results are from measurements in Denver, Colorado. The six frequencies at which we measured are (in MHz) 430, 750, 905, 1834, 2400, and 4860. Both line-of-sight and non-line-of-sight conditions were covered, and we quantify path loss exponents and linear-fit standard deviations as functions of frequency and location. Line-of-sight results agree with prior work, but non-line-of-sight exponents, from 3.6-7.3, are generally larger than in most other references. © 2012 IEEE.
Bharwani A.M.,University of Calgary |
Harris G.C.,Apple USA |
Southwick F.S.,Florida College
Academic Medicine | Year: 2012
An effective interprofessional medical team can efficiently coordinate health care providers to achieve the collective outcome of improving each patient's health. To determine how current teams function, four groups of business students independently observed interprofessional work rounds on four different internal medicine services in a typical academic hospital and also interviewed the participants. In all instances, caregivers had formed working groups rather than working teams. Participants consistently exhibited parallel interdependence (individuals working alone and assuming their work would be coordinated with other caregivers) rather than reciprocal interdependence (individuals working together to actively coordinate patient care), the hallmark of effective teams. With one exception, the organization was hierarchical, with the senior attending physician possessing the authority. The interns exclusively communicated with the attending physician in one-on-one conversations that excluded all other members of the team. Although nurses and pharmacists were often present, they never contributed their ideas and rarely spoke.The authors draw on these observations to form recommendations for enhancing interprofessional rounding teams. These are to include the bedside nurse, pharmacist, and case manager as team members, begin with a formal team launch that encourages active participation by all team members, use succinct communication protocols, conduct work rounds in a quiet, distraction-free environment, have teams remain together for longer durations, and receive teamwork training and periodic coaching. High-performing businesses have effectively used teams for decades to achieve their goals, and health care professionals should follow this example.
Rao L.,University of Central Florida |
Ge Z.,University of Central Florida |
Ge Z.,Apple USA |
Wu S.-T.,University of Central Florida
IEEE/OSA Journal of Display Technology | Year: 2010
The electro-optic properties of Kerr effect based liquid crystal display (LCD) with zigzag electrode structure are studied using a three-dimensional simulator. The optimal bending angle of the zigzag in-plane switching (IPS) electrodes is found to be 90° , which is different from the conventional strip electrodes. Although the zigzag structure exhibits a slightly lower transmittance than the strip IPS electrodes, it significantly suppresses the color shift while providing a relatively wide viewing angle. © 2010 IEEE.
Swietojanski P.,University of Edinburgh |
Ghoshal A.,University of Edinburgh |
Ghoshal A.,Apple USA |
Renals S.,University of Edinburgh
IEEE Signal Processing Letters | Year: 2014
We investigate convolutional neural networks (CNNs) for large vocabulary distant speech recognition, trained using speech recorded from a single distant microphone (SDM) and multiple distant microphones (MDM). In the MDM case we explore a beamformed signal input representation compared with the direct use of multiple acoustic channels as a parallel input to the CNN. We have explored different weight sharing approaches, and propose a channel-wise convolution with two-way pooling. Our experiments, using the AMI meeting corpus, found that CNNs improve the word error rate (WER) by 6.5% relative compared to conventional deep neural network (DNN) models and 15.7% over a discriminatively trained Gaussian mixture model (GMM) baseline. For cross-channel CNN training, the WER improves by 3.5% relative over the comparable DNN structure. Compared with the best beamformed GMM system, cross-channel convolution reduces the WER by 9.7% relative, and matches the accuracy of a beamformed DNN. © 1994-2012 IEEE.
Roach C.,Apple USA |
Menezes R.,Florida Institute of Technology
Communications in Computer and Information Science | Year: 2011
Software engineering, being a relatively new field, has struggled to find ways of gauging the success/failure of development projects. The ability to determine which developers are most crucial to the success of a project, which areas in the project contain the most risk, etc. has remained elusive, thus far. Metrics such as SLOC (Source Lines of Code) continue to be used to determine the efficacy of individual developers on a project despite many well-documented deficiencies of this approach. In this work, we propose a new way to look at software development using network science. We examine one large open-source software development project-the Python programming language-using networks to explain and understand the dynamics of the software development process. Past works have focused on the open source community as a whole and the relationships between the members within. This work differs in that it looks at a single project and studies the relationships between the developers using the source code they create or work on. We begin our analysis with a description of the basic characteristics of the networks used in this project. We follow with the main contribution of this work which is to examine the importance of the developer within their organization based on their centrality measures in networks such as degree, betweenness, and closeness. © 2011 Springer-Verlag.
News Article | September 6, 2009
It’s not really a secret that Japan is absolutely crazy about cell phones. And even though domestic makers churn out more than 100 different handsets every year (some of which are simply amazing), the iPhone is selling over here. SoftBank Mobile, the country’s exclusive iPhone provider, doesn’t release official data, but estimates put sales in Japan at well over one million units so far – not bad at all in this hopelessly over-saturated market. In other words, Japan doesn’t hate the iPhone, as some blogs suggested in the past. It never did. The local developer community has noticed and produced a slew of apps aimed at a global audience. What follows is my subjective selection of the “best” of these made-in-Japan apps, all of which are at least available in English. (I left out iPhone games released by big companies such as Capcom, Konami, Sega or Namco to focus on apps created by startups or individuals based in Japan instead.) My personal favorite is a free (and fantastic) GPS-based photo sharing app called Memory Tree (just like all the apps in the following list, it works worldwide). But here’s a round-up of all the 32 apps I chose, grouped in six categories (games, productivity, tools, photography and art, music, and everything else). 1. Gang Street Wars by DigiDock (iTunes links: $1.99 for a limited time / free version) Addictive mix between real-time strategy and (side-scrolling) tower defense game with cartoon graphics and random gore effects. You play a gang leader whose mission is to conquer bases of rivals by sending out gang members with different combat skills. 2. Broadway Cafe by Artscape and Istpika ($4.99) Pretty deep and professionally designed restaurant simulation game that lets you assume the roles of a waiter, manager and owner. Dash around taking customer orders, serving meals in time or doing the dishes. But you also take care of the interior design of the restaurant, its personnel, finances etc. (the app contains more action elements than it sounds). Broadway Cafe also connects to its Facebook counterpart from where you can recruit Facebook friends to join the game (demo video). 3. Glandarius Wing Strike by IZUMOGASIN ($4.99 / free version) Great-looking 2D shoot ’em up aimed at hardcore gamers. This vertical scroller features six long stages, boss fights, chain attacks and a cool soundtrack. The initial version of the game was so hard that the maker later decided to add an “easy” mode. Definitely the best 2D shooter for the iPhone. 4. Samurai Chess by Conit ($2.99 / free version) As the name of the app says, it’s a Samurai-themed chess game (in 3D). Players can challenge both the CPU or Samurai Chess players anywhere in the world (provided they’re online via 3G or Wi-Fi). 5. iYamato by Geppetto ($0.99 / free version) 2D shooting game in which you defend legendary battleship Yamato against aerial attacks. Not really a deep game, but it’s action-packed and ideal to kill 10 minutes from time to time (demo video). 6. LightBike by Pankaku ($2.99 / free version) LightBike, which made it to the No. 1 in Apple USA’s app sales ranking a few months ago, is a 3D motorcycle racing/action game whose design resembles the setting of the Sci-Fi movie Tron. Up to 4 people can battle it out by using just two iPhones and Wi-Fi (demo video). 7. Vay by SoMoGa ($4.99) Originally released in 1994 for the Sega CD system, Vay is one of the best 2D RPGs ever made. Cute anime-style graphics, retro-Sci-Fi setting, voice output in English, animated cutscenes and most importantly, dozens of hours of old-school gameplay. SoMoGa (based out of Florida) puts the complete original game in your pocket. 8. newtonica by Field System ($ 4.99) Strange, but beautifully designed action game in which you rotate a sphere so that incoming meteors hit the cores with the matching colors. A bestseller in the Japanese App Store with a great soundtrack (demo videos). 9. newtonica2 by Field System ($ 0.99/ free version) The sequel to newtonica is a mix between action and puzzle game, cheaper than the first one and better gameplay-wise. The game’s 36 stages will keep you busy for a while (demo video). There’s also newtonica2 resort, an add-on or remake of sorts (available for $0.99). 10. iNinja by Geppetto ($1.99 / free version) One of the few Ninja-themed action games actually made by a Japanese company. Deflect oncoming Ninja attacks with shuriken (throwing stars), eliminate enemies with knives, land combo kills or set booby traps in 28 levels. There’s also a two-player Wi-Fi mode. 11. ExZeus by Hyper Devbox ($0.99) 3D rail-shooting game with fantastic sound and graphics in Space Harrier style. You control one of three giant robots to fight off an alien invasion. It’s not the longest game out there, but a total steal for this price (demo video). 12. Zeptoliner by Ubiquitous Entertainment ($6.99 / free version) This “outliner” app helps you to arrange your ideas in a systematic way. You can jot down thoughts and then use a number of functions to structure them hierarchically. It’s also possible to import OMPL files to edit documents you created on your computer (demo video). 13. ZeptoPad 3.0 by Ubiquitous Entertainment ($19.99) This note and whiteboard app isn’t cheap, but it’s an extremely versatile, vector-based illustration program. It lets you stream what you do on your iPhone to a computer screen or projector in real-time and has simply too many functions to mention here (click here for details and make sure to check out the video below). 14. gottaDo2 by Istpika ($2.99) A social task manager that lets you knock off tasks from your to-do list to feed the cute little monsters living inside the app. You can watch them grow or punish you if you’re too lazy. It’s also possible to sync tasks with the gottaDo Facebook app. 15. PokéDia by s21g ($2.99) A daily diary/planner app that’s available in 16 different languages. Each page of the virtual diary represents one day, and you can turn pages (move to certain days) by flicking to the right or left. The app lets you jot down notes anywhere on the screen and move the entries around on the page itself and between days. It can be used as a task manager, too (demo video). 16. TapNext by Conit ($3.99 / free version) This app turns your iPhone into a remote control for presentations. Maker Conit says it’s the only software of its kind that’s compatible to Powerpoint, Keynote and OpenOffice Impress and can be used via Wi-Fi or 3G. You can theoretically use a PC located in Europe to deliver a presentation in the USA with TapNext through Skype (details and demo video). 17. ServersMan by FreeBit (free) Launched in February, this app, which turns your iPhone into a personal web server, is still one of the most popular apps in the Japanese App Store. And it has become even more useful with OS 3.0b, adding a number of functions to the already impressive list of features (read more here). And the best app of its kind is free, too. 18. PlayPix 3 snaps by LivingImage ($2.99 for a limited time) PlayPix is like a lighter version of Animoto’s iPhone app. Select three pictures from your photo album, choose a graphical theme and the app will create a slide show with background music for you. You can save the slide show on your iPhone, upload it to YouTube or Facebook and share it via Twitter or Email. During my test, PlayPix actually worked faster than Animoto’s iPhone app (demo video). 19. Memory Tree by XeNN (free) A GPS-based photo sharing app with a fantastic big idea: Take a picture anywhere in the world, “drop” it on the spot you took it at (simply by shaking your iPhone) and add a text to it. This geo-tagged picture can later be “caught” by other Memory Tree users who are in the same area by swinging the iPhone “like a butterfly net” (“Same Place” function). If you click the “Same Time” button, you can catch and view countless photos the users of the app took around the globe in the last hours (regardless of your location), thereby creating common photographic memories worldwide. This is just very cool. 20. Koredoko (free) This app lets you shuffle through geo-tagged photos in the camera roll and shows a Google map of where (and when) you took them (demo video). 21. TiltShift Generator by Takayuki Fukatsu ($0.99 for a limited time) Takayuki Fukatsu is offering seven different photo apps that proved to be so popular that some of the pictures created with them were used in a real-world exhibition [JP]. TiltShift Generator is Fukatsu’s newest app, and it lets you shoot miniature pictures in retro style (samples). But you should check out his other apps, too. 22. Art Remix by Appliya Studio (free) This app is based on a pretty cool idea: Tokyo-based iPhone app publisher Appliya is providing a platform called Appliya Studio [JP] that turns the creative work of artists and photographers into iPhone apps that are then distributed worldwide through the App Store. One of the many apps already available is called Art Remix. It lets you modify a total of 23 artworks with a set of customizable icons and then save and share the remixes with friends. 23. Ukiyo-e Beauties by Appliya ($3.99) A historic Japanese art app that offers a total of five different paintings and 20 woodblock prints from the traditional Ukiyo-e art form (in 1,150 x 800 resolution and 4xzoom). It took maker Appliya several months to create the app in collaboration with two professors of art history (demo video). 24. NESynth by New Forestar ($1.99) For game geeks who happen to like music: This virtual synthesizer simulates 8-bit sounds from games people played in the glorious 80s. In P2P mode, you can hear what the other person plays on your own iPhone (demo video). 25. Rekords by Delaware ($1.99) Rekords is a Japanese music label that distributes songs solely within the iPhone/iPod touch ecosystem. I bought their first record (iTunes link). The music is weird, but you get two English songs and can switch the virtual vinyl record you see on the screen from side A to B by flipping your iPhone. It’s also possible to jump to a certain part of the song by moving the record player’s arm. 26. PocketGuitar by Shinya Kasatani ($0.99) Already a major global success, this app displays a set of virtual guitar strings that you can strum and press with your fingers. Users can choose between six virtual guitars (even a Ukulele is available) and modify the sound with a number of different parameters (demo videos). 27. iShakuhachi by GClue ($0.99) The Shakuhachi is a traditional bamboo flute that’s unknown even to many Japanese people. Users can play it by blowing into the iPhone mic, tilting it and covering the five holes with their fingers. GClue offers an iKoto (Japanese Harp) app, too. 28. Quick Pigeon by Ubiquitous Entertainment (free) Cute push notification messenger app that uses a “virtual carrier pigeon” to send a quick “yes or no” question to people in your contact list. The recipient(s) view the email on their computer or iPhone, press “yes” or “no” and the message reaches you via push notification (along with a twitter sound). 29. Bijin Tokei by PHIRIA ($2.99) This clock app brings 1,440 pictures of Japanese girls to your iPhone (Bijin Tokei means Hot Girl Clock in Japanese). The pictures fade in and out every minute, and each of them is showing a different girl who holds up a sign displaying the current time (to be exact, the models themselves change just every few minutes). 30. Wikiamo by Satoshi Nakagawa (free) Wikiamo is better than the official app for Wikipedia (iTunes link) that launched just a few days ago simply because it makes Wikipedia pages much easier to read. The app also appears to be faster, lets you browse through certain articles when you’re offline (via page-caching) and has some other functions the official app doesn’t offer. 31. NatsuLion by Takuma Mori (free) This app might be a good alternative for people who are still looking for a simple iPhone Twitter client that’s very quick and easy to use. It’s completely ad-free, too. 32. Amamiya Momo by Xtone ($2.99) Amamiya Momo is a virtual anime girlfriend who lives in your iPhone, interacts with you and gets moody quickly. For example, she’s nicer when your’re home than when you’re out on the streets. Her mood also depends on which time of the day it is. There are 200 different pre-programmed patterns of behavior and Japanese voice samples (subbed in English). More info on this GPS-based app can be found here. Nota Bene: I sifted through countless app descriptions and sites from Japanese companies in the last weeks and have to say the vast majority of the English texts I stumbled upon are of horrific quality. Some were even so bad I couldn’t understand what the app is about. This is absolutely embarrassing, especially when you expect users to pay. And why some of the apps have been available in the US App Store for months but never made their way to other countries (i.e the German store where I mostly buy from) is totally beyond me, too. Special thanks to Nobuyuki Hayashi for his contribution to this article.