http://cartel.csail.mit.edu/ 2012-05-09T16:45:49-04:00 http://cartel.csail.mit.edu/ http://cartel.csail.mit.edu/lib/images/favicon.ico text/html 2012-04-25T15:22:29-04:00 http://cartel.csail.mit.edu/doku.php?id=activity_recognition&rev=1335381749&do=diff Speed estimation by using only **GSM** Distance Matrix(A,B) = 3 * |A and B| + (32 - D/|A or B|) D is the Euclidean Distance between two sets (based on its signal strength). where A,B are two GSM fingerprints (a fingerprint is a set of multiple cell tower ids and the corresponding signal strengths) The larger the distance, the more similar of the two scans. text/html 2011-05-18T10:48:54-04:00 http://cartel.csail.mit.edu/doku.php?id=cartel&rev=1305730134&do=diff Road transportation is a “grand challenge” societal problem. With close to a billion vehicles on the road today, and a doubling projected over the next 15-20 years, we face pressing challenges to the efficiency and the safety of this infrastructure. The CarTel project combines mobile computing and sensing, wireless networking, and data-intensive algorithms running on servers in the cloud to address these challenges. CarTel is a distributed, mobile sensing and computing system using phones and … text/html 2012-05-08T15:50:07-04:00 http://cartel.csail.mit.edu/doku.php?id=cita&rev=1336506607&do=diff Code In The Air The figure above shows the high level architecture of CITA. It has three main components. Programming Framework: One of the main visions of CITA is to lower the barrier for programming tasking applications. CITA providers a programming framework that targets both non-developers and developers. text/html 2011-11-18T15:51:39-04:00 http://cartel.csail.mit.edu/doku.php?id=cita_activity&rev=1321649499&do=diff CITA uses accelerometer to differentiate between biking, running, walking, and stationary. We sample data at 10Hz, transform the value into orientation-independent magnitude (L2-norm), and with a time window w, we calculate its variance. Further, we compute its DFT in frequency domain, and use peak frequency power as the third feature. text/html 2011-10-28T16:41:48-04:00 http://cartel.csail.mit.edu/doku.php?id=cita_applications&rev=1319834508&do=diff * Map my driving If I am driving, capture my driving track and show it on a map at the end of the day. Store those tracks over time and produce summaries about my driving pattern. * Location based Reminders Post reminders at a location. The user is notified of the reminder when he visits that location next time. The user can either snooze or cancel the reminder. If he snoozes, it is delivered again the next time until he cancels. text/html 2011-10-04T13:28:48-04:00 http://cartel.csail.mit.edu/doku.php?id=cita_design&rev=1317749328&do=diff The figure shows the components in the CITA server. We explain each component in detail below. Device Manager: In CITA, when users want to program their devices, they register it with the CITA server either through the web interface or through the mobile interface. They will then install a CITA client on their device that runs in the background and gives the server a way to remotely access them and execute tasks. The Device Manager at the server keeps track of all the devices connected to CI… text/html 2012-04-20T14:57:03-04:00 http://cartel.csail.mit.edu/doku.php?id=cita_location&rev=1334948223&do=diff Indoor v.s Outdoor by using **WiFi** Each dot is the maximum signal strength of a scan. Room Level Floor Level Building Level Map Level text/html 2011-10-04T13:23:55-04:00 http://cartel.csail.mit.edu/doku.php?id=cita_programming&rev=1317749035&do=diff Every inbuilt javascript API will work. In addition to javascript features, CITA provides several sync and async APIs to interact with the sensors and system APIs on the phone. APIs to add and remove callbacks * handle = callback.add(“eventmonitor”, “truefunc”, “falsefunc”, params); - for boolean callbacks only * callback.add(“eventmonitor”, “truefunc”, “falsefunc”); - for boolean callbacks only * callback.add(“eventmonitor”, “func”, params); - for data callbacks only * callback.add(… text/html 2011-10-04T12:58:48-04:00 http://cartel.csail.mit.edu/doku.php?id=citabackup&rev=1317747528&do=diff Code In The Air Overview Each CITA application is housed in a WebView. Thus far, all development has been focused on improving the performance of a single application running in a single WebView. The next stage is to create a structure in which multiple WebViews can live, under a centralized command. Once this is done, the next step is to further flesh out the services that we provide developers, and improve the quality of the skeleton application. text/html 2007-07-22T21:27:43-04:00 http://cartel.csail.mit.edu/doku.php?id=fleet_testbed&rev=1185154063&do=diff A CarTel-equipped car in the fleet testbed. ---------- Spatial coverage of the vehicles in the testbed. The red and yellow colors show extremely high activity, while green is lighter activity. Each vehicle runs usually runs for several hours every day, though some vehicles don't run on some days. text/html 2007-07-22T21:23:33-04:00 http://cartel.csail.mit.edu/doku.php?id=p2_pothole_patrol&rev=1185153813&do=diff The Pothole Patrol (P2) uses the opportunistic mobility of sensor-equipped vehicles to detect and report the surface conditions of roads. Each car in the system carries a CarTel node with 3-axis acceleration and GPS sensors, gathering location-tagged vibration data at a frequency of 400 Hz (we would've liked to use a higher sample rate, but the sensors we use max out at 400 samples per second). text/html 2007-07-20T16:10:47-04:00 http://cartel.csail.mit.edu/doku.php?id=portal_walkthrough&rev=1184962247&do=diff The portal shows users where they've recently driven. ---------- Each trip is organized into a trace, which when viewed allows access to all accompanying sensor data. ---------- Every once in a while, after a depressingly slow commute, you can see why on the portal. An average speed of 13 mph is enough to make one sick (or start biking). The red, orange, and yellow segments are slow; the greens are about average, and the blues are real fast (no blue below). text/html 2011-10-21T16:15:48-04:00 http://cartel.csail.mit.edu/doku.php?id=ui_mockups&rev=1319228148&do=diff text/html 2007-07-20T16:18:57-04:00 http://cartel.csail.mit.edu/doku.php?id=wi-fi_monitoring&rev=1184962737&do=diff We have used CarTel to monitor urban WiFi connectivity. In a 2006 paper, we report on the results of about 290 total ``drive hours'' from a few cars under typical driving conditions, in and around the Boston metropolitan area. The study was done over a 1-year duration.