Multiple-Particle Tracking Measurements of Heterogeneities in Solutions of Actin Filaments and Actin Bundles

We helped CustomChat(TM) to refactor their product to be more robust and extensible, to add additional product features such as remote database connectivity, and to increase server capacity to more than 4 times that of their our closest competitor.  In addition, we developed a design and an implementation plan for a clustered version of their server for "Stadium" chats.

AOPS is a modular PC-based small business PBX system.  The system supports up to 256 internal extensions and up to 16 tie lines to the public switched telephone network.  The system has a mapping of virtual to physical extensions, voice mail, call forwarding, system-wide transfer and call management features, and long distance accounting.  The system has a simple software interface, which allows the administrator of the system to specify custom behaviors for the system using the C programming language.

The Rhythm Tree is the world’s largest electronic drum kit. The Rhythm tree is a part of the Brain Opera, an interactive musical exhibition which is currently on display at the House of Music in Vienna, Austria.

The Rhythm Tree has 320 drum pads, which act as input devices for the system. Each drum pad contains a piezoelectric sensor, a PIC microcontroller, an LED, and a RS-485 interface. The drum-pad circuits are potted in a semi-transparent rubber and mounted on a stainless steel frame. Each string of 32 pads connects to a concentrator unit, which converts the RS-485 signals to MIDI. Each group of five strings connects to a PC through a MIDI merger and MIDI interface card. The computer receives signals from the drum-pads and synthesizes music in response, which is played through a distributed set of speakers.

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The ultra-low power wireless traffic sensor is a device intended to be used to instrument a roadway for Intelligent Transportation Systems. The sensor package counts passing vehicles, measures the average roadway speed, and detects ice and water on the road. Clusters of sensors can transmit this information in near real-time to wired base stations for use controlling and predicting traffic, and in clearing road hazards.

The sensor package draws a maximum time-averaged current of 17mA from an internal lithium battery, allowing it to operate in the roadbed for at least 10 years without maintenance. The nodes cost well under $30 to manufacture, and can be installed without running wires under the road, facilitating wide deployment. Unlike many other types of traffic sensors, these sensors count vehicles in bumper-to-bumper traffic just as well as in widely separated traffic. The devices detect vehicles by detecting the perturbations in the Earth’s magnetic field caused by the vehicles. They measure this perturbation using an anisotropic magnetoresistive magnetic field sensor. The radio transmitters in the sensor are frequency-agile, and the sensors use a randomized sparse TDMA protocol, which allows several transmit-only devices to share a channel. The sensor package includes a custom-designed, compact, broadband, inexpensive printed circuit microstrip antenna for the 915 MHz U.S. ISM band. We built a prototype sensor package, and installed it in a pothole in a city street. We used the sensor to monitor the traffic flow rate during free-flowing traffic and a traffic jam.

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