Distributed System

The Embedded Systems group at Microsoft Research has been engaged in joint academic collaborations spanning both teaching and research activities. The results of these collaborations are jointly reviewed, and highlighted to the academic community at the Faculty Summit at Microsoft headquarters in Redmond, WA, during the DemoFest event. This is also a good opportunity to review some of the other research projects that the group is engaged in, with special consideration to the research performed as part of the summer ...

Modern digital communication systems, such as microwave and millimeter wave point-to-point radios and local multipoint distribution system (LMDS) equipment now employ high-order quadrature amplitude modulation (QAM). In addition to the well known effect of additive white Gaussian noise (AWGN) on a QAM system's performance, phase noise and 3rd order intermodulation distortion (IMD) can also be major contributors to system performance degradation. This paper presents a simple analog distortion cancellation method which consists of a low-frequency feedback circuit connected between the FET output (drain) and the input (gate). This low-frequency feedback integrated with active bias is used to reduce phase noise and 3rd order IMD product by approximately 7 dB

The Mapham resonant inverter, proposed as a main driver-inverter in the 20 kHz, ac distribution system for a Space Station, is characterized with various types of load. The effects of load on the inverter's output regulation, harmonic distortions, and dynamic transience are investigated. Failure mode of operation leading to unbounded circuit currents is discussed. A simple control logic is suggested

Abstruct-A new control algorithm for the three-phase buck rectifier with an input filter is developed. The algorithm employs a separate control loop for compensation of the input current displacement factor in steady-state, in addition to the standard output voltage regulation ...

Abstract — This work aims to demonstrate how the requirement of modeling complex systems as the biological ones and the advances in MultiAgent Systems are combined to give a simple, scalable, robust and reliable simulation system. The mobility feature of the BESA ...

— This work aims to demonstrate how the requirement of modeling complex systems as the biological ones and the advances in MultiAgent Systems are combined to give a simple, scalable, robust and reliable simulation system. The mobility feature of the BESA ...

... bus voltage, control of base power flow thus reducing the power demand from the main grid feeder, and ultimately frequency control associated with load sharing within units located in themicro-grid. ... IEEE Task Force on Harmonics Modeling and Simulation, “Test systems ...

A Grid is a decentralized, geographically distributed and heterogeneous system in which resources belong to individuals or multiple organizations. Resource management and job scheduling are two important and difficult tasks in grid computing. Scheduling and execution of jobs in a dynamic environment like Grid often calls for efficient algorithms to schedule the resources required for successful execution of the jobs.

Multiparty interactions have been paid much attention in recent years because they provide the user with a useful mechanism for coordinating a number of entities that need to cooperate in order to achieve a common goal. In this paper, we present an algorithm for implementing them that is based on the idea of locking resources in a given order. It improves on previous results in that it can be used in a context in which the set of participants in an interaction cannot be known at compile time, and setting up ...

Recently, Peyravian and Jeffries [M. Peyravian, C. Jeffries, Secure remote user access over insecure networks, Computer Communications 29 (2006) 660–667] have proposed two set of protocols to perform remote user authentication and password change in a secure manner. The first set of protocols is based on hash functions, where no symmetric or asymmetric encryption scheme is applied. As Peyravian and

... Available online 11 January 2010. Abstract. Singelée and Preneel have recently proposed a enhancement of Hancke and Kuhn's distance bounding protocol for RFID. ... Keywords: Contactless card; Distance bounding protocol; Relay attack; RFID. Article Outline. ...

A new methodology is presented to derive reduced reaction mechanisms for distributed reacting flows by model training in a lumped parameter system (a continuous-stirred tank reactor). The method identifies the relevant transport time scales in the reaction zone of a distributed system along with the local composition vector, over a range of operation conditions. A training box in the parameter space of pressure-transport time scale-composition is then identified. Sensitivity and principal component analyses are subsequently performed at bifurcation points in a lumped parameter system at representative conditions of the training box. The most inclusive chemistry derived in the lumped system captures the proper transport-chemistry coupling and is suitable for the distributed reactor. Application to ignition of hydrogen/air and methane/air mixtures is presented and validated for premixed and diffusion flames in a stagnation flow geometry. (c) 1999 American Institute of Physics.