Motorola

About: Motorola is a company organization based out in Schaumburg, Illinois, United States. It is known for research contribution in the topics: Signal & Communications system. The organization has 27298 authors who have published 38274 publications receiving 968710 citations. The organization is also known as: Motorola, Inc. & Galvin Manufacturing Corporation.

Genetic Algorithms for Project Management

Abstract: The scheduling of tasks and the allocation of resource in medium to large-scale development projects is an extremely hard problem and is one of the principal challenges of project management due to its sheer complexity. As projects evolve any solutions, either optimal or near optimal, must be continuously scrutinized in order to adjust to changing conditions. Brute force exhaustive or branch-and-bound search methods cannot cope with the complexity inherent in finding satisfactory solutions to assist project managers. Most existing project management (PM) techniques, commercial PM tools, and research prototypes fall short in their computational capabilities and only provide passive project tracking and reporting aids. Project managers must make all major decisions based on their individual insights and experience, must build the project database to record such decisions and represent them as project nets, then use the tools to track progress, perform simple consistency checks, analyze the project net for critical paths, etc., and produce reports in various formats such as Gantt or Pert charts. Our research has developed a new technique based on genetic algorithms (GA) that automatically determines, using a programmable goal function, a near-optimal allocation of resources and resulting schedule that satisfies a given task structure and resource pool. We assumed that the estimated effort for each task is known a priori and can be obtained from any known estimation method such as COCOMO. Based on the results of these algorithms, the software manager will be able to assign tasks to staff in an optimal manner and predict the corresponding future status of the project, including an extensive analysis on the time-and-cost variations in the solution space. Our experiments utilized Wall's GALib as the search engine. The algorithms operated on a richer, refined version of project management networks derived from Chao's seminal work on GA-based Software Project Management Net (SPMnet). Generalizing the results of Chao's solution, the new GA algorithms can operate on much more complex scheduling networks involving multiple projects. They also can deal with more realistic programmatic and organizational assumptions. The results of the GA algorithm were evaluated using exhaustive search for five test cases. In these tests our GA showed strong scalability and simplicity. Its orthogonal genetic form and modularized heuristic functions are well suited for complex conditional optimization problems, of which project management is a typical example.

Method and apparatus for transmission and reception of narrowband signals within a wideband communication system

Abstract: Narrowband remote units (101-103) scan over frequencies within a wideband channel spectrum, evaluating frequency-selective channel characteristics. The best sub-channel(s) for communication is determined and reported back to a base station (104) via a channel-quality report message. The base station then utilizes only a narrowband portion, for example, one sub-channel comprised of a plurality of OFDM subcarriers, of the wideband channel for transmitting data to the narrowband unit.

Method for providing autonomous radio talk group configuration

Abstract: A method is provided for autonomous radio talk group configuration among radio transceivers. The radio transceivers are placed in a group configuration mode that operates on a communication channel (310, 320). A configuration master transceiver is selected and the other transceivers designated as configuration slave transceivers (330). The configuration master transceiver transmits radio talk group identification information on the communication channel, and the configuration slave transceivers receive and store this radio talk group identification information for use in radio talk group communications (340).

Effect of SiC Nanoparticle Additions on Microstructure and Microhardness of Sn-Ag-Cu Solder Alloy

Abstract: In this work, lead-free composite solders were produced by mechanically mixing nominal 20 nm moissanite SiC particles with Sn-3.8Ag-0.7Cu solder paste. The effects of the amount of SiC addition on the melting behavior, microstructure, and microhardness of as-solidified composite solders were systematically investigated. In comparison with solder without the addition of SiC nanoparticles, the subgrain of β-Sn, the intermetallic compounds (IMCs) average grain size and distance decreased significantly in the composite solder matrix. This was possibly ascribed to the strong adsorption effect and high surface free energy of the SiC nanoparticles. Our results showed that 0.05 wt.% addition of SiC nanoparticles could improve the microhardness by 44% compared with the noncomposite and that the average grain size and distance changed from 0.5 μm to 0.2 μm and from 0.6 μm to 0.32 μm, respectively. The refined IMCs, acting as a strengthening phase in the solder matrix, enhanced the microhardness of the composite solders, in good agreement with the prediction of the classic theory of dispersion strengthening.

Linear peak current mode control: a simple active power factor correction control technique for continuous conduction mode

Abstract: A simplified power factor correction (PFC) technique for continuous conduction mode (CCM) operated power converters is presented which has the following advantages over conventional peak and average current mode PFC techniques: elimination of the controller multiplier and input voltage sensing circuits; unconditional stability of the current loop; and ease of implementation using low cost standard PWM control ICs (e.g. UC2843). Simulation and experimental results verify the viability of the new controller.