1,610 research outputs found

    The application of optimal control technqiues to advanced manned missions, volume 1

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    Two problems are presented in the area of optimal control and its application to the design of attitude control systems for advanced complex aerospace vehicles. The problems discussed are specification of performance criteria in terms of structural load minimization and/or maximum orbital payload injection requirements of the controlled vehicle; and formulation and solution of the optimization problem such that practical control systems are obtained

    A wearable wireless sensor network for indoor smart environment monitoring in safety applications

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    This paper presents the implementation of a wearable wireless sensor network aimed at monitoring harmful gases in industrial environments. The proposed solution is based on a customized wearable sensor node using a low-power low-rate wireless personal area network (LR-WPAN) communications protocol, which as a first approach measures CO2 concentration, and employs different low power strategies for appropriate energy handling which is essential to achieving long battery life. These wearables nodes are connected to a deployed static network and a web-based application allows data storage, remote control and monitoring of the complete network. Therefore, a complete and versatile remote web application with a locally implemented decision-making system is accomplished, which allows early detection of hazardous situations for exposed workers

    Γ (Gamma): cloud-based analog circuit design system

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    Includes bibliographical references.2016 Summer.With ever increasing demand for lower power consumption, lower cost, and higher performance, designing analog circuits to meet design specifications has become an increasing challenging task, On one hand, analog circuit designers must have intimate knowledge about the underlining silicon process technology's capability to achieve the desired specifications. On the other hand, they must understand the impact of tweaking circuits to satisfy a given specification on all circuit performance parameters. Analog designers have traditionally learned to tackle design problems with numerous circuit simulations using accurate circuit simulators such as SPICE, and have increasingly relied on trial-and-error approaches to reach a converging point. However, the increased complexity with each generation of silicon technology and high dimensionality of searching for solutions, even for some simple analog circuits, have made trial-and-error approaches extremely inefficient, causing long design cycles and often missed market opportunities. Novel rapid and accurate circuit evaluation methods that are tightly integrated with circuit search and optimization methods are needed to aid design productivity. Furthermore, the current design environment with fully distributed licensing and supporting structures is cumbersome at best to allow efficient and up-to-date support for design engineers. With increasing support and licensing costs, fewer and fewer design centers can afford it. Cloud-based software as a service (SaaS) model provides new opportunities for CAD applications. It enables immediate software delivery and update to customers at very low cost. SaaS tools benefit from fast feedback and sharing channels between users and developers and run on hardware resources tailored and provided for them by software vendors. However, web-based tools must perform in a very short turn-around schedule and be always responsive. A new class of analog design tools is presented in this dissertation. The tools provide effective design aid to analog circuit designers with a dash-board control of many important circuit parameters. Fast and accurate circuit evaluations are achieved using a novel lookup-table transistor models (LUT) with novel built-in features tightly integrated with the search engine to achieve desired speed and accuracy. This enables circuit evaluation time several orders faster than SPICE simulations. The proposed architecture for analog design attempts to break the traditional analog design flow using SPICE based trial-and-error methods by providing designers with useful information about the effects of prior design decisions they have made and potential next steps they can take to meet specifications. Benefiting from the advantages offered by web-hosted architectures, the proposed architecture incorporates SaaS as its operating model. The application of the proposed architecture is illustrated by an analog circuit sizer and optimizer. The Γ (Gamma) sizer and optimizer show how web-based design-decision supporting tool can help analog circuit designers to reduce design time and achieve high quality circuit

    Leveraging the Sales Force with Portal Technology at the American Subsidiary of a Japanese Motor Company Case Series (A), (B) and (C)

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    Managers understand the need to have information aligned with their businesses - they see and feel its consequences every day. They also understand the goal of technology-based information systems (IS) delivers the right information to the right people at the right time so that both strategic and operational decisions can be made properly and quickly. This was the approach followed by the American subsidiary of a Japanese motor company. The firm implemented a single, unified, Web-based interface to centralize and synchronize data access to 12 stand-alone dealership sales applications. The implementation took less than six months and less than 500,000wasexpended.Immediateresultswerethatthesalesmanagersbecamesignificantlymoreefficientwiththeirtime,theautomobiledivisionrecognizedacostsavingsof500,000 was expended. Immediate results were that the sales managers became significantly more efficient with their time, the automobile division recognized a cost savings of 1.4 million through a more efficient use of employee resources, and there was an estimated $10 million savings corporate wide as a result of employee efficiency gains throughout the organization. Despite all of these benefits, the automobile division\u27s chief information officer was faced with the decision of whether or not to return to fix the data integration and timeliness problems that remained among the division\u27s autonomous sales applications. This case study series highlights the objectives, outcomes, and challenges that managers must address while implementing Web-based portals. This case series also provides a better understanding for identifying, leveraging, and improving operational efficiency within a firm

    Energy Efficiency in Communications and Networks

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    The topic of "Energy Efficiency in Communications and Networks" attracts growing attention due to economical and environmental reasons. The amount of power consumed by information and communication technologies (ICT) is rapidly increasing, as well as the energy bill of service providers. According to a number of studies, ICT alone is responsible for a percentage which varies from 2% to 10% of the world power consumption. Thus, driving rising cost and sustainability concerns about the energy footprint of the IT infrastructure. Energy-efficiency is an aspect that until recently was only considered for battery driven devices. Today we see energy-efficiency becoming a pervasive issue that will need to be considered in all technology areas from device technology to systems management. This book is seeking to provide a compilation of novel research contributions on hardware design, architectures, protocols and algorithms that will improve the energy efficiency of communication devices and networks and lead to a more energy proportional technology infrastructure

    Body sensor network for in-home personal healthcare

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    A body sensor network solution for personal healthcare under an indoor environment is developed. The system is capable of logging the physiological signals of human beings, tracking the orientations of human body, and monitoring the environmental attributes, which covers all necessary information for the personal healthcare in an indoor environment. The major three chapters of this dissertation contain three subsystems in this work, each corresponding to one subsystem: BioLogger, PAMS and CosNet. Each chapter covers the background and motivation of the subsystem, the related theory, the hardware/software design, and the evaluation of the prototype’s performance

    A chemo-centric view of human health and disease

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    Efforts to compile the phenotypic effects of drugs and environmental chemicals offer the opportunity to adopt a chemo-centric view of human health that does not require detailed mechanistic information. Here we consider thousands of chemicals and analyse the relationship of their structures with adverse and therapeutic responses. Our study includes molecules related to the aetiology of 934 health-threatening conditions and used to treat 835 diseases. We first identify chemical moieties that could be independently associated with each phenotypic effect. Using these fragments, we build accurate predictors for approximately 400 clinical phenotypes, finding many privileged and liable structures. Finally, we connect two diseases if they relate to similar chemical structures. The resulting networks of human conditions are able to predict disease comorbidities, as well as identifying potential drug side effects and opportunities for drug repositioning, and show a remarkable coincidence with clinical observations

    Soil Moisture Sensor

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    Since water is an important resource and not all communities around the world can afford to be liberal with their water needs; it has become important to use available water as efficiently as possible, especially in agriculture. For the purpose of reducing the overwatering of crops, an unattended ground moisture sensor can be implemented to measure the moisture level in the soil surrounding the plants. This will allow a farmer to know when to water or stop watering crops. For convenience, the moisture data information should be transmitted wirelessly to the user. The design of an unattended ground moisture sensor and wireless communication/user interface system is discussed. The sensor design consists of a Wheatstone bridge for determining the resistance of the soil, followed by a differential amplifier for converting the measured resistance into a voltage. This is done because there exists a correlation between moisture and resistance. This voltage is interpreted by a micro controller as moisture data and sent wirelessly to a Lora receiver. The receiver then relays that information to the user via a mobile or web based app

    Enhancing Mindfulness-Based Stress Reduction Through a Mobile Application

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    The goal of this Major Qualifying Project (MQP) was to improve upon the initial design of a mobile application that would assist college students in the practice of Mindfulness Based Stress Reduction (MBSR). The team assisted in building a foundation for UMass Medical so they can apply for a grant to have this project be fully funded and become a fully functioning mobile application. This MQP was a continuation of a previous MQP’s work that explored some of the initial ideas on how to design the application. The team created functional mockups of the original idea and surveyed college students to get their feedback on the initial design
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