69 research outputs found

    Emotional response inhibition in bipolar disorder: a functional magnetic resonance imaging study of trait- and state-related abnormalities

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    BACKGROUND: Impaired response inhibition and poor impulse control are hallmarks of the manic phase of bipolar disorder but are also present during depressive and, to a lesser degree, euthymic periods. The neural mechanisms underlying these impairments are poorly understood, including how mechanisms are related to bipolar trait or state effects. METHODS: One-hundred four unmedicated participants with bipolar mania (BM) (n = 30), bipolar depression (BD) (n = 30), bipolar euthymia (BE) (n = 14), and healthy control subjects (n = 30) underwent functional magnetic resonance imaging during emotional and nonemotional go/no-go tasks. The go/no-go task requires participants to press a button for go stimuli, while inhibiting the response to no-go trials. In separate blocks, participants inhibited the response to happy faces, sad faces, or letters. RESULTS: The BE group had higher insula activity during happy face inhibition and greater activity in left inferior frontal gyrus during sad face inhibition, demonstrating bipolar trait effects. Relative to the BE group, BD and BM groups demonstrated lower insula activity during inhibition of happy faces, though the depressed sample had lower activity than manic patients. The BD and BM groups had a greater response to inhibiting sad faces in emotion processing and regulation regions, including putamen, insula, and lateral prefrontal cortex. The manic group also had higher activity in insula and putamen during neutral letter inhibition. CONCLUSIONS: These results suggest distinct trait- and state-related neural abnormalities during response inhibition in bipolar disorder, with implications for future research and treatment

    Harnessing the power of volunteers, the internet and Google Earth to collect and validate global spatial information using Geo-Wiki

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    Information about land cover and land use is needed for a wide range of applications such as nature protection and biodiversity, forest and water management, urban and transport planning, natural hazard prevention and mitigation, monitoring of agricultural policies and economic land use modelling. A number of different remotely-sensed global land cover products are available but studies have shown that there are large spatial discrepancies between these different products when compared. To address this issue of land cover uncertainty, a tool called Geo-Wiki was developed, which integrates online and mobile applications, high resolution satellite imagery available from Google Earth, and data collection through crowdsourcing as a mechanism for validating and improving globally relevant spatial information on land cover and land use. Through its growing network of volunteers and a number of successful data collection campaigns, almost 5 million samples of land cover and land use have been collected at many locations around the globe. This paper provides an overview of the main features of Geo-Wiki, and then using a series of examples, illustrates how the crowdsourced data collected through Geo-Wiki have been used to improve information on land cover and land use

    On the Selection of Parts and Processes during Design of Printed Circuit Board Assemblies

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    We consider a multiobjective optimization model that determines components and processes for given conceptual designs of printed circuit board assemblies. Specifically, out model outputs a set of solutions that are Pareto optimal with respect to a cost and a quality metric. The discussion here broadly outlines an integer programming based solution strategy, and represents in-progress work being carried out in collaboration with a manufacturing firm

    A Summary of Satellite Orbit Related Calculations

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    The configuration of satellite network systems is based on the quantities and properties related to the satellite orbit. It is extremely important to carefully define parameters and equations describing the orbit path correctly to make the whole configuration correct. Three different coordinate systems are in use to define satellite orbit: the Latitude-Longitude-Altitude coordinate system, the Right Ascension-Declination coordinate system and the Azimuth-Elevation coordinate system. These coordinate systems are equivalent with respect to the position of the satellite of interest and can easily be converted one to another. One of these coordinate systems would be used depending on the nature of the problem to be solved. Based upon these coordinate systems, the position of a satellite, the visibility of a satellite and antenna direction from a ground station, and a footprint radius of a satellite, etc. can be calculated.<P

    Object Oriented Hybrid Network Simulation

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    As the complexity and diversity of networks have grown, simulation has proved an important tool in their design, analysis, testing and performance estimation of networks. Hybrid networks involve a variety of network elements - both mobile (e.g., satellites, mobile radio) and fixed nodes (e.g., switches, hubs, network gateways) linked via varied broadcast, multicast and point-to-point communication channels. Because of their complex nature, design and evaluation of hybrid networks is a particularly complicated task. Major requirements of a hybrid network simulation tool are (i) Flexibility and Adaptability - to accommodate all kinds of hybrid networks and protocols, (ii) Advanced Network Visualization Techniques - to clearly visualize complex communication network systems, (iii) Data Management - to organize and analyze the vast quantities of data generated in a typical simulation run, and (iv) Distributed Implementation - to fully utilize available computing resources to speed up simulation. This paper describes the design and functional description of an Object-Oriented Hybrid Network Simulation tool. Its object oriented design and implementation (in C++) allows flexibility through incorporation of new, user specified network elements, protocols and functional blocks. Advanced visualization techniques are combined with the graphical user interface to allow better visualization of complex network structures. A sophisticated geographical database is also incorporated to aid terrestrial mobile, and satellite network systems. To handle and effectively analyze the vast quantities of data generated, an object-oriented database is incorporated into the simulation. In addition to network simulation, the tool is also designed to serve other needs. An interface is provided to allow the user to run real network applications over the simulated network, allowing network application designers to judge the performance of their applications over various network configurations. Incorporation of a database allows computation of network performance dynamically. A network management tool receiving network performance data both from the actual and the simulated network may use the simulation data to make a long term prediction of the actual network behavior to perform long-term network management

    Integrated Product and Process Design Environment Tool for Manufacturing T/R Modules

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    We present a decision making assistant tool for integrated product and process design environment for manufacturing applications. Specifically, we target microwave modules which use Electro-mechanical components and require optimal solutions to reduce cost, improve quality, and gain leverage in time to market the product. This tool will assist the product and process designer to improve their productivity and also enable to cooperate and coordinate their designs through a common design interface. We consider a multiobjective optimization model that determines components and processes for a given conceptual designs for microwave modules. This model outputs a set of solutions that are Pareto optimal with respect to cost, quality, and other metrics. In addition, we identify system integration issues for manufacturing applications, and propose an architecture which will serve as a building block to our continuing research in virtual manufacturing applications

    Integrated Network Management of Hybrid Networks

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    We describe our collaborative efforts towards the design and implementation of a next generation integrated network management system for hybrid networks (INMS/HN). We describe the overall software architecture of the system at its current stage of development. This network management system is specifically designed to address issues relevant for complex heterogeneous networks consisting of seamlessly interoperable terrestrial and satellite networks. Network management systems are a key element for interoperability in such networks. We describe the integration of configuration management and performance management. The next step in this integration is fault management. In particular we describe the object model, issues of the Graphical User Interface (GUI), browsing tools and performance data graphical widget displays, management information database (MIB) organization issues. Several components of the system are being commercialized by Hughes Network Systems. A revised version of this report has been published in Proceedings of the 1st Conference of Commercial Development of Space, Part One, pp. 345-350, Albuquerque, New Mexico, January 7-11, 1996.</ul

    Hybrid Network Management

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    We describe our collaborative efforts towards the design and implementation of a next generation integrated network management system for hybrid network (INMS/HN). We describe the overall software architecture of the system at its current stage of development. This network management system if specifically designed to address issues relevant for complex heterogeneous networks consisting of seamlessly interoperable terrestrial and satellite networks. Network management systems are a key element for interoperability in such networks. We describe the integration of configuration management and performance management. The next step in this integration is fault management. In particular we describe the object model, issues of the Graphical User Interface (GUI), browsing tools and performance data graphical widget displays, management, information database (MIB) organization issues. Several components of the system are being commercialized by Hughes Networks Systems. A revised version of this technical report has been published in Proceedings of the AIAA: 16th International Communications Satellite Systems Conference and Exhibit, Part 1, pp. 490-500, Washington, D.C., February 25- 29, 1996.</ul

    Next Generation Network Management Technology

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    Today's telecommunications networks are becoming increasingly large, complex, mission critical and heterogeneous in several dimensions. For example, the underlying physical transmission facilities of a given network may be ï²­ixed media (copper, fiber- optic, radio, and satellite); the sub networks may be acquired from different vendors due to economic, performance, or general availability reasons; the information being transmitted over the network may be ï²­ultimedia (video, data, voice, and images) and, finally, varying performance criteria may be imposed e.g. data transfer may require high throughput while the others, whose concern is voice communications, may require low call blocking probability. For these reasons, future telecommunications networks are expected to be highly complex in their services and operations. Due to this growing complexity and the disparity among management systems for individual sub networks, efficient network management systems have become critical to the current and future success of telecommunications companies. This paper addresses a research and development effort which focuses on prototyping configuration management, since that is the central process of network management and all other network management functions must be built upon it. Our prototype incorporates ergonomically designed graphical user interfaces tailored to the network configuration management subsystem and to the proposed advanced object-oriented database structure. The resulting design concept follows open standards such as Open Systems Interconnection (OSI) and incorporates object oriented programming methodology to associate data with functions, permit customization, and provide an open architecture environment. A revised version of this technical report has been published in The 12th Symposium on Space Nuclear Power and Propulsion/Commercialization, pp. 75-82, Albuquerque, NM, January 8-12, 1995.</ul
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