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971.
Presented in this paper is a topology reconstruction algorithm from a set of unorganized trimmed surfaces. Error-prone small geometric elements are handled to give proper topological information. It gives complete topology to topologically complete models, and it is also tolerant to incomplete models. The proposed algorithm is vertex-based in that clues for topological information are searched from the set of vertices first, not from that of edges.  相似文献   
972.
973.
In this work we present a bulk silicon technology platform able to cointegrate gate-all-around (GAA) MOSFETs and local SOI waveguides with pentagonal cross section. Wire diagonals of 100-800 nm are obtained using a lithographic resolution of 0.8 mum. Well-functioning triangular multigate MOSFETs are reported, and tested up to 150 degC. A significant increase is observed in the low-field mobility mu0 for small devices (Weffles500 nm), which is attributed to local volume inversion in the corners. Preliminary characterization of the optical waveguides is carried out, showing optical losses of a few dB/cm. The processing is entirely CMOS compatible, does not require access to advanced lithography equipment, and is based on a silicon bulk substrate. Thus, this technology might serve as the basis for a low-cost, high-performance optical signaling platform  相似文献   
974.
Modeling Crosstalk Effects in CNT Bus Architectures   总被引:1,自引:0,他引:1  
Carbon nanotubes (CNTs) have been widely proposed as interconnect fabric for nano and very deep submicron (silicon-based) technologies due to their robustness to electromigration. In this paper, issues associated with crosstalk among bus lines implemented by CNTs are investigated in detail. CNT-based interconnects are modeled and the effects of crosstalk on performance and correct operation are evaluated by simulation. Existing models are modified to account for geometries in bus architectures made of parallel single-walled nanotubes and a single multiwalled nanotube. New RLC equivalent circuits are proposed for these bus architectures. A novel bus architecture with low crosstalk features is also proposed. This bus architecture is made of dual-walled nanotubes arranged in parallel. In this architecture, the crosstalk-induced delay and corresponding uncertainty (as well as crosstalk-induced peak voltage) are significantly reduced; a modest area penalty is incurred. Reductions up to 59% for the crosstalk-induced delay and up to 81% for the crosstalk-induced peak voltage are reported. These results confirm that the proposed bus arrangement noticeably improves performance and provides reliable operation  相似文献   
975.
Wafer-type piezoelectric transducers are effective transducers for the excitation and detection of ultrasonic Lamb waves in plate-like structures. Such transducers are, however, vulnerable to corrosion and physical damage when mounted in exposed locations. In this paper we describe an inductively coupled Lamb wave transducer that eliminates the need for direct electrical connections. Signals are coupled into and out of the transducer using two probe coils. In this paper we explore the operation of inductively coupled transducers both analytically and experimentally. Finite-element analysis is used to determine inductances and the coupling constant, and electrical circuit analysis to determine the transfer function and its dependence on the gap between the probe coils and the transducer. Experiments show that return signals of millivolt amplitude are obtained when the transducer is excited with 10-V amplitude pulses. These transducers are suitable for permanent mounting on structures to be monitored for cracks or flaws  相似文献   
976.
Solar cells are the most commonly used devices in customer products to achieve power autonomy. This paper discusses a complementary approach to provide power autonomy to devices on a human body, i.e., thermoelectric conversion of human heat. In indoor applications, thermoelectric converters on the skin can provide more power per square centimeter than solar cells, particularly in adverse illumination conditions. Moreover, they work day and night. The first sensor nodes powered by human heat have been demonstrated and tested on people in 2004-2005. They used the state-of-the-art 100-muW watch-size thermoelectric wrist generators fabricated at IMEC and based on custom-design small-size BiTe thermopiles. The sensor node is completed with a power conditioning module, a microcontroller, and a wireless transceiver mounted on a watchstrap  相似文献   
977.
Conceptual and Implementation Models for the Grid   总被引:1,自引:0,他引:1  
The Grid is rapidly emerging as the dominant paradigm for wide area distributed application systems. As a result, there is a need for modeling and analyzing the characteristics and requirements of Grid systems and programming models. This work adopts the well-established body of models for distributed computing systems, which are based upon carefully stated assumptions or axioms, as a basis for defining and characterizing Grids and their programming models and systems. The requirements of programming Grid applications and the resulting requirements on the underlying virtual organizations and virtual machines are investigated. The assumptions underlying some of the programming models and systems currently used for Grid applications are identified and their validity in Grid environments is discussed. A more in-depth analysis of two programming systems, the Imperial College E-Science Networked Infrastructure (ICENI) and Accord, using the proposed definitions' structure is presented.  相似文献   
978.
Jones  C. 《Software, IEEE》2003,20(6):22-27
Research on over 18 years of software projects reveals that developing large systems involves substantially more activities and a greater variety of specialized personnel than developing smaller systems. Perhaps the most significant observation is that good quality control is the best overall indicator of a successful project. Schedule delays and cost overruns most often occur when you discover during testing that the application has so many bugs that it doesn't work. Projects using QA teams, formal design and code inspections, and pretest defect tracking always had shorter testing cycles and therefore were more likely to be deliverable on schedule.  相似文献   
979.
在捷克共和国的Nova.Hut厂连铸机的投产阶段,必须满足用相对高的浇铸速度生产包晶钢这一特殊要求。为此采取了各种措施,如保护渣的精心选择及优化、结晶器液面控制的精确调整以及使用带抛物线锥度窄面板(DIAFACE)的结晶器。  相似文献   
980.
Evaluative responses appear to involve 2 seemingly distinct sets of processes: those that are automatically activated and others that are more consciously controlled. Using functional magnetic resonance imaging, the authors investigated the brain systems associated with automatic and controlled evaluative processing. Participants made either evaluative (good-bad) or nonevaluative (past-present) judgments about famous names. Greater amygdala activity was observed for names rated as "bad" relative to those rated as "good," regardless of whether the task directly involved an evaluative judgment (good-bad) or not (past-present). Good-bad judgments resulted in greater medial and ventrolateral prefrontal cortex (PFC) activity than past-present judgments. Furthermore, there was greater ventrolateral PFC activity in good-bad judgments marked by greater ambivalence. Together, these findings indicate a neural distinction between processes engaged for automatic and controlled evaluation. Whereas automatic processes are sensitive to simple valence, controlled processes are sensitive to attitudinal complexity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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