摘要 :
In this application paper we explore techniques to classify anomalous structures (defects) in data generated from Molecular Dynamics (MD) simulations of Silicon (Si) atom systems. These systems are studied to understand the proces...
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In this application paper we explore techniques to classify anomalous structures (defects) in data generated from Molecular Dynamics (MD) simulations of Silicon (Si) atom systems. These systems are studied to understand the processes behind the formation of various defects as they have a profound impact on the electrical and mechanical properties of Silicon. In our prior work [12, 13, 14] we presented techniques for defect detection. Here, we present a two-step dynamic classifier to classify the defects. The first step uses up to third-order shape moments to provide a smaller set of candidate defect classes. The second step assigns the correct class to the defect structure by considering the actual spatial positions of the individual atoms. The dynamic classifier is robust and scalable in the size of the atom systems. Each phase is immune to noise, which is characterized after a study of the simulation data. We also validate the proposed solutions by using a physical model and properties of lattices. We demonstrate the efficacy and correctness of our approach on several large datasets. Our approach is able to recognize previously seen defects and also identify new defects in real time.
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Numerical simulation is replacing experimentation as a means to gain insight into complex physical phenomena. Analyzing the data produced by such simulations is extremely challenging, given the enormous sizes of the datasets invol...
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Numerical simulation is replacing experimentation as a means to gain insight into complex physical phenomena. Analyzing the data produced by such simulations is extremely challenging, given the enormous sizes of the datasets involved. In order to make efficient progress, analyzing such data must advance from current techniques that only visualize static images of the data, to novel techniques that can mine, track, and visualize the important features in the data. In this paper, we present our research on a unified framework that addresses this critical challenge in two science domains: computational fluid dynamics and molecular dynamics. We offer a systematic approach to detect the significant features in both domains, characterize and track them, and formulate hypotheses with regard to their complex evolution. Our framework includes two paradigms for feature mining, and the choice of one over the other, for a given application, can be determined based on local or global influence of relevant features in the data.
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Changing environmental interests and new fire safety performance concerns in the wire and cable industry (WCI) have generated studies into the fire hazard and eco-performance of various data and communication cabling system altern...
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Changing environmental interests and new fire safety performance concerns in the wire and cable industry (WCI) have generated studies into the fire hazard and eco-performance of various data and communication cabling system alternatives for computers and local area networks (LAN). To accurately assess the various alternatives, the installed electronic functionality and fire safety performance requirements of the various end-use product options must be equivalent. For high fire performance communication cables (HFP-cables), many existing local and national regulations differentiate between end product performance options and building fire protection needs. High fire-performance, high societal-value based PVC sheathed and perfluoropolymer (PFP) insulated (PVC/PFP) cables can be routed directly in concealed plenum spaces in buildings, while products that do not meet specific high fire performance criteria, such as low-smoke zero-halogen (LSZH/PE) cables or riser-rated cables (CMR or PVC/PE), often must be protected inside other structures that do meet these building fire standards, typically using steel conduit or trunking. However, some low fire performance LAN cables, even fire-protected inside steel conduits, failed to meet the minimum flame spread and smoke criteria that HFP-cables must meet in real-scale cable, fire tests at BRE/FRS and Underwriters Laboratories (when tested as a cable in steel conduit system). Life cycle analysis (LCA) via ISO 14040 methodology is used to evaluate the various cabling alternatives using an appropriate functional unit; a CAT 6 communication LAN cabling system in a typical office building, including cable, steel conduit, couplings and supports as required per building codes for the installation. Key environmental impact assessments for energy consumption, greenhouse gas emissions, and human toxicity are all shown to favor the PVC/PFP systems once the steel conduit is included in the analysis to fire-protect the LSZH/PE or PVC/PE cables. The additional fire safety and installation advantages provided by the PVC/PFP cables more than offsets for the environmental burdens associated with the initial manufacture of just the cable, thereby providing superior overall fire safety, environmental performance, and economic benefits versus LSZH/PE and PVC/PE cables in steel conduits.
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摘要 :
Changing environmental interests and new fire safety performance concerns in the wire and cable industry (WCI) have generated studies into the fire hazard and eco-performance of various data and communication cabling system altern...
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Changing environmental interests and new fire safety performance concerns in the wire and cable industry (WCI) have generated studies into the fire hazard and eco-performance of various data and communication cabling system alternatives for computers and local area networks (LAN). To accurately assess the various alternatives, the installed electronic functionality and fire safety performance requirements of the various end-use product options must be equivalent. For high fire performance communication cables (HFP-cables), many existing local and national regulations differentiate between end product performance options and building fire protection needs. High fire-performance, high societal-value based PVC sheathed and perfluoropolymer (PFP) insulated (PVC/PFP) cables can be routed directly in concealed plenum spaces in buildings, while products that do not meet specific high fire performance criteria, such as low-smoke zero-halogen (LSZH/PE) cables or riser-rated cables (CMR or PVC/PE), often must be protected inside other structures that do meet these building fire standards, typically using steel conduit or trunking. However, some low fire performance LAN cables, even fire-protected inside steel conduits, failed to meet the minimum flame spread and smoke criteria that HFP-cables must meet in real-scale cable fire tests at BRE/FRS and Underwriters Laboratories (when tested as a cable in steel conduit system) [10]. Life cycle analysis (LCA) via ISO 14040 methodology is used to evaluate the various cabling alternatives using an appropriate functional unit; a CAT 6 communication LAN cabling system in a typical office building, including cable, steel conduit, couplings and supports as required per building codes for the installation. Key environmental impact assessments for energy consumption, greenhouse gas emissions, and human toxicity are all shown to favor the PVC/PFP systems once the steel conduit is included in the analysis to fire-protect the LSZH/PE or PVC/PE cables. The additional fire safety and installation advantages provided by the PVC/PFP cables more than offsets for the environmental burdens associated with the initial manufacture of just the cable, thereby providing superior overall fire safety, environmental performance, and economic benefits versus LSZH/PE and PVC/PE cables in steel conduits.
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摘要 :
Changing environmental interests and new fire safety performance concerns in the wire and cable industry (WCI) have generated studies into the fire hazard and eco-performance of various data and communication cabling system altern...
展开
Changing environmental interests and new fire safety performance concerns in the wire and cable industry (WCI) have generated studies into the fire hazard and eco-performance of various data and communication cabling system alternatives for computers and local area networks (LAN). To accurately assess the various alternatives, the installed electronic functionality and fire safety performance requirements of the various end-use product options must be equivalent. For high fire performance communication cables (HFP-cables), many existing local and national regulations differentiate between end product performance options and building fire protection needs. High fire-performance, high societal-value based PVC sheathed and perfluoropolymer (PFP) insulated (PVC/PFP) cables can be routed directly in concealed plenum spaces in buildings, while products that do not meet specific high fire performance criteria, such as low-smoke zero-halogen (LSZH/PE) cables or riser-rated cables (CMR or PVC/PE), often must be protected inside other structures that do meet these building fire standards, typically using steel conduit or trunking. However, some low fire performance LAN cables, even fire-protected inside steel conduits, failed to meet the minimum flame spread and smoke criteria that HFP-cables must meet in real-scale cable, fire tests at BRE/FRS and Underwriters Laboratories (when tested as a cable in steel conduit system). Life cycle analysis (LCA) via ISO 14040 methodology is used to evaluate the various cabling alternatives using an appropriate functional unit; a CAT 6 communication LAN cabling system in a typical office building, including cable, steel conduit, couplings and supports as required per building codes for the installation. Key environmental impact assessments for energy consumption, greenhouse gas emissions, and human toxicity are all shown to favor the PVC/PFP systems once the steel conduit is included in the analysis to fire-protect the LSZH/PE or PVC/PE cables. The additional fire safety and installation advantages provided by the PVC/PFP cables more than offsets for the environmental burdens associated with the initial manufacture of just the cable, thereby providing superior overall fire safety, environmental performance, and economic benefits versus LSZH/PE and PVC/PE cables in steel conduits.
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摘要 :
The simulation of defect dynamics and evolution is a technologically relevant challenge for computational materials science. The diffusion of small defects in silicon unfolds as a sequence of structural transitions. The relative i...
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The simulation of defect dynamics and evolution is a technologically relevant challenge for computational materials science. The diffusion of small defects in silicon unfolds as a sequence of structural transitions. The relative infrequency of transition events requires simulation over extremely long time scales. We simulate the diffusion of small interstitial clusters (I{sub}1, I{sub}2, I{sub}3) for a range of temperatures using large-scale molecular dynamics (MD) simulations with a realistic tight-binding potential. A total of 0.25 μsee of simulation time is accumulated for the study. A novel real-time multiresolution analysis (RTMRA) technique extracts stable structures directly from the dynamics without structural relaxation. The discovered structures are relaxed to confirm their stability.
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摘要 :
The simulation of defect dynamics and evolution is a technologically relevant challenge for computational materials science.The diffusion of small defects in silicon unfolds as a sequence of structural transitions.The relative inf...
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The simulation of defect dynamics and evolution is a technologically relevant challenge for computational materials science.The diffusion of small defects in silicon unfolds as a sequence of structural transitions.The relative infrequency of transition events requires simulation over extremely long time scales.We simulate the diffusion of small interstitial clusters (I_1,I_2,I_3) for a range of temperatures using large-scale molecular dynamics (MD) simulations with a realistic tight-binding potential.A total of 0.25 mu sec of simulation time is accumulated for the study.A novel real-time multiresolution analysis (RTMRA) technique extracts stable structures directly from the dynamics without structural relaxation.The discovered structures are relaxed to confirm their stability.
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Diarrhea is one of the main causes of death in children under five years old. Drinking water contaminated with water borne pathogens is one of the main sources of diarrhea Currently the primary method of water disinfection is chlo...
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Diarrhea is one of the main causes of death in children under five years old. Drinking water contaminated with water borne pathogens is one of the main sources of diarrhea Currently the primary method of water disinfection is chlorination. However, chlorination has a number of deleterious effects. A byproduct of chlorination is leftover chlorine which has a negative impact on the environment. Furthermore, the long-term health effects of human consumption of chlorinated water are unknown. Therefore many water treatment centers employ alternative disinfection methods in place of chlorination or to minimize chlorine usage. In one method multivalent metallic salts are mixed with water to induce attraction between charged contaminants. The aggregated contaminants sediment out of the water and settle at the basin where they are removed from the system in a process called flocculation. Typically the efficacy of multivalent salt flocculation is studied by jar test. In this laboratory procedure salts are mixed with contaminants under a variety of conditions to determine optimal salt type and concentration for water treatment. Although jar test studies provide a way to optimize disinfection, they cannot be used to understand the physical basis for flocculation.
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