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Consistent constitutive modeling of metallic target penetration using empirical, analytical, and numerical penetration models

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Defence Technology（防务技术） 2016年第2期12卷 201-213页

作者： John(jack) P.RIEGEL III David DAVISON R3 Technology Inc. 7324 Fountain Spring Ct. Shock Transients Inc.

Historically, there has been little correlation between the material properties used in(1) empirical formulae,(2) analytical formulations, and(3) numerical models. The various regressions and models may each provide excellent agreement for the depth of penetration into semi-infinite targets. But the input parameters for the empirically based procedures may have little in common with either the analytical model or the numerical model. This paper builds on previous work by Riegel and Anderson(2014) to show how the Effective Flow Stress(EFS) strength model, based on empirical data, can be used as the average flow stress in the analytical Walker–Anderson Penetration model(WAPEN)(Anderson and Walker,1991) and how the same value may be utilized as an effective von Mises yield strength in numerical hydrocode simulations to predict the depth of penetration for eroding projectiles at impact velocities in the mechanical response regime of the materials. The method has the benefit of allowing the three techniques(empirical, analytical, and numerical) to work in tandem. The empirical method can be used for many shot line calculations, but more advanced analytical or numerical models can be employed when necessary to address specific geometries such as edge effects or layering that are not treated by the simpler methods. Developing complete constitutive relationships for a material can be costly. If the only concern is depth of penetration, such a level of detail may not be required. The effective flow stress can be determined from a small set of depth of penetration experiments in many cases, especially for long penetrators such as the L/D = 10 ones considered here, making it a very practical approach. In the process of performing this effort, the authors considered numerical simulations by other researchers based on the same set of experimental data that the authors used for their empirical and analytical assessment. The goals were to establish a baseline with a full constitut

关键词：本构模型渗透模型数值模型金属靶材料性质流动应力程序模拟数值计算

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CONCURRENT PRODUCT PORTFOLIO PLANNING AND MIXED PRODUCT ASSEMBLY LINE BALANCING

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Chinese Journal of Mechanical Engineering 2007年第1期20卷 96-99页

作者： BRYAN April HU S jack KOREN Yoram Department of Mechanical Engineering University of Michigan Ann Arbor USA

Reconfigurable products and manufacturing systems have enabled manufacturers to provide ＂cost effective＂ variety to the market. In spite of these new technologies, the expense of manufacturing makes it infeasible to supply all the possible variants to the market for some industries. Therefore, the determination of the right number of product variantsto offer in the product portfolios becomes an important consideration. The product portfolio planning problem had been independently well studied from marketing and engineering perspectives. However, advantages can be gained from using a concurrent marketing and engineering approach. Concurrent product development strategies specifically for reconfigurable products and manufacturing systems can allow manufacturers to select best product portfolios from marketing, product design and manufacturing perspectives. A methodology for the concurrent design of a product portfolio and assembly system is presented. The objective of the concurrent product portfolio planning and assembly system design problem is to obtain the product variants that will make up the product portfolio such that oversupply of optional modules is minimized and the assembly line efficiency is maximized. Explicit design of the assembly system is obtained during the solution of the problem. It is assumed that the demand for optional modules and the assembly times for these modules are known a priori. A genetic algorithm is used in the solution of the problem. The basic premise of this methodology is that the selected product portfolio has a significant impact on the solution of the assembly line balancing problem. An example is used to validate this hypothesis. The example is then further developed to demonstrate how the methodology can be used to obtain the optimal product portfolio. This approach is intended for use by manufacturers during the early design stages of product family design.

关键词： Product portfolio Assembly system design Assembly line balancing Concurrent design and manufacturing Optimization

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QUANTIZATION AND TRAINING OF LOW BIT-WIDTH CONVOLUTIONAL NEURAL NETWORKS FOR OBJECT DETECTION

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Journal of Computational Mathematics 2019年第3期37卷 349-359页

作者： Penghang Yin Shuai Zhang Yingyong Qi jack Xin Department of Mathematics University of CaliforniaLos AngelesCA 90095USA Department of Mathematics University of CaliforniaIrvineCA 92697USA

We presen t LBW-Net,an efficient optimization based method for qua nt ization and training of the low bit-width convolutional neural networks(CNNs).Specifically,we quantize the weights to zero or powers of 2 by minimizing the Euclidean distance between full-precision weights and quantized weights during backpropagation(weight learning).We characterize the combinatorial nature of the low bit-width quantization *** 2-bit(ternary)CNNs,the quantization of N weights can be done by an exact formula in O(N log N)*** the bit-width is 3 and above,we further propose a semi-analytical thresholding scheme with a single free parameter for quantization that is computationally *** free parameter is further determined by network retraining and object detection *** LBW-Net has several desirable advantages over full-precision CNNs,including considerable memory savings,energy efficiency,and faster *** experiments on PASCAL VOC dataset show that compared with its 32-bit floating-point counterpart,the performance of the 6-bit LBW-Net is nearly lossless in the object detection tasks,and can even do better in real world visual scenes,while empirically enjoying more than 4× faster deployment.

关键词： Quantization Low bit width deep neural networks Exact and approximate analytical formulas Network training Object detection

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Post-exascale supercomputing:research opportunities abound

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Frontiers of Information Technology & Electronic Engineering 2018年第10期19卷 1203-1208页

作者： Zuo-ning CHEN jack DONGARRA Zhi-wei XU Chinese Academy of Engineering Electrical Engineering and Computer Science Department University of Tennessee Institute of Computing Technology Chinese Academy of Sciences

Exascale supercomputing refers to the scientific research efforts and activities to build and use supercomputers that can perform scientific computing at the speed of exaflops,or 10^(18) floating-point(64-bit)operatio... 详细信息

关键词：计算研究机科学研究浮点操作

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Phylogenetic context of a deep-sea clam(Bivalvia:Vesicomyidae) revealed by DNA from 1 500-year-old shells

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Zoological Research 2023年第2期44卷 353-356页

作者： Yi-Xuan Li Yanjie Zhang jack Chi-Ho Ip Jing Liu Chong Chen Crispin TSLittle Yusuke Yokoyama Moriaki Yasuhara Jian-Wen Qiu Department of Biology Hong Kong Baptist UniversityHong Kong SARChina Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) GuangzhouGuangdong 511458China School of Life Sciences Hainan UniversityHaikouHainan 570228China Laboratory of Marine Organism Taxonomy and Phylogeny Institute of OceanologyChinese Academy of SciencesQingdaoShandong 266071China X-STAR Japan Agency for Marine-Earth Science and Technology(JAMSTEC)2-15 Natsushima-choYokosukaKanagawa 237-0061Japan School of Earth and Environment University of LeedsLeeds LS29JTUK Life Sciences Department Natural History MuseumLondon SW75BDUK Department of Earth and Planetary Science University of TokyoHongo113-0033Japan School of Biological Sciences Area of Ecology and BiodiversitySwire Institute of Marine ScienceInstitute for Climate and Carbon Neutralityand Musketeers Foundation Institute of Data ScienceUniversity of Hong KongHong Kong SARChina State Key Laboratory of Marine Pollution City University of Hong KongHong Kong SARChina

DEAR EDITOR,Ancient DNA(a DNA) from mollusc shells is considered a potential archive of historical biodiversity and ***, such information is currently lacking for mollusc shells from the deep ocean, especially those from acidic chemosynthetic environments theoretically unsuitable for longterm DNA preservation. Here, we report on the recovery of mitochondrial and nuclear gene markers by Illumina sequencing of a DNA from three shells of Archivesica nanshaensis – a hydrocarbon-seep vesicomyid clam previously known only from a pair of empty shells collected at a depth of 2626 m in the South China Sea.

关键词： shells evolution acidic

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Mechanism of tunneling-induced cave-in of a busy road in Fukuoka city,Japan

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Underground Space 2018年第2期3卷 140-149页

作者： Jinchun Chai jack Shuilong Shen Da-Jun Yuan Department of Civil Engineering and Architecture Saga UniversitySaga 840-8502Japaon State Key Laboratory of Ocean Engineering School of Naval ArchitectureOceanand Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration(CISSE) Shanghai 200240China School of Ciwil Engineer ing Bejing Jiao Tong Universityand Turmel and Underground Engineering Research CenterMinistry of EducationBejing 100044China

A road cave-in accident caused by tunneling is described,and the possible mechanism of failure is *** cave-in measured about 30 m×27 m in plane,and about 15 m in *** about 19 m below the ground surface at the site,a tunnel construction was *** above the tunnel,there was a weathered shale layer approximately t 2.66 m thick;above this layer,there were sand and gravel *** groundwater level was estimated to be about 5 m below the ground *** arch analysis,it is shown that the most likely cause of the accident was the low strength of the weathered shale layer and the high water pressure above the tunnel,which resulted in tensile failure of the weathered shale *** All Ground Fasten(AGF)pre-support measure was adopted,but it might make very limited contribution to the increase in the tensile strength of the shale layer in the cross-sectional direction of the tunnel.

关键词： Tunneling Road cave-in Arch analysis Tensile failure

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A New Sequential Image Prediction Method Based on LSTM and DCGAN

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Computers, Materials & Continua 2020年第7期64卷 217-231页

作者： Wei Fang Feihong Zhang Yewen Ding jack Sheng School of Computer&Software Jiangsu Engineering Center of Network MonitoringNanjing University of Information Science&TechnologyNanjing210044China State Key Laboratory for Novel Software Technology Nanjing UniversityNanjing210023China Department of Economics FinanceInsurance and Risk Management University of Central ArkansasConway72035USA

Image recognition technology is an important field of artificial *** with the development of machine learning technology in recent years,it has great researches value and commercial *** a matter of fact,a single recognition function can no longer meet people’s needs,and accurate image prediction is the trend that people *** paper is based on Long Short-Term Memory(LSTM)and Deep Convolution Generative Adversarial Networks(DCGAN),studies and implements a prediction model by using radar image *** adopt a stack cascading strategy in designing network connection which can control of parameter convergence *** new method enables effective learning of image features and makes predictive models to have greater generalization *** demonstrate that our network model is more robust and efficient in terms of timing prediction than 3DCNN and traditional *** sequential image prediction model architecture proposed in this paper is theoretically applicable to all sequential images.

关键词： Image prediction LSTM DCGAN

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Experimental study of water and dissolved pollutant runoffs on impervious surfaces

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Journal of Hydrodynamics 2016年第1期28卷 162-165页

作者：肖洋张涛涛 Dongfang LIANG jack M.CHEN State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University College of Water Conservancy and Hydropower Engineering Hohai University Department of Engineering University of Cambridge

The water and dissolved pollutant runoffs on impervious surfaces are the essential factor to be considered in design methods to minimize the impacts of the diffuse water pollution. In this paper, experiments are conducted to study the water and dissolved pollutant runoffs on impervious surfaces for different rainfall intensities and surface roughnesses. It is shown that a larger rainfall intensity and a smaller surface roughness reduce the time of concentration and increase the pollutant transport rate. Most of the pollutant runoffs take place at the initial stage of the rainfall. The pollutant transport rate rapidly reaches a peak and then gradually drops to zero.

关键词： rainfall-runoff diffuse pollution overland flow flooding urban runoff

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最早的知识积累

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环球科学 2024年第15期 15-15页

作者：杰克·塔米西亚林清(翻译) 不详

说到知识的传承与发扬,人类在自然界中堪称独一无二。经过一代代的试错,人类不断更新着技术,学会了如何制作矛头和轮子一以及从牛车到特斯拉汽车的所有后续产品。人类能够学习过往的技术创造,分享知识并将其传给后代。这样在代际间积累... 详细信息

说到知识的传承与发扬,人类在自然界中堪称独一无二。经过一代代的试错,人类不断更新着技术,学会了如何制作矛头和轮子一以及从牛车到特斯拉汽车的所有后续产品。人类能够学习过往的技术创造,分享知识并将其传给后代。这样在代际间积累的文化,成为了人类演化过程中的重要财富。

关键词：后续产品知识积累传承与发扬演化过程独一无二

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Genetic parameters of drinking and feeding traits of wean-to-finish pigs under a polymicrobial natural disease challenge

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Journal of Animal Science and Biotechnology 2022年第1期13卷 17-35页

作者： Jian Cheng Austin M.Putz John C.S.Harding Michael K.Dyck Frederic Fortin Graham S.Plastow Pig Gen Canada jack C.M.Dekkers Department of Animal Science Iowa State UniversityAmesIA 50011USA Hendrix Genetics Swine Business UnitBoxmeerThe Netherlands 5831CK Department of Large Animal Clinical Science University of SaskatchewanSaskatoonSK S7N 5A2Canada Department of Agriculture Food and Nutritional ScienceUniversity of AlbertaEdmontonAB T6G 2R3Canada Centre de Developpement du Porc du Quebec Inc. Quebec City G1V 4M6Canada PigGen Canada Research Consortium GuelphOntario N1H4G8Canada

Background:The pork industry faces unprecedented challenges from disease,which increases cost of production and use of antibiotics,and reduces production efficiency,carcass quality,and animal *** solution is to improve the overall resilience of pigs to a broad array of common diseases through genetic *** changes in feeding and drinking are usually the very first clinical signs when animals are exposed to stressors such as *** in feeding and drinking behaviors in diseased pigs may reflect the way they cope with the challenge and,thus,could be used as indicator traits to select for disease *** objectives of this study were to estimate genetic parameters of feeding and drinking traits for wean-to-finish pigs in a natural polymicrobial disease challenge model,to estimate genetic correlations of feeding and drinking traits with growth rate and clinical disease traits,and to develop indicator traits to select for disease ***:In general,drinking traits had moderate to high estimates of heritability,especially average daily water dispensed,duration,and number of visits(0.44 to 0.58).Similar estimates were observed for corresponding feeding traits(0.35 to 0.51).Most genetic correlation estimates among drinking traits were moderate to high(0.30 to 0.92)and higher than among feeding traits(0 to 0.11).Compared to other drinking traits,water intake duration and number of visits had relatively stronger negative genetic correlation estimates with treatment rate and mortality,especially across the challenge nursery and finisher(−0.39 and−0.45 for treatment rate;−0.20 and−0.19 for mortality).Conclusion:Most of the recorded drinking and feeding traits under a severe disease challenge had moderate to high estimates of heritability,especially for feed or water intake duration and number of *** and genetic correlations among the recorded feeding traits under disease were generally low but drinking traits show

关键词： Disease resilience Feeding and drinking behavior Genetic parameters Pigs

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