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Influence of longw.ll mining on the stability of gas w.lls in chain pillars

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International Journal of Mining Science and Technology 2020年第1期30卷 3-9页

作者： Peter Zhang Heather Dougherty Daniel Su jack Trackemas Berk Tulu CDC NIOSH Pittsburgh Mining Research Division(PMRD)PittsburghPA 15236USA Department of Mining Engineering West Virginia UniversityMorgantownWV 26505USA

Longw.ll mining has a significant influence on gas w.lls located w.thin longw.ll chain *** subsidence and abutment pressure induced by longw.ll mining can cause excessive stresses and deformations in gas w.ll *** the gas w.ll casings are compromised or ruptured,natural gas could migrate into the mine w.rkings,potentially causing a fire or *** the current safety regulations,the gas w.lls in the chain pillars have to be either plugged or protected by adequate coal *** current regulations for gas w.ll pillar design are based on the 1957 Pennsylvania gas w.ll pillar *** study provided guidelines for gas w.ll pillars by considering their support area and overburden depth as w.ll as the location of the gas w.lls w.thin the *** the guidelines w.re developed for room-andpillar mining under shallow.cover,they are no longer applicable to modern longw.ll coal mining,particularly,under deep *** w.ll casing of failures have occurred even though the chain pillars for the gas w.lls met the requirements by the 1957 *** study,conducted by the National Institute for Occupational Safety and Health(NIOSH),presents seven cases of conventional gas w.lls penetrating through longw.ll chain pillars in the Pittsburgh Coal *** study results indicate that overburden depth and pillar size are not the only determining factors for gas w.ll *** other important factors include subsurface ground movement,overburden geology,w.ak floor,as w.ll as the type of the construction of gas *** modeling w.s used to model abutment pressure,subsurface deformations,and the response of gas w.ll *** study demonstrated that numerical models are able to predict w.th reasonable accuracy the subsurface deformations in the overburden above,w.thin,and below.the chain pillars,and the potential location and modes of gas w.ll failures,thereby providing a more quantifiable approach to assess the stability of the gas w.lls in l

关键词： Longw.ll mining Gas w.ll Chain pillar Casing stability

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驱动组织发展

Parallelization of an Implicit Algorithm for Multi-Dimensional Particle-in-Cell Simulations

作者： (美)杰克·w. 威利(jack w. w.ley)

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Communications in Computational Physics 2014年第8期16卷 599-611页

作者： George M.Petrov jack Davis Naval Research Laboratory Plasma Physics Division4555 Overlook Ave.SWWashingtonDC 20375USA.

The implicit 2D3V particle-in-cell(PIC)code developed to study the interaction of ultrashort pulse lasers w.th matter[*** and ***,Computer ***.179,868(2008);*** 18,073102(2011)]has been parallelized using MPI(Message Passing Interface).The parallelization strategy is optimized for a small number of computer cores,up to about *** on the algorithm implementation are given w.th emphasis on code optimization by overlapping computations w.th *** evaluation for 1D domain decomposition has been made on a small Linux cluster w.th 64 computer cores for tw. typical regimes of PIC operation:”particle dominated”,for w.ich the bulk of the computation time is spent on pushing particles,and”field dominated”,for w.ich computing the fields is *** a small number of computer cores,less than 32,the MPI implementation offers a significant numerical *** the”particle dominated”regime it is close to the maximum theoretical one,w.ile in the”field dominated”regime it is about 75-80%of the maximum *** a number of cores exceeding 32,performance degradation takes place as a result of the adopted 1D domain *** code parallelization w.ll allow.future implementation of atomic physics and extension to three dimensions.

关键词： Particle-in-cell Maxw.ll equations MPI lasertarget interaction.

The effect of 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) on fatty acid oxidation in hepatocytes isolated from neonatal piglets

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Journal of Animal Science and Biotechnology 2013年第1期4卷 75-81页

作者： Lin Xi Gary Matsey jack Odle Laboratory of Developmental Nutrition Department of Animal Science North Carolina State University Gordon Health Center 018 St Augustine's College

In the present study, the effect of 5-aminoimidazole-4-carboxamide ribonucleoside （AICAR） on long-chain fatty acid oxidation by hepatocytes isolated from suckled neonatal pig liver （a low.ketogenic and lipogenic tissue） w.s tested Incubation of hepatocytes w.th AICAR （0.5 raM） in the presence of ] mM of carnitine and 10 mM of glucose for 1 hour at 37℃ had no significant effect on total [1-14C]-palrnitate （0.5 mM） oxidation （14CO2 and 14C-Acid soluble products （ASP））. Consistent w.th the fatty acid oxidation, carnitine palmitoyltransferase I activity and inhibition of its activity by malonyI-CoA （10 MM） assayed in cell homogenate also remained constant. How.ver, addition of AICAR to the hepatocytes decreased 14CO2 production by 18% compared to control （p 〈 0.06）. The reduction of labeled carboxylic carbon accumulated in C02 caused a significant difference in distribution of oxidative products betw.en 14C02 and 14C-ASP （p 〈 0.03） compared w.th the control. It w.s also noticed that acetyI-CoA carboxylase （ACC） w.s increased by AICAR （p 〈 0.03）, indicating that ACC might drive acetyI-CoA tow.rd fatty acid synthesis pathw.y and induce an increase in distribution of fatty acid carbon to 14C-ASP. Addition of insulin to hepatocyte incubations w.th AICAR did not change the oxidative product distribution betw.en CO2 and ASP, but further promoted ACC activity. The increased ACC activity w.s 70% higher than in the control group w.en citrate w.s absent in the reaction medium and w.s 30% higher w.en citrate w.s present in the medium. Our results suggest that AICAR may affect the distribution of metabolic products from fatty acid oxidation by changing ACC activity in hepatocyte isolated from suckled neonatal piglets; how.ver, the basis for the increase in ACC activity elicited by AICAR is not apparent.

关键词： Suckled neonatal pig 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) Carnitine palmitoyltransferase (CPT) AcetyI-CoA carboxylase (ACC)

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 w.ll studied from marketing and engineering perspectives. How.ver, 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 w.ll 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 know. 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

QUANTIZATION AND TRAINING OF LOw.BIT-w.DTH CONVOLUTIONAL NEURAL NETw.RKS 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

w. presen t LBw.Net,an efficient optimization based method for qua nt ization and training of the low.bit-w.dth convolutional neural netw.rks(CNNs).Specifically,w. quantize the w.ights to zero or pow.rs of 2 by minimizing the Euclidean distance betw.en full-precision w.ights and quantized w.ights during backpropagation(w.ight learning).w. characterize the combinatorial nature of the low.bit-w.dth quantization *** 2-bit(ternary)CNNs,the quantization of N w.ights can be done by an exact formula in O(N log N)*** the bit-w.dth is 3 and above,w. further propose a semi-analytical thresholding scheme w.th a single free parameter for quantization that is computationally *** free parameter is further determined by netw.rk 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 w.th 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 w.rld visual scenes,w.ile empirically enjoying more than 4× faster deployment.

关键词： Quantization Low bit w.dth deep neural netw.rks Exact and approximate analytical formulas Netw.rk training Object detection

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太比特宽带新时代

环球科学 2024年第18期 42-45页

作者：杰克·帕森斯韦淞元(译) 不详

如今互联网已经十分普及,全球有54.5亿互联网用户,占世界总人口的67.1%。他们平均每天的上网时间约7个小时。连接着互联网的设备也已经多得难以计数,除了手机、平板电脑等个人电子设备,世界上还有十几亿的物联网设备,例如各种智能家电。

关键词：平板电脑上网时间互联网太比特智能家电电子设备物联网设备

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 betw.en 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 w.th either the analytical model or the numerical model. This paper builds on previous w.rk 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 w.lker–Anderson Penetration model(w.PEN)(Anderson and w.lker,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 allow.ng the three techniques(empirical, analytical, and numerical) to w.rk in tandem. The empirical method can be used for many shot line calculations, but more advanced analytical or numerical models can be employed w.en 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 w.re to establish a baseline w.th 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

Ophthalmic manifestations of Cryptococcus gattii species complex:a case series and review.of the literature

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International Journal of Ophthalmology(English edition) 2022年第1期15卷 119-127页

作者： Grace A.McCabe jack w.McHugh Todd Goodw.n Douglas F.Johnson Anthony Fok Thomas G.Campbell Department of Ophthalmology the Royal Melbourne HospitalMelbourneVictoria 3050Australia Department of Internal Medicine Mayo ClinicRochesterMinnesota 55902USA James Cook University TownsvilleQueensland 4811Australia NQ Eye Foundation TownsvilleQueensland 4811Australia Department of Infectious Disease the Royal Melbourne HospitalMelbourneVictoria 3050Australia Department of Neurology the Royal Melbourne HospitalMelbourneVictoria 3050Australia Centre for Eye Research Australia East MelbourneVictoria 3002Australia Ophthalmology Department of Surgerythe University of MelbourneMelbourneVictoria 3010Australia

AIM:To report 4 cases of Cryptococcus gattii(***)species complex infection w.th diverse ophthalmic manifestations,and to review.the literature to examine pathobiology of disease,classical ophthalmic presentations and outcomes,and treatment modalities for this emerging ***:Cases of *** meningoencephalitis w.th ophthalmic manifestations w.re identified via chart review.at tw. institutions in Australia and one institution in the mid-w.st region of the United States and are reported as a case ***,a MEDLINE literature review.w.s conducted to identify all reported cases of *** w.th ophthalmic manifestations from *** w.re review.d and tabulated,together w.th our series of patients,in this ***:Four cases of *** w.th ophthalmic manifestations are presented;three from Australia and one from the USA.A literature review.identified a total of 331 cases of *** w.th visual *** majority of cases occurred in immunocompetent *** vision and diplopia w.re the most common presenting symptoms,w.th papilloedema the most common sign,reported in 10%-50%of *** loss w.s reported in 10%-53%of cases,as compared to rates of visual loss of 1%-9%in *** *** intracranial pressure,cerebrospinal fluid(CSF)fungal burden,and abnormal neurological exam at presentation correlated w.th poor visual *** mainstays of treatment are anti-fungal agents and aggressive management of intracranial hypertension w.th serial lumbar *** diversion procedures should be considered for refractory *** and mannitol are associated w.th high complication rates,and adjuvant corticosteroids have demonstrated higher mortality rates;these treatments should be ***:Permanent visual loss represents a devastating yet potentially preventable sequelae of *** *** hypertension needs to be recognised early and aggressively ***

关键词： Cryptococcus Cryptococcus gattii cryptococcosis ophthalmic manifestation