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CONCURRENT PRODUCT PORTFOLIO PLANNING AND MIXED PRODUCT AssEMBLY LINE BALANCING

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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system for Measuring Elevator Guide Rail Quality and Its Calibration

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Transactions of Tianjin University 2006年第2期12卷 84-91页

作者：李醒飞 hu s jack 张国雄郭敬滨 state Key Laboratory of Precision Measurement Technology and Instruments Tianjin University Tianjin 300072China Department of Mechanical Engineering University of Michigan Ann ArborMI 48109USA

A system for measuring the quality parameters of elevator guide rails is developed. The quality parameters the system can measure include straightness, flatness, squareness, width and height of the rail. The system consists of six parts：main guideway, auxiliary guideway, reference rail, saddle, control casing and measured rail. The guide rail to be measured is mounted on a bed. The straightness errors of surfaces are checked by five linear displacement sensors mounted on the saddle. The deviation of readings from the sensor, which is in contact with top guiding surface, gives the straightness error of the surface and height of the rail. The other four sensors are used to measure side guiding surfaces respectively and give other parameters including flatness on the surfaces, squareness, width and height of the rail. A novel calibration method is also developed to calibrate the straightness motion error of the system in horizontal and vertical directions. The deflection deformation of the measured rail is fitted by using a fourth-order polynomial. Experimental results show that the uncertainty of the system on the side surfaces after compensating the straightness motion error is less than 0. 01 mm, and the uncertainty of the system on the top surface after compensating the straightness motion error and the deflection deformation of the rail is less than 0. 03 mm.

关键词： error compensation elevator rail calibration method

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可重构PKM模块的选型原则——理论与实践

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机械工程学报 2005年第8期41卷 36-41页

作者：黄田李曚吴孟丽梅江平赵学满 hu s.jack 美国 MI48109 天津大学机械工程学院密歇根大学机械工程系天津 300072

可重构与多功能是并联构型装备(PKM)的重要发展趋势,模块化设计是实现这类装备可重构性的使能技术。首先借助线性空间理论,简要论述了少自由度并联机构的组成原理。按照支链对动平台提供约束和驱动的作用不同,将支链分为四种类型,并据... 详细信息

可重构与多功能是并联构型装备(PKM)的重要发展趋势,模块化设计是实现这类装备可重构性的使能技术。首先借助线性空间理论,简要论述了少自由度并联机构的组成原理。按照支链对动平台提供约束和驱动的作用不同,将支链分为四种类型,并据此得到少自由度并联机构的三种组合方案。基于对可重构性、多功能,以及速度、剐度特别是精度的考虑,提出可重构PKM模块的选型原则,认为含简式恰约束支链的并联机构较适于搭建兼顾上述需求的PKM模块,进而将可重构PKM模块的设计转化为恰约束支链的选型问题。在此基础上,提出一种含主动恰约束支链的5自由度混联机械手模块——TriVariant,其具有与Tricept机械手完全相同的自由度数目和类型, 且几乎继承了后者的全部优点。最后给出若干用TriVariant搭建可重构装备的应用示例。

关键词：并联机构模块化设计可重构装备

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Magnetohydrodynamic behaviors in a resistance spot weld nugget under different welding currents

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science China(Technological sciences) 2008年第9期51卷 1507-1515页

作者： s. jack hu The University of Michigan Ann Arbor MI 48109 USA

Magnetohydrodynamic behaviors in a resistance spot weld nugget under different welding currents are investigated based on a multiphysics coupled numerical model, which incorporates phase change and variable electrical contact resis-tances at faying surface and electrode-workpiece contact surface. The patterns of the flow field and thermal field at the end of the welding phase under different welding currents are obtained. The evolutions of fluid flow and heat transfer during the whole welding process are also revealed systematically. The analysis results are also compared with a traditional electrothermal coupled model to obtain the quantitative effects of the magnetohydrodynamic behaviors on the resistance spot weld nugget formation.

关键词： resistance spot welding magnetic force fluid flow heat transfer

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Heterogeneity of mature oligodendrocytes in the central nervous system

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Neural Regeneration Research 2025年第5期20卷 1336-1349页

作者： Chao Weng Adam M.R.Groh Moein Yaqubi Qiao-Ling Cui Jo Anne stratton G.R.Wayne Moore jack P.Antel Neuroimmunology Unit Montreal Neurological Institute-HospitalDepartment of Neurology and NeurosurgeryMcGill UniversityMontrealQCCanada Department of Neurology Renmin Hospital of Wuhan UniversityWuhanHubei ProvinceChina

Mature oligodendrocytes form myelin sheaths that are crucial for the insulation of axons and efficient signal transmission in the central nervous *** evidence has challenged the classical view of the functionally static mature oligodendrocyte and revealed a gamut of dynamic functions such as the ability to modulate neuronal circuitry and provide metabolic support to *** the recognition of potential heterogeneity in mature oligodendrocyte function,a comprehensive summary of mature oligodendrocyte diversity is *** delve into early 20th-century studies by Robertson and Río-Hortega that laid the foundation for the modern identification of regional and morphological heterogeneity in mature ***,recent morphologic and functional studies call into question the long-assumed homogeneity of mature oligodendrocyte function through the identification of distinct subtypes with varying myelination ***,modern molecular investigations,employing techniques such as single cell/nucleus RNA sequencing,consistently unveil at least six mature oligodendrocyte subpopulations in the human central nervous system that are highly transcriptomically diverse and vary with central nervous system *** and disease related mature oligodendrocyte variation denotes the impact of pathological conditions such as multiple sclerosis,Alzheimer's disease,and psychiatric ***,caution is warranted when subclassifying mature oligodendrocytes because of the simplification needed to make conclusions about cell identity from temporally confined *** studies leveraging advanced techniques like spatial transcriptomics and single-cell proteomics promise a more nuanced understanding of mature oligodendrocyte *** research avenues that precisely evaluate mature oligodendrocyte heterogeneity with care to understand the mitigating influence of species,sex,central nervous system region,age,and disease,

关键词： aging central nervous system diseases electron microscopy heterogeneity immunohistochemistry myelin sheath natural history neuroglia oligodendroglia single-cell gene expression analysis

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Principles to support Modular software Construction

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Journal of Computer science & Technology 2017年第1期32卷 3-10页

作者： jack B. Dennis Department of Electrical Engineering and Computer science Massachusetts Institute of Technology Cambridge MA 02139 U.S.A.

The construction of large software systems is always achieved through assembly of independently written components -- program modules. For these software components to work together, they must share a common set of data types and principles for representing structured data such as arrays of values and files. This common set of tools for creating and operating on data objects is provided by the infrastructure of the computer system： the hardware, operating system and runtime code. Because the nature and properties of these tools are crucial for correct operation of software components and their inter-operation, it is essential to have a precise specification that may be used for verifying correctness of application software on one hand, and to verify correctness of system behavior on the other. We call such a specification a program execution model （PXM）. It is evident that the properties of the PXM implemented by a computer system can have serious impact on the ability of application programmers to practice modular software construction. This paper discusses the concept of program execution models and presents a set of principles that a PXM must satisfy to provide a sound basis for modular software construction. Because parallel program execution on computer systems with many processing units is an essential part of contemporary computing environments, the expression of parallelism and modular software construction using components involving parallel operations is included in this treatment. The conclusion is that it is possible to build computer systems that implement a PXM within which any parallel program may be used, unmodified, as a component for building more substantial parallel programs.

关键词： program execution model data flow model codelet abstract architecture parallel computing

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Building geospatial infrastructure

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Geo-spatial Information science 2020年第1期23卷 1-9页

作者： jack Dangermond Michael F.Goodchild Esri RedlandsCAUSA Department of Geography University of CaliforniaSanta BarbaraCAUSA

Many visions for geospatial technology have been advanced over the past half *** researchers saw the handling of geospatial data as the major problem to be *** vision of geographic information systems arose as an early international *** visions included spatial data infrastructure,Digital Earth,and a nervous system for the *** accelerating advances in information technology,a new vision is needed that reflects today’s focus on open and multimodal access,sharing,engagement,the Web,Big Data,artificial intelligence,and data *** elaborate on the concept of geospatial infrastructure,and argue that it is essential if geospatial technology is to contribute to the solution of problems facing humanity.

关键词： spatial data handling National spatial Data Infrastructure Digital Earth Big Data citizen engagement

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Optimizing dietary lipid use to improve essential fatty acid status and reproductive performance of the modern lactating sow:a review

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Journal of Animal science and Biotechnology 2016年第3期7卷 272-289页

作者： David s.Rosero R.Dean Boyd jack Odle Eric van Heugten The Hanor Company FranklinKY 42134USA Department of Animal science North Carolina State UniversityRaleighNC 27695USA

Dietary lipid supplementation benefits the prolific and high-producing modern lactating sow. A comprehensive review of recent studies showed that lipid supplementation increases average daily energy intake, which is partitioned for lactation as indicated by greater milk fat output and improved litter growth rate. Recent compelling findings showed that addition of particular lipids during lactation improved the subsequent reproductive outcome of sows. such benefits were related to the level of dietary essential fatty acids（EFA, linoleic acid, C18：2n-6; and α-linolenic acid, C18：3n-3） during lactation. Lactation diets without supplemental EFA resulted in a pronounced negative balance（intake minus milk output） of linoleic（-25.49 g/d） and α-linolenic acid（-2.75 g/d）; which compromised sow fertility（farrowing rate 〈 75 % and culling rates 〉 25 % of weaned sows）. This phenomenon seems to be increasingly important with advancing sow age because of a progressive reduction of body EFA pool over successive lactations. The net effect of supplemental EFA during lactation was to create a positive EFA balance, which improved the subsequent reproduction of sows. Adequate linoleic acid intake improved the proportion of sows that farrowed in the subsequent cycle（Farrowing rate（%） = [（-1.5 × 10^-3× linoleic acid intake（g/d）^2）＋（0.53 × linoleic acid intake（g/d））＋（45.2）]; quadratic P = 0.002, R^2= 0.997, RMsE = 0.031）. In addition, increasing linoleic acid intake increased the number of pigs born in the subsequent cycle（total pigs born（n） = [（9.4 × 10^-5× linoleic acid intake（g/d）^2）＋（0.04 × linoleic acid intake（g/d））＋（10.94）]; quadratic P = 0.002, R^2= 0.997, RMsE = 0.031）. supplemental α-linolenic acid resulted in a rapid return to estrus（sows bred： sows weaned = 94.2 %; wean-to-estrus interval = 4.0 d） and achieved a high retention of pregnancy（sows pregnant： sows bred = 98 %）. Collectively, we conclude that a minimum dietary intake of10 g/d of α-linolenic acid, simultaneous wit

关键词： Essential fatty acids Lactating sow subsequent reproduction supplemental lipids

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半空心铆钉自冲铆接的工艺参数及铆接质量的判定

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天津大学学报 2007年第4期40卷 494-498页

作者：万淑敏 s.jack hu 李双义张连洪刘秀全天津大学机械工程学院天津300072 密西根大学机械工程系

自冲铆接是在板料和铆钉之间形成连接而不需要预冲孔的新工艺.探讨了检测自冲铆接质量的直接试验法和观测法,并在原有观测法的基础上提出了补充意见.开展了模具设计、铆钉尺寸选择及二者与板料匹配等方面的研究,提出了模具设计的依据和... 详细信息

自冲铆接是在板料和铆钉之间形成连接而不需要预冲孔的新工艺.探讨了检测自冲铆接质量的直接试验法和观测法,并在原有观测法的基础上提出了补充意见.开展了模具设计、铆钉尺寸选择及二者与板料匹配等方面的研究,提出了模具设计的依据和方法.同时进行了自冲铆接效果的试验研究,结合自冲铆接试验结果,分析了模具、铆钉以及板料的材质性能等因素对铆接质量的影响.研究和试验分析表明,自行设计的半空心铆钉和模具可以获得良好的铆接质量,可作为模具设计的参考和依据.

关键词：连接工艺自冲铆接模具汽车轻量化

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Molecular network of neuronal autophagy in the pathophysiology and treatment of depression

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Neuroscience Bulletin 2015年第4期31卷 427-434页

作者： jack Jia Weidong Le sbarro Institute for Cancer Research and Molecular Medicine Center of BiotechnologyCollege of Science and TechnologyTemple University New Jersey Medical Institute Center for Translational Research on Neurological Disease First Affiliated HospitalDalian Medical University

Major depressive disorder （MDD） is a complicated multifactorial induced disease, characterized by depressed mood, anhedonia, fatigue, and altered cognitive function. Recently, many studies have shown that antidepressants regulate autophagy. In fact, autophagy, a conserved lysosomal degradation pathway, is essential for the central nervous system. Dysregulation of autophagic pathways, such as the mammalian target of rapamycin （mTOR） signaling pathway and the beclin pathway, has been studied in neurodegenerative diseases. However, autophagy in MDD has not been fully studied. Here, we discuss whether the dysregulation of autophagy contributes to the pathophysiology and treatment of MDD and summarize the current evidence that shows the involvement of autophagy in MDD.

关键词： major depressive disorder autophagy roTOR antidepressant

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