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Engineering Design Optimization Based on Intelligent Response Surface Methodology

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Journal of Shanghai Jiaotong university(Science) 2008年第3期13卷 285-290页

作者：宋国辉吴瑜李从心 National Die & Mould cad Engineering research center Shanghai Jiaotong University

An intelligent response surface methodology (IRSM) was proposed to achieve the most competitive metal forming products, in which artificial intelligence technologies are introduced into the optimization process. It is used as simple and inexpensive replacement for computationally expensive simulation model. In IRSM, the optimal design space can be reduced greatly without any prior information about function distribution. Also, by identifying the approximation error region, new design points can be supplemented correspondingly to improve the response surface model effectively. The procedure is iterated until the accuracy reaches the desired threshold value. Thus, the global optimization can be performed based on this substitute model. Finally, we present an optimization design example about roll forming of a "U" channel product.

关键词：工程设计最优化智能响应表面方法论滚轧成形粗集理论

Solving Resource-constrained Multiple Project Scheduling Problem Using Timed Colored Petri Nets

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Journal of Shanghai Jiaotong university(Science) 2009年第6期14卷 713-719页

作者：吴瑜庄新村宋国辉许晓栋李从心 National Die and Mould cad Engineering research center Shanghai Jiaotong University

To solve the resource-constrained multiple project scheduling problem(RCMPSP) more effectively,a method based on timed colored Petri net(TCPN) was proposed.In this methodology,firstly a novel mapping mechanism between traditional network diagram such as CPM(critical path method)/PERT(program evaluation and review technique) and TCPN was presented.Then a primary TCPN(PTCPN) for solving RCMPSP was modeled based on the proposed mapping mechanism.Meanwhile,the object PTCPN was used to simulate the multiple projects scheduling and to find the approximately optimal value of RCMPSP.Finally,the performance of the proposed approach for solving RCMPSP was validated by executing a mould manufacturing example.

关键词：赋时着色Petri网调度问题资源受限项目计划评审技术求解映射机制关键路径法

Finite element simulation of stretch forging using a mesh condensation method

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Science China(Technological Sciences) 2010年第1期53卷 227-234页

作者： CHEN Wen & CUI ZhenShan National Die & Mold cad Engineering research center,Shanghai Jiao Tong University,Shanghai 200030,China National Die & Mold cad Engineering research center Shanghai Jiao Tong University Shanghai China

In order to reduce the computation time of finite element simulations of stretch forging process,a mesh condensation method is presented and applied to a three-dimensional rigid-viscoplastic finite element program.In this method,a conventional mesh for the whole zone of a workpiece is condensed to a computational mesh for the active deformation zone.Two vital problems are solved,which are automatic construction of the computational mesh and treatment of interfaces between the deformation zone and the rigid zone.The mesh condensation method is compared with conventional finite element method by simulations of a six-bite stretch forging process.Some simulation results including forging load,temperature distribution and effective strain distribution are illustrated.The efficiency and accuracy of this method are verified.

关键词： mesh condensation method finite element method stretch forging incremental forging

GATE TYPE SELECTION BASED ON FUZZY MAPPING

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Chinese Journal of Mechanical Engineering 2002年第1期15卷 31-34,61页

作者： Wang Yu Xing Yuan Ruan Xueyu National Die & Mold cad Engineering research center，Shanghai Jiaotong University， Shanghai 200030，China Shanghai Jiaotong University National Die & Mold CAD Engineering Research Center 上海 200030

Gate type selection is very important for mould design. Improper gate typemay lead to poor product quality and low production efficiency. Although numerical simulationapproach could be used to optimize gate location, the determination of gate type is still up todesigners' experience. A novel method for selecting gate type based on fuzzy logic is proposed. Theproposed methodology follows three steps: Design requirements for gate is extracted and generalized;Possible gate types (design schemes) are presented; The fuzzy mapping relationship between gatedesign requirements and gate design scheme is established based on fuzzy composition and fuzzyrelation transition matrices that are assigned by domain experts.

关键词： Gate type selection Fuzzy logic

A Multi-objective Optimal Approach to Automated Construction of Sacrificial Multi-piece Molds

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Journal of Shanghai Jiaotong university(Science) 2008年第5期13卷 542-546页

作者：王会凤周雄辉陈巍 National Die and Mold cad Engineering research center Shanghai Jiaotong University

Sacrificial multi-piece molds can be used for producing complex parts. To obtain the optimal design of molds automatically, a multi-objective optimal approach is proposed. Mold pieces number, material utilization and partitioning area are taken as the objective functions, and the machinability of each mold piece is taken as constraint condition. Genetic algorithm (GA) is adopted to realize global optimization of partitioning process. Each mold piece in optimal scheme can be manufactured by milling and drilling operations, which reduce the tooling cost and shorten product cycle obviously. Using the proposed approach, mold design can be significantly automated for making complex parts.

关键词：计算机辅助技术信息处理机械加工性遗传算法

CAE-Based Robust Optimization for Deep-Drawing Process of Sheet Metal Forming Using Grey Relational Analysis Method

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Journal of Shanghai Jiaotong university(Science) 2007年第3期12卷 301-307页

作者：谢延敏于沪平陈军阮雪榆 National Die & Mold cad Eng. research center Shanghai Jiaotong Univ.

The theory of grey systems is a new technique for performing prediction, relational analysis and decision making in many areas. The grey relational analysis was used to optimize the deep-drawing process parameters with considerations of the multiple response (the wrinkle, crack and thinning variation). The deep-drawing parameters, such as the blank holding force (F_ bh ), the radii of punch and die (R_1,R_2), the coefficients of friction (μ_1,μ_2,μ_3) are considered. An orthogonal array is used for the experimental design. The multiple response values are obtained making use of finite element analysis (FEA). Optimal process parameters are determined by the grey relational grade obtained from the grey relational analysis for multi-performance characteristics (the wrinkle, crack and the thinning). The analysis of variance (ANOVA) for the grey relational grade is implemented. The results show that the quality of stamped parts can be improved effectively through the new approach. The grey relational analysis can be applied in sheet metal forming.

关键词：灰色相关分析机械设计冷冲压加工金属成形

Regularization Method to the Parameter Identification of Interfacial Heat Transfer Coefficient and Properties during Casting Solidification

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Journal of Shanghai Jiaotong university(Science) 2007年第4期12卷 511-516页

作者：隋大山崔振山 National Die & Mould cad Eng.research center Shanghai Jiaotong Univ.

The accurate material physical properties, initial and boundary conditions are indispensable to the numerical simulation in the casting process, and they are related to the simulation accuracy directly. The inverse heat conduction method can be used to identify the mentioned above parameters based on the temperature measurement data. This paper presented a new inverse method according to Tikhonov regularization theory. A regularization functional was established and the regularization parameter was deduced, the Newton-Raphson iteration method was used to solve the equations. One detailed case was solved to identify the thermal conductivity and specific heat of sand mold and interfacial heat transfer coefficient (IHTC) at the meantime. This indicates that the regularization method is very efficient in decreasing the sensitivity to the temperature measurement data, overcoming the ill-posedness of the inverse heat conduction problem (IHCP) and improving the stability and accuracy of the results. As a general inverse method, it can be used to identify not only the material physical properties but also the initial and boundary conditions' parameters.

关键词： casting inverse heat conduction problem parameter identification regularization method interfacial heat transfer coefficient

Cognitive impairment in cerebral small vessel disease induced by hypertension

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Neural Regeneration research 2024年第7期19卷 1454-1462页

作者： Weipeng Wei Denglei Ma Lin Li Lan Zhang Department of Pharmacy Xuanwu Hospital of Capital Medical UniversityBeijingChina Beijing Geriatric Medical research center Beijing Engineering Research Center for Nervous System DrugsNational Center for Neurological DisordersNational Clinical Research Center for Geriatric DiseasesBeijingChina

Hypertension is a primary risk factor for the progression of cognitive impairment caused by cerebral small vessel disease,the most common cerebrovascular disease.Howeve r,the causal relationship between hypertension and cerebral small vessel disease remains unclear.Hypertension has substantial negative impacts on brain health and is recognized as a risk factor for cerebrovascular disease.Chronic hypertension and lifestyle factors are associated with risks for stro ke and dementia,and cerebral small vessel disease can cause dementia and stroke.Hypertension is the main driver of cerebral small vessel disease,which changes the structure and function of cerebral vessels via various mechanisms and leads to lacunar infarction,leukoaraiosis,white matter lesions,and intracerebral hemorrhage,ultimately res ulting in cognitive decline and demonstrating that the brain is the to rget organ of hypertension.This review updates our understanding of the pathogenesis of hypertensioninduced cerebral small vessel disease and the res ulting changes in brain structure and function and declines in cognitive ability.We also discuss drugs to treat cerebral small vessel disease and cognitive impairment.

关键词： blood-brain barrier cerebral small vessel disease cognitive impairment dementia endothelial dysfunction enlarged perivascular space hypertension lacunar infarction neuroinflammation treatment white matter high signal intensity

Synthesis of boron nitride nanorod and its performance as a metalfree catalyst for oxidative desulfurization of diesel fuel

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Chinese Journal of Chemical Engineering 2024年第4期68卷 120-132页

作者： Tanaz Ghanadi Gholamreza Moradi Alimorad Rashidi Catalyst research center Faculty of Chemical and Petroleum EngineeringRazi UniversityKermanshahIran Nanotechnology research center Research Institute of Petroleum Industry(RIPI)TehranIran

In order to reduce the sulfur compounds in diesel fuel,boron nitride(BN)has been used as a novel metal efree catalyst in the present research.This nanocatalyst was synthesized via template-free approach followed by heating treatment at 900℃in nitrogen atmosphere that the characteristics of the sample were identified by the X-ray diffraction,Fourier-transform infrared spectroscopy,Raman spectroscopy,field emission scanning electron microscopy,transmission electron microscopy,atomic force microscopy,and N2 adsorptionedesorption isotherms.The results of structural and morphological analysis represented that BN has been successfully synthesized.The efficacy of the main operating parameters on the process was studied by using response surface methodology based on the BoxeBehnken design method.The prepared catalyst showed high efficiency in oxidative desulfurization of diesel fuel with initial sulfur content of 8040 mg·kg^(-1)S.From statistical analysis,a significant quadratic model was obtained to predict the sulfur removal as a function of efficient parameters.The maximum efficiency of 72.4%was achieved under optimized conditions at oxidant/sulfur molar ratio of 10.2,temperature of 71℃,reaction time of 113 min,and catalyst dosage of 0.36 g.Also,the reusability of the BN was studied,and the result showed little reduction in activity of the catalyst after 10 times regeneration.Moreover,a plausible mechanism was proposed for oxidation of sulfur compounds on the surface of the catalyst.The present study shows that BN materials can be selected as promising metal-free catalysts for desulfurization process.

关键词： Desulfurization Boron nitride(BN)nanostructure Experimental design BoxeBehnken