其他论文
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⊙第101篇⊙
基于自由曲面点云的快速原型制作技术研究
(下载论文全文请点击上面的链接)
注意:本论文已在《机械工程学报》2003,39(1):56-59,83发表
使用者请注明论文出处
孙玉文 贾振元
(大连理工大学现代制造技术研究所大连1 16024)
王越超 刘伟军
(中国科学院机器人学开放研究实验室)
摘 要: 针对不附加任何拓扑和几何信息的云状数据三维重建问题,提出了对点云直接进行分层处理快速制作原型的新方法。在对点集进行空间结构划分的基础上,采用最小距离关联点对方法提取层面轮廓线数据,并对其加以匀化和精整从而直接生成快速成形机的层片接口文件,避免了常规方法存在的耗时和需要很高的造型技巧等不足,而且片面的错误校验与修补等繁琐工作也将不再进行,提高了快速成形前处理的效率,非常适合分层实体制造(LOM)等成形工艺。
关键词: 反求工程 点云数据 直接分层 快速原型技术
RAPID PROTOTYPING MANUFACTURING BASED ON CLOUD DATA FROM FREE-FORM SURFACE
SunYuwen Jin Zhenyuan
(Dalian University ofTechnology)
Wang Yuechao Liu Weijun
(Robotics Laboratory,Chinese Academy ofScience)
Abstract: Physical model
recovered from cloud dada only with coordinate information is of great importance
in the integration of reverse engineering and rapid prototyping technology.
A new method, that rapidly generates prototype from sampled points, is proposed.
Based on establishing the spatial partitioning representation of point cloud,
the contour data in each layer is firstly calculated and sequenced, then amended
to generate exact slice file. It overcomes lots of drawbacks in traditional
integration such as consuming time and needing expert modeling skills. Moreover,
without the intermediate transactions of STL file, the work of checking and
repairing mistakes of facets is avoided. It is very suitable for laminated
object manufacturing and greatly improves the pretreatment efficiency of RP
technology.
Keywords: Reverse engineering; Data cloud; Direct slicing;
Rapid prototyping
⊙第102篇⊙
基于矢量分析的数控加工轨迹设计方法研究
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注意:本论文已在《机械工程学报》2005,41(3):160-164,170发表
使用者请注明论文出处
孙玉文 束长林 刘健
(大连理工大学精密与特种加工教育部重点实验室大连116023)
摘 要: 描述了基于矢量分析和NURBS的数控加工轨迹设计方法。基于给定的被加工曲面在其参数域上的优化走刀方向集合,并依据标量场与梯度场的转化关系,建立了精确逼近离散方向矢量的走刀矢量场拟合模型,由此给出了数控加工轨迹的矢量表达形式。以NURBS作为发生矢量场的流函数并借助其较强的局部调控能力,通过调整控制点列,可望实现数控加工轨迹拓扑形状的整体优化调控。验证实例表明该方法能够进行复杂形状数控加工轨迹的精细设计,有利于保证精度指标下曲面加工效率的最大化。
关键词: 加工轨迹 矢量场 NURBS
VECTOR ANALYSIS BASED TOOLPATH GENERATION FOR PRECISION SURFACE MACHINING
Sun Yuwen Shu Changlin Liu Jian
(Key Laboratory for Precision & Non-traditional Machining ofMinistry of
Education, Dalian University of Technology, Dalian 116023)
Abstract:A toolpath generation
method is presented for NC machining based on vector analysis and NURBS. Given
optimal cutting directions at sampled points in the parameter domain of the
NURBS surface, a vector field model fitting to these scattered vectors is
established according to the conversion between scalar field and gradient
field. Thus, tool paths inthe parameter domain can be represented as vector
curves of a 2D vector field. Moreover, using NURBS as the stream function
of generating gradient field, a global shape optimization of tool-paths can
be easily completed by adjusting the control point array of the stream function.
The example shows that theprecise design method of tool paths is very useful
in high- efficiency machining of complex shapes.
Keywords: Tool paths; Vector field; NURBS
⊙第103篇⊙
中国生物质燃料乙醇项目能量生产效率评估
(下载论文全文请点击上面的链接)
注意:本论文已在《农业工程学报》2005,21(11):121-123发表
使用者请注明论文出处
(EI 已经收录本文)
戴杜1,刘荣厚2,浦耿强1,王成焘1
(1上海交通大学机械与动力工程学院,上海 200030;
2上海交通大学农业与生物学院,上海 201101)
摘 要:为了对玉米和木薯乙醇的能量和可再生能量生产效率进行评估,该文统计了玉米和木薯乙醇生命周期能耗,并用市场价值量法按照主副产品的能耗进行了分配。计算出玉米和木薯燃料乙醇的净能量和净可再生能量。并计算了单产和化肥用量变化时的净能量和净可再生能量的变化。计算结果显示,玉米、木薯乙醇的净能量分别为1.472 MJ/L和2.417 MJ/L,净可再生能量分别为1.474 MJ/L和2.459 MJ/L。使用玉米、木薯生产燃料乙醇在能量生产和再生能量生产上都是可行的,木薯乙醇比玉米乙醇可行性更高,单产和化肥用量是提高能源利用和再生能源的关键因素,加强副产品的开发和使用有机肥代替化肥有利于提高系统的能效,提高系统的可再生性。
关键词:燃料乙醇;净能量;可再生能源
中图分类号:S216.2 文献标示码:A
Evaluation on Energy Production Efficiency of Biomass based Fuel Ethanol Program
Dai Du1, Liu Ronghou2, Pu Gengqiang1, Wang Chengtao1
(1 School of Mechanical and Power Engineering, Shanghai Jiaotong University, Shanghai 200030, China; 2 School of Agriculture and Biology, Shanghai Jiaotong University, Shanghai 201101, China)
Abstract: To assess corn and cassava fuel ethanol production energy efficiency, this paper estimates life cycle energy consumption of corn and cassava fuel ethanol, allocates energy uses between fuel ethanol and its byproducts, and finally, works out net energy value (NEV) and net renewable energy (NREV). It also gives NEV and NREV results of corn and cassava under changed yields and chemicals uses. The results show that NEV of corn and cassava ethanol are 1.472 MJ/L and 2.417 MJ/L, respectively, and NREV of corn and cassava ethanol are 1.474 MJ/L and 2.459 MJ/L, respectively. Corn and cassava ethanol utilization are energy and renewable energy feasible, and cassava ethanol has better feasibility than corn ethanol. Yield and chemicals use are key factors to improve NEV and NREV. Better byproducts utilization and substitution of organic fertilizer for chemical fertilizer help to improve energy efficiency and renewability
Keywords: fuel ethanol; net energy; renewable energy
⊙第104篇⊙
Energy efficiency and potentials of cassava fuel ethanol in Guangxi region of China
(下载英语论文全文请点击上面的链接)
注意:本论文已在Energy Conversion and Management 47 (2006) 1686–1699发表
使用者请注明论文出处
(SCI、EI 已经收录本文)
Du Dai a, Zhiyuan Hu b, Gengqiang Pu a, He Li c, Chengtao Wang a
a School of Mechanical and Power Engineering, Shanghai Jiao Tong University, Shanghai 200030, PR China
b Automobile School, Tongji University, Shanghai 200092, PR China
c Hi-tech Development Division, Guangxi Development Planning Committee, Nanning 530012, PR China
Abstract:
The Guangxi Zhuang autonomous region has plentiful cassava resources, which is an ideal feedstock for fuel ethanol
production. The Guangxi government intends to promote cassava fuel ethanol as a substitute for gasoline. The purpose of
this study was to quantify the energy efficiency and potentials of a cassava fuel ethanol project in the Guangxi region based
on a 100 thousand ton fuel ethanol demonstration plant at Qinzhou of Guangxi. The net energy value (NEV) and net
renewable energy value (NREV) are presented to assess the energy and renewable energy efficiency of the cassava fuel ethanol
system during its life cycle. The cassava fuel ethanol system was divided into five subsystems including the cassava
plantation/treatment, ethanol conversion, denaturing, refueling and transportation. All the energy and energy related
materials inputs to each subsystem were estimated at the primary energy level. The total energy inputs were allocated
between the fuel ethanol and its coproducts with market value and replacement value methods. Available lands for a cassava
plantation were investigated and estimated. The results showed that the cassava fuel ethanol system was energy and
renewable energy efficient as indicated by positive NEV and NREV values that were 7.475 MJ/L and 7.881 MJ/L, respectively.
Cassava fuel ethanol production helps to convert the non-liquid fuel into fuel ethanol that can be used for transportation.
Through fuel ethanol production, one Joule of petroleum fuel, plus other forms of energy inputs such as
coal, can produce 9.8 J of fuel ethanol. Cassava fuel ethanol can substitute for gasoline and reduce oil imports. With
the cassava output in 2003, it can substitute for 166.107 million liters of gasoline. With the cassava output potential, it
can substitute for 618.162 million liters of gasoline. Cassava fuel ethanol is more energy efficient than gasoline, diesel fuel
and corn fuel ethanol but less efficient than biodiesel.
Keywords: Cassava; Net energy; Renewable energy; Fuel ethanol
⊙第105篇⊙
基于混合模型的E10燃料生命周期评估
(下载论文全文请点击上面的链接)
注意:本论文已在《上海交通大学学报》2006,40(2):355-358发表
使用者请注明论文出处
(EI已经收录本文)
戴 杜,于随然,浦耿强,王成焘
(上海交通大学 机械与动力工程学院 上海 200030)
摘 要:常规过程式生命周期评估方法在计算中会截断误差,导致评估结果被低估。投入产出方法可以避免截断误差的产生但不包括产品生命周期的使用阶段。为了对E10燃料的生命周期进行评估,本文建立了一个混合生命周期评估模型。生物质生产、乙醇生产/混配以及废物处理/回收3个子过程采用了投入产出生命周期评估方法,燃料燃烧子过程采用了过程式生命周期评估方法。并对两种方法的排放值进行求和,计算出E10燃料生命周期VOC、CO、NOX、PM10、SOX、CH4、N2O、CO2排放值分别为21.245、321.488、26.829、3.110、5.904、9.126、3.028、31345.721
g/kg。该结果与过程式生命周期评估结果一致。
关键词:生命周期;E10燃料;投入产出;生物质
中图分类号:TK6 文献标识码:A
E10
Fuel Life Cycle Assessment Based on Hybrid Model
DAI Du, YU Sui-ran, PU Geng-qiang, WANG Cheng-tao
(School of Mechanical Eng., Shanghai Jiaotong Univ., Shanghai 200030, P.R.China)
Abstract:
Truncation error occurs in process life cycle assessment (PLCA), which makes
underestimation of assessment results. Economic input-output assessment (EIOLCA)
can avoid truncation error but excludes use stage of life cycle. To assessing
life cycle of E10 fuel. A hybrid assessment model for life cycle of E10 fuel
is established. EIOLCA method is used for sub processes of biomass production,
ethanol production/mixing and dispose/recycle, and PLCA method is used for
sub process of combustion. Through aggregating, the life cycle emission results
shows that emission of VOC, CO, NOX, PM10, SOX, CH4, N2O, CO2 are 21.245,
321.488, 26.829, 3.110, 5.904, 9.126, 3.028, 31345.721 gram per kilogram ethanol
output, respectively. These results are consistent to results with PLCA method.
Keywords: life cycle; E10 fuel; input-output; biomass
⊙第106篇⊙
Fabrication
of enclosed nanochannels in poly(methylmethacrylate) using proton beam writing
and thermal bonding
(下载英文论文全文请点击上面的链接)
注意:本论文已在APPLIED PHYSICS
LETTERS 88, 093515,2006发表
使用者请注明论文出处
P. E. Shao(邵培革), A. van Kan, L. P. Wang, K. Ansari, A. A. Bettiol,
and F. Watt
Center for Ion Beam Applications (CIBA), Physics Department, National University
of Singapore,
2 Science Drive 3, Singapore 117542, Singapore
Abstract: We report a technique for fabricating enclosed nanochannels in polymethylmethacrylatePMMA using proton beam writing coupled with thermal bonding. Using proton beam writing, straight-walled high-aspect-ratio channels can be directly fabricated through a relatively thick PMMA resist layer spin coated on a Kapton film. By thermally bonding the fabricated structures onto bulk PMMA, peeling off the Kapton substrate, and bonding the remaining exposed side to PMMA, enclosed high-aspect-ratio nano/microchannels can be fabricated. Such enclosed channels can be incorporated into fluidic polymeric devices, and the process is compatible with the fabrication of multilevel three-dimensional fluidic chips with vertical interconnects.
⊙第107篇⊙
自锚式悬索桥空间耦合自由振动分析的理论研究
(下载论文全文请点击上面的链接)
注意:本论文已在《北华大学学报》(自然科学版)2003,4(1):84-88发表
使用者请注明论文出处
刘春城1,郭立文2,石磊1
(1.大连理工大学土木建筑学院,辽宁大连 116023;
2.吉林省红石林业局,吉林桦甸 132024)
摘 要:摘要:基于大位移非线性弹性理论的广义变分原理,考虑了加劲梁轴向压缩应变能和剪切应变能的影响,建立了三跨自锚式悬索桥空间耦合自由振动的大位移不完全广义势能泛函,通过约束变分导出了自锚式悬索桥的竖向挠曲振动、横向挠曲振动、纵向振动及扭转振动的基础微分方程,为自锚式悬索桥的固有振动性状分析提供可靠的理论依据.
关键词:自锚式悬索桥;耦合;自由振动;泛函;广义变分中
图分类号:U448.25 文献标识码: A
The
oretical Study on Space Coupling Free Vibration Analysis of Self-anchored
Suspension Bridge
Liu Chuncheng1, Guo Liwen2, Shi Lei1
(1.Institute of Civil Engineering and Architecture of Dalian University of
Technology, Dalian, 116023, China
2.Hongshi Forestry Bureau in Jinlin Province, 132024, China)
Abstract:
Based on the generalized potential energy variational principal of nonlinear
elasticity theory with large deflection, the incomplete generalized potential
energy functional with large deflection is established on the space coupling
free vibration of three-span self-anchored suspension bridge by considering
the effect of axial compressive and shearing strain energy of stiffening girder.
By constraint variation, the differential equations of vertical vibration,
later vibration, longitudinal vibration and torsional vibration have been
derived. It can provide the theoretical basis for the analysis of free vibration
of self-anchored suspension bridge.
Keywords: Self-anchored; Coupling; Free vibration; Function;
Generalized variation
⊙第108篇⊙
压弯耦合效应下自锚式悬索桥自由振动研究
(下载论文全文请点击上面的链接)
注意:本论文已在《哈尔滨工业大学学报》2004,36(1):109-111发表
使用者请注明论文出处
(EI已经收录本文)
刘春城[1][2] 张哲[1] 石磊[1]
( [1]大连理工大学桥梁研究所,辽宁,大连 116023
[2]北华大学交通建筑学院,吉林,吉林 132013)
摘 要:基于大位移非线性弹性理论的广义变分厚理,考虑了加劲梁的压弯耦合和剪切应变能的影响,建立了三跨自锚式悬索桥空间耦合自由振动的大位移不完全广义势能泛函,通过约束变分导出了自锚式悬索桥的竖向挠曲振动、横向挠曲振动和纵向振动的基础微分方程,忽略非线性项的影响,进而得到线性振动微分方程.以一座拟建的自锚式混凝土悬索桥为例,求出了竖向振动方程自振频率的解析解,并与数值解作了比较,证明了这一理论和方法为自锚式悬索桥的固有振动特性分析能提供可靠的依据。
关键词:自锚式悬索桥;压弯耦合;自由振动
中图分类号:U442.55 文献标识码:A
Free
vibration analysis of self-anchored suspension bridges subjected to axial
and flexural action efect
LIU Chun.cheng1,2,ZHANG Zhe1 ,SHI Lei1
(1.Bridg,-Institute,Dalian University ofTechnology,Dalian 116023,China;
2.School of Transportation and Architecture,Beihua University,Jilin 132013,China)
Abstract:
Based on the generalized potential energy variational principle of nonlinear
elasticity theory with large deflection,the incomplete generalized potential
energy functional is established on the space coupling free vibration of three-span
self-anchored suspension bridge by considering the effect of coupling of flexural
and axial action,and shearing strain energy of stifening girder.By constraint
variation,the diferential equa tions of vertical vibration,lateral vibration
and longitudinal vibration have been derived.With the nonlinear items disregarded,the
linear differential equations are established.A self-anchored suspension
bridge being constructed is taken as an example for the solution of frequency
of linear vertical vibration,and the results are verified by comparing then
with those obtained using the numerical methods,and theoretical basis is
therefore provided for the analysis of free vibration of self—anchored suspension
bridges.
Keywords: self-anchored suspension bridge; coupling of flexural
and axial action; free vibration
⊙第109篇⊙
两级模糊优选模型及非结构性模糊决策理论在桥梁方案比选中的应用
(下载论文全文请点击上面的链接)
注意:本论文已在《公路交通科技》2004,21(7):79-82发表
使用者请注明论文出处
王会利,李海滨,黄才良,石 磊
(大连理工大学桥梁研究所,辽宁 大连 116023)
摘 要:选择桥梁设计方案,涉及诸多因素,这些因素在某些情况下相容,在某些情况下又相斥。为了协调这些复杂关系,并降低人为因素的影响,本文引入两级模糊优选模型及非结构性模糊决策理论。并运用此模型,进行一桥梁的设计选型优化,得到了比较理想的结果,证明了此模型在桥梁方案比选中的实用性。
关键词:模糊优选;非结构性模糊决策;桥梁方案比选
中图分类号:U442 5 文献标识码:A
Two-extreme
fuzzy optimum model and non-structural fuzzy decision theory applying to bridge
type selection
Wang Hui-li, Li Hai-bin, Huang Cai-liang, Shi Lei
(The Bridge Science Resaerch Institute, Dalian University of Technology, Liaoning
Dalian 116023,China)
Abstract:
Several factors influence type selection of bridge. Some are consistent, others
are inconsistent. In order to harmonize the relations among the factors and
decrease the subjective influence, the two-extreme fuzzy optimum model and
non-structural fuzzy decision theory are introduced. The method of fuzzy optimum
decision has been successfully used in an example of type selection of a bridge,
which includes four design projects.
Key words: Fuzzy optimum decision; Non-structural fuzzy decision;
Type selection of bridge
⊙第110篇⊙
多支承激励下自锚式悬索桥空间地震反应分析
(下载论文全文请点击上面的链接)
注意:本论文已在《哈尔滨工业大学学报 》2004,36(11):1568-1570发表
使用者请注明论文出处
(EI已经收录本文)
刘春城1,2 张哲1 石磊1
(1.大连理工大学桥梁研究所,辽宁 大连 116023
2.北华大学 交通建筑学院 吉林 吉林 132013)
摘 要:基于随机振动理论,考虑了地震动空间效应,对一座主跨240米自锚式混凝土悬索桥在多支承激励下进行了地震反应分析,以及在地震波的三向正交分量独立作用和联合作用下的地震反应进行了数值计算,探讨了行波效应和部分相干效应对自锚式悬索桥地震反应的影响.
关键词:多支承激励 自锚式悬索桥 地震反应
Spatial
seismic response analysis of self-anchored suspension bridges subjected to
multiple-support excitations
Liu Chun-cheng1,2, Zhang Zhe1, Shi Lei1
(1.Bridge Science Resaerch Institute, Dalian University of Technology, Liaoning
Dalian 116023,China
2.School of Transportation and Architecture, Beihua University, Jilin 132013,
China)
Abstract:
Based on random vibration theory, by taking into account the seismic action
with spatial variation, the earthquake respons of a self-anchored suspension
bridge with center span of 240m to multiple-support excitation is investigated,
and numerical calculation is presented for seismic response of self-anchored
suspension bridge by considering traveling effect and correctated effect is
discussed in detail.
Key words: multiple-support excitations; self-anchored suspension
bridge; earthquake reponse
⊙第111篇⊙
Darboux
Transformation and Soliton-like Solutions for a Generalized q-KdV Hierarchy
(下载英语论文全文请点击上面的链接)
注意:本论文已在Journal of the Physical Society
of Japan,Vol. 73, No. 11, November, 2004, pp. 2991–2995发表
使用者请注明论文出处
Engui FAN(范恩贵)
Institute of Mathematics and Key Lab for Nonlinear Mathematical Models and
Methods,
Fudan University, Shanghai 200433, P. R. China
(Received July 5, 2004)
Abstract:By
introducing a q-deformed spectral problem, we derive a new generalized q-KdV
hierarchy with variable coefficients. Darboux matrix technique is further
extended to construct an explicit and universal Darboux transformation for
the q-KdV hierarchy. It is found that the Darboux transformation admits a
theorem of permutability theorem and a superposition formula. In particular,
the soliton-like solutions whose speeds may depend on time variable t are
obtained by applying the Darboux transformation and superposition formula.
KEYWORDS: generalized q-KdV hierarchy, Darboux transformation,
theorem of permutability, soliton-like solution
⊙第112篇⊙
An
algebro-geometric solution for a Hamiltonian system with application to dispersive
long wave equation
(下载英文论文全文请点击上面的链接)
注意:本论文已在JOURNAL
OF MATHEMATICAL PHYSICS ,46, 032701, 2005:1-21发表
使用者请注明论文出处
Y. C. Hon(a)
Department of Mathematics, City University of Hong Kong, Hong Kong SAR, People’s
Republic of China
E. G. Fan(b) (范恩贵)
Institute of Mathematics, Fudan University, Shanghai 200433, People’s Republic
of China
(Received 14 October 2003; accepted 3 December 2004; published online 8 February
2005)
Abstract:By
using an iterative algebraic method, we derive from a spectral problem a hierarchy
of nonlinear evolution equations associated with dispersive long wave equation.
It is shown that the hierarchy is integrable in Liouville sense and possesses
bi-Hamiltonian structure. Two commutators, with zero curvature and Lax representations,for
the hierarchy are constructed, respectively, by using two different systematic
methods. Under a Bargmann constraint the spectral is nonlinearized to a completely
integrable finite dimensional Hamiltonian system. By introducing the Abel–Jacobi
coordinates, an algebro-geometric solution for the dispersive long wave equation
is derived by resorting to the Riemann theta function.
⊙第113篇⊙
基于装配函数的车床虚拟装配
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注意:本论文已在《机电一体化》2004,10(5):42-45发表
使用者请注明论文出处
周立波, 田中旭, 邸义
上海大学CIMS和机器人中心 上海 200072
摘要:虚拟装配是虚拟制造的关键技术之一,装配过程仿真是实现产品虚拟装配的一个重要环节。在分析了虚拟机床装配仿真过程的基础上,提出了一种机床虚拟装配的描述语言及其相对应的虚拟装配函数的实现方案。这种语言能够使机床技术人员用直观、便捷的方法来实现虚拟机床的装配,并通过实例验证了该技术的有效性。
关键词:装配函数 虚拟装配 装配仿真 描述语言
Virtual Assembly of Lathe Based on Assembly Function
Zhou Libo,Tian Zhongxu, Di Yi
(CIMS & Robot Center, Shanghai University, Shanghai, China, 200072)
Abstract:Virtual assembly is one of the key technologies of virtual manufacture, and animation and simulation module of assembly process is an important link to realize product virtual assemble. Based on analyzing the process of simulation of machine assembly,the realization of a language and virtual assembly function, which describes simulation of machine assembly is introduced,。Machine technician can use this language to show the assembly expediently,and an example is given to show the validity of the technology.
Keywords: assembly function; virtual assembly; assembly simulation; description language
⊙第114篇⊙
A New Routing Algorithm of Two-tier LEO/MEO Mobile Satellite Communication Systems
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注意:本论文已在2005 Asia-Pacific Conference on Communications, Perth, Western Australia, 3 - 5 October 2005.发表
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Wu Di, Li Qing
(Dept. of Computer Science Dalian University of Technology Liaoning, China, 116024)
Abstract:The performance of a two-tier LEO/MEO satellite
network including inter-satellite links (ISL’s) is analyzed. Specific
emphasis is laid on the design of an ATM-based routing scheme
for the ISL part of the system (MEO layer). The approach is to
prepare a virtual topology by means of virtual path connections
(VPC’s) connecting all pairs of end nodes in the ISL sub-network
for a complete period in advance, similar to implementing a set of
(time dependent) routing tables. The search for available
end-to-end routes within the ISL network is based on a new
routing Algorithm (S-DRA) integrates the advantages of Static
Routing and Dynamic Routing. Additionally, a new quick
clustering scheme is introduced to monitor the faults to guarantee
the usability of VPC. The new algorithm guarantees that: 1) the
survey of VPC route is not carried on blindly no longer because of
the application of the clustering scheme, 2) the flow of control
information is reduced, 3) whereas the channel of link is
allowable, it can reduce handover frequency as much as possible.
Finally, a simulation on MEO layer analyzes the performance of
the new routing algorithm.
Index Terms--satellite network, ISLs, routing algorithm
⊙第115篇⊙
复杂产品开发活动序列分析方法研究
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注意:本论文已在《中国机械工程》2005,.16(17):1536-1540发表
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曹守启1 陈 云2 韩彦岭3 方明伦1
1.上海大学,上海,200072
2.上海财经大学,上海,200433
3.北京科技大学,北京,100083
摘 要:应用图论中可达矩阵的性质与原理对产品开发活动的组织方式及其序列作了定量分析,实现对产品开发活动的按区域划分,从而明确了影响产品开发过程中的主要路线和关键环节;通过对产品开发可能路径持续时间和作用概率的分析研究,为并行产品开发过程的组织和实施提供决策依据.
关键词:复杂产品;任务分解;活动序列;开发过程;关键路径
分类号:TH16;TP399
文章编号:1004-132X(2005)17-1536-05
Cao Shouqi1 Chen Yun2 Han Yanling3 Fang Minglun1
1、Shanghai University,Shanghai,200072
2、Shanghai University of Finance&Economics,Shanghai.200433
3.University of Science and Technology Beijing,Beijing,100083
Abstract:Research on Analysis Method of Development Activity Sequences for Intricate ProductsAbstract:This paper made quantitative analyses to activity sequences and organization schema of production development with the principle of reachability matrix in graphics theory, realized division according to activity zone of product development, and effects on primary route and critical juncture of development definitely. By researches on time duration and action probability of product development, we provided the decision-making reliance for organization and execution of development routes.
Key words:intricate product; task decomposition; activity sequence; development process; critical path
⊙第116篇⊙
基于约束的复杂产品开发过程与活动路线分析
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注意:本论文已在《机械科学与技术》 2005,.24(12):1391-1395发表
使用者请注明论文出处
曹守启1 陈云2 韩彦岭1 方明伦1
1.上海大学,上海,200072
2.上海财经大学,上海,200433
摘 要:为实现在不同阶段、按不同层次和区域分析和控制产品开发微观过程的目的,提出一种基于"自组织-被组织"方法论规划和设计产品开发过程的方法.在面向过程的任务分层分解和基于约束的产品开发活动组织过程表达中,把与过程相关的约束和影响因素,通过节点间逻辑状态及其取值概率来反映和体现;应用图论中可达矩阵性质与原理定量分析产品开发活动序列及其组织路线,实现产品开发宏观过程管理和微观过程控制的有机结合,使产品开发活动的组织方式、状态演化和工作流程始终处于透明和可控的环境下观察和分析,帮助项目管理人员明确影响产品开发过程的主要路线和关键环节,克服传统方法综合多个要素、跨越整个过程建模和分析的困难.
关键词:自组织;任务分解;活动序列;约束;关键路径
分类号:TH16;TP399 文献标识码:A
文章编号:1003-8728(2005)12-1391-05
Cao Shouqi1 Chen Yun2 Han Yanling1 Fang Minglun1
1、Shanghai University,Shanghai,200072
2、Shanghai University of Finance&Economics,Shanghai.200433
Abstract:Analysis of Complicated Product Development Process and its Activity Line Based on RestraintCao Shouqi,Chen Yun, Han Yanling, Fang Minglun (1. CIMS and Robot Center, Shanghai University, Shanghai 200072; 2. Shanghai University of Finance and Economics, Shanghai 200433)Abstract:In order to realize the purposes of analyzing and controlling micro-processes of product development according to different levels and regions in different phases, a planning and design method of the product development processes is put forward on the basis of self-organizing and organized methodology. In the process of stratifcation and decomposition of task and product development based on restraint, the influence and restraint factors in connection with the processes are reflected and embodied by logic state and evaluation probability. By applying quality and principle of reachability matrix in graphics theory, activity sequence and its route of product development are analyzed quantitatively; macroscopic process management and microcosmic process control of product development are realized, and the organization mode, state evolution and work flow of product development activities are observed and analyzed under a transparent and controllable environment all the time. All these help project managers to know about the primary route and key point juncture of product development processes and overcome the difficulty of traditional methods in the way .of modeling and analysis by synthesizing multiple elements and crossing entire processes.
Key words:self-organizing; task decomposition ; activity sequence; restraint ; critical path
⊙第117篇⊙
非均质材料零件的材料设计
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张秀娟[1] 陈克彰[2] 冯辛安[3]
[1]大连铁道学院机械工程系,辽宁大连116028
[2]香港大学机械工程系 ,香港
[3]大连理工大学机械学院,辽宁大连116024
摘 要:阐述了非均质材料零件设计优化的数学模型,并采用灵敏度分析以及最速下降法对其各个材料区域的材料性能进行设计优化,得到最佳材料性能参数后,再从非均质材料数据库中找到相应的工程材料,合成满足设计要求的非均质材料零件.该方法为设计者提供了切实可行的非均质材料零件的材料设计方法.
关键词:非均质材料零件 材料设计 数学优化模型 灵敏度分析 最速下降法
分类号: TH140.8
ZHANG Xiu—juan ,CHEN Ke—zhang ,FENG Xin—an
(1.Dept.of Mechanical Engineering.Dalian Railway Institute.Dalian 116028 China;2.Dept,of Mechanical Engineering.The University of Hong Kong.Hong Kong;3.Dept、of Mechanical Engineering.Dalian University of Technology.Dalian 1 16024 China)
Abstract:TMs paper presents the mathematical mod el for the optimization of heterogeneous components I an d the method using sensitivity analysis and steepest descent method to optimize material properties,the component is then identified.After searching for the materials from heterogeneous material database according to the corresponding optimum material data and combining the heterogene- OUS compo nents,the material is synthetized.To designer,this method is feasible and effective for the material design of heterogene-
OUS compo nents.
Key words:heterogeneous components;mathema~cal model:sensitivity analysis and optimization;steepest descent method
⊙第118篇⊙
数字制造的概念与关键技术
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注意:本论文已在《现代制造工程》 2005,9:106-109发表
使用者请注明论文出处
张秀娟
大连交通大学机械工程学院,辽宁大连,116028
摘 要:阐述数字制造的基本概念与内涵,全面介绍数字制造的关键技术和应用,并提出数字制造的发展趋势。
关键词:数字制造 概念与内涵 关键技术 发展趋势
ZHANG Xiu—juan ,CHEN Ke—zhang ,FENG Xin—an
(1.Dept.of Mechanical Engineering.Dalian Railway Institute.Dalian 116028 China;2.Dept,of Mechanical Engineering.The University of Hong Kong.Hong Kong;3.Dept、of Mechanical Engineering.Dalian University of Technology.Dalian 1 16024 China)
Abstract:The concept and connotation of digital manufacturing are introduced. Key techniques and applications of digital manufacturing are described. The development trend of digital manufacturing is put forward lastly.
Key words:Digital manufacturing Concept and connotation Key techniques Development trend
⊙第119篇⊙
流形网格上机构运动轨迹的参数化生成方法
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注意:本论文已在
《机械工程学报》(中文版))2006,42(8):84-88,94发表
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孙玉文1 王海霞1 刘伟军2 王越超2
(1. 大连理工大学精密与特种加工教育部重点实验室 大连 116024;
2. 中国科学院沈阳自动化研究所 沈阳 110016)
摘 要:在三角网格模型上操作机构的运动轨迹生成通常采用截面线法,当网格边界形状复杂时由此生成的运动轨迹很难保证与边界的一致性,从而产生较多较短的路径。基于调和映射技术,提出了复杂网格曲面上机构运动轨迹参数化生成的一般方法。通过将复杂网格模型同胚映射到平面上的圆形区域或矩形区域,建立了在参数曲面基础上的ZigZag型及轮廓型等参数线轨迹的具体规划模型,给出了该种情况下轨迹离散点、行距及机构运动干涉的计算方法与解决方案。实例表明该轨迹生成方法具有良好的边界一致性,并因其固有的轨迹磨光性质提高了运动机构的动力学性能及运行效率。
关键词:三角网格 调和映射 轨迹规划 可接近性分析
un Yuwen1 Wang Haixia1 Liu Weijun2
Wang Yuechao2
(1. Key Laboratory for Precision & Non-traditional Machining of Ministry of Education, Dalian University of Technology, Dalian 116024;
2. Shenyang Institute of Automation, Chinese Academy of Science, Shenyang 110016 )
Abstract:Triangular mesh surface has gained wide applications in industrial field. However, the tool path generation methods for polyhedral machining are very limited and the iso-plane method is still the common used method. A conformal map based iso-parametric method for kinematic path generation is proposed. Through establishing the parametric relations between the triangular meshes embedded in the 3D space and the rectangular or circular region on the 2D plane, the Zigzag or contour paths are finally implemented by inversely mapping the planar iso-parametric paths into the physical space. Also, the issues of CC point and side interval calculation as well as interference detection are discussed in detail. The results show that the proposed method is boundary-conformed and can improve machining dynamics and efficiency greatly.
Key words:Triangular mesh, Conformal map, Tool path, Accessibility analysis
⊙第120篇⊙
SKIN-CORE STRUCTURE IN MESOPHASE PITCH-BASED CARBON FIBERS: CAUSES AND PREVENTION
(下载英文论文全文请点击上面的链接)
注意:本论文已在Carbon, Vol. 36, No. 12, pp. 1719–1724, 1998发表
使用者请注明论文出处
YONG-GEN LU¨(吕永根) ,a,* DONG WU,b QING-FANG ZHA,a LANG LIU¨ a and
CHANG-LING YANGa
a.Institute of Coal Chemistry, Chinese Academy of Sciences, Shanxi, 030001 Taiyuan,
People’s Republic of China
b.Department of Chemical Engineering, Taiyuan University of Science and Technology, Shanxi,
030001 Taiyuan, People’s Republic of China
Abstract:To prohibit skin-core structure from appearing in mesophase pitch based carbon fiber (CF)
with a large diameter (30–50 mm), measures such as decreasing oxidation temperature, prolonging
holding time and increasing the oxygen partial pressure in the oxidative atmosphere were taken. EPMA
(electron probe X-ray micro-analyzer) was utilized to detect the oxygen content distribution along the
diameter of oxidized pitch fiber (OF). The transverse structure of OFs and CFs was observed under a
scanning electron microscope (SEM). It was found with certainty that the skin-core structure in CFs is
caused by steep oxygen content gradient along the diameter of their OFs. The oxygen distribution in
OFs was controlled by the oxidative stabilization conditions. In this work, the CF whose precursor fiber
had been oxidized at 240°C in a flow of pure oxygen for 10 hours exhibits no skin-core structure and
possesses a high tensile strength. The kinetics of stabilization was also studied. It can be concluded that
those factors which increase oxygen diffusion or depress oxidative reaction are effective in overcoming
skin-core structure in CFs. ? 1998 Elsevier Science Ltd. All rights reserved.
Key words:A. Carbon fibers, mesphase, B. EPMA, D. Diffusion.
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