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Multi-Volume CAD Modeling for Heterogeneous ObjectDesign and Fabrication

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Journal of Computer Science & Technology 2000年第1期15卷 27-36页

作者： SUN Wei(Department of Mechanical Engineering and MechanicsDrexel University, Philadelphia, PA 19104, U.S.A.)E-mail: sunwei@drexel.edu or rpdc@drexel.edu Department of Mechanical Engineering and Mechanics Drexel University Philadelphia U.S.A.

The current computer-aided technologies in design and product development, the evolution of CAD modeling, and a framework of multi-volume CADmodeling system for heterogeneous object design and fabrication are presented inthis paper. The multi-volume CAD modeling system is presented based on nonmanifold topological elements. Material identifications are defined as design attributes introduced along with geometric and topological information at the designstage. Extended Euler operation and reasoning Boolean operations for merging andextraction are executed according to the associated material identifications in thedeveloped multi-volume modeling system for heterogeneous object. An applicationexample and a pseudo-processing algorithm for prototyping of heterogeneous structure through solid free-form fabrication are also described.

关键词： CAD CAD modeling heterogeneous modeling multi-volume modeling nonmanifold modeling solid freeform fabrication

Getting 'holistic' about land rehabilitation in hot arid regions

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Science China Earth Sciences 2002年第Z1期45卷 109-114页

作者： Adrian Williams curtin.edu.au) Centre for the Management of Arid Environments Locked Bag 22 Kalgoorlie WA 6430 Australia (email: A. Williams

The paper describes Western Australian examples and causes of land degradation. Itoutlines shortcomings in the methodologies used to rehabilitate these areas. From this a protocolis suggested for an ‘holistic' approa... 详细信息

关键词： vegetation, rehabilitation, arid regions, community participation.

Property transformation under specification change

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Frontiers of Computer Science 2011年第1期5卷 1-13页

作者： Zheng Fu (1) zhengfu@itee.uq.edu.au Graeme Smith (1) School of Information Technology and Electrical Engineering The University of Queensland QLD Australia

Formal specifications of software systems need to evolve in many ways during system development. Not only are changes required to refine the specification toward an implementation, they are also required in response to changes in requirements, or to incorporate different aspects of the system, e.g., fault tolerance or timing, initially ignored in order to simplify reasoning. This paper presents an approach for evolving Z specifications by the step-wise application of a number of simple rules. These rules not only document the evolution of the specification, but also make precise how properties of the system evolve with the specification. Hence, reasoning about these properties performed on the original specification need not be repeated on the new specification.

关键词： formal methods Z refinement temporallogic system property

The determination of larval metamorphic competence of Styela canopus Savigny

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Acta Oceanologica Sinica 2003年第3期22卷 459-466页

作者： Caihuan Ke hawaii.edu. +Corresponding author E-mail: chke *** Department of Oceanography Institute of Subtropic Oceanography Key Laboratory for Marine Environmental Science of the Ministry of Education Xiamen University Xiamen 361005 China. E-mail:yinghuan

The larvae of Styela canopus show the highest rates of settlement and metamorphosis when treated with 40 mM KCl-elevated seawater at 25 degreesC in temperature and 27.0 in salinity. Induced by 40 mM KCl-elevated seawater, it took Styela canopus larvae approximately 3 h after hatching to develop competence to settle and metamorphose. The present experiment shows that Styela canopus larvae is an ideal model organism for examining the efficiency of antifouling substance.

关键词： Styela canopus larvae settlement metamorphosis ascidian

Integrating Interaction Framework for Agent Negotiation

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Journal of Donghua University(English Edition) 2003年第4期20卷 76-82页

作者：肖正光 cs. sjtu. edu. cn 王振杰 cs. sjtu. edu. cn 徐良贤 cs. sjtu. edu. cn Department of Computer Science and Engineering Shanghai Jiao Tong University Shanghai 200030 China (xiao-zg wang-zj xu-lx)

Agent negotiation has become increasingly important since the advent of electronic *** are two kinds of interactions in the process of agent *** is the interaction between different agents,and the other is the interaction between the agent and the human *** this paper,firstly,we introduce Q language,a scenario description language for designing interactions between agents and human *** we propose an integrating interaction framework for agent negotiation,in which both kinds of interactions are described by Q *** framework can make the interaction process open and easy to be understood by the *** can understand how the negotiation process goes and what is happening in the system including some erroneous or inappropriate actions caused by the negotiation *** gives the users a chance to terminate or change the behavior of negotiation agent in time to avoid unfavorable negotiation *** addition,users can customize the agent's behaviors through visible interactions with it.

关键词： automated negotiation interactive agent agent-mediated e-commerce

Ecowas in the Last Three Decades: Challenges to Economic Integration

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Ecowas in the Last Three Decades: Challenges to Economic Int...

作者： edu EASSEY EKA 外交学院

学位级别：硕士

Economic co-operation at the regional and sub-regional level has been an important feature ofthe economic development policies of developing countries. The Economic Community of WestAfrican States （ECOWAS） was established in1975with a view to promote economic co-operation and integration in West Africa. The creation marked the successful outcome ofprotracted negotiations that had began shortly after independence, which reflected the mountingsense of unease in Africa and throughout the third world that political independence did notsignify effective control of the new states of their economies, The reality was, majority of themwere either too small or too poor to make any reasonable impact in the emerging internationalpolitical economy, hence the need for a platform on which all the countries of the region can pulltheir economics together to form a collective front for the benefit of all. But almost four decadesafter the ECOWAS treaty was signed by member states, the desired economic gains fromintegrating their economies is still far from being achieved as the integrating process has taken avery slow pace. Findings by this research revealed two broad interwoven factors responsible for the slow pace ofeconomic integration in ECOWAS, economic and political factors. It was discovered that weakcommitment by the three major and largest economies （NIGERIA, GHANA AND COTED’IVOIRE） which accounts for almost70%of the total ECOWAS population and contributesabout80%of it GDP, In implementing ECOWAS policies and protocols has led to tradeprotectionism and setting up of trade barriers leading to very low trade among them. This is sobecause their economies are competitive rather than complimentary. Political factors considered to have had a great effect include instability in the polity occasionedby civil wars and unrest in West Africa, weak political institutions, national policies, overlappingmembership as well as failure of the three major economies to provide the needed lea

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Research on Fisheries Investment Attraction in Equatorial Guinea

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Research on Fisheries Investment Attraction in Equatorial Gu...

作者： BERNARDO NDONG edu 大连海洋大学

学位级别：硕士

Fisheries production and growth,especially from the marine sector,are significant for the socioeconomic growth of Equatorial Guinea and its significant contribution to the country’s economic development the Gross Domestic Product or *** Guinea is blessed with a lot of marine fisheries resources that could increase the production of ***,initial supply from the production of domestic is far below the fish needs of the *** research is mainly focused on investment attraction in Equatorial Guinea in the sector of fisheries and also focused on marine *** research adopted a desk review ***’s mainly divided into different sections and chapters such as the Equatorial Guinea fisheries sector,marine fisheries resources in Equatorial Guinea,the status of marine fisheries production and growth in Equatorial Guinea,influential factors of investment,and current situations of investment in the fisheries sector of Equatorial *** research will also provide problem analysis on fisheries investment in Equatorial Guinea,and also gives some policy suggestions on increasing investment in Equatorial *** paper mainly concludes that the contribution of aquaculture to marine fisheries growth has been low,in contrast to the marine capture fisheries growth in Equatorial *** research will also demonstrate that despite the availability of rules and regulations,noncompliance by fisher folks has not helped to enhance marine fisheries growth in Equatorial ***,mainly recommends that the culture of marine fishes should be intensified in order to increase the investment in the Fishery sector in Equatorial *** most economic sectors,enhances capital and investments are often considered virtuous,mainly showing confidence in the future and expected *** the sector of fisheries,however,investments are often harmful,as they may lead to enhances incapacity of the fleet,which is not desirable considering the fully explo

关键词：赤道几内亚渔业投资吸引潜力

Exponential Growth Solutions of Elliptic Equations

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Acta Mathematica Sinica,English Series 1999年第4期15卷 525-534页

作者： Fengbo Hang Fanghua Lin Courant Institute,251 Mercer Street,New York,NY 10012,U S A E-mail:fengbo@cims.nyu.edu linf@cims.nyu.edu Courant Institute New York USA

We show that for a class of second order divergence form elliptic equations on an infinite strip with the Dirichlet boundary condition,the space of fixed order exponential growth solutions is of finite *** optimal estimation of the dimension is *** also show that the finiteness property may not be true if one drops some of the conditions we make in our result.

关键词： Elliptic equations Exponential growth function Poincarés inequality Mean value inequality

Dynamic Modeling and Simulation of a Commercial Naphtha Catalytic Reforming Process

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Chinese Journal of Chemical Engineering 2005年第1期13卷 74-80页

作者：胡永有 iit.edu 徐巍华侯卫锋苏宏业褚健 His current address is Department of Chemical and Environmental Engineering Illinois Institute of Technology Chicago IL 60616 USA. E-mail: huyongy National Laboratory of Industrial Control Technology Institute of Advanced Process Control Zhejiang University Hangzhou 310027 China

A first principles-based dynamic model for a continuous catalyst regeneration (CCR) platforming process, the UOP commercial naphtha catalytic reforming process, is developed in this paper. The lumping details of the naphtha feed and reaction scheme of the reaction model are given. The process model is composed of the reforming reaction model with catalyst deactivation, the furnace model and the separator model, which is capable of capturing the major dynamics that occurs in this process system. Dynamic simulations are performed based on Gear numerical algorithm and method of lines (MOL), a numerical technique dealing with partial differential equations (PDEs). The results of simulation are also presented. Dynamic responses caused by disturbances in the process system can be correctly predicted through simulations.

关键词： catalytic reforming dynamic modeling simulation method of lines process control