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Virtual hairy brush for digital painting and calligraphy

Science in China(Series F) 2005年第3期48卷 285-303页

作者： XUSonghua LauFrancisC.M XUCongfu PANYunhe StateKeyLabofCAD&CG ZhejiangUniversityHangzhou310027China StateKeyLabofCAD&CG ZhejiangUniversityHangzhou310027China//ComputerScienceDepartmentYaleUniversityNewHavenCT06511USA DepartmentofComputerScience TheUniversityofHongKongPokfulamRoadHongKongChina

The design of user friendly and expressive virtual brush systems for interactive digital painting and calligraphy has attracted a lot of attention and effort in both computer graphics and human-computer interaction circles for a long time. Providing a digital environment for paper-less artwork creation is not only challenging in terms of algorithmic design, but also promising for its potential market values. This paper proposes a novel algorithmic framework for interactive digital painting and calligraphy based a novel virtual hairy brush model. The algorithms in the kernel of our simulation framework are built upon solid modeling techniques. Implementing the algorithms, we have developed a virtual hairy brush prototype system with which end users can interactively produce high-quality digital paintings and calligraphic artwork. (The latest progress of our virtual brush project is reported at the website “http://***/~songhua/e-brush/”.)

关键词： virtual hairy brush digital painting and calligraphy simulation algorithm solid modeling non- photorealistic rendering.

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A novel algorithm to simulate DWDM transmission systems amplified by backward multipumped fiber Raman amplifiers

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MICROWAVE AND OPTICAL TECHNOLOGY LETTERS 2002年第4期35卷 333-337页

作者： Tong, Z Wei, H Jian, SH No Jiaotong Univ Inst Lightwave Technol Beijing 100044 Peoples R China

We propose a new and efficient numerical algorithm to simulate DWDM transmission systems amplified by backward multi-wavelength-pumped Raman amplifiers. In this model, system impacts caused by dispersion, nonlinearity, and ASE are considered, and calculated results have satisfying accuracy. As an application, we model a 64 X 10 Gb/s Raman broadband mufti-span system, and arrive at some useful conclusions. (C) 2002 Wiley Periodicals, Inc.

关键词： fiber Raman amplifiers simulation algorithm split-step Fourier method average power analysis eye-pattern closure penalty

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OPTIMIZATION OF COLLIMATORS FOR IMAGING POSITRON EMITTERS BY A GAMMA-CAMERA

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EUROPEAN JOURNAL OF NUCLEAR MEDICINE 1985年第6-7期11卷 230-234页

作者： NEWIGER, H JORDAN, K HANOVER UNIV MED NUKL MESSTECH ABT KONSTANTY GUTSCHOW STR 8 D-3000 HANOVER 61 FED REP GER

The imaging of positron-emitting isotopes using a gamma camera requires special collimators. A ray-tracing method for simulating the point-spread function of collimators and, therefore, the total gamma camera system is presented. Simulated data obtained by this method showed good agreement with experimental data. Using this method, optimal lead and tungsten collimators for positron emitters were devised;at an object distance of B = 100 mm, these yielded a point-spread function with an FWHMtot = 9.1 mm using an intrinsic resolution of FWHMintr = 8.0 mm.

关键词： Gamma camera High-energy collimator Positron emitters simulation algorithm Optimization algorithm Ray-tracing method Optimal collimator

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On the uniform random upper bound family of first significant digit distributions

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JOURNAL OF INFORMETRICS 2015年第2期9卷 349-358页

作者： Huerlimann, Werner Feldstr 145 CH-8004 Zurich Switzerland

The first significant digit patterns arising from a mixture of uniform distributions with a random upper bound are revisited. A closed-form formula for its first significant digit distribution (FSD) is obtained. The one-parameter model of Rodriguez is recovered for an extended truncated Pareto mixing distribution. Considering additionally the truncated Erlang, gamma and Burr mixing distributions, and the generalized Benford law, for which another probabilistic derivation is offered, we study the fitting capabilities of the FSD's for various Benford like data sets from scientific research. Based on the results, we propose the general use of a fine structure index for Benford's law in case the data is well fitted by the truncated Erlang member of the uniform random upper bound family of FSD's. (C) 2015 Elsevier Ltd. All rights reserved.

关键词： Benford's law Stigler's law Uniform distribution simulation algorithm Extended truncated Pareto Erlang distribution

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Research on Freight Train Operation Control simulation on Long Steep Downhill Lines

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ASCE-ASME JOURNAL OF RISK AND UNCERTAINTY IN ENGINEERING SYSTEMS PART A-CIVIL ENGINEERING 2021年第3期7卷

作者： Yang, Yanqiang Mao, Baohua Wang, Min Beijing Jiaotong Univ Key Lab Transport Ind Big Data Applicat Technol C Beijing 100044 Peoples R China

Steep ramps are often unavoidable in route design, leading to adverse effects on freight transportation organization. For operators, how to safely and effectively run trains on steep downhill lines is a challenging task. In response to the requirement, firstly, the control principles of electric freight trains, including safety demands, rapid running, use of driving modes, and periodic braking, are analyzed. Then, a fast train operation simulation algorithm (FTOSA) is proposed to realize the control principles. Finally, a real case study is carried out, and FTOSA is compared with existing simulation software in China. The results showed that FTOSA could generate a high-efficiency speed profile on long steep downhill lines under the constraints of train safety control. This work can provide some references for the operation of electric freight trains. (C) 2021 American Society of Civil Engineers.

关键词： Electric freight trains Operation control Steep downhill simulation algorithm

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Modeling and simulation of the assembly accuracy of aero-engine rotors in the docking processes using a specially designed novel multi-DOF NC motion platform

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AEROSPACE SCIENCE AND TECHNOLOGY 2021年 113卷 106648-106648页

作者： Zhou, Tianyi Gao, Hang Dalian Univ Technol Minist Educ Key Lab Precis & Nontradit Machining Technol Dalian 116024 Peoples R China

The assembly accuracy of aero-engine rotor parts is strictly required in the docking processes. The application of a multi-degrees-of-freedom (multi-DOF) numerical control (NC) motion platform could potentially replace traditional manual docking operations for its better performance. A key issue is ensuring the assembly accuracy qualified by using the new mechanism. In this paper, a systematic study is carried out on modeling and simulation of the docking assembly accuracy of aero-engine rotors using a specially designed novel multi-DOF NC motion platform. A simulation algorithm based on the Monte Carlo method is proposed, to simulate large quantities of rotor assemblies under different docking conditions. To construct the algorithm, new general models are proposed to indicate the geometric errors and assembly accuracy in typical rotor parts. A motion error model of a novel multi-DOF NC motion platform is established using the differential transformation method. Then, simulation results are analyzed to guide the precision design of the six driving systems in the motion platform, and verified by experiments. The results show that the optimized precision setting of the motion platform achieves the qualified rates of assembly accuracy exceeding 92.0% under most docking conditions. For the six items representing assembly accuracy, the deviation rates between the simulation and experimental results are less than 23.0%. The modeling and simulation study has referential significance for both theory and practice. (C) 2021 Elsevier Masson SAS. All rights reserved.

关键词： Aero-engine rotor Docking Assembly accuracy Multi-DOF NC platform simulation algorithm Assembly error analysis

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Heuristic algorithm to optimize the manufacturing system design to get maximum profit

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INTERNATIONAL JOURNAL OF INTERACTIVE DESIGN AND MANUFACTURING - IJIDEM 2008年第4期2卷 233-243页

作者： Bhat, B. N. Shishir Dr MGR Univ Dept Mech Engn Madras Tamil Nadu India

Agile manufacturing has become a topic of great interest over the past several years. The entire domain of modeling and analyzing different types of agile manufacturing environments and systems, however, remain largely unexplored. The objective of this paper is to provide fundamental insight into how manufacturing systems should be designed and reconfigured over time in order to cope with different agile manufacturing factors. To achieve this objective, three approaches are developed and integrated into one simulation-based model. The first approach is used to model different agile manufacturing environments. The second approach is used to define various ways in which manufacturing systems can be designed and reconfigured (i.e., design/reconfiguration strategies). The third comprises the cost and objective functions used to measure system performance when different design/reconfiguration strategies are used in different agile manufacturing environments. Based upon the assumptions adopted, the experimental work performed suggests that despite the fact that agility incurs high costs, agile manufacturing systems are indeed necessary for certain manufacturing environments in which product life cycles are short yet demand per product type is high. Therefore, it is important in certain manufacturing environments to focus on reconfiguration in short periods of time, even at the expense of higher reconfiguration costs.

关键词： simulation algorithm Agile manufacturing system Operating strategy

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Space as the final frontier in stochastic simulations of biological systems

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FEBS LETTERS 2005年第8期579卷 1789-1794页

作者： Lemerle, C Di Ventura, B Serrano, L European Mol Biol Lab D-69117 Heidelberg Germany

Recent technological and theoretical advances are only now allowing the simulation of detailed kinetic models of biological systems that reflect the stochastic movement and reactivity of individual molecules within cellular compartments. The behavior of many systems could not be properly understood without this level of resolution, opening up new perspectives of using computer simulations to accelerate biological research. We review the modeling methodology applied to stochastic spatial models, also to the attention of non-expert potential users. Modeling choices, current limitations and perspectives of improvement of current general-purpose modeling/simulation platforms for biological systems are discussed. (c) 2005 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

关键词： spatial modeling stochastic simulation reaction-diffusion simulation algorithm modeling software

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Multicast Routing Based on Hybrid Genetic algorithm

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Journal of Beijing Institute of Technology 2005年第2期14卷 130-134页

作者：曹元大蔡刿 School of Software Beijing Institute of Technology Beijing100081 China School

A new multicast routing algorithm based on the hybrid genetic algorithm (HGA) is proposed. The coding pattern based on the number of routing paths is used. A fitness function that is computed easily and makes algorithm quickly convergent is proposed. A new approach that defines the HGA's parameters is provided. The simulation shows that the approach can increase largely the convergent ratio, and the fitting values of the parameters of this algorithm are different from that of the original algorithms. The optimal mutation probability of HGA equals 0.50 in HGA in the experiment, but that equals 0.07 in SGA. It has been concluded that the population size has a significant influence on the HGA's convergent ratio when it's mutation probability is bigger. The algorithm with a small population size has a high average convergent rate. The population size has little influence on HGA with the lower mutation probability.

关键词： multicast routing hybrid genetic algorithm(HGA) simulation algorithm Steiner tree

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FERN - a Java framework for stochastic simulation and evaluation of reaction networks

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BMC BIOINFORMATICS 2008年第1期9卷 356-356页

作者： Erhard, Florian Friedel, Caroline C. Zimmer, Ralf Univ Munich Inst Informat LFE Bioinformat D-80333 Munich Germany

Background: Stochastic simulation can be used to illustrate the development of biological systems over time and the stochastic nature of these processes. Currently available programs for stochastic simulation, however, are limited in that they either a) do not provide the most efficient simulation algorithms and are difficult to extend, b) cannot be easily integrated into other applications or c) do not allow to monitor and intervene during the simulation process in an easy and intuitive way. Thus, in order to use stochastic simulation in innovative high-level modeling and analysis approaches more flexible tools are necessary. Results: In this article, we present FERN (Framework for Evaluation of Reaction Networks), a Java framework for the efficient simulation of chemical reaction networks. FERN is subdivided into three layers for network representation, simulation and visualization of the simulation results each of which can be easily extended. It provides efficient and accurate state-of-the-art stochastic simulation algorithms for well-mixed chemical systems and a powerful observer system, which makes it possible to track and control the simulation progress on every level. To illustrate how FERN can be easily integrated into other systems biology applications, plugins to Cytoscape and CellDesigner are included. These plugins make it possible to run simulations and to observe the simulation progress in a reaction network in real-time from within the Cytoscape or CellDesigner environment. Conclusion: FERN addresses shortcomings of currently available stochastic simulation programs in several ways. First, it provides a broad range of efficient and accurate algorithms both for exact and approximate stochastic simulation and a simple interface for extending to new algorithms. FERN's implementations are considerably faster than the C implementations of gillespie2 or the Java implementations of ISBJava. Second, it can be used in a straightforward way both as a stand-alo

关键词： Stochastic simulation Reaction Network simulation algorithm Stochastic simulation algorithm Molecule Number

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