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作者： Jang, H.S. Kim, J.H. Kim, K.S. Jung, G.Y. Lee, J.J. Kim, G.H. Division of Nano and Bio Technology Daegu-Gyeongbuk Institute of Science and Technology Dalseo-gu Daegu 704-230 Korea Republic of Department of Material Science and Engineering Program for Integrated Molecular System Gwangju Institute of Science and Technology Gwangju 500-712 Korea Republic of Nano-Mechanical Systems Research Division Korea Institute of Machinery and Materials Daejeon 305-343 Korea Republic of

We report on how to increase transmittance of a 0.2 mm thick polycarbonate (PC) film by periodic subwavelength anti-reflection structures in the visible spectral range. Subwavelength anti-reflection structures like moth-eyes are fabricated into the polycarbonate substrate itself by thermal nanoimprinting lithography (TH-NIL), which uses silicon stamps that have periodic structures such as gratings (lines and spaces) and pillared dots, and are fabricated by laser interference lithography (LIL) and transformer coupled plasma etching. To increase transmittance of a polycarbonate film, we control the periods and shapes of patterns, the number of patterned surfaces, and the overlapping direction of patterns that are fabricated into its surfaces. As a result of this, we show that average transmittance improves as the pattern period gets shorter and as both surfaces of the film are patterned. We also show that the spectrum range gets larger as the pattern period gets shorter and is determined by the longer pattern period in the case of designing a film to have different pattern period on its surfaces. The maximum average transmittance of a polycarbonate film increases up to approximately 6% compared to a bare sample in the 470-800 nm spectral range. Copyright © 2011 American Scientific Publishers All rights reserved.

关键词： Polycarbonates

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Hardware Particle Swarm Optimization with passive congregation for embedded applications

Hardware Particle Swarm Optimization with passive congregati...

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Southern Conference on programmable Logic

作者： Muñoz, Daniel M. Llanos, Carlos H. Coelho, Leandro Dos S. Ayala-Rincón, Mauricio Department of Mechanical Engineering Automation and Control Group/GRACO University of Brasilia Brasilia D.F. Brazil Industrial and Systems Engineering Graduate Program Pontifical Catholic University of Parana Curitiba Parana Brazil Department of Computer Science and Mathematics University of Brasilia Brasilia D.F. Brazil

ISBN: (纸本)9781424488483

Achieving high performance optimization algorithms for embedded applications can be very challenging, particularly when several requirements such as high accuracy computations, short elapsed time, area cost, low power consumption and portability must be accomplished. This paper proposes a hardware implementation of the Particle Swarm Optimization algorithm with passive congregation (HPPSOpc), which was developed using several floating-point arithmetic libraries. The passive congregation is a biological behavior which allows the swarm to preserve its integrity, balancing between global and local search. The HPPSOpc architecture was implemented on a Virtex5 FPGA device and validated using two multimodal benchmark problems. Synthesis, simulation and execution time results demonstrates that the passive congregation approach is a low cost solution for solving embedded optimization problems with a high performance. © 2011 IEEE.

关键词： Digital arithmetic

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Opposition-based shuffled PSO with passive congregation applied to FM matching synthesis

Opposition-based shuffled PSO with passive congregation appl...

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IEEE Congress on Evolutionary Computation

作者： Munoz, Daniel M. Llanos, Carlos H. Dos S. Coelho, Leandro Ayala-Rincon, Mauricio Department of Mechanical Engineering Automation and Control Group/GRACO University of Brasilia Brasilia D.F. Brazil Industrial and Systems Engineering Graduate Program LAS/PPGEPS Pontifical Catholic University of Parana Curitiba Parana Brazil Department of Computer Science and Mathematics University of Brasilia Brasilia D.F. Brazil

ISBN: (纸本)9781424478347

Synthesis of musical instruments or human voice is a time consuming process which requires theoretical and experimental knowledge about the synthesis engine. Commonly, performers need to deal with synthesizer interfaces and a process of trial and error for creating musical sounds similar to a target sound. This drawback can be overcome by adjusting automatically the synthesizer parameters using optimization algorithms. In this paper a hybrid particle swarm optimization (PSO) algorithm is proposed to solve the frequency modulation (FM) matching synthesis problem. The proposed algorithm takes advantage of a shuffle process for exchanging information between particles and applies the selective passive congregation and the opposition-based learning approaches to preserve swarm diversity. Both approaches for injecting diversity are based on simple operators, preserving the easy implementation philosophy of the particle swarm optimization. The proposed hybrid particle swarm optimization algorithm was validated for a three-nested FM synthesizer, which represents a 6-dimensional multimodal optimization problem with strong epistasis. Simulation results revealed that the proposed algorithm presented promising results in terms of quality of solutions. © 2011 IEEE.

关键词： Global optimization

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Study of classification of failure states for Small Unmanned Ground Vehicle by response surface methodology

Study of classification of failure states for Small Unmanned...

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International Conference on Ubiquitous Robots and Ambient Intelligence (URAI)

作者： Young Kook Kim Dooyeol Koh Sang Hoon Lee Soohyun Kim Robotics Program Korea Advanced Institute of Science and Technology Daejeon South Korea Division of Mechanical Engineering School of Mechanical AeroSpace and Systems Engineering Korea Advanced Institute of Science and Technology Daejeon South Korea 5th Research and Development Institute-2 Agency for Defense Development Daejeon South Korea

ISBN: (纸本)9781457707223

SUGV(Small Unmanned Ground Vehicle) used for human rescue and military operation is need to overcome the environment that tough terrains such as a hole or high obstacles. As far as the survival of the vehicle and the preserving ability of the information in the vehicle are concerned, it is essential to have an approach for recognizing unattainable driving states. However, despite the fact that the study of obstacle avoidance and stabilization of SUGV is focused on, it is hardly found out ways of classifying unattainable driving states with the sensors mounted on the SUGV unit. In order to overcome the problem, this paper proposes a practical way for classifying SUGV Failure State(SFS) with the meaningful parameters by statistical method, response surface methodology(RSM).

关键词： Response surface methodology Equations Vehicles Mathematical model Robot sensing systems

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Hardware Particle Swarm Optimization with passive congregation for embedded applications

Hardware Particle Swarm Optimization with passive congregati...

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Southern Conference on programmable Logic

作者： Daniel M. Muñoz Carlos H. Llanos Leandro dos S. Coelho Mauricio Ayala-Rincón Department of Mechanical Engineering Automation and Control Group/GRACO University of Brasilia Brazil Industrial and Systems Engineering Graduate Program LAS/PPGPES Pontifical Catholic University of Paraná Curitiba Parana Brazil Department of Computer Science and Mathematics University of Brasilia Brazil

关键词： Hardware Computer architecture Software Field programmable gate arrays Benchmark testing Optimization Software algorithms

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Opposition-based shuffled PSO with passive congregation applied to FM matching synthesis

Opposition-based shuffled PSO with passive congregation appl...

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Congress on Evolutionary Computation

作者： Daniel M. Muñoz Carlos H. Llanos Leandro dos S. Coelho Mauricio Ayala-Rincón Department of Mechanical Engineering Automation and Control Group/GRACO University of Brasilia Brasilia Brazil Industrial and Systems Engineering Graduate Program LAS/PPGEPS Pontifical Catholic University of Paraná Curitiba Parana Brazil Department of Computer Science and Mathematics University of Brasilia Brasilia Brazil

关键词： Frequency modulation Optimization Equations Convergence Particle swarm optimization Genetic algorithms

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Finite-temperature elasticity of fcc Al: Atomistic simulations and ultrasonic measurements

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Physical Review B 2011年第6期84卷 064101-064101页

作者： Hieu H. Pham Michael E. Williams Patrick Mahaffey Miladin Radovic Raymundo Arroyave Tahir Cagin Department of Chemical Engineering Texas A&M University College Station TX 77843 USA Department of Mechanical Engineering Texas A&M University College Station TX 77843 USA Department of Industrial and Systems Engineering Texas A&M University College Station TX 77843 USA Materials Science and Engineering Program Texas A&M University College Station TX 77843 USA

Though not very often, there are some cases in the literature where discrepancies exist in the temperature dependence of elastic constants of materials. A particular example of this case is the behavior of C12 coefficient of a simple metal, aluminum. In this paper we attempt to provide insight into various contributions to temperature dependence in elastic properties by investigating the thermoelastic properties of fcc aluminum as a function of temperature through the use of two computational techniques and experiments. First, ab initio calculations based on density functional theory (DFT) are used in combination with quasiharmonic theory to calculate the elastic constants at finite temperatures through a strain-free energy approach. Molecular dynamics (MD) calculations using tight-binding potentials are then used to extract the elastic constants through a fluctuation-based formalism. Through this dynamic approach, the different contributions (Born, kinetic, and stress fluctuations) to the elastic constants are isolated and the underlying physical basis for the observed thermally induced softening is elucidated. The two approaches are then used to shed light on the relatively large discrepancies in the reported temperature dependence of the elastic constants of fcc aluminum. Finally, the polycrystalline elastic constants (and their temperature dependence) of fcc aluminum are determined using resonant ultrasound spectroscopy (RUS) and compared to previously published data as well as the atomistic calculations performed in this work.

关键词： THERMOELASTICITY DENSITY functionals MOLECULAR dynamics FLUCTUATIONS (Physics) POLYCRYSTALLINE semiconductors

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Potential of SERS for rapid detection of melamine and cyanuric acid extracted from milk

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Sensing and Instrumentation for Food Quality and Safety 2010年第1期4卷 13-19页

作者： Liu, Bin Lin, Mengshi Li, Hao Food Science Program Division of Food Systems and Bioengineering University of Missouri Columbia MO 65211 United States Department of Mechanical and Aerospace Engineering University of Missouri Columbia MO 65211 United States

Melamine, a nitrogen-rich chemical, was implicated in the pet and human food recalls in 2007 and in the global food safety scares in 2008 involving milk and other milk-derived products. In this study, we investigated the feasibility of using surface-enhanced Raman spectroscopy (SERS) coupled with SERS-active gold substrates for rapid detection of trace amounts of melamine and its analogue (that is, cyanuric acid) in liquid milk. Raman signals of tested samples were significantly enhanced by SERS. The identification limit for SERS using gold substrate can reach 2 ppm of melamine in liquid milk. Partial least squares (PLS) models were established for the quantification of melamine in liquid milk by SERS: R = 0.90, RMSEP = 1.48 × 10-5. Our results demonstrate that rapid detection of melamine in milk can be achieved by SERS;while detection of cyanuric acid in milk remains a challenging task due to rapid enol-keto tautomerism of cyanuric acid. The SERS method is faster and simpler than other traditional methods, and requires minimum sample preparation. These results demonstrate that SERS could be used to detect food contaminants such as melamine in foods and food ingredients quickly and accurately. © 2009 Springer science+Business Media, LLC.

关键词： Substrates

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Experimental study for reducing tip noise generated from trailing-Edge flap of a supersonic configuration

Experimental study for reducing tip noise generated from tra...

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2010 Asia-Pacific International Symposium on Aerospace Technology, APISAT 2010

作者： Zhong, Lei Hiroki, Ura Masayoshi, Noguchi Department of Mechanical Systems Engineering Tokyo University of Science Suwa Nagano-ken Japan Aviation Program Group Japan Aerospace Exploration Agency Tokyo Japan

ISBN: (纸本)9787561228999

Noise reduction is an import problem to realize the next generation supersonic transport to achieve environmentally acceptable noise level at take-off and landing. The objective of this study is to reduce the flap tip noise by extending trailing-edge flap in spanwise. Noise measurement was conducted to investigate effects of flap tip devices on noise reduction for a supersonic civil transport configuration. Noise sources of airframe noise were identified by using a phased-array microphone measurement system, and it showed that the airframe noise mainly contributed from tips of the leading-edge and trailing-edge flaps. Results showed that noise levels were reduced by flap tip devices, and effects of noise reduction were confirmed.

关键词： Aerodynamics Flap Noise Supersonic transport

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Study of Integral Variable Structure Control Method for Stability of SI Engine Idling Speed

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Journal of Software Engineering and Applications 2010年第8期3卷 813-819页

作者： Yang Zhang Nobuo Kurihara Science Program in Mechanical Systems Hachinohe Institute of Technology Graduate School of Engineering Hachinohe Institute of Technology

The intake air control system of a gasoline engine is a typical nonlinear system, and included among the adverse fac-tors that always induce poor idle-speed control stability are dead time and disturbances in the intake air control process. In this paper, to improve the responsiveness when idling with regard to disturbances, a mean-value engine model (MVEM) with dead time was constructed as the control object, and the two servo structures of sliding mode control (SMC) were studied for better idle control performance, especially in transient process of speed change. The simulation results confirmed that under the constraint condition of control input, the robustness of idle speed control that is being subjected to torque disturbances and noise disturbances can be greatly improved by use of the servo structure II.

关键词： SI Engine Idle Speed Control Variable Structure Integral Sliding Mode Control Simulation

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