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World Congress on Intelligent Control and Automation (WCICA)

作者： Chaotao Liu Zushu Li Xiaohui Zeng Institute of Intelligent Automation Chongqing University Chongqing China School of Mechatronics and Automotive Engineering Chongqing Jiaotong University Chongqing China Institute of Artificial Intelligence System Chongqing Institute of Technology Chongqing China Chongqing Meida Base of Flowers and Plants Chongqing China

The main process in hydroponics plants cultivating is aquatic induction. Aquatic induction is the process of cultivating plants in the right artificial environment to induce aerenchyma formation, which can make plants be grown in water. With long-time practices and researches, rules and environment parameters for aquatic induction was summarized. And a set of fuzzy control system for hydroponics cultivating was developed. Making use of the experience from practices, a method was put forward to control dissolved oxygen, CO 2 and EC in some hydroponics cultivating greenhouses without oxygen detector, CO 2 detector and EC detector. The result of the system running shows that the system can achieve hydroponics cultivating without watchers.

关键词： Niobium Fuzzy control Detectors Automation Springs Artificial intelligence Intelligent control

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Vibration and buckling of a carbon nanotube inserted with a carbon chain

Vibration and buckling of a carbon nanotube inserted with a ...

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International Conference on (ICEPT) Electronic Packaging Technology

作者： Zhili Hu X.M. Guo Johan Liu Key Laboratory of Advanced Display and System Applications Ministry of Education & SMIT Center School of Mechatronics Engineering and Automation Shanghai University Shanghai China Shanghai Institute of Applied Mathematics and Mechanics Shanghai University China SMIT Center & Bionano Systems Laboratory Department of Microtechnology and Nanoscience Chalmers University of Technology Gothenburg Sweden

An elastic string-elastic shell model is developed to study vibration behaviors of a carbon nanowire. The present model predicts that non-coaxial vibration between the C-chain and the innermost tube does not occur due to negligible bending rigidity of the C-chain. In addition, it is found that the C-chain has most significant effect on the lowest frequency associated with radial vibration mode for circumferential wave-number 2 (n=2). In particular, the effect of the C-chain on axisymmetric radial breathing frequencies (n=0) predicted by the present model is found to be in reasonable agreement with known experimental and modeling results available in the literature.

关键词： Electron tubes Mathematical model Vibrations Equations Strain Carbon Force

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Numerical investigation on the effect of filler distribution on effective thermal conductivity of thermal interface material

Numerical investigation on the effect of filler distribution...

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International Conference on (ICEPT) Electronic Packaging Technology

作者： Cong Yue Yan Zhang Johan Liu Zhaonian Cheng Jing-yu Fan Key Laboratory of Advanced Display and System Applications Ministry of Education & SMIT Center School of Mechatronics Engineering and Automation Shanghai University Shanghai China SMIT Center & Bionano Systems Laboratory Department of Microtechnology and Nanoscience Chalmers University of Technology Gothenburg Sweden Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai China

Thermal interface materials have been widely adopted in the thermal management for electronics system. Most of the thermal interface materials are made of polymers with thermally conductive particles distributed inside to enhance the thermal conductivity. Thus it is essential to figure out the effective thermal conductivity of this composite material. In the present paper, a parameterized cubic cell model had been developed and implemented by the finite element method. The numerical simulations were carried out to investigate the effect of the filler distributions on the effective thermal conductivity of the thermal interface materials. The volume percentage loadings of the particles ranging from 13% to 74% had been considered, and different particle distribution patterns had also been analyzed. The simulation results were compared with the experimental data as well as other models. A fairly good agreement was obtained for the particle volume percentage loading under consideration, which verified the developed cubic cell model.

关键词： Thermal conductivity Conductivity Materials Mathematical model Electronic packaging thermal management Numerical models Finite element methods

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Multi-chip integrated high-power white LED device on the multi-layer ceramic substrate

Multi-chip integrated high-power white LED device on the mul...

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Electronic Components and Technology Conference (ECTC)

作者： Luqiao Yin Weiqiao Yang Yansheng Guo Kejun Ma Shuzhi Li Mingfa Chen Jia Li Jianhua Zhang School of Mechatronics and Automation Shanghai University Shanghai China Key Laboratory of Advanced Display and System Applications Ministry of Education Shanghai China Shanghai Research Center of Engineering and Technology for Semiconductor Lighting Shanghai China Rainbow Optoelectronics Material Shanghai Company Limited Shanghai China Microelectronics Technology Institute of East China Shanghai University Shanghai China

In order to solve the thermal issue and improve the thermal resistance of LED, a device with multi-chip packaged on multi-layer composite ceramic substrate is successfully packaged. The top layer of the substrate is low temperature co-fire ceramic (LTCC), while the base layer is aluminum nitride (AINx) ceramic. 18 chips(one watt) are used in the device, and all of them are simultaneously packaged on a composite ceramic substrate which is 55 mm in length and 20 mm in width. The 18 chips are designed into two rows, and three chips in series for six parallels. At the same time the same chips are packaged on aluminum (Al) substrate and alumina (AlOx) substrate. After wire bonding photoelectric parameters of the three package modules are tested, the results show that the properties of the AINx-based package has the best performances, the thermal resistance of the device is far smaller than the other devices packed on the Al substrate and the AlOx substrate. After phosphor coatings the AINx-based multi-layer ceramic substrate package has 896.1 lm (43.4 lm/W) loading 350 milliampere (mA) to each chip, and has 1081.3 lm (35.4 lm/W) loading 500 mA. The multi-chip module has little light degradation adding 500 mA to each chip after working in the room temperature for one afternoon. At last the module is simulated by ANSYS software, the highest junction temperature of the chips in the module is about 70.8degC when 1.8 watts electric power is loaded to each chip, this temperature is far lower than 125degC which will damage the chip, and he highest simulation temperature of the aluminum heat slug is about 39.3degC. The temperature of the aluminum heat slug is about 41.0degC which is tested by thermocouple in the experiments, and it is closely to the simulation temperature 39.3degC. At last the relationship between pn-junction temperature and thermal conductivity coefficient of the silver (Ag) paste , the relationship between pn-junction temperatures and convection coefficient ha

关键词： Light emitting diodes Ceramics Temperature Packaging Thermal resistance Thermal conductivity Testing Aluminum nitride Wire Bonding

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Study on lift-up speed of aerodynamic compliant foil thrust bearings

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Journal of Pharmaceutical Analysis 2007年第1期19卷 63-66,85页

作者：杨利花石建华刘恒虞烈 Mechatronics Engineering Depart ment of Lanzhou Jiaotong University Mechatronics and Information System Institute of Xi'an Jiaotong University

Objective The experimental study on the lift-up speed of a new kind of compliant aerodynamic foil thrust bearings was performed on the multifunctional test rig established for testing the performances of foil gas *** The lift-up speed of foil gas thrust bearing under given axial load was analyzed through the spectrum of axial displacement response in frequency *** The test results indicated that the difference in the spectrum of axial displacement responses before and after lifting up of the rotor was *** lifting up of the rotor,there were only larger components of rotation frequency and lower harmanic *** the rotor wasn't lift-up,there were also larger components of other frequencies in the *** So by analyzing the spectrum of axial displacement response,the results showed that the lift-up speed was about 1860rpm when the axial load was 31N.

关键词： foil gas thrust bearings frequency domain lift-up speed displacement response

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Effect of encapsulation on OLED characteristics with anisotropic conductive adhesive

Effect of encapsulation on OLED characteristics with anisotr...

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Electronics system-Integration Technology Conference, ESTC

作者： Yan Zhang Mans Andreasson Johan Liu Thorvald Andersson Hsuan-Yi Liao Itsuo Watanabe Key Laboratory of Advanced Display and System Applications Ministry of Education & SMIT Center School of Mechatronics Engineering and Automation Shanghai University Shanghai China Applied seminconductor Physics Department of Microtechnology and Nanoscience Chalmers University of Technology Gothenburg Sweden SMIT Center Bionano Systems Laboratory Department of Microtechnology and Nanoscience Chalmers University of Technology Gothenburg Sweden Advanced Interconnect Material Division Hitachi Chemical Company Limited Chikusei Ibaraki Japan

Organic light emitting devices (OLEDs) is one of the most potentially interesting display technologies in the flat panel display (FPD) field. This paper investigates the effects of OLED structures and a perimeter encapsulation to protect the OLED from atmospheric exposure. Firstly, the electric features of the OLED devices with and without a copper phtalocyanine layer were measured, and the one with the additional buffer layer showed a lower turn-on voltage. Then the OLED device sample was encapsulated with a glass cover bonded to the substrate with an adhesive matrix containing micro-particles. The samples were stored in ambient conditions, and the IV characteristics were studied with shelf-time as a parameter. The measurement results indicated that the encapsulation had a significant improvement on the device operation. After two weeks of storage the encapsulated samples showed less degradation and the current density at a given operating bias was about fifty percent higher than without encapsulation.

关键词： Encapsulation Organic light emitting diodes Anisotropic magnetoresistance Conductive adhesives Flat panel displays Protection Copper Atmospheric measurements Electric variables measurement Buffer layers

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Micro deformation of probe by polarized laser irradiation and its application to sub-micron positioning

Micro deformation of probe by polarized laser irradiation an...

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4th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2007

作者： Naruo, Naoki Kakuta, Akira Furukawa, Yuji Department of Mechanical System Engineering Tokyo University of Agriculture and Technology Japan Department of Human Mechatronics Systems Tokyo Metropolitan University Japan

Sub-micron expansion process of micro-bar such as probes has been observed when irradiated by a polarized Ultra Violet (UV) laser. Influences of laser polarization, laser fluence, micro-bar size, its crystallographic orientation and heat have been investigated. It could show that the expansion is not influenced by a thermal cause, rather, suggested that the cause comes from the change of crystal lattice distance.

关键词： Deformation

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VSPDT: An optimizer for single point diamond turning

VSPDT: An optimizer for single point diamond turning

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作者： Li, J.G. Lee, W.B. Cheung, C.F. To, S. Du, J.J. Yin, Z.Q. School of Mechatronics Engineering Harbin Institute of Technology Harbin 150001 China Dept. of Industrial and System Engineering Hong Kong Polytechnic University Hong Kong Hong Kong

Virtual manufacturing (VM), which primarily aimed at reducing the lead times to market and costs associated with new product development, offers various test-beds for the time-consuming and expensive physical experimentation. Since surface roughness and form accuracy play essential roles in the functional performance of the products machined with ultra-precision machining technology. An optimizer, VSPDT (virtual single point diamond turning) system was developed for the purpose of form error compensation and optimal cutting parameters selection. In this paper, the keys issues for developing VSPDT using virtual manufacturing technology were highlighted such as framework of system, virtual workpiece, virtual machining and inspection, etc. At the end of the paper, A VSPDT was developed and applied to predict and compensate the form error, select optimal cutting parameters by using a 2-axis CNC ultra-precision turning machine.

关键词： Diamond cutting tools

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Specification of shear zone characteristics in achieving desired residual stress profile

Specification of shear zone characteristics in achieving des...

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2007 ASME International Conference on Manufacturing Science and engineering

作者： Hanna, Carl R. Liang, Steven Y. Chao, Ru-Min George W. Woodruff School of Mechanical Engineering Georgia Institute of Technology Atlanta GA 30332-0405 United States Department of System and Naval Mechatronics Engineering National Cheng Kung University Tainan Taiwan

ISBN: (纸本)0791842908

Surface integrity of a machined component in meeting the demands of a specific application requirement is defined by several characteristics. The residual stress profile at the surface and sub-surface of the workpiece is often one of these characteristics as it carries a direct effect on the fatigue life of a machined component. Machined residual stress is difficult to predict since it is governed by less than predictable high stresses, temperature gradients, and phase transformation occurring during the cutting process. A significant amount of effort have been dedicated by researchers to predict residual stress in a workpiece using analytical, experimental, and numerical modeling methods. Nonetheless, no method is available that could express the cutting process parameters and tool geometry parameters as functions of machined residual stress profile to allow process planning in achieving desired residual stress profile. This paper presents a physics-based approach to predict the shear zone characteristics during an orthogonal cutting operation. Using machined residual stress requirement at the surface as an input, information such as the shear angle ,the shear stress in the shear zone, the depth of cut and consequently the cutting forces are obtained by inverse calculations procedure based on the rolling/sliding contact theory, the McDowell hybrid residual stress algorithm and the specific cutting energy. This work constitutes a basis for further design and optimization of process and tool geometry parameters in achieving a specified residual stress profile. Experimental data are presented to validate the developed model. Copyright © 2007 by ASME.

关键词： Process control

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A new topology for photovoltaic 4 series DC/DC converter with high efficiency under wide load range

A new topology for photovoltaic 4 series DC/DC converter wit...

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7th Internatonal Conference on Power Electronics, ICPE'07

作者： Lee, Jong Pil Min, Byung Duk Kim, Jeong Joong Ryul, Kang Yul Kim, Tae Jin Yoo, Dong Wook Song, Eui Ho Yoo, Ji N Power Conversion and System for RES Group Korea Electrotechnology Research Institute Changwon 641 -600 Korea Republic of School of Mechatronics Control and Instrumentation Engineering Changwon University Korea Republic of School of Electrical Engineering Korea University Korea Republic of

ISBN: (纸本)9781424418725

The paper proposes a new topology for photovoltaic dc/dc converter with high efficiency under wide input voltage range is proposed. Photovoltaic dc/dc is a very crucial part of power conditioning system(PCS). Considering that output characteristic of photovoltaic cell has wide voltage range, depending on the operating conditions of photovoltaic cell, the dc/dc converter also needs to have wide input voltage range to regulate the constant output voltage. In addition, a high rated voltage of power switch(MOSFET) for dc/dc converter is necessary in order to be compatible with the high maximum output voltage of photovoltaic cell's maximum output voltage. Also photovoltaic power conditioning system should have a high efficiency under operation condition. To satisfy PV PCS condition series connected non-isolated dc/dc converter topology is proposed. This paper examines the proposed topology employing four modules and shows that it dramatically enhances the energy efficiency from low load to high load condition by reducing the required power level for dc/dc converter by one-third of conventional dc/dc converter. A case of 25kW prototype as the PV dc/dc converter is introduced to experimentally verify the proposed topology. © 2008 IEEE.

关键词： Topology

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