• Title/Summary/Keyword: multi-physics

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A Method to Destripe Imaging Spectroradiometer Data of SZ-3

  • Xiaoxiang, Zhu;Tianxi, Fan;Qian, Huang
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.1278-1280
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    • 2003
  • Striping is a main factor for imaging spectroradiometer data, which is obtained by multi-sensor scanning on spacecraft. The reason causing stripes and the development of striping removal methods are simply described in this paper, particularly, the principle of Matching Empirical Distribution Functions is introduced in detail. By using this method, some experiments are done to destripe imaging spectrometer data of SZ-3. The result shows that the method of Matching Empirical Distribution Functions is available for destirping Imaging spectroradiometer data of SZ-3, and the quality of image is improved obviously. This will help to process the future similar instruments data.

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DSSC광전극의 나노구조 제어 및 투명전극 소재 개발

  • Jung, Hyun-Suk
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.28-28
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    • 2010
  • Photoelectrochemical solar cells such as dye-sensitized cells (DSSCs), which exhibit high performance and are cost-effective, provide an alternative to conventional p-n junction photovoltaic devices. However, the efficiency of such cells plateaus at 11-12%, in contrast to their theoretical value of 33%. Improvements in efficiency can only occur through a fundamental understanding of the underlying physics, materials, and device designs of DSSCs. A photoelectrode consisting of semiconducting oxide nanoparticles and a transparent conducting oxide electrode (TCO) is a key component of DSSC and design of photoelectrode materials is one of promising strategies to improving energy conversion efficiency. We introduce monodisperesed $TiO_2$ nanoparticles prepared by forced hydrolysis method and their superiority as photoelectrode materials was characterized with aids of optical and electrochemical analysis. Multi-layered TCO materials are also introduced and their feasibility for use as photoelectrodes is discussed in terms of optical absorption and charge collecting properties.

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CFD/CAE Analysis of QC/DC Bellows for LNG Bunkering (LNG 벙커링용 QC/DC 밸로즈의 유동/구조 해석)

  • Jang, Sung-Cheol;Eom, Jeong-Pil;Jung, Hyun-Cheol
    • Journal of the Korean Society of Industry Convergence
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    • v.21 no.5
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    • pp.191-195
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    • 2018
  • By using an ANSYS product suite (CFX, Ansys Multiphysics), which is a powerful tool for multiphysics analysis of complicated physical phenomena, we performed a structural stress analysis based on fluid flow and heat transfer phenomena within a quick connect/disconnect (QC/DC) bellows system. Considering the extremely low temperatures in the QC/DC environment, an approach to the problem based on complex multi-physics phenomena, where different phenomena interact with each other, is crucial. Therefore, we use a numerical analysis technique where fluid-thermal-structural interactions are combined. In conclusion, when low temperature fluids flow inside bellows, the expected service life is conspicuously reduced due to the thermal stress caused by heat transfer. Therefore, in future research, a structure with considerably reduced thermal stress by robust design optimization will be derived.

Block Sparse Signals Recovery Algorithm for Distributed Compressed Sensing Reconstruction

  • Chen, Xingyi;Zhang, Yujie;Qi, Rui
    • Journal of Information Processing Systems
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    • v.15 no.2
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    • pp.410-421
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    • 2019
  • Distributed compressed sensing (DCS) states that we can recover the sparse signals from very few linear measurements. Various studies about DCS have been carried out recently. In many practical applications, there is no prior information except for standard sparsity on signals. The typical example is the sparse signals have block-sparse structures whose non-zero coefficients occurring in clusters, while the cluster pattern is usually unavailable as the prior information. To discuss this issue, a new algorithm, called backtracking-based adaptive orthogonal matching pursuit for block distributed compressed sensing (DCSBBAOMP), is proposed. In contrast to existing block methods which consider the single-channel signal reconstruction, the DCSBBAOMP resorts to the multi-channel signals reconstruction. Moreover, this algorithm is an iterative approach, which consists of forward selection and backward removal stages in each iteration. An advantage of this method is that perfect reconstruction performance can be achieved without prior information on the block-sparsity structure. Numerical experiments are provided to illustrate the desirable performance of the proposed method.

Approach to food taste with meta food physics (식품의 맛에 대한 초식품물리학적 해석)

  • Chun, Jae Kun
    • Food Science and Industry
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    • v.51 no.1
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    • pp.61-71
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    • 2018
  • The evaluation of food taste is one of the important activities of human consciousness and it is practiced by sensory analysis using 5 terminal sensorial consciousness among many other functions. These consciousness activities may be conducted by 3 way branching transformation (3-WBT) logic, which choose one out of 3 options under the multi-layered consciousness decision making system. On the basis of this logic, cognitive sensory evaluation (CSE) method was developed to carry out questionnaire survey covering objective and subjective issues during consumption of food for pregnant women. The results of the CSE for several food items was presented with the Table-pattern called CSET covering consciousness factors and their effects on the food consumers.

Silyl-group functionalized organic additive for high voltage Ni-rich cathode material

  • Jang, Seol Heui;Jung, Kwangeun;Yim, Taeeun
    • Current Applied Physics
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    • v.18 no.11
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    • pp.1345-1351
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    • 2018
  • To allow stable cycling of layered nickel-rich cathode material at high voltage, silyl-functionalized dimethoxydimethylsilane is proposed as a multi-functional additive. In contrast to typical functional additive, dimethoxydimethylsilane does not make artificial cathode-electrolyte interfaces by electrochemical oxidation because it is quite stable under anodic polarization. We find that dimethoxydimethylsilane mainly focuses on scavenging nucleophilic fluoride species that can be produced by electrolyte decomposition during cycling, leading to improving interfacial stability of both nickel-rich cathode and graphite anode. As a result, the cell cycled with dimethoxydimethylsilane-controlled electrolyte exhibits 65.7% of retention after 100 cycle, which is identified by systematic spectroscopic analyses for the cycled cell.

Development of a Multi-Physics Model of Polymer Electrolyte Membrane Fuel Cell Using Aspen Custom Modeler (Aspen Custom Modeler를 이용한 고분자전해질 연료전지 다중 물리 모델 개발)

  • SON, HYEYOUNG;HAN, JAESU;YU, SANGSEOK
    • Transactions of the Korean hydrogen and new energy society
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    • v.32 no.6
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    • pp.489-496
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    • 2021
  • The performandce of polymer electrolyte membrane fuel cell depends on the effective management of heat and product water by the electrochemical reaction. This study is designed to investigate the parametric change of heat management along the channel of polymer electrolyte membrane. The model was developed by an aspen custom modeler that it can solve differential equation with distretization model. The model can simulate water transport through the membrane electrolyte that is coupled with heat generation. In order to verify the model, it is compared with the experimental data. The water transport behavior is then evaluated with the simulation model.

Application of multi-physics simulation for vibration performance of the hand after contacting the ball with the volleyball player

  • Wang, Yangping;Sun, Shuze
    • Structural Engineering and Mechanics
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    • v.83 no.5
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    • pp.681-692
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    • 2022
  • The vibrational response of the two bones in a Volleyball player's arm under ball impact is conducted. The two bones in hand, Ulna and Radius, are modeled as two cylindrical shells. The formulations associated with the shells' vibration are obtained using the energy method. Then, the results are extracted with the aid of the two-dimensional form of DQM in conjunction with Runge-Kutta. The results are validated by means of a published paper. Lastly, the role of parameters in determining vibrational frequency as well as deflection is explored through parametric studies. It was shown that the impactor speed and the time of the impact could be essential factors in determining the vibration behavior of the bones. This work can be used in the further investigation of the behavior of bones and physiological structures.

Introduction of Handhold FFT Analyzer, Vibration Measuring Instrument of Environment and Habitability on Ship, Multi Purpose Sound Level Meter on Rion Co., Ltd.(Japan) (일본 Rion 사의 휴대용 FFT 분석기, 선박 및 환경 진동계 및 휴대용 다용도 소음계의 소개)

    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.05a
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    • pp.1037-1040
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    • 2004
  • Sound and vibrations enter every aspect of our daily lives. Some, like music and verbal communications, soothe and relax us; others, such as the noise and vibration from traffic or machinery, can threaten our well being. The Rion Co., Ltd. was eslablished in 1944 as an affiliate of physics and acoustic pioneer, Kobayashi Institute of Physical Research. The RION lineup affords a full line of easy-to handle measuring, recording, and analyzing equipment with innumerable applications for monitoring and maintaining a comfortable environment. RION's concern takes in all manner of sound and vibration. Our activities extend from measuring reverberation time in concert halls and testing the soundproofing characteristics of housing materials to the control and maintenance of machine noise and vibration levels.

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