• Title/Summary/Keyword: Simultaneous Model

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Combined Bed Combustion and Gas Flow Simulation for a Grate Type Incinerator (폐기물 층 연소와 노내 유동 해석)

  • Ryu, Chang-Kook;Shin, Dong-Hoon;Choi, Sang-Min
    • 한국연소학회:학술대회논문집
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    • 2000.05a
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    • pp.67-75
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    • 2000
  • Computational fluid dynamics(CFD) analysis of the thermal flow in a municipal solid waste(MSW) incinerator combustion chamber provides crucial insight on the incinerator performance. However, the combustion of the waste bed is typically treated as an arbitrarily selected profile of combustion gas. A strategy for simultaneous simulation of the waste bed combustion and the thermal flow fields in the furnace chamber was introduced to substitute the simple inlet condition. A waste bed combustion model was constructed to predict the progress of combustion in the bed and corresponding generation of the gas phase species, which assumes the moving bed as a packed bed of homogeneous fuel particles. When coupled with CFD, it provides boundary conditions such as gas temperature and species distribution over the grate, and receives radiative heat flux from CFD. The combined simulation successfully predicted the physical processes of the waste bed combustion and its interaction with the flow fields for various design and operating parameters, which was limited in the previous CFD simulations.

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The Effect of Factors in The Concurrent Engineering on the Efficiency of the Product Development Processes (동시공학의 제 요인들이 제품개발의 효율성에 미치는 영향)

  • 손달호
    • Journal of the Korean Operations Research and Management Science Society
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    • v.21 no.3
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    • pp.89-108
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    • 1996
  • During the whole product design and development processes, the concurrent engineering relies on strong and permanent interactions between the departmental functions. Concurrent or simultaneous engineering in new product development is a new concept which needs to be redefined. This paper deals with a concurrent engineering model which represents how concurrency, as an organizational process, is related to a interfunctional project team. Four dimensions shaping the sucess of the concurrent engineering are suggested with detailed meausrement instruments. Moreover, an empirical study on the effects of the four dimensions on the efficiency of the product development processes is carried out in the field of electronic industries.

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Performance Analysis of Reed-Solomon Coded DS/CDMA System in Mixed Fading Channel (혼합 페이딩 채널에서 Reed-Solomon 부호화된 DS/CDMA 시스템의 성능 분석)

  • 노재성;조성언;조성준
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.6 no.4
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    • pp.544-551
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    • 2002
  • In this paper, BER performance of DS/CDMA-BPSK system is analyzed in mixed lading channel that is consist of Rayleigh fadins Rician fading, and shadowed Rician fading. From the results, we know that proposed mixed fading model is very suitable to describe the different channel situations. and, the occupancy probability and the shadowing depth are very dependent to the system performance. Finally, we know that the Reed-Solomon coded DS/ CDMA-BPSK system is very robust to simultaneous user interference and mixed lading channel.

A Proposed Model for Prosowing Seed Treatments to Promote Germination and Seedling Emergence (발아 및 입묘율 향상을 위한 파종전 종자처리 모형설정에 대한 제언)

  • Kang, Jin-Ho;Yoon, Soo-Young
    • Korean Journal of Medicinal Crop Science
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    • v.11 no.5
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    • pp.321-328
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    • 2003
  • Various presowing seed treatments have been used to enhance the rates of germination and afterward seedling emergence. Seeds treated by them occasionally have not shown the same rate in indoor and field. The presowing treatments considering germination mechanism and factors affecting germination should be totally included in indoor experiments so that the results drawn could be reproduced in the field. Seed drying after the treatments and field conditions after sowing especially able to show Phytochromemediated responses related to light treatment must be determined prior to force the treatments to seeds. After set up these prerequisites to promote the rates of germination and emergence, many seed treatments proposed so far must be fixed how to be done; alone, sequential and simultaneous.

Numerical Study of Snowfall Mechanism arounf Seoul Region

  • Kang, Sung-Dae
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • v.10 no.S_1
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    • pp.29-33
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    • 2001
  • A numerical simulation was carried out to investigate the mechanism of snowfall around the Seoul region during a cold air-outbreak in the winter season. A particular case was selected for this study(Dec. 19, 1999). The inflow directions of the synoptic flow in the upper and lower levels were westerly and north-westerly, respectively. Plus, there was a deep trough and thermal ridge at a level of 500/700/850 hPa over the Bal-Hae region, in the northern part of the Korean peninsula. According to the model results, snowfall occurred around the Seoul region with the simultaneous existence of a strong static instability in the lower atmosphere, northerly or westerly dry air advection, and strong thermal advection toward the Seoul region. There was a strong convergence thereby indicating the existence of convective rolls in the clouds. The main energy source of convection over the Yellow sea was a sensible heat flux. The main moisture source was convection. Radiative cooling in the cloud layer intensified the static instability in the lower atmosphere.

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Determination of Required Cover Depth of Concrete Exposed to Simultaneous Attack of Carbonation and Chloride Ion (중성화와 염소이온의 동시 복합환경에 노출된 콘크리트의 적정 피복두께의 결정)

  • 이창수;윤인석;이규동
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.11a
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    • pp.90-93
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    • 2003
  • The most common deteriorating processes of concrete structures in the world-wide are carbonation and chloride ion. In this paper, chloride profiles of carbonated concrete is predicted to considering two layer composite model, which is based on Fick's 2nd law. From the experimental result on combined deterioration of chloride and carbonation, it was examined that high chloride concentration was built up to 3-5㎜ over depth from carbonation depth. The analytical modeling of chloride diffusion, which was based on the Fick's 2nd law of diffusion, was suggested to depict the relative influence of the carbonation depth.

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OBSERVATIONAL STUDIES OF MAGNETICALLY ACTIVE STARS

  • BUDDlNG E.;ALLEN D.;CRAWFORD D. L.;JONES K. M.;SLEE O. B.;ZEILIK M.
    • Journal of The Korean Astronomical Society
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    • v.29 no.spc1
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    • pp.205-208
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    • 1996
  • Multi-wavelength observing has been particularly fruitful in cool star research. There have been some well-observed examples, eg AB Dor, though ambiguity remains. This raises issues of data information content and model parameter determinacy, which are examined firstly in an optical context. We then widen the discussion to show how multi-site and multi-wavelength data can be combined to point to better constrained models. Particular cases, involving near-simultaneous radiometry and photometry, are discussed to clarify such modelling.

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1,8-cineole protected human lipoproteins from modification by oxidation and glycation and exhibited serum lipid-lowering and anti-inflammatory activity in zebrafish

  • Cho, Kyung-Hyun
    • BMB Reports
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    • v.45 no.10
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    • pp.565-570
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    • 2012
  • We recently reported that a water extract of laurel or turmeric, 1,8-cineole enriched fractions, showed hypolipidemic activity in the zebrafish model. Therefore, the present study investigated the cineole's anti-oxidant and anti-inflammatory activities in lipoprotein metabolism in vitro and in vivo. Cineole had inhibitory effects on cupric ion-mediated oxidation of lipoproteins in general, while simultaneously enhancing ferric ion removal ability in high-density lipoprotein (HDL). Hypercholesterolemia was induced in zebrafish using cholesterol-feeding treatment, 4% cholesterol, for 3 weeks. After feeding with or without the addition of cineole, the results revealed that cineole possessed lipid-lowering and anti-inflammatory activities in hypercholesterolemic zebrafish. In addition, serum amyloid A and interleukin-6 levels were lowered and lipid accumulation was decreased in the liver. Conclusively, 1,8-cineole was found to have anti-oxidant activities in lipoprotein metabolism both in vitro and in vivo with simultaneous reduction of lipid accumulation in the liver of zebrafish.

An Effective Method for the Nesting on Several Irregular Raw Sheets (임의 형상의 여러 원자재 위에서의 효과적인 배치방안)

  • 조경호;이건우
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.8
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    • pp.1854-1868
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    • 1995
  • An effective nesting algorithm has been proposed to allocate the arbitrary shapes on one or several raw sheets by applying the well-known simulated annealing algorithm as the optimization technique. In this approach, both the shapes to be allocated and the raw sheets are represented as the grid-based models. This algorithm can accommodate every possible situations encountered in cutting apparel parts from the raw leather sheets. In other words, the usage of the internal hole of a shape for other small shapes, handling of the irregular boundaries and the interior defects of the raw sheets, and the simultaneous allocation on more than one raw sheets have been tackled on successfully in this study. Several computational experiments are presented to verify the robustness of the proposed algorithm.

Fast Speaker Adaptation in Noisy Environment using Environment Clustering (잡음 환경하에서 환경 군집화를 이용한 고속화자 적응)

  • Kim, Young-Kuk;Song, Hwa-Jeon;Kim, Hyung-Soon
    • Proceedings of the KSPS conference
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    • 2007.05a
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    • pp.33-36
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    • 2007
  • In this paper, we investigate a fast speaker adaptation method based on eigenvoice in several noisy environments. In order to overcome its weakness against noise, we propose a noisy environment clustering method which divides the noisy adaptation utterances into utterance groups with similar environments by the vector quantization based clustering using a cepstral mean as a feature vector. Then each utterance group is used for adaptation to make an environment dependent model. According to our experiment, we obtained 19-37 % relative improvement in error rate compared with the simultaneous speaker adaptation and environmental compensation method

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