• 제목/요약/키워드: Channel Variation

검색결과 800건 처리시간 0.032초

CONSIDERATIONS IN THE DEVELOPMENT OF FUTURE PIG BREEDING PROGRAM - REVIEW -

  • Haley, C.S.
    • Asian-Australasian Journal of Animal Sciences
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    • 제4권4호
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    • pp.305-328
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    • 1991
  • Pig breeding programs have been very successful in the improvement of animals by the simple expedient of focusing on a few traits of economic importance, particularly growth efficiency and leanness. Further reductions in leanness may become more difficult to achieve, due to reduced genetic variation, and less desirable, due to adverse correlated effects on meat and eating quality. Best linear unbiased prediction (BLUP) of breeding values makes possible the incorporation of data from many sources and increases the value of including traits such as sow performance in the breeding objective. Advances in technology, such as electronic animal identification, electronic feeders, improved ultrasonic scanners and automated data capture at slaughter houses, increase the number of sources of information that can be included in breeding value predictions. Breeding program structures will evolve to reflect these changes and a common structure is likely to be several or many breeding farms genetically linked by A.i., with data collected on a number of traits from many sources and integrated into a single breeding value prediction using BLUP. Future developments will include the production of a porcine gene map which may make it possible to identify genes controlling economically valuable traits, such as those for litter size in the Meishan, and introgress them into nucleus populations. Genes identified from the gene map or from other sources will provide insight into the genetic basis of performance and may provide the raw material from which transgenic programs will channel additional genetic variance into nucleus populations undergoing selection.

A Micro Mixer with Recirculation Zones (재순환 영역이 존재하는 마이크로 혼합기)

  • Lee, Jong-Kwang;Kim, Young-Dae;Choe, Jae-Hoon;Kwon, Se-Jin
    • Transactions of the Korean Society of Mechanical Engineers A
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    • 제30권12호
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    • pp.1642-1648
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    • 2006
  • This paper describes enhancement of the mixing efficiency of a multilamination micro mixer by adding a number of recirculation zones downstream of the mixing zone. Numerical simulation was employed to estimate the mixing efficiency and the pressure drop under various conditions. Numerical results indicated that recirculation micro mixer brought about not only the increase of the mixing efficiency but also the decrease of the pressure drop. Micro mixers were fabricated using photosensitive glass by anisotropic wet etching technique. The width and height of the micro channel were $150{\mu}m$ and $500{\mu}m$, respectively. The performance of micro mixer was measured using color intensity variation of the fluid. Except for extremely low Re below 40, the recirculation micro mixer of the present study showed improved mixing. And the enhancement of the mixing increased as Re rose. When Re increased beyond 400, more than 90% of the mixing was observed in the experiment.

Incorporating Fuzzy Inference into Watermarking in the Transform Domain (변환영역에서의 퍼지추론을 적용한 워터마킹)

  • Kim, Yoon-Ho
    • Journal of Advanced Navigation Technology
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    • 제10권4호
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    • pp.364-370
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    • 2006
  • In this paper, the decision method of optimal sub-band which is supposed to embedded watermark incorporating fuzzy inference into transform-based watermarking is proposed. After performing the DCT, maximum variation of human visual properties, such as text degree, contrast sensitivity function is calculated, and by using these, membership function is generated. After embedding the watermark to the selected bands obtained from fuzzy inference, performance of imperceptibility and robustness are evaluated. In order to testify the proposed scheme, such attacks as JPEG, filtering, cropping are utilized. and in addition, by using an AWGN channel of OFDM/QPSK system, PSNR as well as correlation are calculated, and finally evaluated the performance.

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On the Variation of the Boundary Layer as Hull Surface Roughness (선체 표면 거칠기가 경계층 변화에 미치는 영향)

  • Gim, Ok-Sok;Oh, Woo-Jun;Shon, Chang-Bae;Lee, Gyoung-Woo
    • Journal of Navigation and Port Research
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    • 제34권6호
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    • pp.429-434
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    • 2010
  • The experimental study of the hull surface roughness on a developing turbulent boundary layer which exposed to a variety of operating environments were investigated by performing particle image velocimetry(PIV) in a circulating water channel. The Reynolds number based on the width of roughness was about Re=1000. the roughness elements used were periodically arranged two-dimensionally. the flow visualization, time-mean velocity fields and vorticity fields to measure the flow characteristics were obtained. The investigation shows that the vortex generation and its progress inside the walls. And the center of the vortex was located at the middle of the height of the surface roughness.

LABELLING OF SOME PLANAR GRAPHS WITH A CONDITION AT DISTANCE TWO

  • Zhang, Sumei;Ma, Qiaoling
    • Journal of applied mathematics & informatics
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    • 제24권1_2호
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    • pp.421-426
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    • 2007
  • The problem of vertex labeling with a condition at distance two in a graph, is a variation of Hale's channel assignment problem, which was first explored by Griggs and Yeh. For positive integer $p{\geq}q$, the ${\lambda}_{p,q}$-number of graph G, denoted ${\lambda}(G;p,q)$, is the smallest span among all integer labellings of V(G) such that vertices at distance two receive labels which differ by at least q and adjacent vertices receive labels which differ by at least p. Van den Heuvel and McGuinness have proved that ${\lambda}(G;p,q){\leq}(4q-2){\Delta}+10p+38q-24$ for any planar graph G with maximum degree ${\Delta}$. In this paper, we studied the upper bound of ${\lambda}_{p,q}$-number of some planar graphs. It is proved that ${\lambda}(G;p,q){\leq}(2q-1){\Delta}+2(2p-1)$ if G is an outerplanar graph and ${\lambda}(G;p,q){\leq}(2q-1){\Delta}+6p-4q-1$ if G is a Halin graph.

Transient cooling experiments with a cooper block in a subcooled flow boiling system (과냉비등류에 있어서 동블록을 이용한 과도적 냉각실험)

  • 정대인;김경근;김명환
    • Journal of Advanced Marine Engineering and Technology
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    • 제11권1호
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    • pp.72-79
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    • 1987
  • When the wall temperature is very high, a stable vapor film covers the heat transfer surface. The vapor film creates a strong thermal resistance when heat is transferred to the liquid though it. This phenomenon, called "film boiling" is very important in the heat treatment of metals, the design of cryogenic heat exchangers, and the emergency cooling of nuclear reactors. In the practical engineering problems of the transient cooling process of a high temperature wall, the wall temperature history, the variation of the heat transfer coefficients, and the wall superheat at the rewetting points, are the main areas of concern. These three areas are influenced in a complex fashion such factors as the initial wall temperature, the physical properties of both the wall and the coolant, the fluid temperature, and the flow state. Therefore many kinds of specialized experiments are necessary in the creation of precise thermal design. The object of this study is to investigate the heat transfer characteristics in the transient cooling process of a high temperature wall. The slow transient cooling experiment was carried out with a copper block of high thermal capacity. The block was 240 mm high and 79 mm O.D.. The coolant flowed throuogh the center of a 10 mm diameter channel in the copper block. In the copper block, three sheathed thermocouples were placed in a line perpendicular to the flow. These thermocouples were used to take measurements of the temperature histories of the copper block.

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An experimental study on the effect of parameters for onset of nucleate boiling in concentric annuli flows (이중 동심관 유동에서 핵비등 시발점의 영향인자에 대한 실험적 연구)

  • Song, J.H.;Kim, K.C.;Lee, S.H.;Park, J.H.;Suk, H.C.
    • Proceedings of the KSME Conference
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    • 대한기계학회 2000년도 춘계학술대회논문집B
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    • pp.373-378
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    • 2000
  • An experimental investigation on the incipience of nucleate boiling in forced flow of water is performed as a verification and extension of previous analysis. The effects of the subcooling, Reynolds number and surface curvature on the onset of nucleate boiling(ONB) in a concentric annulus flow channel with smooth inner heating surface is investigated experimentaly. Through flow visualization, the boiling phenomenon was observed directly and the experimental results were examined to find ONB heat flux. The results show that the variation of heat flux at ONB is increased linearly as the Reynolds number and subcooling are increased. The effect of surface curvature is very great specially for a small radius when radius of the inner heating tube is increased, the heat flux at ONB is almost inversely increased for the range of this investigation. It is found that the effect of convex surface curvature on ONB heat flux is very significant for a small radius.

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Removal Rate and Non-Uniformity Characteristics of Oxide CMP (Chemical Mechanical polishing) (산화막 CMP의 연마율 및 비균일도 특성)

  • Jeong, So-Young;Park, Sung-Woo;Park, Chang-Jun;Lee, Kyoung-Jin;Kim, Ki-Wook;Kim, Chul-Bok;Kim, Sang-Yong;Seo, Yong-Jin
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 한국전기전자재료학회 2002년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 일렉트렛트 및 응용기술
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    • pp.223-227
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    • 2002
  • As the channel length of device shrinks below $0.13{\mu}m$, CMP(chemical mechanical polishing) process got into key process for global planarization in the chip manufacturing process. The removal rate and non-uniformity of the CMP characteristics occupy an important position to CMP process control. Especially, the post-CMP thickness variation depends on the device yield as well as the stability of subsequent process. In this paper, every wafer polished two times for the improvement of oxide CMP process characteristics. Then, we discussed the removal rate and non-uniformity characteristics of post-CMP process. As a result of CMP experiment, we have obtained within-wafer non-uniformity (WIWNU) below 4 [%], and wafer-to-wafer non-uniformity (WTWNU) within 3.5 [%]. It is very good result, because the reliable non-uniformity of CMP process is within 5 [%].

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Biological Effect and Chemical Composition Variation During Self-Fermentation of Stored Needle Extracts from Pinus densiflora Siebold & Zucc.

  • Paudyal, Dilli P.;Park, Ga-Young;Hwang, In-Deok;Kim, Dong-Woon;Cheong, Hyeon-Sook
    • Journal of Plant Biotechnology
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    • 제34권4호
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    • pp.313-322
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    • 2007
  • Extract of Japanese red pine needles has been used in Asia pacific regions since long periods believing its valuable properties as tonic and ability of curing diseases of unidentified symptoms. Some selective compounds present in the extract and their effects were analyzed. Carbohydrates and vitamin c were identified using HPLC; terpenoid compounds by GC-MS; anti-bacterial analysis by paper discs, plates count and gastrointestinal motility by whole cell patch clamp. The extract is a mixture of compounds therefore its diverse effect was expected. Self-fermentation in extract proceeds after spontaneous appearance of yeast strains without inoculation. Effects and composition of the extract vary with varying period of self-fermentation. Extract inhibits the growth of bacteria dose dependently exhibiting its antibacterial properties however effectiveness increases with increase in fermentation period. The extract also can modulate gastrointestinal motility in murine small intestine by modulating pace maker currents in ICC mediated through ATP sensitive potassium channel.

Influence of River Discharge Fluctuation and Tributary Mixing on Water Quality of Geum River, Korea (유량변화와 지류유입에 따른 금강의 수질 변화)

  • Shim, Moo Joon;Lee, Soo Hyung
    • Journal of Korean Society on Water Environment
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    • 제31권3호
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    • pp.313-318
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    • 2015
  • To study the influence of changes in river discharge on water quality of the main stem of the Geum River, we investigated variation of inflow load from tributaries with river discharge. We also studied the mixing behavior of pollutants during mixing of waters of the main stem and Gap Stream. For this study, we collected water quality data such as suspended solids (SS), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total organic carbon (TOC), total nitrogen (TN) and total phosphorus (TP) representing pre-monsoon, monsoon, and post-monsoon events of 2013 from a website of Water Information System. Based on inflow load, the Gap and Miho streams may be ones of tributaries which may largely influence water quality of main stem in upper river region. The Suksung and Nonsan Streams seemed to further affect water quality downstream. Results of modified EMMA indicated SS and TP may have another source(besides Gap Stream) at pre-monsoon, monsoon, and post-monsoon period. In contrast, TN and organic matter (BOD, COD, TOC) were conservative at pre-monsoon and post-monsoon. However, when river discharge increased, these pollutants may also came from unspecified non-point sources. Therefore, we need to attempt to find non-point sources for the pollutants in the main channel of upper Geum River region.