• 한국축산식품학회지
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• 제44권1호
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• pp.87-102
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• 2024

This study aims to compare the chemical composition, quality, and muscle fiber characteristics of cull sows and commercial pigs, investigating the effect of changes in muscle fiber characteristics on pork quality. The proximate composition, color, pH, water-holding capacity (drip loss and cooking loss), protein solubility, total collagen content, and muscle fiber characteristics of cull sows (n=20) and commercial pigs (n=20) pork were compared. No significant differences were found between cull sows and commercial pigs in terms of proximate composition, drip loss, protein solubility, or total collagen content of their meat (p<0.05). However, cull sow pork exhibited a red color and a higher pH (p<0.05). This appears to be the result of changes in muscle fiber number and area composition (p<0.05). Cull sow meat also displayed better water-holding capacity as evident in a smaller cooking loss (p<0.05), which may be related to an increase in muscle fiber cross-sectional area (p<0.05). In conclusion, muscle fiber composition influences the pork quality; cull sow pork retains more moisture when cooked, resulting in minimal physical loss during processing and can offer more processing suitability.

• 가정과삶의질연구
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• 제20권4호
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• pp.149-164
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• 2002

The purpose of this study was to identify the types of social networks of urban housewives according to different network composition patterns and to analyze the structural and functional characteristics of identified types. The data used in this study were collected from 589 full-time housewives residing in Taejeon city. The major findings are as follows: 1) The social networks of housewives in urban nuclear families were classified into eight types: the kin network, the non-kin network, the kin-centered network, the friend-centered network, the neighbor-centered network, the associate-centered network, the parallel network, and the decentralized network. 2) The structual characteristics (size, density, homogeneity, duration, proximity, frequency, closeness, direction) varied according to the type. The kin network type and the non-kin network type showed extreme degrees in network characteristics. The parallel network type and the decentralized network type showed an average level of network characteristics. The kin-, friend-, neighbor-, and the associate-centered types showed network characteristics of an intermediate level between the single-category types and the decentralized type. 3) The average levels of function of social network types were different in only two(service support, interference) of the six function areas(emotional support, service support, material support, information support, social companionship support, interference). The average level of service support by the non-kin network type was higher than other types. The average level of interference by the kin-centered network type was higher than other types, and that of the neighbor-centered network type was lower than other types. On the other hand, the total amount of function performance of social network types was different in all function areas. The total amount of social support given by the decentralized network type was greater than the other types. The total amount of interference given by the non-kin network type was smaller than the other types.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제51권3호
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• pp.134-140
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• 2002

Deep submicron NMOSFETs with elevated source/drain can be fabricated using self-aligned selective epitaxial growth(SEG) of silicon for enhanced device characteristics with shallow junction compared to conventional MOSFETs. Shallow junctions, especially with the heartily-doped S/D residing in the elevated layer, give hotter immunity to Yt roll off, drain-induced-barrier-lowering (DIBL), subthreshold swing (SS), punch-through, and hot carrier effects. In this paper, the characteristics of both deep submicron elevated source/drain NMOSFETs and conventional NMOSFETs were investigated by using TSUPREM-4 and MEDICI simulators, and then the results were compared. It was observed from the simulation results that deep submicron elevated S/D NMOSFETs having shallower junction depth resulted in reduced short channel effects, such as DIBL, SS, and hot carrier effects than conventional NMOSFETs. The saturation current, Idsat, of the elevated S/D NMOSFETs was higher than conventional NMOSFETs with identical device dimensions due to smaller sheet resistance in source/drain regions. However, the gate-to-drain capacitance increased in the elevated S/D MOSFETs compared with the conventional NMOSFETs because of increasing overlap area. Therefore, it is concluded that elevated S/D MOSFETs may result in better device characteristics including current drivability than conventional NMOSFETs, but there exists trade-off between device characteristics and fate-to-drain capacitance.

• 대한기계학회논문집B
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• 제21권2호
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• pp.213-223
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• 1997

Premixed flame is better than diffusion flame to accomplish a high loading combustion. Since the turbulent characteristics of unburned mixture has a great influence on the flame structure, it is general that many researchers realize a high loading combustion with strengthening turbulent intensity of unburned mixture. Because turbulent premixed flame reacts efficiently on the condition of distributed reaction region, we made high turbulent premixed flame in the doubled impingement field. We investigated turbulent characteristics of unburned mixture with increasing shear force and visualized flames with direct and Schlieren photographs. And the combustion characteristics of flame was elucidated by instantaneous temperature measurement with a thermocouple, by ion currents with a micro electrostatic probe, by radical luminescence intensity and local equivalence ratio. Extremely strong turbulent of small scale is generated by impingement of mixture, and turbulent intensity of unburned mixture increased with the mean velocity. As a result of direct photographs, visible region of flame became longer due to increasing central direction flux. But as strengthed turbulent intensity, visible region of flame turned to shorter and reaction occurred efficiently. As strengthened turbulent intensity of mixture with increasing flux of central direction, maximum fluctuating temperature region moved to radial direction and fluctuation of temperature became lower. The reason is influx of central direction which caused flame zone to move toward radial direction, to maintain flame zone stable and to make flame scale smaller.

• 물과 미래
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• 제26권3호
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• pp.137-148
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• 1993

종확산 방정식에 대한 유한차분 모형으로서, 5차의 보간다항식을 사용한 Holly-Preissmann 기법과 Generalized Crank-Nicholson 기법을 결합한 혼합모형을 개발하였다. 순간적으로 부하된 오염원의 종확산문제에 본 모형 및 특성곡선을 고려한 다른 수치기법들을 적용하여 정확해와 비교하였다. 보 모형에 의한 계산결과, Courant 수에 관계없이 수치진동이 전혀 발생하지 않았으며, 최대농도 발생지점도 정확해와 일치하였다. 모형의 적용에 있어서 시간가중치 $\theta$의 값이 작을수록 계산의 정확성이 전반적으로 향상되는 것으로 나타났으며, $\theta$의 값을 크게 할수록 최대농도값을 과대평가하는 경향을 보였다. 전반적으로 Courant 수가 작을수록 정확한 계산결과를 나타내고 있으나 그 민감도는, 특히 $\theta$의 값이 작을수록, 매우 작게 나타났다. 3차의 보간다항식을 사용하는 혼합모형 및 연산자 분리방법들과의 비교결과, 이송항이 지배적일수록 본 모형이 정확해와 가장 근사한 계산결과를 보임을 알 수 있었다.

• 터널과지하공간
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• 제25권6호
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• pp.543-555
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• 2015

최근 대단면 갱도로 개발하고 있는 국내 석회석광산은 작업공간 환기를 위하여 과거 석탄광산에 광범위하게 사용되던 형태의 국부 선풍기를 주로 이용하고 있다. 대단면 갱도에서의 낮은 정압손실을 고려할 때 고풍압 선풍기는 과다 설비용량으로 인하여 비용측면에서 심각한 한계를 보이고 있다. 대단면 갱도에서의 최적 선풍기는 안전한 작업환경 유지를 위한 충분한 환기량을 공급할 수 있어야 할 뿐만 아니라 저운전비용도 보장하여야 한다. 본 연구는 대단면 갱도 내에서 높은 환기효율과 경제성을 가지는 저풍압 국부선풍기를 개발함이 목적이다. 이론적 연구와 아울러 2개소의 단면적이 다른 현장 실험 연구를 통하여 저풍압 선풍기의 환기효율을 분석하였다. 본 연구결과는 작업공간 공기질 및 작업환경 개선을 위한 국부선풍기의 경제성과 효율 제고에 적용 가능할 것으로 기대된다.

• 한국분무공학회지
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• 제19권1호
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• pp.1-8
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• 2014

Liquefied petroleum gas (LPG) is regarded as an alternative fuel for spark ignition engine due to similar or even higher octane number. In addition, LPG has better fuel characteristics including high vaporization characteristic and low carbon/hydrogen ratio leading to a reduction in carbon dioxide emission. Recently, development of LPG direct injection system started to improve performance of vehicles fuelled with LPG. However, spray characteristics of LPG were not well understood, which is should be known to develop injector for LPG direct injection engines. In this study, effects of operation condition including ambient pressure, temperature, and injection pressure on spray properties of n-butane were evaluated and compared to gasoline in a multi-hole injector. As general characteristics of both fuels, spray penetration becomes smaller with an increase of ambient pressure as well as a reduction in the injection pressure. However, it is found that evaporation of n-butane was faster compared to gasoline under all experimental condition. As a result, spray penetration of n-butane was shorter than that of gasoline. This result was due to higher vapor pressure and lower boiling point of n-butane. On the other hand, spray angle of both fuels do not vary much except under high ambient temperature conditions. Furthermore, spray shape of n-butane spray becomes completely different from that of gasoline at high ambient temperature conditions due to flash boiling of n-butane.

• 한국전자파학회논문지
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• 제18권5호
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• pp.471-477
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• 2007

본 논문은 전자파 장해 및 복사 내성 측정의 대용 시험 시설로서 활용될 수 있는, 다중 유전체로 구성된 평탄형 QRD(Quadratic Residue Diffuser)를 사용한 전자파 잔향실에 대한 연구이다. 잔향실은 $2.5{\sim}3$ GHz 대역에서 사용 가능하도록 설계되었으며, 기존 QRD의 특성을, 다양한 유전체를 이용하여 낮은 평탄형 구조물로 구현하였고, 이를 적용한 전자파 잔향실 내부에서의 전자기장 특성 변화 및 시험 공간 확장에 관해서 비교 분석하였다. 잔향실 내부의 전자기장 분포 해석을 위해서 FDTD(Finite-Difference Time-Domain) 수치 해석 방식을 이용하였다. 잔향실 내에 새로 제안된 확산기를 사용하면, 기존 확산기에 비해 물리적인 크기가 줄어들 뿐만 아니라 전자기장 균일도, 편파 특성 및 공차 등의 성능이 비슷하거나 우수해짐을 확인하였다. 따라서 다중 유전체로 구성된 평탄형 확산기를 사용한 잔향실이 기존의 QRD를 사용한 잔향실에 비해 전자기적 성능 및 공간 활용면에서 우수한 시험시설임을 확인하였다.

• 복식
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• 제57권8호
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• pp.48-59
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• 2007

The purpose of this research is to develop a basic pattern of corset look taking into consideration characteristics of human body and fit, by transforming 3 dimensional information obtained from draping of standard body type of women in their 20s, which constitute the biggest consumer group of corset look in Korea, on the basis of body shape of women best reflecting 3 dimensional characteristics. In order to develop a corset look pattern suitable for standard body type of women in their 20s, wear tests of A, B, and C types of patterns in terms of the bust in the standard body type that bust circumference 86.7cm and chest circumference 87.0cm were evaluated best. Taking into consideration above findings, fer the purpose of developing a corset look pattern having an excellent fit and reflecting characteristics of Korean women in their 20s with standard body type, a corset look pattern was designed with proper ease calculated by draping incorporated, and through alteration and complementation of such a pattern, a study pattern was produced. This study is expected to provide tips for standard body type women in their 20s with smaller bust circumference to choose clothing allowing for a better fit able to make up for weakness of their body, while presenting to clothing makers ways of designing and size-setting in terms of characteristics of body type of these consumers.

• 한국운동역학회지
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• 제21권2호
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• pp.131-140
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• 2011

The purpose of this study was to evaluate the kinematic characteristics of 5th hurdle clearance during the 100m hurdle final competition at the 2010 Colorful DaeGu pre-championship meeting. This study was also intended to provide the technical data for better performance for preparing the 2011 world championship. Lee and Jung need to change technical movement by reducing the distance of the take-off point from the hurdle and by decreasing the vertical velocity of the C.G.(center of gravity) at the takeoff. Powell's angle of the take-off leg showed bigger at the touchdown and smaller at the takeoff comparing to Lee's and Jung's. Furthermore, Powell's horizontal velocity of the C.G. was maintained at the takeoff and touchdown. So, Lee and Jung need to change angle of the take-off leg the same as Powell's. Both Lee and Jung need to increase the angle of landing leg at the touchdown. In addition to increasing the angle Jung needs to improve the knee and ankle velocity with the hurdling leg.