• 설비공학논문집
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• 제11권4호
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• pp.511-517
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• 1999

Determining the simultaneous flow rate in any particular section of piping is the important step in order to determine the size of water supply piping. Now we are using the diversity curve of common water closet in order to determine the simultaneous flow rate of water supply piping, but there is a difference between a determined flow rate of general water closet and that of water closet for water saving. This study aims to find out the fixture unit of a flush valve type water closet for water saving in office building, and to determine the correlation between the fixture units and peak flow rates on the basis of the probability theory. A flush valve type water closet for water saving that have a 7.5 second duration of flush operation with an average design flow rate 72 $\ell$/fin was considered. Simulation results indicate that the number 5 is shown to be reasonable to the fixture unit of water closet for water saving. And the design can be undersized considerably with the revised diversity curves using modified fixture unit.

• Animal cells and systems
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• 제6권1호
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• pp.19-22
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• 2002

Life table studies were conducted in the laboratory for the eulophid gregarious pupal parasitoid, Tetrastichus sp., on Hyphantria cunea Drury at a constant temperature of 28.2$\pm$2$^{\circ}C$, 50-60% RH to evaluate their impact on the host and their potential biological control. Development of immature stage took 20.1$\pm$2.7 d: adult females lived for 23.2$\pm$2.2 (range, 16-27)d and produced a mean of 53.6$\pm$26.6 adult progeny per female, with a sex ratio of 1: 9.5 (M:F). The intrinsic rate of natural increase (r$_{m}$) was 0.178/ female/day; the net reproductive rate (R$_{o}$), 46.74; the capacity for increase (r$_{c}$) 0.177; the finite rate of increase (λ) 1.19/female/day; thus each female contributed 46.74 individuals to the population in a mean generation time of 21.6 d. Biological factors in determining the life history trait variation of the parasitoid were discussed.d.d.d.

• 대한수의학회지
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• 제28권2호
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• pp.271-277
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• 1988

In order to study the marked variation of red blood cell sedimentation rate in some species of animals, the packed cell volume, volume percentage of erythrocytes in whole blood, was reshuffled of 20%, 40% and 60% using heteroplasma of chicken and goat, and the red blood cell sedimentation rate was measured in Westergren tubes at $27{\pm}1^{\circ}C$ and $8{\pm}1^{\circ}C$. The results obtained were summarized as follows: 1. The values of packed cell volume(PCV) of goat and chicken were $40.7{\pm}4.1%$ and $30.2{\pm}2.2%$ respectively. 2. The sedimentation rates of reshuffled red blood cell were settled faster at lower PCV than higher PCV, i.${\acute{e}}$. there was a reverse relationship between the sedimention rate and PCV. 3. Red blood cells of chicken settled quickly, where as those of goat settled very slowly. Chicken red blood cell sedimented rapidly even in goat plasma, and goat red blood cell sedimented slowly in chicken plasma. These findings indicate that the plasma is not the only factor determining the rapid red blood cell sedimentation rate of chicken. 4. The sedimentation rate of reshuffled red blood cell of chicken and goat were accelerated at higher temperature than lower temperature.

• 대한기계학회논문집A
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• 제20권9호
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• pp.2792-2799
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• 1996

It was shown in the previous study that the numerically derived elastic work factor for CLS specimen was independent of fiber direction for a unidirectional case. Also, it was proposed the elastic work factor could be used to determine energy release rate from a single test record. In the present study, elastic work factor was derived from a simple beam theory to investigate its dependence on material property and geometric condition. Also, the elastic work factor of CLS specimen was applied experimentally to determine critical energy release rate in order to prove its validity determining critical energy release rate from a single specimen. For this purpose, critical energy release rate determined using the elastic work factor was compared with that determined by the compliance method. The results showed that while elastic work factor is affected by $t_2/t_1$ and $L_2/L_1$ it is independent of fiber angle for a unidirectional case. It was also found that critical energy release rates determined by both methods are comparable each other, thus elastic work factor approach can be used to determine energy release rate from a single test specimen.

• 한국작물학회지
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• 제44권2호
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• pp.102-105
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• 1999

Mineralization of organic N is an important factor in determining the appropriate rate of organic matter application to paddy fields. A kinetic analysis was conducted for nitrogen mineralization of rice, barley, Chinese milk Ovetch (Astragalus sinicus L.; MV) and narrow leaf vetch straw in paddy soil. Nitrogen immobilization occurred rapidly and its rate increased in straw with high C/N ratio. The amount of nitrogen mineralization was rapid in the first year of rice-vetch cropping system. The rate constant (K) depended on the C/N ratio of organic matter. Mineralization of straw increased at high temperature. The amount of available N increment resulted in fast mineralization of straw, especially in rice and barley straw. Chinese milk vetch had the greatest mineralization rate at all temperatures and fertilization levels followed by narrow-leaf vetch. However, rice and barley straws with high C/N ratio immobilized the soil N at the initial incubation duration. Chinese milk vetch or narrow leaf vetch was not effectively mineralized in mixed treatments with rice or barley straw. The mineralization rate of organic matter was mostly affected by the C/N ratio of straw and temperature of incubation. Organic matter with low C/N ratio should be recommended to avoid the immobilization of soil N and the increasing mineralization rate of straw.

• 설비공학논문집
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• 제23권11호
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• pp.747-753
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• 2011

The purpose of this study was to quantify the impact of the ventilation rate on heating and cooling energy consumption in a detached house. For it, a series of simulations for the application of the diverse ventilation rate (ACH) were computationally conducted for a prototypical detached residential building in the cold climate (Detroit, Michigan) and hot/humid climate (Miami, Florida) of USA. Analysis revealed that ventilation is a significant heat losing source in the cold climate; thus, the higher ventilation rate significantly increases the heating energy consumption and energy cost in the cold climate; while the impact on energy increase for heating and cooling energy consumption is similar in hot/humid climate with less significancy compared to cold climate. The research outcome of this study could be a fundamental data for determining the optimal ventilation rate in terms of indoor air quality, but also building energy performance well.

• 한국시뮬레이션학회논문지
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• 제13권1호
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• pp.41-50
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• 2004

The purpose of this paper is to analyse the manager's policy to maximize the profit in a multiple-server queueing facility with a limited queue capacity. We assume that the level of advertizing effects on the arrival rate of customers to the facility. The model without ‘word of mouth effect’ is assumed that the arrival rate is independent on the qualify of service level. We estimate the service quality by the balking rate of customers from system. We extend this to the model with ‘word of mouth effect’. To achieve the maximum profit, the most important factor is the considerably high utilization of facility for both models. Given service rate, we should maintain an effective arrival rate to some extent. To this end, among the available options, an increase of advertizing effort is more desirable than reducing the fee if the service value of customers remains unchanged. We also investigate whether the variability of service time has a significant impact on determining the optimal policy. The cost of service variability is not so expensive as that in a single server model due to the reduced variability of service times in a multiple-server model.

• 유통과학연구
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• 제22권9호
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• pp.27-38
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• 2024

Purpose: Sustainable economic growth is a top priority for any country, and inflation is crucial in determining future economic circumstances. Few research exists regarding the impacts of risk management practices on performance outcomes in the supply chain with the mediating role of inflation rate. Hence, this study investigates the important role of risk management practices in the context of high inflation rate. Research design, data and methodology: The PLS-SEM model is applied to identify the effects of risk management practices on operational performance and supply chain performance. The author distributed online and offline surveys to administrators at various businesses. After applying the filtration criteria, 309 responses were retained for further data analysis. Results: This research demonstrates that risk management practice is critical and adds to supply chain performance success. Managers should enhance all risk management procedures to regulate and manage hazards in the supply chain. This allows managers to anticipate and identify potential threats with ease, particularly in high inflation rate situation. Conclusions: The outcomes of this study demonstrate how fully implemented risk management practices can improve operational performance and supply chain performance, as well as control the impact of inflation rate.

• 멤브레인
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• 제17권3호
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• pp.254-268
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• 2007

다양한 재료특성(Si/Al 몰비, 두께, 구조적 불완전성)을 갖는 Na형 faujasite 제올라이트 분리층을 다공성 $\alpha$-알루미나 튜브 표면에 수열조건에서 이차성장 시키고 $CO_2/N_2$ 분리거동을 $CO_2/N_2$ 몰비가 1인 혼합기체에 대하여 $30^{\circ}C$에서 평가하였다. 수열조건 중에서 수열용액 내의 $SiO_2$ 양은 형성된 제올라이트 분리층의 재료특성에 가장 큰 영향을 주는 변수임을 확인하였다. 즉, 수열용액 내의 $SiO_2$ 양이 증가함에 따라서 형성된 제올라이트 분리층의 Si/Al 몰비, 두께, 구조적 불완전성(discontinuity)은 동시에 증가하였다. 본 논문에서는 불완전한 치밀화에 의해 잔존하는 결정립간 공극(void), GIS Na-P1 상에 의해 형성된 균열(crack) 등 구조적 불완전성이 $CO_2/N_2$ 분리에 가장 큰 영향을 주는 재료특성이며, 투과부에서의 $CO_2$ 탈착이 전체 $CO_2$ 투과의 율속단계(rate-determining step)임을 확인하였다.

• 전기전자학회논문지
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• 제2권2호
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• pp.233-238
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• 1998

본 논문에서는 G.726 ADPCM 음성방식을 기존의 단일 압축을 대신 16Kbps 와 40Kbps의 두 가지 압축율을 사용한 가변 압축방식에 의한 음성 코딩 방식을 다루었다. 음성의 묵음 또는 소 신호 부분은 음질의 향상보다는 데이터 비트 수를 줄이기 위한 저 전송 16Kbps 압축율을 적용하였고 임계값 이상의 대 신호 부분은 음질을 향상하기 위하여 40Kbps의 압축율을 적용하여 모든 신호를 단일 압축율로 코팅하는 방식에 비하여 전체적으로 압축율을 높여 전송 비트 수를 줄이면서 음질을 저하시키지 않도록 하였다. 분 논문에서는 시뮬레이션을 통하여 여러 가지의 임계값에 의한 가변 압축 코딩 방식에 대하여 압축율과 음질의 관계 를 다루었다. 또한 고정된 임계값에 대하여 입력 음성의 크기를 여러 가지로 변동하여 주변 배경잡음과 포화에 의한 음질의 저하를 고찰하여 가변 율에 의한 음성의 코딩방식에서 임계값과 입력의 크기가 음질 및 압축율에 미치는 영향을 다루었다. 각 시뮬레이션의 경우에 대하여 실지 음성의 원음에 대한 음질의 충실 도를 임의의 집단에 대하여 비교하여 음질의 충실 도를 확인하였다. 추후의 연구를 통하여 DSP에 의한 실시간 처리 시스템의 구현을 하고자 한다.