• Title/Summary/Keyword: 2중효용

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Performance Analysis of New Working Solution for Absorption Refrigeration Machine using Treated Sewage (하수처리수이용 신용액 흡수식 냉동기의 성능해석)

  • 권오경;유선일;윤정인
    • Journal of Energy Engineering
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    • v.7 no.2
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    • pp.231-240
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    • 1998
  • The global environmental problems such as CFC, energy losses in heat recovery system as well as summer peak time power demands, the development of high efficiency absorption refrigeration systems is one of the most promising method in this problems. The absorption refrigeration system to utilize treated sewage is available for environmental protection and energy conservation. Simulation analysis on the double-effect absorption refrigeration cucles with parallel or series flow type has been performed. LiBr+LiI+LiCl+LiNO$_3$ solution was selected as the new working fluid. The main purpose of this study is evaluating the possibilities of effective utilization of treated sewage as a cooling water for the absorber and condenser. The other purpose of the present study is to determine the optimum designs and operating conditions based on the operating constraints and the coefficient of performance in the parallel or series flow type. In this study, we found out the characteristic of new working solution through the cycle simulation and compared LiBr solution to evaluate. The absorption refrigeration machine using the new working fluid was obtained better results COP rise and compactness of system by comparison with LiBr solution.

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The efficacy of computerized tomographic scan for chest trauma (흉부외상 환자에 대한 전산화 단층촬영의 효용성)

  • Roh, Hwan-Kyu;Choi, Ho;Kim, Young-Jin;Kim, Jung-Tae;Soh, Dong-Moon;Ryu, Han-Young;Lee, Cheol-Joo
    • Journal of Chest Surgery
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    • v.31 no.3
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    • pp.298-303
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    • 1998
  • Computerized tomography(CT) is an effective technique in the initial evaluation of the abdomen and head following blunt trauma. To evaluate the efficacy of CT of the thorax, a retrospective study comparing early thoracic CT scanning with initial chest roentgenogram (CXR) was carried out on 134 patients with blunt trauma on the chest. Among 134 patients, 45 patients had normal initial chest roentgenogram and 24 patients showed normal CT findings. Sensitivities of diagnosing pneumothorax and pleural effusion by CXR were low (46.2 and 62.9% respectively), whereas 71.4%(45/63) of patients had thoracostomy only by CXR. Although sometimes abused, CT of the thorax is effective in the initial diagnosis.

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Thermodynamic Analysis of an Absorption Heat Pump Heating System with LiBr-Water Solution (2 중효용 흡수식 히트점프의 난방 성능 해석)

  • Won, S.H.;Lee, W.Y.;Chung, H.S.
    • Solar Energy
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    • v.9 no.3
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    • pp.73-80
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    • 1989
  • This paper presents as assessment based on steady-state thermodynamic analysis and computer modeling of a double effect generation absorption heating cycle for solar air-conditioning to find operating temperature ranges. The influences of component temperatures on the heating coefficients of performance and mass flow ratio have been investigated to obtain optimum operating conditions for the proposed air conditioning system. And the single and double effect absorption cycles are compared with each other over the same range of temperatures.

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A Study on the Influence of the Selective Attributes of Home Meal Replacement on Perceived Utilitarian Value and Repurchase Intention: Focus on Consumers of Large Discount and Department Stores (HMR(Home Meal Replacement) 선택속성이 지각된 효용적 가치, 재구매 의도에 미치는 영향에 관한 연구: 대형 할인마트와 백화점 구매고객을 대상으로)

  • Seo, Kyung-Hwa;Choi, Won-Sik;Lee, Soo-Bum
    • Journal of the East Asian Society of Dietary Life
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    • v.21 no.6
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    • pp.934-947
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    • 2011
  • The purpose of this study is to analyze products for good taste and convenience, which become an engine to constantly create customers. In addition, this study is aimed at investigating the relationship between the selective attributes of Home Meal Replacement, the perceived utilitarian value, and the repurchase intention, and drawing new suggestions on the Home Meal Replacement market from a new marketing perspective. Based on a total of 215 samples, this study reviewed the reliability and fitness of the research model and verified a total of 5 hypothesized using the Amos program. The result of study modeling was GFI=0.905, AGFI=0.849, NFI=0.889, CFI=0.945, and RMR=0.0.092 at the level of $x^2$=230.22 (df=126, p<0.001). First, the food quality (${\beta}$=0.221), convenience (${\beta}$=0.334), packing (${\beta}$=0.278), and employee service (${\beta}$=0.204) of home meal replacement consideration attributes had a positive (+) influence on perceived utilitarian value. Second, perceived utilitarian value (${\beta}$=0.584) had a positive (+) influence on repurchase intention. The factors to differentiate one company from other competitors in terms of the utilitarian value are the quality of food, convenience, wrapping, and services by employees. This study has illustrated the need to focus on the development of a premium menu to compete with other companies and to continue to research and develop nutritious foods that are easy to cook. Moreover, the key factors to have a distinct and constant competitive edge over other companies are the alleviation of consumer anxiety over wrapping container materials, the development of more designs, and the accumulation of service know-how. Therefore, it is necessary for a company to strongly develop the key factors based on its resources as a core capability.

Assessing Relative Importance of Laver Attributes for Infants Using Conjoint Analysis (컨조인트 분석을 이용한 영유아 김 선택 속성의 상대적 중요도 분석)

  • Lee, Ho-Jin;Lee, Min-A;Park, Hye-Kyung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.45 no.6
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    • pp.894-902
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    • 2016
  • The purpose of this study was to analyze the attributes considered as important by parents in the selection of laver for infants through conjoint analysis techniques. A total of 917 questionnaires were distributed in January 2016, of which 211 were completed (23.0%). Statistical data analyses were performed using SPSS/Win 21.0 for descriptive statistics and conjoint analysis. The conjoint design was applied to evaluate the hypothetical laver for infants. According to the analysis of attributes and levels of laver for infants, the relative importance of each attribute was follows: seasoning (26.55%), flavor (19.33%), texture (18.75%), oil (15.15%), size (10.61%), and certification (9.61%). The results of the conjoint analysis indicate that parents raising infants preferred laver with the characteristics of non-seasoning, general flavor, softness, half-size, organic certification, and perilla oil. The most preferred laver for infants gained a 53.7% potential market share from choice simulation compared with laver being sold. Using utility and relative importance, the laver market for infants was classified into two segments. As a result of market segmentation, parents of cluster 1 preferred the laver model being sold (soy seasoning) while parents of cluster 2 preferred the optimized laver model (non-seasoning).

Characteristic Analysis of Double Effect Absorption Refrigeration Machine using $H_{2}O/LiBr+HO{(CH_{2})}_{3}OH$ ($H_{2}O/LiBr+HO{(CH_{2})}_{3}OH$를 이용한 2중 효용 흡수식 냉동기 특성해석)

  • 문춘근
    • Journal of Advanced Marine Engineering and Technology
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    • v.22 no.6
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    • pp.792-799
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    • 1998
  • Further improvement of existing $H_{2}O/LiBr$ absorption refrigeration machine is absolutely neces-sary to promote the utilization of gas-cooling system Among various methods to improve the per-formance of the absorption refrigeration machine this research has focused on the use of a new working fluid that has better properties than the existing $H_{2}O/LiBr$ working fluid. In the series of the research, $H_{2}O/LiBr+HO{(CH_{2})}_{3}OH$ system was selected as the most promisable candidate. The absorption refrigeration machine is water-cooled double-effect, $H_{2}O/LiBr+HO{(CH_{2})}_{3}OH$ sys-tem with series flow type. In this study we found out the characteristic of new working solution through the cycle simulation and compared the result with that of LiBr solution to evaluate. Theoptimum designs and operating conditions were determined based on the operating constraints and the coefficient of performance. Results demonstrate that new working fluid subsrantially increases COP by as much as 10% and has a wider working range with 8% higher crystallization limits compared to the conventional $H_{2}O/LiBr$.

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An Analysis of three-dimensional collision probability according to approaching objects to the KOMPSAT series (아리랑 위성들의 경향에 따른 및 3차원 충돌확률 분석)

  • Seong, Jae-Dong;Kim, Hae-Dong;Lim, Seong-Min
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.41 no.2
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    • pp.156-163
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    • 2013
  • Collision probability is the most common method to measure the risk of space debris, it is widely used that two dimensional linear collision probability using the closest approach distance. This paper represents the characteristics of object that approach KOMPSAT 2, 3, 5 that have operated or will be operated by Korea. And more precise method than two dimensional linear collision probability, we analyzed the properties of three dimensional nonlinear collision probability using STK/Nonlinear Collision Probability Tool. Through this, efficiency of three dimensional nonlinear collision probability for KOMPSAT series satellites was investigated. The result represents that three dimensional nonlinear collision probability showed the precise outcome at a relative velocity of less than 350m/s. Also, KOMPSAT series satellites appeared to few low relative velocity approaches and showed low efficiency for the three dimensional nonlinear collision probability.

Thermodynamic Analysis of a Double-Effect Absorption Heating System Using Water-LiBr- LiSCN Solution As $20{\sim}40^{\circ}C$ Range Solar Evaporator Heating (태양열을 증발기 열원으로 사용($20{\sim}40^{\circ}C$범위)하며 LiSCN+LiBr 수용액을 사용하는 흡수식 2중효용 난방시스템의 열역학적 해석)

  • Won, Seung-Ho
    • Journal of the Korean Solar Energy Society
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    • v.26 no.4
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    • pp.73-81
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    • 2006
  • In this paper, with water-LiBr-LiSCN mixture which utilizes solar energy as mid temperature range evaporator heat source, a thermodynamic analysis was performed to provide design data for a double-effect absorption heating system. A comparative study of the water-LiBr-LiSCN mixture against the water-LiBr pair was conducted by a computer simulation. The computer simulation is based on mass, material and heat balance equations for each part of the system. Coefficients of performance and flow ratios for effects of different operating temperatures are investigated. It is found that the heating COP is higher for the water-LiBr-LiSCN mixture than for the water-LiBr pair, and FR is lower for the former.