• Current Optics and Photonics
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• 제8권1호
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• pp.105-111
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• 2024

We investigate the effect of photon loss on pair production in a hybrid atom-light system. The loss of light field not only affects the generation of photons, but also prevents the generation of atomic collective excitation, although the atoms are not influenced directly. We propose an unbalanced homodyne detection of the number of atomic collective excitation that overcomes the challenge caused by counting uncertainty in practical measurement. In discussion, we show that the intermode correlations and the number correlation is closely related to the initial input state, while the quadrature correlations are independent of the initial state and always exhibit opposite intermode correlations even in the presence of loss.

• 동아시아식생활학회지
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• 제18권6호
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• pp.1089-1098
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• 2008

The principal objective of this study was to reveal the relationship between the menu management indicators and menu performance indicators in contract-foodservice operations. Menu indicators differed according to the type of business, type of contract, type of serving, and number of service lines. In accordance with the results of our correlation analysis, we noted significant correlations between menu performance indicators and menu management indicators. The first of these was the correlation between the food cost ration and meal counts, food loss, and the use of prepared vegetables. The second of these was the correlation between food cost per meal and forecasting error, food loss, and inventory turnover. The last of these correlations was the negative correlation between menu CSI(customer satisfaction index) and the use of prepared vegetables. According to the results of our canonical correlation analysis, 2 significant functions were identified. In the first function, we noted significant correlations between meal counts, use of prepared vegetables, food loss, and food cost ratio. Additionally, we noted significant correlations between forecasting error, inventory turnover, food loss, and food cost per meal in the second function. Menu management indicators had no influence on customer satisfaction.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2000년도 유체기계 연구개발 발표회 논문집
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• pp.110-115
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• 2000

The mean streamline analysis using the empirical loss correlations has been developed for performance prediction of industrial mixed-flow fan impellers in the present study. New simple, but effective, models for the additional Euler input work characteristic and an internal recirculation loss due to internal flow reversal under the low flowrate conditions are proposed in this paper. Comparison of overall performance predictions with six sets of test data of mixed-flow fans is accomplished to demonstrate the accuracy of the proposed models. Predicted performance curves by the present set of loss models agree fairly well with experimental data for a variety of mixed-flow fan impellers over the entire operating conditions. The prediction method presented herein can be used efficiently in the conceptual design phase of mixed-flow fan impellers.

• 한국심리학회지 : 문화 및 사회문제
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• 제13권2호
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• pp.1-15
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• 2007

본 연구는 고령자들이 경험하는 상실감이 주관적 안녕감에 어떠한 영향을 미치는 살펴보고자 하였다. 이를 위해서 만 65세 이상 고령자 총 100명을 대상으로 자료를 수집하여 분석한 결과, 고령자 상실감 요인인 '건강 상실', '관계의 상실', '경제적 상실', '사별 상실'은 '생활 만족도'와는 부적인 상관을 나타냈으며, '정적 정서'와는 '사별 상실'을 제외한 세 요인들이 부적인 상관을 나타냈다. 그리고 '부정 정서'와는 '경제적 상실'을 제외한 나머지 세 요인들과는 정적인 상관을 가지고 있었다. 그리고 경로분석을 통해 상실감 하위요인들이 주관적 안녕감에 이르는 과정을 살펴보았다. 그 결과, '건강 상실'요인은 주관적 안녕감의 '정적 정서'와 '부적 정서'에 영향을 미치는 요인으로 나타났다. 그리고 '관계의 상실'요인은 '생활 만족도'와 '정적 정서'에 유의한 영향을 미치는 것으로 나타났다. 한편 '경제적 상실'과 '사별 상실'요인은 주관적 안녕감에 미치는 유의한 영향력이 없는 것으로 나타났다. 이것은 고령자들의 건강문제와 가족관계에서는 정서적 지원이 중요하고, 특히. 고령자의 건강문제와 가족관계에서 가족의 지원이 중요함을 시사한다.

• Journal of Mechanical Science and Technology
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• 제18권11호
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• pp.2021-2031
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• 2004

A new nondimensional method for predicting the windmilling performance of centrifugal -flow turbojet engines in flight has been developed. The method incorporates loss correlations to estimate the performance of major engine components. Given basic engine geometry, flight Mach number, and ambient conditions, this method predicts transient and steady-state windmilling performance. Thus, this method can be used during the preliminary design stage when detailed hardware geometry and component performance data are not yet available. A nondimensional time parameter is newly defined, and using this parameter, the transient performance of different types of turbojets (e.g. centrifugal vs. axial) is compared. In addition, the predictions' sensitivity to loss correlations, slip factors, and inlet ambient temperatures are analyzed.

• 한국사회복지학
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• 제65권2호
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• pp.335-356
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• 2013

이 연구는 저소득층이 겪는 물리적 자원에서의 상실과 획득이 안녕감에 어떠한 영향을 주는지 그리고 이들이 경제환경과 상호작용하며 경험하는 경제적 안정감이 그러한 상실 및 획득의 영향을 받아 안녕감에 어떠한 역할을 하는지를 탐색하고자 하였다. 이에 자활센터를 이용하는 저소득층 남녀 성인 254명을 대상으로 물리적 자원의 상실과 획득, 경제안정, 안녕감의 수준을 살펴보고, 자원의 상실 및 획득 각각이 안녕감에 영향을 주는 관계와 이 관계에서 경제안정 수준이 보이는 매개역할을 구조방정식모형 분석으로 검토하였다. 주요 연구결과는 첫째, 참여자들은 물리적 자원을 약간 잃거나 얻은 수준이고 획득이 상대적으로 높았다. 둘째, 경제안정 및 안녕감과의 관계에서 자원상실은 유의한 부적관계를, 획득은 유의한 정적 관계를 보였다. 셋째, 자원상실은 경제안정과 안녕감 각각에 대해 유의한 부적인 직접효과를 보인 한편 경제안정의 감소를 통해 안녕감을 감소시키는 간접효과도 유의하였다. 끝으로, 자원획득 역시 경제안정과 안녕감 각각에 대해 유의한 직접효과를 보이고 또 경제안정을 통한 정적인 간접효과가 유의하여 자원상실과 획득 두 모형 모두에서 부분매개모형이 지지되었다. 이러한 결과에 기초하여 사회복지실천에서 저소득층 성인의 생활과 밀접히 관련되는 물리적 자원의 상실 및 획득, 경제안정, 안녕감을 활용할 방안과 조사연구에서 가질 수 있는 함의를 찾고 제언하였다.

• 대한기계학회논문집
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• 제18권12호
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• pp.3357-3368
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• 1994

Total pressure losses required to calculate the total-to-total efficiency are estimated by integrating empirical loss coefficients of four loss mechanisms along the mean-line of blades as follows; blade profile loss, secondary flow loss, end wall loss and tip clearance loss. The off-design points are obtained on the basis of Howell's off-design performance of a compressor cascade. Also, inlet-outlet air angles and camber angle are obtained from semi-empirical relations of transonic airfoils' minimum loss incidence and deviation angles. And nominal point is replaced by the design point. It is concluded that relatively simple loss models and Howell's off-design data permit us to calculate the off-design performance with satisfactory accuracy. And this method can be easily extended for off-design performance prediction of multi-stage compressors.

• Nuclear Engineering and Technology
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• 제42권6호
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• pp.656-661
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• 2010

Lead-alloys are very attractive nuclear coolants due to their thermo-hydraulic, chemical, and neutronic properties. By utilizing the HELIOS (Heavy Eutectic liquid metal Loop for Integral test of Operability and Safety of PEACER$^2$) facility, a thermal hydraulic benchmarking study has been conducted for the prediction of pressure loss in lead-alloy cooled advanced nuclear energy systems (LACANES). The loop has several complex components that cannot be readily characterized with available pressure loss correlations. Among these components is the core, composed of a vessel, a barrel, heaters separated by complex spacers, and the plenum. Due to the complex shape of the core, its pressure loss is comparable to that of the rest of the loop. Detailed CFD simulations employing different CFD codes are used to determine the pressure loss, and it is found that the spacers contribute to nearly 90 percent of the total pressure loss. In the system codes, spacers are usually accounted for; however, due to the lack of correlations for the exact spacer geometry, the accuracy of models relies strongly on assumptions used for modeling spacers. CFD can be used to determine an appropriate correlation. However, application of CFD also requires careful choice of turbulence models and numerical meshes, which are selected based on extensive experience with liquid metal flow simulations for the KALLA lab. In this paper consistent results of CFX and Star-CD are obtained and compared to measured data. Measured data of the pressure loss of the core are obtained with a differential pressure transducer located between the core inlet and outlet at a flow rate of 13.57kg/s.

• Nuclear Engineering and Technology
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• 제15권2호
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• pp.123-134
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• 1983

냉각재 상실 사고시에 격납 용기로부터 열 제거능력의 추정은 격납용기의 기본적인 설계변수인 최고 압력 및 온도의 예측에 있어서 매우 중요하다. 지금까지 격납 용기내의 열전달에 관하여 실험 및 해석적인 방법에 의하여 연구한 결과들을 종합하여 검토해 봄으로서 현재의 수준을 알 수 있었으며, 이들 관계시의 잘못된 사용을 피하고 보다 정확한 예측을 위해서는 더욱 깊은 연구가 필요하다고 생각된다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집B
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• pp.574-579
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• 2000

In this study. an off-design performance prediction program for centrifugal pumps is developed. To estimate the losses in an impeller flow passage, two-zone model and two-element in series(TEIS) model are used. At impeller exit. the mixing process occurs with an increase in entropy. In two-zone model. there are both primary zone and secondary zone for an isentropic core flow and an average of all non-isentropic streamtubes respectively. The level of the core flow diffusion in an impeller was calculated by using TEIS model. While internal losses in an impeller an automatically estimated by using the above models, some empirical correlations far estimating external losses. far example, disk friction loss, recirculation loss and leakage loss are used. In order to analyze the vaneless diffuser flow. the momentum equations for the radial and tangential directions are used and solved together with continuity and energy equations.