• 대한간호학회지
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• 제41권6호
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• pp.750-757
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• 2011

Purpose: Cost-benefit analysis is one of the most commonly used economic evaluation methods, which helps to inform the economic value of a program to decision makers. However, the selection of a correct benefit estimation method remains critical for accurate cost-benefit analysis. This paper compared benefit estimations among three different benefit estimation models. Methods: Data from community-based chronic hypertension management programs in a city in South Korea were used. Three different benefit estimation methods were compared. The first was a standard deterministic estimation model; second, a repeated-measures deterministic estimation model; and third, a transitional probability estimation model. Results: The estimated net benefit of the three different methods were $1,273.01, $-3,749.42, and $-5,122.55 respectively. Conclusion: The transitional probability estimation model showed the most correct and realistic benefit estimation, as it traced possible paths of changing status between time points and it accounted for both positive and negative benefits.

• 대한화학회지
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• 제35권5호
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• pp.487-492
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• 1991

이상기체방정식을 수정, 보완하는 방법으로 실제기체를 설명하려는 노력은 van der Waals eqn.이 후 100년이 지나도록 별 진전을 보이지 못하고 있다. 이제 기체란 연속적인 변화를 통해 액체가 되는 유체임에 근거하여 액체론으로부터 실제기체방정식을 유도하였다. 이 때 적용된 액체이론은 Roulette 이론적으로 액체분자를 퍼텐샬우물의 깊이에 따라 Einstein분자, Lennard-Jones분자, van der Waals 분자로 나누어 액체의 다양한 특성을 잘 설명해 준 바 있다. 이 이론을 통해 얻어진 기체상태방정식은 임계점의 경계조건과 반전온도의 실험값에서 a, b, n을 구하여 52가지의 물질에 대해 두루 통용되는 식임을 알 수 있었다. 또한 Dense gas, 초임계유체와 같이 밀도가 큰 영역에서도 잘 맞는 것을 알 수 있었다.

• 한국식품조리과학회지
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• 제19권5호
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• pp.647-658
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• 2003

Foodservice at elementary schools has been provided nation-wide. It is predictable that foodborne diseases would increase continuously. Formation of a counterplan is urgently needed. This study was designed to identify the stage which contains the critical control points (CCPs) for the microbiological management of HACCP (Hazard Analysis Critical Control Point) at the foodservice provided at elementary schools. Foodservice places at four elementary schools in Seoul were sampled and the overall hygiene of cooking, utensils and equipment, employees, and environment by season were examined. The results showed that the number of bacteria in overall samples was increased and that E. coli, Salmonella and Staphylococcus by biochemical test emerged in more diverse samples in summer than in spring. Particularly, the number of aerial bacteria in summer was three-fold greater than that in either spring or winter. E. coli 0157 was not detected, although Salmonella was identified by PCR analysis in the meat knives, chopping boards, waste bins and meat dish at elementary school foodservice. According to this data, cross-contamination should be managed in the stage of mixing up the ingredients with improper equipments and insanitary treatments. Thus, the establishment of SSOP (Sanitation Standard Operating Procedures) and GMP (Good Manufacturing Practice) at elementary school foodservice is stringently required, along with sanitation education for workers and employees as CCPs.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1997년도 춘계학술발표회논문집(1)
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• pp.292-297
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• 1997

An alternating conditional expectation (ACE) algorithm, a kind of non-parametric regression method, is proposed to generate empirical correlations automatically. The ACE algorithm yields an optimal relationship between a dependent variable and multiple independent variables without any preprocessing and initial assumption on the functional forms. This algorithm is applied to a collection of 12,879 CHF data points for forced convective boiling hi vertical tubes to develop a new critical heat flux (CHF) correlation. The meat root mean square, and maximum errors of our new correlation are -0.558%, 12.5%, and 122.6%, respectively. Our CHF correlation represents the entire set of CHF data with an overall accuracy equivalent to or better than that of three existing correlations.

• 산업공학
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• 제12권3호
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• pp.401-405
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• 1999

We present a simulation model to generate the spatial distribution of mobiles in cellular communication network. Three types of spatial distributions are considered; biased, random, and ratio-based distributions. This study also points out and corrects the critical errors performed by Das and Morgera(1997) in getting random location of mobiles. By applying a simple path loss model, the effects of our correction on the signal-to-interference(SIR) ratio are discussed. The numerical results indicate that the variation of SIR in the Das's biased distribution is larger than that of other distributions. As compared with the random distribution, the average SIR error of the biased distribution is 91.1%.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.691-692
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• 2001

Until tile 1980s, the disposal of End of Life Vehicles (ELV) was considered unproblematic in Japan, Korea. and Taiwan. But in recent years, as environmental problems have attracted increasing attention. the processing oi ELV has become one of the most critical environmental issues. Discarded ELV represent a serious source of waste generation and pollution. In this paper, I will analyze the ELV problem from three view points: 1) ELV abandoned in the environment; 2) Significant environmental hazards caused by dismantling operations; and 3) Problems of how to deal with Automobile Shredder Residue (ASR).

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1996년도 봄 학술발표회 논문집
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• pp.9-18
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• 1996

The primary objective of this paper is to grasp many characteristics of buckling behavior of latticed spherical domes under various conditions. The Arc-Length Method proposed by E.Riks is used for the computation and evaluation of geometrically nonlinear fundamental equilibrium paths and bifurcation points. And the direction of the path after the bifurcation point is decided by means of Hosono's concept. Three different nonlinear stiffness matrices of the Slope-Deflection Method are derived for the system with rigid nodes and results of the numerical analysis are examined in regard in geometrical parameters such as slenderness ratio, half-open angle, boundary conditions, and various loading types. But in case of analytical model 2 (rigid node), the post-buckling path could not be surveyed because of Newton-Raphson iteration process being diversed on the critical point since many eigenvalues become zero simultaneously.

• 한국생산제조학회지
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• 제23권5호
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• pp.428-434
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• 2014

Measurement of the absolute displacement of the moving machinery components in three-dimensions (3D) is of critical functional importance. This paper describes the system that measures motion associated with six degrees-of-freedom in 3D. Wire-sensors are used to estimate the positions of an object in a 3D Cartesian coordinate system, based on the values of their initial position and the measured values. For inducing the transfer function, which represents the motion of an object, the number of the minimum measurement points is determined. Also, the experimental measuring device is configured to visualize the behavior of a rectangular object in real-time. The software for measuring the six types of motions is directly programmed using a commercial software.

• 산업경영시스템학회지
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• 제40권1호
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• pp.144-149
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• 2017

This study empirically analyzes the effect of IT SME ventures' external information network diversity on their production period reduction and productivity improvement generated from technology development. This research constructs a mediating model based on the open innovation perspective and tests it with the 138 samples of South Korean IT SME ventures based on the ordinary least squares regression. This research is expected to make a good contribution by shedding a new light on the following three points about the critical role of IT SME ventures' external information network diversity in increasing their production period reduction and productivity improvement generated from technology development which has scarcely been illuminated in the extant studies in the field of the management of technology for SMEs. First, IT SME ventures' external information network diversity positively influences their production period reduction. Second, the external information network diversity positively influences IT SMEs' ventures' productivity improvement. Third, IT SME ventures' production period reduction partially mediates the influence of IT SME ventures' external network diversity on their productivity improvement. These three fresh points are expected to provide useful theoretical and practical implications. Related to the theoretical implication, this research provides a fresh implication that IT SME ventures' external information network diversity positively influences not only their production period reduction but also productivity improvement generated from technology development. Concerning the practical implication, this study suggests that the CEOs in IT SME ventures make strategic efforts to use more diverse external information sources in order to increase their production period reduction and productivity improvement generated from technology development.

• Nutrition Research and Practice
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• 제4권2호
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• pp.163-172
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• 2010

The purposes of this study were to assess hospital foodservice quality and to identify causes of quality problems and improvement strategies. Based on the review of literature, hospital foodservice quality was defined and the Hospital Foodservice Quality model was presented. The study was conducted in two steps. In Step 1, nutritional standards specified on diet manuals and nutrients of planned menus, served meals, and consumed meals for regular, diabetic, and low-sodium diets were assessed in three general hospitals. Quality problems were found in all three hospitals since patients consumed less than their nutritional requirements. Considering the effects of four gaps in the Hospital Foodservice Quality model, Gaps 3 and 4 were selected as critical control points (CCPs) for hospital foodservice quality management. In Step 2, the causes of the gaps and improvement strategies at CCPs were labeled as "quality hazards" and "corrective actions", respectively and were identified using a case study. At Gap 3, inaccurate forecasting and a lack of control during production were identified as quality hazards and corrective actions proposed were establishing an accurate forecasting system, improving standardized recipes, emphasizing the use of standardized recipes, and conducting employee training. At Gap 4, quality hazards were menus of low preferences, inconsistency of menu quality, a lack of menu variety, improper food temperatures, and patients' lack of understanding of their nutritional requirements. To reduce Gap 4, the dietary departments should conduct patient surveys on menu preferences on a regular basis, develop new menus, especially for therapeutic diets, maintain food temperatures during distribution, provide more choices, conduct meal rounds, and provide nutrition education and counseling. The Hospital Foodservice Quality Model was a useful tool for identifying causes of the foodservice quality problems and improvement strategies from a holistic point of view.