• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2004년도 유체기계 연구개발 발표회 논문집
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• pp.180-186
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• 2004

Average Bi-directional flow tube was suggested to measure single and two phase flow rate. Its working principle is similar with Pilot tube, however, it makes it possible to eliminate the cooling system which is normally needed to prevent from flashing in the pressure impulse line of Pilot tube when it is used in the depressurization condition. 3-dimensional steady state flow analyses using FLUENT 5.4 code were performed to validate the application of the averagebi-directional flow tube in case of water and air flow In this study, sensitivity studies have been performed to optimize the design features of the average hi-directional flow tube which can be applied for the various experimental conditions. For Re numbers above 1000, the k values are nearly constant regardless of the Re numbers and flow types and calculation results and experimental data coincides quite well. The current FLUENT calculation results suggest that linearity of the k values in various design features of the average BDFT is highly promising, which means that it is quite reasonable to select the typical design of the average BDFT for the convenience of the experimental conditions.

• 한국컴퓨터정보학회논문지
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• 제17권4호
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• pp.75-82
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• 2012

PPG 신호는 심장의 박동에 동기된 유사 주기 신호이다. 본 논문에서는 PPG 신호의 유사주기성을 이용한 주기적 이동평균필터 방법을 제안한다. 이 필터링 방법은 PPG 신호를 주기적으로 분리하여 각 주기 신호의 같은 순번에 있는 샘플들끼리 평균을 취하는 방법이다. 연속된 PPG 신호의 주기 중에 동잡음이 혼입되었다면 주기를 기준으로 PPG 신호를 분리한 후, 각 주기의 샘플수를 조정하여 같은 샘플수를 가지게 만든다. 이 주기들을 2차원으로 배열한 후 현재 주기부터 이전 각 주기의 샘플끼리 평균을 취함으로써 훼손 없이 동잡음을 제거할 수 있었다.

• 한국연초학회지
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• 제19권1호
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• pp.40-45
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• 1997

This study was conducted to evaluate the personal effects of tobacco smoke and environmental tobacco smoke(ETS) by measuring the concentration of nicotine and cotinine in the urine. While 129 urine samples were being collected, Personal characteristics such as sex, age, number of years since a Person has been a smoker, average consumption number of cigarettes per day, and number of smoker in family were also surveyed. Collected urine samples were used for analysis of nicotine and cotinine by GC/NPD after Passing the extrelut column. In the urine of the smoker, the average contents of nicotine and cotinine were 5.38$\mu\textrm{g}$/ml and 3.14 $\mu\textrm{g}$/ml, respectively. The average contents of nicotine and cotinine were 0.18$\mu\textrm{g}$/ml and 0.07$\mu\textrm{g}$/ml in the urine of male non-smoker, respectively. The contents of nicotine and cotinine in the non-smoker's urine were dependent on sex and age. On the other hand, the contents of nicotine and cotinine in smoker's urine were dependent on average consumption amount of cigarettes per day. Also, there was a direct relation between nicotine levels in the smoker's urine and the average consumption number of cigarettes Per day of smoker. The Possible sources of nicotine and cotinine in the non-smoker's urine seemed to be caused by food, beverage and En, Our results indicate that the number of smoker in family had no effect on increasing nicotine and cotinine contents in the urine of non-smoker.

• 설비공학논문집
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• 제8권1호
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• pp.120-139
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• 1996

Experiment was performed to study the heat transfer characteristics in 27 kinds of 15 : 1 scale models of multi-louverred fin heat exchangers with a wide range of variables(R $e_{Lp}$ =100~1, 800, $L_p$/F$p$=0.3~0.9, $\theta$=20$^{\circ}$~40$^{\circ}$). Thermofoil heaters were used to heat the louver fins and the local average Nusselt number for each louver in the louver array was obtained at constant wall temperature conditions. Correlations are developed to predict the heat transfer characteristics and drag coefficients. Generally, the heat transfer characteristics in the multi-louvered fins is shown to be similar to those of the laminar heat transfer on a flat plate. As the Reynolds number, the louver pitch to fin pitch ratio$L_p$/F$p$and the louver angle($\theta$) increase respectively, the average Nusselt number increases, but the variation of average Nusselt number as a function of the louver angle is smaller than that as a function of the louver pitch to fin pitch ratio. In case of$L_p$/F$p$ <0.5, the average Nusselt number of the 3rd louver is especially lower than the others, it is expected that it is due to the flow structure such as a recirculation flow and a flow separation.

• ETRI Journal
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• 제11권1호
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• pp.109-122
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• 1989

We developed new quadtree and octree representation schemes which reduce the storage requirements from exponential to polynomial. The new schemes not only lessen the large storage requirements of the existing quadtree and octree representation schemes but guarantee an exact representation of the original object. These are made possible by adopting a new set of termination conditions that ensure finiteness of the quadtree and octree during the decomposition. These new data structures are analyzed theoretically and tested empirically. For space complexity, we analyzed its best case, worst case, and average case. Given an $n_e$-gon, we show that the expected number of nodes in our quadtree isO($$$n_e^1.292$) For a polyhedron with $n_f$ faces, the expected number of nodes in the new octree is O($$$n_f^1.667$). For time complexity, we again analyzed the best, worst, and average cases for constructing such quadtree and octree and find the average to be the same as those of the space complexity. Finally, random $n_e$- gons are generated as test data. Regression equations are fitted and are shown to support the claims on the average case performance.

• 한국환경과학회지
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• 제15권10호
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• pp.935-943
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• 2006

This study focuses on analyzing the inflow characteristic of contaminants of city water that flows into a main water system like a reservoir, and intends to provide basic data which can be efficiently reflected on water quality management policy and decision making of a reservoir. The conclusion obtained from the analysis of the inflow of a main water system by analyzing the inflow property of city water contaminants is as follows. In the case of Chungju-cheon stream which is the city water, pollution load from the basic outflow is low when it rains, and with high load of basic outflow during the dry season, due to the discharge of pollutants from the city, the quality of water becomes worse. In the case of Chungju-cheon stream, average BOD is $4.53mg/{\ell}$ when it rains, and the contaminants increase and flow in about 7.8% compared to the average BOD during the average droughty season. The average SS concentration in water is $798.67mg/{\ell}$ and increased 97.2% compared to the average droughty season.

• 대한가정학회지
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• 제34권2호
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• pp.201-215
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• 1996

The purpose of the study was to examine the effects of household characteristics to family savings. Family savings were defined in four ways such as monthly savings, average propensity to save, financial assets, and net financial assets. The household characteristics dealt with were family income, household size, number of earners, age, occupation, education, housing tenure, and urbanization. The data used in the study was Survey of Family Finance 1990. The main statistical method was multiple regression. Family income was found to the most important variable to determine four family saving variables holding other characteristics constant. Also, household size had significant negative effects on family savings. Two-earner households were found to have higher average propensity to save and less financial assets compared to single-earner households. Fro monthly savings and average propensity to save, the households with forties andfifties household head tended to be less than others, while financial assets tended to increase with the age of household head. Compared to salary earner households, blue-colored households had significantly lower average propensity to save, and the households with professionals had significantly higher financial assets. The college-graduated households tended to have less monthly savings than the elementary-graduated households. Also, the housing renters were found to have more monthly savings and higher average propensity to save, compared to the housing owners.

• 한국실내디자인학회논문집
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• 제23권4호
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• pp.140-148
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• 2014

The objective of this study is to address Effective Learning Methodology by subjects to acquire National Certification which is an essential requirement to get employed. For this purpose, analysis was completed after conducting a survey on the class to obtain Interior Architecture Engineer Certification. 23 applicants were selected based on effectiveness of each subject, level of difficulty, degree of understanding, mentoring effect, self-driven learning, and group discussion. Results are as below. Upon the first written test, Interior Design Theory and Chromatics showed a high learning effectiveness in self-driven learning and mentoring. Ergonomics showed a high learning effectiveness in mentoring, self-driven learning and group discussion while Building Materials, Architecture Construction presented a high effectiveness only in mentoring and group discussion. Architecture Environment showed average learning effectiveness in mentoring and group discussion and showed a low effectiveness in self-driven learning. Upon the second practice test, Interior Architecture Construction and Planning/Management of Construction Materials presented an average learning effectiveness in mentoring and group discussion. Process Control and Adding Up(Supply Calculation) showed a low learning effectiveness in self-driven learning and presented an average to below average learning effectiveness in mentoring and group discussion. Lastly, Interior Design Plan, Interior Design Drawings presented average learning effectiveness in mentoring and group discussion however they showed a high effectiveness in self-driven learning.

• Nuclear Engineering and Technology
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• 제20권2호
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• pp.80-87
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• 1988

소형냉각재상실사고(SBLOCA)와 대형냉각재상실사고(LBLOCA)중에 노심의 Average Channel과 Hot Channel에서의 유량분포를 예측하였다. 아울러 REALP5/MOD2 코드를 사용하여 두 채널사이의 교차류고려여부가 실제사고 분석결과에 미치는 영향을 평가하였다. 현재까지 SBLOCA계산에서는 노심을 한개의 채널로 모델하는 것이 충분하다고 판단되어 왔으나 본 계산결과에 의하면 보수적인 계산을 위해서는 Hot Channel 모델링이 필요한 것으로 밝혀졌다. 그러나 LBLOCA Blowdown Phase존에서는 교차류의 고려 여부에 상관없이 Hot Channel 이 Average Channel보다 보수적 인 결과를 가져오며, 교차류의 영향도 미세한 것으로 판명되었다.

• 정보처리학회논문지A
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• 제11A권5호
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• pp.401-406
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• 2004

이 논문에서는 정적분의 근사 값을 계산하는 여러 적분 문제 중에서 보간 법을 사용하는 수치적분법의 평균오차에 대해서 연구한다. 특히 가장 널리 쓰이고 있는 방법 중의 하나인 복합 Newton-Cotes 구적법의 평균오차에 대해서 연구한다. 주어진 구간을 등 간격으로 나누었을 때, 각 점에서의 함수 값을 information으로 사용할 경우, 복합 Newton-Cotes 구적법의 평균오차를 계산하였으며, 이 때 이 오차는 가장 최소임을 이 논문에서 증명한다.