• Journal of Korean Society for Atmospheric Environment
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• 제9권E호
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• pp.358-363
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• 1993

Total particulate mater (TPM), $NO_2$ and $NH_3$ were measured simultaneously in the smoking and non-smoking locations during an eleven month period from March 1986 to January 1987 at three sites in Chicago : Illinois Institute of Technology Cafeteria, Rush-Presbyterian St. Lukes Medical Center Cafeteria and a downtown office building. From this study, the mean concentrations of $NO_2$ and $NH_3$ were not significantly different between the smoking and non-smoking locations at any sampling site ; however, there was a statistical difference for TPM between the smoking and non-smoking locations. Activity factor was useful for describing the contribution from indoor source. The linear regression analysis was reasonable method for discriminating the individual contribution of source to determine the emission factor. The TPM emission factor determined from this technique was in good agreement with value from the literature.

• 대한가정학회지
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• 제39권1호
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• pp.221-232
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• 2001

The purpose of this study was to develop a scale for evaluation of preschool children's peer competence and to examine its validity and reliability. The 15 items of the preliminary scale were completed by teachers, and peer rating scale for assessment of peer acceptance was administered to 365 children 5 to 6 years of age. The methods for data analysis included item analysis, factor analysis for construct validity, Pearson correlations between teacher's ratings of peer competence and children's ratings of peer acceptance for concurrent validity, and Cronbach's u for reliability. The 15 items of the scathe were found be satisfactory in terms of item response distribution and item discrimination. Factor analysis revealed that a 3-factor solution was the best fit: sociability, prosocial behavior, leadership in peer relations. Correlations between teacher's ratings and children's ratings were as significant. Cronbach'so ranged from .88 to .93 for three subscales and .93 for the total scale. It was concluded that the psychometric properties of the peer competence scale in general were acceptable for use.

• 건설안전기술
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• 통권51호
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• pp.93-105
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• 2010

The object of this study is to understand the psychological factor of the worker on safety and recommend experimental factor of safety education program. The following are the methods of this study. We analyzed the statistical data from survey to workers(N=139) about the psychological factor on safely. The survey consisted of 34 questions about 4 factors like private external characteristic, psychological characteristic, characteristics on behavior, and experience and reason of disaster. As the result of the analysis of the multi regression model on the base of correlation of each of the major factors, psychological health, effort on practicing, and satisfaction on their life were the variables with high influence on the safety mind of workers. So, it is good safety strategy for effective working to maintain healthy life with optimistic minds, and try to practice actively as usual. After considering the result, for the development of safety education program for working, we have to consider psychological factors of our workers that influence their safety and try to improve the experimental education opportunity, and it will be effective.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.1348-1350
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• 2000

Zero-voltage and zero-current switched single-stage approach with high power factor is presented to reduce the switching losses and to achieve sinusoidal, unity power factor input currents. This single-stage approach, which combines a boost converter used as PFC with a half-bridge converter used as do to do conversion into one power stage, has a simple structure and low cost. At the same time, since the switches of the proposed converter are designed to be turned on at zero-voltage and off at zero-current, the switching losses could be reduced considerably. Detailed analysis and experimental results are presented on the proposed converter, which is operated at constant switching frequency and in discontinuous conduction mode.

• Nuclear Engineering and Technology
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• 제14권1호
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• pp.17-21
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• 1982

본 논문에서는 원자력발전소 부지의 안전성 평가 방법으로서 부지의 인구를 평가하는 USNRC의 SPF를 보다 발전시켜 정상 가동시나 사고시 방출되는 방사성 물질이 대기에로의 확산으로 인하여 주거 인구가 받는 영향을 고려하여 SPMF를 정의하고 고리 부지에 대한 SPF와 SPMF를 비교함으로써 SPMF모델의 타당성을 검토했다. 아울러 미국 주요 발전소와 국내 발전소 부지의 SPF를 비교하여 국내발전소 부지의 상대적 안전성을 평가했다.

• 한국태양에너지학회 논문집
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• 제33권4호
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• pp.46-50
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• 2013

This paper investigated wind turbine degradation quantitatively by analyzing the short-term operation records of the Shinan Wind Power Plant. Instead of a capacity factor which is needed to be normalized its variability due to monthly wind speed change, this study suggests an analysis method by taking the difference between the theoretical power output calculated from the nacelle wind speed and actual power output as the quantitative index of performance degradation. For three-year SCADA data analysis of the Shinan Wind Power Plant, it was confirmed that power output degradation rate of 0.54% per year. This value is within the average reduction rate 0.4%/year~0.9%/year of normalized capacity factor of the onshore wind power plants in U.K. and Denmark; however, lower than the rate 2%/year of Canadian wind power plants.

• 한국식품조리과학회지
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• 제24권3호
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• pp.367-374
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• 2008

The principal objective of this study was to determine the influence of physical evidence's performance on perception of value at family restaurants in Seoul. Frequency analysis, t-test, ANOVA, reliability analysis, factor analysis, multiregression analysis were employed to analyze the data. The physical evidence was divided into 3 factors. Factor 1, 'matters related to appearances and decoration'; and Factor 3, matters related to atmosphere' differed significantly with monthly pocket money. However, all factors differed significantly by partner. Additionally, all factors positively(+) influenced customer's perception of value. In particular, factor 1, 'matters related to appearances and decoration' was the most positive factor. As a result, physical evidence can be regarded as efficient marketing tactic by which the intangible factors of restaurant-business may be removed. Therefore, food-service companies should endeavor to manage physical evidence ideally as a means of reducing the negative characteristics of service toward customers and inducing customers perceptions of value at family restaurants.

• 대한기계학회논문집
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• 제10권2호
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• pp.208-214
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• 1986

본 연구에서는 균열 닫힘에 관한 연구의 일환으로 5083-O 알루미늄합금을 사용하고 소규모강복조건하에서 일정진폭하중피로시험을 시행하여 이 재료의 피로균열 진전속도와 균열닫힘에 관하여 검토하였다.

• 한국의학물리학회지:의학물리
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• 제29권4호
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• pp.115-122
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• 2018

Although the current internationally recommended standard for the use factor (U) applied to CyberKnife is 0.05 (5%), the CyberKnife shielding standard is applied more stringently. This study, based on clinical data, was aimed at examining the appropriateness of existing shielding guidelines. Sixty patients treated with G4 CyberKnife were selected. The patients were divided into two groups, according to whether they underwent skull or spine tracking. Based on the results, the use factors for each wall ranged from 0.028 (2.8%) to 0.031 (3.1%) for the intracranial treatment and 0.020 (2.0%) to 0.022 (2.2%) for the body treatment. Excessive barrier thickness resulted in inefficient use of space and higher cost to the institutions. Furthermore, because the use factor is influenced by the position of the robot, the use factor determined based on the clinical data of this study would facilitate more reasonable treatment room design.

• 대한수학회지
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• 제59권4호
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• pp.757-774
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• 2022

Let a and b be positive even integers. An even [a, b]-factor of a graph G is a spanning subgraph H such that for every vertex v ∈ V (G), d_H(v) is even and a ≤ dH(v) ≤ b. Let κ(G) be the minimum size of a vertex set S such that G - S is disconnected or one vertex, and let σ₂(G) = min_uv∉E(G) (d(u)+d(v)). In 2005, Matsuda proved an Ore-type condition for an n-vertex graph satisfying certain properties to guarantee the existence of an even [2, b]-factor. In this paper, we prove that for an even positive integer b with b ≥ 6, if G is an n-vertex graph such that n ≥ b + 5, κ(G) ≥ 4, and σ₂(G) ≥ ${\frac{8n}{b+4}}$, then G contains an even [4, b]-factor; each condition on n, κ(G), and σ₂(G) is sharp.