• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제52권7호
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• pp.327-334
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• 2003

We have investigated the quench behavior of the series connection of resistive type superconducting fault current limiter (SFCL) components based on YBCO films. Equal shunt resistors $R_s$ across individual SFCL components successfully produced simultaneous Quenches for 5 components in series, resulting in equal application of voltage to all components. If the two components having the highest and the lowest critical currents ($I_c$) quench safely, others quench altogether The highest shunt resistance is to guarantee the safe quenches of all components, leading to the equal voltage applications within the first half cycle after a fault in the short circuit test. The highest $R_s$ was found to be 28 ［$\Omega$］ for the components in the given quench environment. Considering the safe quenches and protection coordination, the optimal $R_s$ was suggested to be approximately a half of the highest $R_s$,, allowing wide selection of $R_s$ and $I_c$'s. This design provides a practical wav of connecting small SFCL components in series for high voltage application.

• 농업과학연구
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• 제39권2호
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• pp.189-194
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• 2012

It is well-known fact that woodworking activity could contribute in enhancing creativity, scientific problem-solving ability, spatial perception ability and prosocial behavior of children. However, there is little chance that children experience woodworking at home or in kindergarten. This study was conducted to know how much children and adults have done woodworking in there daily life and how they perceived children's woodworking activity. Woodworking activities for children (N=207, 5 and 6 year old kids) with adults (N=271, only fathers) were carried out in 10 kindergartens of Cheongju. Actually, the survey result shows that very few children and adults experienced woodworking in their daily life. 62.8% of children and 34.3% of adults surveyed responded that they had never done woodworking. However, the greater part of children and adults evaluated the woodworking activity positively. Over 95% of children surveyed responded that their woodworking activity was fun and they want to play woodworking again. Over 73% of adults surveyed responded that children's woodworking activity was safe, and over 99% of adults surveyed responded that they can recommend children's woodworking activity to others. In conclusion, the development of safe tools and programs for children's woodworking activity helps its spread and activation.

• 한국화재소방학회논문지
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• 제25권6호
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• pp.156-167
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• 2011

최근 건물의 대형화, 고층화, 복잡화가 이루어지고 있으며, 건축물 화재 발생건수와 이로 인한 인명 및 재산 피해의 증가함에 따라 화재피난 시뮬레이션을 통한 건축물의 안전성 점검의 필요성이 대두되고 있다. 따라서 본 연구에서는 외산 프로그램에 의존하고 있는 화재피난 시뮬레이션 분야에 한국인의 특성을 고려한 시뮬레이션 시스템을 구현하고자 하였다. 그 결과 3차원 공간 정보 기반으로 공간의 토폴로지를 생성하고, 피난 경로를 탐색하는 화재피난 시뮬레이션을 구축하였다.

• 드라이브 ㆍ 컨트롤
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• 제9권4호
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• pp.8-13
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• 2012

Recently, researches about the eco-friendly vehicles such as hybrid electric vehicle, fuel cell vehicle and electric vehicle have been actively carried out. The regenerative braking system is a key technology to improve the vehicle energy utilization efficiency because it transforms the kinetic energy to the electric energy through the electric motor. This new braking system requires cooperative control between electric controlled brake and regenerative brake. Therefore, it is necessary to establish fault-diagnosis and fail-safe evaluation criteria to secure reliability of the regenerative braking system. In this paper, the failure types and causes in regenerative braking system were analyzed. The transient behavior characteristics were examined based on fault-diagnosis and fail-safe upon failure of regenerative braking system.

• 한국식생활문화학회지
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• 제36권3호
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• pp.284-292
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• 2021

The food service industry has grown larger with changes in the economic and socio-cultural environment. In this saturated food service industry, generation X and MZ are the main consumer forces that demand attention. That is because a generation is the main psychographic factor that reflects personal values and lifestyle based on one's life cycle. From such a perspective, a generation in marketing has been used as a variable to predict a market by supplementing demographic factors. Accordingly, this study classified generations into generation X and generation MZ with the use of the 2019 consumer behavior survey for food by Korea Rural Economic Institute (KREI) and then investigated the factors influencing group and personal dining-out expenses. The analysis was carried out applying the Tobit model using SPSS and R. The positively influential variables on generation X's personal dining-out expenditure were male, single person, high income and simple lifestyle, whereas housewives, personal ethical consciousness, behavioral ethical consciousness, and safe dietary life were negatively influential variables. The positively influential variables on generation MZ's personal dining-out expenditures were male, dual-income, high education level, corporate and governmental ethical consciousness, while the number of family members and safe dietary life were negatively influential variables.

• 청정기술
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• 제26권4호
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• pp.279-285
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• 2020

Laboratories and industrial processes typically involve the use of flammable substances. An important property used to estimate fire and explosion risk for a flammable liquid is the flash point. In this study, flash point data at 101.3 kPa were determined using a SETA closed cup flash point tester on the following solvent mixtures: {2,2,4-trimethylpentane + methylcyclohexane}, {2,2,4-trimethylpentane + ethylbenzene}, and {2,2,4-trimethylpentane + p-xylene}. The purpose of this work is to obtain flash point data for binary mixtures of 2,2,4-trimethylpentane with three hydrocarbons (methylcyclohexane, ethylbenzene, and p-xylene), which are representative compounds of the main aromatic hydrocarbon fractions of petroleum. The measured flash points are compared with the predicted values calculated using the GE models' activity coefficient patterns: the Wilson, the Non-Random Two-Liquid (NRTL), and the UNIversal QUAsiChemical (UNIQUAC) models. The non-ideality of the mixture is also considered. The average absolute deviation between the predicted and measured lower flash point s is less than 1.99 K, except when Raoult's law is calculated. In addition, the minimum flash point behavior is not observed in any of the three binary systems. This work's predicted results can be applied to design safe petrochemical processes, such as identifying safe storage conditions for non-ideal solutions containing volatile components.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제28권2호
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• pp.7-16
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• 2022

Purpose: This study aimed to present an analysis model evaluating evacuation performance considering patient types and procedural evacuation in the medical facility. The user group of the medical facility, including users challenged in evacuation behavior, entails the risk of many casualties. Therefore, it is necessary to plan an evacuation procedure that considers the evacuation characteristics of users. Methods: Through the review of precedent studies, the evacuation procedure of the medical facility, the classification of patient types, and the evacuation procedure was set as conditions and variables for the analysis. The result caused by a variety of conditions and variables were explored. Results: 1) The total evacuation completion time and congestion time were shortened at the procedural evacuation. Moreover, it derived many users from evacuating at the initial phase. 2) The proposed model can provide a basis for proposing a space planning direction that considers the possibility of not carrying out the evacuation plan. 3) It supports safe evacuation by identifying variables that reduce overcrowding by comparing the congestion time of overcrowded spaces. 4) The analysis model can identify the overcrowded space through the evacuation route and suggest the basis for architectural improvements that reduce overcrowding. Implications: The study results can be used to analyze the performance of evacuation procedures and support the establishment of evacuation procedures and building plans for safe evacuation for medical facilities.

• 한국산학기술학회논문지
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• 제14권7호
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• pp.3502-3507
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• 2013

스카이브릿지가 연결되는 건물에 강접합될 경우에는 비정형성이 크게 되어 지진하중에 매우 불리하게 거동할 수 있다. 따라서, 마찰진자베어링(FPS)이나 납고무베어링(LRB)와 같은 연결시스템을 사용하여 스카이브릿지와 구조물을 연결하게 된다. 이러한 연결시스템은 큰 지진하중이 발생하였을 때 스카이브릿지가 연결된 건물에서 분리되어 낙교하지 않도록 신중하게 설계되어야 한다. 본 논문에서는 수직방향 인장력에대해서 저항성이 없는 마찰진자감쇠기를 이용한 연결시스템을 설계하는 과정에서 반드시 검토해야할 사항을 분석하였다. 이를 위하여 실제 시공된 누리꿈 스퀘어를 예제구조물로 선택하였고 예상되는 지진하중이 가해졌을 때 스카이브릿지 연결시스템에서 발생하는 응답을 분석하여 낙교를 방지할 수 있는 설계 프로세스를 정립하였다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2008년도 정기 학술대회
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• pp.397-401
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• 2008

Knowledge of dynamic characteristics of structural elements often can make difference between success and failure in the design of structure due to resonance effect. In this paper an analytical model of a cantilever beam having midpoint load is considered for structural optimization. This involves creating the geometry which allows parametric study of all design variables. For that purpose optimization of cantilever beam is elaborated in order to find the optimum geometry which minimizes its volume eventually for minimum weight using ANSYS. But such geometry could be obtained by different combinations of width and height, so that it may have the same cross sectional area yet different dynamic behavior. So for optimum safe design, besides minimum volume it should have minimum vibration as well. In order to predict vibration different dynamic analyses are performed simultaneously to solve the eigenvalues problem assuming no damping initially through MATLAB simulations using state space form for modal analysis, which identifies the resonant frequencies and mode shapes belonging to the lowest three modes of vibration. And next by introducing damping effects tip displacement, bending stress and the vertical reaction force at the fixed end is evaluated under some dynamic load of varying frequency, and finally it is discussed how resonance can be avoided for particular design. Investigation of results clearly shows that only structural analysis is not enough to predict the optimum values of dimension for safe design. Potentially this technique will meet maintenance and cost goals of many organizations particularly for the application where dynamic loading is invertible and helps a lot ensuring that the proposed design will be safe for both static and dynamic conditions.

• Human Ecology Research
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• 제62권1호
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• pp.181-196
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• 2024

This study examined the influence of perceptions of food risk and food labeling on the purchase of labeled food items and the intention to pay higher prices for safe food. Data were obtained from the Korea Rural Economic Institute's Consumer Behavior Survey for Food 2020. The analysis focused on the responses of 6,355 consumers, all of whom were mainly responsible for food purchases. The analysis investigated the moderating effect of food risk perception on the relationship between food labeling perception and the purchase of labeled food. Regarding the purchase of labeled food, statistically significant effects were noted for gender, educational level, perception of food labeling, and perception of food risk; however, the interaction effect of perceptions of food labeling and food risk was not statistically significant. With regard to the intention to pay higher prices for safe food, except for age, statistically significant effects were observed for gender, educational level, food expenditure, perception of food labeling, and perception of food risk; moreover, the interaction effect of perceptions of food labeling and food risk was significant. The results indicate that consumers reporting low food labeling perception and low purchase of labeled food were most vulnerable regarding food safety; therefore, it is necessary to provide such consumers with food label provision methods and specified education programs.