• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1845-1850
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• 2003

The underground utility tunnels are important facility as a mainstay of country because of communication developments. The communication and electrical duct banks as well as various utility lines for urban life are installed in the underground utility tunnel systems. If a fire breaks out in this life-line tunnel, the function of the city will be discontinued and the huge damages are occurred. In order to improve the safety of life-line tunnel systems and the fire detection, the behaviors of the fire-induced smoke flow and temperature distribution are investigated. In this study we assumed that the fire is occurred at the contact or connection points of cable. Numerical calculations are carried out using different velocity of ventilation in utility tunnel. The fire source is modeled as a volumetric heat source. Three-dimensional flow and thermal characteristics in the underground tunnel are solved by means of FVM (Finite Volume Method) using SIMPLE algorithm and standard ${\kappa}-{\varepsilon}$ model for Reynolds stress terms. The numerical results of the fire-induced flow characteristics in an underground utility tunnel with different velocity of ventilation are graphically prepared and discussed.

• Asian-Australasian Journal of Animal Sciences
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• 제19권2호
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• pp.262-265
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• 2006

The antioxidative properties of lactobacilli originating from humans (Lactobacillus acidophilus KCTC 3111, Lactobacillus jonsonii KCTC 3141, Lactobacillus acidophilus KCTC 3151, and Lactobacillus brevis KCTC 3498) were investigated using in vitro methods, including inhibition of lipid peroxidation, resistance to hydrogen peroxide and hydroxyl radical, hydroxyl radical scavenging activity, and glutathione peroxidase (GPX) activity. L. acidophilus KCTC 3111 showed the highest inhibition of lipid peroxidation in both intact cells (49.7%) and cell lysate (65.2%). This strain exhibited resistance to hydrogen peroxide and hydroxyl radical, which was viable for 7 h in the concentration of 1.0 mM hydrogen peroxide. In addition, this strain showed high hydroxyl radical scavenging activity. In the GPX activity assay, the highest activity was measured in L. brevis 3498. GPX activity of L acidophilus 3111 was lower than that of L. brevis 3498.

• 전력전자학회논문지
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• 제3권4호
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• pp.323-329
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• 1998

계통연계형 태양광발전시스템을 PWM 쵸퍼와 전류형 인버터로 구성하였다. 전류형 인버터의 직류리액터를 경감하는 방법으로, 직류측에 병렬공진회로를 삽입함에 따라 맥동전력의 일부를 교류 전해콘덴서에 축적하여 직류전류의 맥동을 억제하는 방법과, 쵸퍼의 변조파를 전원주파수의 2배로 제어하여 직류전류의 맥동을 억제하는 것을 비교 검토하였다. 그리고 태양전지전류와 쵸퍼의 변조율만을 이용하여 태양전지가 항상 최대출력점에서 동작하도록 하였다. 계통과 연계함으로서 출력전력이 부하전력보다 큰 경우에는 잉영전력을 계통전원에 공급하고, 발전전력 부하전력에 대해 부족한 경우에는 계통전원이 부족분을 공급하는 것을 확인하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권1호
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• pp.193-214
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• 2017

In this paper, we study the problem of network utility maximization in a CSMA based multi-hop wireless network. Existing work in this aspect typically adopted continuous time Markov model for performance modelling, which fails to consider the channel conflict impact in actual CSMA networks. To maximize the utility of a CSMA based wireless network with channel conflict, in this paper, we first model its weighted network capacity (i.e., network capacity weighted by link queue length) and then propose a distributed link scheduling algorithm, called CSMA based Maximal-Weight Scheduling (C-MWS), to maximize the weighted network capacity. We derive the upper and lower bounds of network utility based on C-MWS. The derived bounds can help us to tune the C-MWS parameters for C-MWS to work in a distributed wireless network. Simulation results show that the joint optimization based on C-MWS can achieve near-optimal network utility when appropriate algorithm parameters are chosen and also show that the derived utility upper bound is very tight.

• 한국문헌정보학회지
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• 제37권2호
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• pp.107-134
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• 2003

이 연구의 목적은 우리 도서관이 생산해 내고 있는 목록의 가치를 '유용성'의 관점에서 논의하는데 있다. 특히, 도서관 이용자의 관점에서 도서관목록이 그들의 정보요구를 충족시키는데 얼마나 유용하게 활용되고 있는지에 대해 실증적으로 분석해 보고자 하였다. 이를 위해, 목록이용자들의 견해를 중시하면서 도서관목록의 유용성을 측정해 낼 수 있는 체계적인 기준을 도출하였다. 그리고 이러한 기준에 근거하여 현 단계 도서관목록의 유용성을 직접 측정하였다. 유용성에 대한 측정 결과는 구체적인 사례와 함께 제시하였으며, 유용성을 저하시키는 요인을 상세하게 설명하였다.

• 아태비즈니스연구
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• 제12권4호
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• pp.241-251
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• 2021

Purpose - Drawing on the content-process approach, this study examines the effect of employees' perceived utility of education and training in small and medium enterprises (SMEs) on their satisfaction. In addition, this study investigates how the human resource management department' activities moderate the relationship between employees' perceived utility of education and training and satisfaction. Design/methodology/approach - This study predicts the positive relationship between employees' perceived utility of education and training and satisfaction, and HR activities strengthens this positive relationship. To test these hypotheses, this study utilized Human Capital Corporate Panel (HCCP) datasets, especially 2017 data at the individual level. The number of the final sample is 425 for the test. Moreover, this study used the hierarchical regression model with SPSS. Finding - As predicted, the analytical results with the hierarchical regression model showed that employees' percieved utility of education and training and satisfaction were positively related. In addition, HR activities strengthened this relationship between employees' percieved utility of education and training and satisfaction. Research implications or Originality - This study will provide academic and practical implications for future research on human resource development, especially SMEs by deepening an understanding of the important factors in order to increase employees' satisfaction of education and training. the number of viewers is found in most American films released in Korea.

• 복식문화연구
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• 제30권6호
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• pp.919-932
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• 2022

This study analyzed the trends of applications for patents, utility models, and designs related to leggings in order to understand the trend of development of technologies for leggings products that are continuously growing in the fashion market. In this study, trends in patent, utility model, and design applications related to leggings products filed from 2001 to 2020 with the Korean Intellectual Property Office were analyzed. As a result, first, the trends of applications for patents, utility models, and designs by year showed that the applications began to rise from 2006 and increased sharply in the 2010s. Second, applications for patents and utility models were analyzed by subject and, according to the results, the applications for compression shaping functionality were the most frequent, followed by those for construction/sewing, those for accessories and others, those for system/device, and those for multi-functionality. Third, when applications for designs were classified by target for wearing and by type of leggings, applications for general leggings designs were the most frequently filed, followed by applications for: item attachment type leggings, shapewear leggings, leggings for men, leggings for pregnant women, leggings for children, and leggings for the disabled. Although this study is limited to domestic patents, utility models, and design applications, it collected useful information related to leggings products and presented directions for future development.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2004년도 학술대회 논문집
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• pp.233-235
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• 2004

This paper studies protective coordination of utility interconnected multiple distirbuted generations(DG). The study of protective coordination interconnected DG has been conducted. A protective coordination of utility disturbed by reverse current of DG. Therefore, A protetive device is not operate when reverse current flows. In this paper, we use phase difference between V and I. Also, we studied protective coordination algorithm of utility interconnected multiple DG.

• 기술사
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• 제33권4호
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• pp.27-32
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• 2000

The automatic utility program in electrical facilities has specially developed to fulfill the needs of electric CAD designers . Designers had separately managed the designing factors such as design, estimates and calculation sheets . However, this automatic utility program produces calculation sheets and volume reports simultaneously while designed. The program also accumulates all data automatically in database in order to be utilized as the statistics and the design data for later project management. Moreover, it is easy for new and inexperienced users to access by using the standard electric symbol libraries and utility modules.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 F
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• pp.2601-2603
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• 1999

This paper describes on the development of Controller for the Utility Car combined photovoltaic. The Utility Car is generally composed of Controller, separately excited DC motor. battery and potbox. According to using battery, Utility Car have the problem of small operation time. So operating time is expanded by using parallel operating sollar cell and battery.