• 드라이브 ㆍ 컨트롤
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• 제19권4호
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• pp.29-35
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• 2022

In this paper, we developed a workload index for monitoring the durability test using operation information of an excavator. First, the acceleration and cylinder pressure were selected as load factors by analyzing operation data. Through load correlation analysis according to each load factor, Root Mean Square (RMS) and Work Load Range (WLR) were respectively derived as a load feature representing mechanical load. In addition, the workload index was used to quantify load features. For applying the workload index to monitoring, a real-time monitoring system consisting of sensors and embedded controller was installed on the excavator and the system was integrated with a remote monitoring environment using a wireless network. Results of load monitoring and analysis verified that the developed workload index was effective from the viewpoint of the relative comparison of the workload.

• 드라이브 ㆍ 컨트롤
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• 제19권3호
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• pp.39-46
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• 2022

In South Korea, to evaluate the rollover safety of domestic vehicles, the maximum slope angle of the vehicle is specified, which is verified by the rollover safety test of driving vehicles. However, the domestic rollover safety test is not suitable for buses, because the small amount of static stability factor (SSF) will invalidate the rollover experimental equation due to the high center of mass position of buses. To solve the above problems, a dynamic model of the bus is prepared with assumptions of mass and suspension spring properties. Subsequently, the maximum slope angle of the model was computed by using the simulation of multi-body dynamics, and the result was compared with actual test results to validate the dynamics model. Also, the rollover Fishhook (roll stability) test was conducted in the simulation for driving model. During the simulation, roll angle and roll rate were calculated to check if a rollover occurred. Through the rollover simulation of buses, the domestically regulated formula for rollover safety and the procedure of rollover test for driving vehicles are evaluated. The conclusion is that the present regulation of rollover test should be reconsidered for buses to ensure to get the valid results for rollover safety.

• 벤처창업연구
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• 제16권2호
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• pp.79-93
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• 2021

'왜?'창업을 하려는 지에 대한 질문은 어떠한 특정의 행동을 하려는 데에 대한 가장 기초적인 단계라고 할 수 있다. 즉, 어떠한 특정의 목적을 설정함에 있어서 개인은 자신의 결정에 대한 확신의 정도가 영향을 미친다는 선행연구들이 존재하고 있다. 이에 근거하여 본 연구는 성격 5요인을 매개로 한 대학생의 목표 지향적 행동모델이 자기결정성 및 창업의지에 미치는 영향을 분석하여 대학생의 창업교육 방향성 도출을 위한 기초자료를 제공하는 데 목적을 두고 있다 연구목적을 달성하기 위해 서울 경기도 지역에 소재한 국공립 및 사립 대학교에 재학하면서 벤처 동아리에 소속된 대학생을 대상으로 2019년 10월 01일에서 11월 11일까지 자기보고식 설문을 실시하였고, 연구결과를 요약하면 다음과 같다. 첫째, 대학생들의 목표 지향적 행동모델이 자기결정성에 미치는 영향을 살펴보면, 태도와 주관적 규범, 지각된 행동통제가 통계적으로 유의미한 정적 영향을 미쳤고, 긍정적 기대와 부정적 기대는 통계적으로 유의미한 영향을 미치지 않았다. 둘째, 대학생들의 목표 지향적 행동모델이 창업의지에 미치는 영향을 살펴보면, 지각된 행동통제와 긍정적 기대는 통계적으로 유의미한 정적 영향을 미쳤으며, 부정적 기대는 통계적으로 유의미한 부적 영향을 미쳤다. 셋째, 회귀모델 I에서는 대학생의 창업의지와 목표 지향적 행동모델 중에 지각된 행동통제, 긍정적 기대가 통계적으로 유의미한 정적 영향을 미쳤고, 부정적 기대는 통계적으로 유의미한 부적 영향을 미쳤다. 성격 5요인을 매개변수로 투입한 회귀모델 II에서는 지각된 행동통제, 긍정적 기대가 통계적으로 유의미한 정적 영향을 미쳤고, 부정적 기대는 통계적으로 유의미한 부적 영향을 미쳤다. 본 연구는 대학생의 목표 지향적 행동모델이 자기결정성 및 창업의지를 실행함에 있어 중요 변인임을 확인할 수가 있었다. 또한 자신의 성격 5요인을 긍정적인 피드백으로 활용하여 자신의 삶을 계획하고 성취하기 위해 목표를 세우고 계획하고 활용할 수 있는 성격을 매개역할이 확인되어 중요한 역할을 수행하고 있음이 증명 되었다.

• Nutritional Sciences
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• 제8권3호
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• pp.189-195
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• 2005

To assess the effect of pinitol supplementation and strength training for two weeks on the anaerobic capacity during and after exercise, and improvement of glucose metabolism during the recovery period of muscular fatigue with repeated acute bouts of cycling exercise, a total of 24 healthy young men were recruited and randomly and equally divided into three groups; pinitol supplementation group (PSG), placebo group (PLG), and control group (CON). Using a randomized double-blinded design, subjects in PSG were provided pinitol supplement, consumed orally 1.2 g/day, and participated in the resistance exercise program and cycling exercise for two weeks. Subjects in PLG underwent the same protocol as those in PSG but consumed the same amount of placebo. No supplementation and exercise program was given to CON. Before and after the intervention, all subjects were tested for their anaerobic capacities evaluated by Wingate test twice separated by 30 min. During the test, peak anaerobic power (PP), mean anaerobic power, total work, and fatigue index were evaluated During resting and recovery, blood samples were drawn and plasma pinitol, myo-inositol, chiro-inositol, insulin, free fatty acid, glucose, and lactate levels were analyzed After two weeks, PP and relative PP of the second biking were improved from the first biking in PSG only (p<0.05). No changes were found in all other variables of Wingate test in all groups. No statistical differences between groups and pre- and post-intervention were observed in concentrations of pinitol, myo-inositol, and chiro-inositol, but pinitol concentration was higher during recovery compared to the baseline in all groups and testings (p<0.05). Lactate level during recovery was higher than the resting level, but no other blood parameters were significantly changed. In conclusion, two weeks of pinitol supplementation in conjunction with short duration of anaerobic training in healthy young men did not induce any obvious benefits in terms of anaerobic capacity and energy metabolism Individual and/or population susceptibility may be one factor responsible for adopting pinitol supplementation.

• Asian Journal for Public Opinion Research
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• 제5권1호
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• pp.41-62
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• 2017

The political reformation in Indonesia is a determinant factor of the change in political communications and the roles of media. Currently, the political elites need media support, since it contextually has a significant role. Whoever has a good relationship with the media, will be loved by the public. On the other hand, the media also have a vested interest in the elite in running businesses and building the power of industry. Policies and capital pose a challenge to maintaining the continuity of the media. Independence and control of media are at stake, when the interests of the media and the elite collaborate with each other and then build a benefit on both sides. Meanwhile, the role of social media also cannot be neglected. The Indonesian political communication system is characterized by the presence of social media in a pseudo-relationship between the elite and the public. This paper tries to explain the growing trends of research in the academic environment and the research trends in political practice in Indonesia after the occurrence of post-reformation era in legislative and executive elections. The method used is the meta-analysis of research outcomes of university (dissertations) and secondary data sources. Data processing is done by meta-analysis of secondary data. The results of meta-analysis research indicate that, the objective conditions, in Indonesia, especially the political conditions, stimulate new spaces in communication research. The study of political communication becomes dominant in the academic environment. In addition, communication research is also characterized by a shift from the linear perspective (positivistic paradigm) to the interactive perspective (naturalistic paradigm). On the other hand, the development of politic and governance situations in Indonesia has prompted the establishment of polling agencies that help citizens understand the maps of political power and candidates in general elections and regional head elections.

• 한국정밀공학회지
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• 제23권2호
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• pp.199-206
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• 2006

Automatic grease lubricator is equipment that provides adequate amount of fresh grease constantly to the shaft and the bearings of machines. It minimizes the friction heat and reduces the friction loss of machines to the least. This research is to develop automatic grease lubricator by gear driven mechanism with controlled operation time. The ultimate design of this equipment is to lubricate an adequate amount of grease by a simple switch clicking according to the advanced set cycle. The backlash of the gear was minimized to increase the output power. To increase the power of gear mechanism, the binding frequency and the thickness of the coil were changed. To control the rotating cycles of the main shaft according to its set numbers, different resistance and chips were used to design the circuit to controls electrical signals with pulse. The body of the lubricator was analyzed by stress analysis with different constructed angle. The stress analysis for differing loading pressures applied to the exterior body of grease lubricator due to the setup angle, was found that the maximum stress was distributed over the outlet part where the grease lubricator suddenly narrowed contracts. Digital mock-up was analyzed and the rapid prototyping(RP) trial products were tested with PCB circuit and grease. The evaluation of the outlet capacity for RP trial products was conducted, because the friction caused by the outlet on the wall surface was an important factor in the operation of the equipment. Finally, the finishing process was applied to decrease the roughness of the surface to a comparable level and was able to test the performance examination for the product.

• 한국산학기술학회논문지
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• 제14권9호
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• pp.4447-4454
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• 2013

2011년 10월 국내 최초로 다목적댐 저수지에 100kW급 수상태양광발전 상용화 실증 플랜트가 합천댐에 설치되었다. 수상태양광발전 설비는 육상에 설치하는 태양광발전 설비와는 달리 수상부유체, 계류장치, 수중케이블 등 설치에 많은 어려움이 있다. 특히 수상이라는 환경적 제약으로 인해 육상 태양광 시공 방법으로 공정 관리를 할 수 없는 많은 변수가 속출한다. 수상태양광발전의 구조체는 수상태양광 모듈 및 기타 전기설비를 수상에 부상시키기 위한 설비로서 바람이나 태풍 등 기상환경에 견뎌야 하고 수질에 악영향을 미치지 말아야하며 시공성, 경제성 등 종합적인 고려가 필요하다. 본 논문에서는 100kW 수상태양광 시공사례를 바탕으로 수상태양광의 구조체, 계류장치, 수중케이블, 전력설비 및 원격감시제어시스템의 시공기술에 대한 기초자료를 제공하였다. 본 연구에서 시공된 100kW 수상태양광은 현재 평균 설비이용률 15%로 운영중에 있다.

• Nuclear Engineering and Technology
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• 제52권5호
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• pp.869-877
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• 2020

A 24-month Advanced Power Reactor 1400 (APR1400) core with a very-low-boron (VLB) concentration has been investigated for an inherently safe and high-performance PWR in this work. To develop a high-performance APR1400 which is able to do the passive frequency control operation, VLB feature is essential. In this paper, the centrally-shielded burnable absorber (CSBA) is utilized for an efficient VLB operation in the 24-month cycle APR1400 core. This innovative design of the VLB APR1400 core includes the optimization of burnable absorber and loading pattern as well as axial cutback for a 24-month cycle operation. In addition to CSBA, an Er-doped guide thimble is also introduced for partial management of the excess reactivity and local peaking factor. To improve the neutron economy of the core, two alternative radial reflectors are adopted in this study, which are SS-304 and ZrO₂. The core reactivity and power distributions for a 2-batch equilibrium cycle are analyzed and compared for each reflector design. Numerical results show that a VLB core can be successfully designed with 24-month cycle and the cycle length is improved significantly with the alternative reflectors. The neutronic analyses are performed using the Monte Carlo Serpent code and 3-D diffusion code COREDAX-2 with the ENDF/B-VII.1.

• 대한안전경영과학회지
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• 제24권1호
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• pp.61-72
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• 2022

This study aims to propose a conceptual design of information displays for supporting responsive actions under severe accidents in Nuclear Power Plants (NPPs). Severe accidents in NPPs can be defined as accident conditions that are more severe than a design basis accident and involving significant core degradation. Since the Fukushima accident in 2011, the management of severe accidents is increasing important in nuclear industry. Dealing with severe accidents involves several cognitively complex activities, such as situation assessment; accordingly, it is significant to provide human operators with appropriate knowledge support in their cognitive activities. Currently, severe accident management guidelines (SAMG) have been developed for this purpose. However, it is also inevitable to develop information displays for supporting the management of severe accidents, with which human operators can monitor, control, and diagnose the states of NPPs under severe accident situations. It has been reported that Ecological Interface Design (EID) framework can be a viable approach for developing information displays used in complex socio-technical systems such as NPPs. Considering the design principles underlying the EID, we can say that EID-based information displays can be useful for dealing with severe accidents effectively. This study developed a conceptual design of information displays to be used in severe accidents, following the stipulated design process and principles of the EID framework. We particularly attempted to develop a conceptual design to make visible the principle knowledge to be used for coping with dynamically changing situations of NPPs under severe accidents.

• 한국인터넷방송통신학회논문지
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• 제22권4호
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• pp.127-132
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• 2022

철도차량에 탑재된 전장품 중 가장 큰 하중을 차지하는 것은 주변압기로 낮은 운전 주파수(60Hz)로 인해 전력밀도가 0.2~0.4 MVA/ton 정도로 낮아 경량화에 중요한 요소로 작용하고 있다. 따라서 철도차량용 주변압기를 개선하기 위해 몰드 변압기, 반도체 변압기 등에 관한 연구가 국내외적으로 활발히 진행 중이다. 한편 국내외 철도차량에 대부분 적용되는 견인전동기로 최근에는 유도전동기를 대체하여 영구자석 동기전동기(PMSM)를 적용하려는 시도가 이루어지고 있다. 영구자석 동기전동기(PMSM)는 유도전동기에 비해 높은 출력밀도와 효율 확보가 가능하지만 제작에 필요한 재료의 가격이 비싸고 설계가 유도전동기 대비 다소 어렵다는 단점이 있다. 이러한 문제점을 고려하여 본 논문에서는 소형 경량화가 가능한 반도체 변압기를 적용하고, 철도차량의 경량화, 고효율화 등의 요구사항에 맞춰 구조가 간단하면서 회전수가 높고 고토크, 저비용인 SRM을 적용할 수 있는 연구내용을 제안하고자 한다.