• 한국콘텐츠학회논문지
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• 제22권10호
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• pp.526-534
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• 2022

국토교통부에서는 2014년 8월 국가와 민간이 따로 추진하던 교통정보의 수집과 제공에 대한 투자효율 및 효과를 극대화 시기키 위해 민·관이 역할을 분담한 ITS 혁신방안을 마련한 바 있다. 혁신방안의 주요내용은 교통정보의 민·관 공유로 소통정보는 민간이 수집하는 정보를 활용하고 국가는 공사, 사고, 기상악화 등 돌발상황과 같은 안전과 관련된 정보 수집에 집중하여 특정 지점에 설치되어 실시간 돌발 상황 제공에 한계가 있는 도로전광표지판 이외에 스마트폰, 내비게이션을 통해서도 안전과 관련된 정보를 실시간으로 제공하는 것이다. 본 연구에서는 실제 공공 및 민간 교통정보 공유에 따른 국도 ITS 추진의 효율성을 기하기 위해 일반국도 교통정보제공 사례 분석을 통해 민간 교통정보를 포함한 연계 교통정보의 문제점을 분석하여 교통정보제공 정확성 향상을 위한 연계 교통정보 우선순위 조정안을 제시하였으며 기존 ITS 운영구간에 대한 교통량 수준, 연계 교통정보의 가용성 등을 분석하여 ITS 수집장비의 운영 또는 철거여부를 검토하였고 아울러 해당사례를 토대로 ITS 수집장비 설치 판단기준을 제시하였다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2004년도 학술대회 논문집
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• pp.237-240
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• 2004

For the paralleled operation of DC/DC converters, the current sharing between each modules is the most important for the reliability of the power system. Interleaving method is commonly used with many paralleling schemes for the reduction of the ripple in the output voltage of paralleled converters and there are many commercial IC for interleaving application appliable. But for all of them, it is impossible to detect the number of module in operating and then change the phase of them automatically. In this paper, a novel paralleling method is proposed for the converter parallel operation, which detects the number of modules in active and sets the phases of PWM signals applied to each modules autonomously. This can greatly improve the output voltage ripple and reliability of the system. The expandibility of modular number can be done very easily by just adding several parts.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2007년도 춘계학술대회 논문집
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• pp.235-240
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• 2007

A large power fuel cell generation system needs a parallel operation of de-de boost converter. Therefore, this paper proposed parallel operation algorithms of de-de boost converters for the large scale fuel cell generation system of 250[kW] and the operating principle along with the control method in detail. This paper uses a maximum current sharing method as a parallel operation method and also the phase shift full bridge de-de converter as a de-de boost converter. Simulation and experimental results on two prototype converter modules of 500W show that the parallel operation method can be applied to the 250[kW] power converter.

• 조명전기설비학회논문지
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• 제23권11호
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• pp.44-51
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• 2009

A variety of Urban Rail Transit (URT) systems have been operating and they have different technology bases, causing a lot of difficulties in taking measures against trouble, training, upgrading, interoperability and so on. As such, a standardization project has been carried out to solve the problems by setting up the national standards for URT systems. A common database was built to provide the integrated engineering environment to the community of URT project. This paper discusses the design of the database and how it can be utilized in the successful promotion of the project. The products of the projects are stored into the database with traceability management to be referred to by other new URT projects for reusing and sharing the acquired knowledge through cross organizations.

• 조명전기설비학회논문지
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• 제28권5호
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• pp.68-75
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• 2014

Cascaded applications of surge protective devices(SPDs) are required in order to reduce the stress on the electrical and electronics equipment being protected, and the energy coordination between the cascaded SPDs is very important. This paper deals with the experimental results obtained from the installation conditions of full-scale SPDs. The energy coordination between the upstream Class I SPD and the downstream Class II SPD was measured using a $10/350{\mu}s$ impulse current due to direct lightning flashes. The distances between the cascaded SPDs were 3, 10, and 50m, and the maximum test current was 12.5kA. As a result, the energy sharing between cascaded SPDs was dependent on the voltage protection level of each SPD and the distance between two SPDs. An overview of how to select SPD ratings in applications of cascaded SPDs system was discussed based on the energy coordination between the two SPDs. The proposed test results for the energy coordination between two-stage cascaded SPDs can be used in effective applications of SPDs.

• Advances in Energy Research
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• 제8권4호
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• pp.243-252
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• 2022

The hybrid wind-solar energy concept has a big influence on the spread of wind and solar power projects in India since it combines the benefits of both industries while also providing extra benefits such as resource sharing such as land, infrastructure, and power evacuation systems. Furthermore, while the hybrid policy may reduce certain barriers to the installation of wind and solar energy in India, there are still some issues that must be resolved rapidly in order to ensure a sustainable installation. According to the study's findings, the installation of wind and solar power plants is significantly influenced by energy policy. The wind-solar hybrid energy strategy will also be crucial in the near future for growing the usage of renewable energy sources. Aside from that, the establishment of Green Energy Open Access (GEOA) and the restart of the trading of Renewable Energy Certificates (REC) would promote the quick deployment of standalone and hybrid renewable power projects throughout the nation, enabling it to reach 500 GW of installed non-fossil energy capacity by 2030.

• 조명전기설비학회논문지
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• 제29권6호
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• pp.70-77
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• 2015

This paper describes the experimental results obtained from various installation conditions of cascaded metal oxide varistor(MOV)-based SPDs with the objectives to analyze the coordination of the cascaded surge protective devices(SPDs) and to propose the proper selection and installation methods of the cascaded SPDs. The residual voltage, discharge current and energy sharing between the upstream and downstream SPDs in the $10/350{\mu}s$ direct lightning current wave were measured and discussed. The coordination of cascaded MOV-based SPDs is closely related to the varistor voltage and installation methods of SPDs. In cascaded SPDs without dedicated decoupling elements, the natural impedance of leads connecting two SPDs can act as a decoupler for the coordination of MOV-based SPDs. Even if the varistor voltage of the upstream SPD is higher than that of the downstream SPD at long distances between two SPDs, the energy coordination of cascaded SPDs could effectively be fulfilled in the conditions of large surge currents and the optimum voltage protection level can be achieved. Consequently, if the distance between voltage limiting type SPDs is long, the coordination of the cascaded SPDs should be determined by taking into account the decoupling effects due to the intrinsic inductance of leads connecting the upstream and downstream SPDs.

• 대한토목학회논문집
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• 제34권5호
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• pp.1517-1524
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• 2014

최근 휘발유 가격 폭등, 기후변화 등으로 인한 사회 환경 문제가 증가함에 따라 새로운 친환경 교통수단에 대한 관심이 증가 하고 있다. 이러한 친환경 교통수단 중 하나로 유럽에서는 일찍이 공유자전거(Bike sharing)를 도입하여 운영하고 있으며, 대전시 또한 "타슈"라는 이름으로 2009년부터 서비스가 시작되고 있다. 본 연구에서는 대전시 공유자전거를 대상으로 이용효율을 높이고 최적의 공유자전거 정거장 위치결정을 위한 기초 연구로서 공유자전거 이용 특성을 알아보고 이용수요에 미치는 요인을 다중회귀분석을 이용하여 분석하는 것을 목적으로 한다. 이용특성을 살펴본 결과 공원 인근에서 공유자전거 정거장의 설치 비율에 비해 이용비율이 상대적으로 높았으며, 주중보다 주말 이용수요가 높은 것으로 나타나 대전의 경우 레저를 주목적으로 이용하고 있음을 알 수 있었다. 또한 공유자전거를 빌린 장소로 다시 회귀하는 비율이 매우 높았으며, 절대적 근접 중심성 지표를 기준으로 분석한 결과 공유자전거 정거장의 분포가 균등하게 분포되어 있지 않아 특정 지역(둔산, 유성 등)에 이용패턴이 치우쳐져 있음을 확인하였다. 이용수요에 영향을 미치는 요인으로서는 버스승하차 인원, 자전거도로 연장, 공원여부, 수변공간까지의 거리, 젊은층 비율 등이며, 선정된 변수의 신뢰도(R-Square)는 0.74 수준으로 우수한 것으로 분석되었다.

• Geomechanics and Engineering
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• 제18권4호
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• pp.363-371
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• 2019

In this study, the load carrying behavior of piled rafts installed in inclined bearing rock layer was investigated for rock-mounted and -socketed conditions. It was found that settlements induced for an inclined bearing rock layer are larger than for a horizontal layer condition. The load capacity of piled rafts for the rock-mounted condition decreased as rock-layer inclination angle (${\theta}$) increased, while vice versa for the rock-socketed condition. The load capacities of raft and piles both decreased with increasing ${\theta}$ for the rock-mounted condition. When bearing rock layer was inclined, loads carried by uphill-side piles were greater than those by downhill-side piles. The values of differential settlements of rock-mounted and -socketed conditions were not significantly different whereas slightly higher for the rock-socketed condition. The values of load sharing ratio (${\alpha}_p$) and its variation with settlement were not markedly changed by the inclination of bedrock. It was shown that ${\alpha}_p$ for piled rafts installed in rock layer was not affected by ${\theta}$ whereas actual loads carried by raft and piles may vary depending on the pile installation and rock-layer inclination conditions.

• 산업공학
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• 제13권3호
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• pp.444-454
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• 2000

Due to the improvement of modern information technologies, sharing stock information among the supply chain members is a common practice nowadays. Many companies are planning to adopt the information systems to possess the real-time shared stock information. Thus, it is needed to quantify the value of shared stock information. The purpose of this paper is to evaluate the value of the shared stock information for two-echelon distribution systems. Existing reorder policies can be classified into installation stock policies and echelon stock policies. Since installation stock policies do not utilize the shared stock information, and both classes of policies may show poor performances for distribution systems, we cannot evaluate the value of the shared stock information with the existing policies. Thus, we provide a new type of reorder policy, named order risk policy. We define the order risk using marginal analysis, and prove the optimality. Through computational experiment that compares the order risk policy with the existing policies, it is shown that a significant cost reduction is achieved with the effective utilization of the shared stock information. We also show the effect of the system characteristics on the value of the shared stock information.