• 드라이브 ㆍ 컨트롤
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• 제12권3호
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• pp.18-24
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• 2015

The plug-in hybrid electric vehicle has a high fuel economy and can be driven long distances. Its different modes include the electric vehicle, hybrid electric vehicle, and only engine operating mode. A power management strategy is important to determine which mode should be selected. The strategy makes the vehicle more efficient using appropriate power sources for driving. However, the strategy usually needs a driving speed profile which is future driving cycle. If the profile is known, the strategy easily determines which mode is driven efficiently. However, it is difficult to estimate the speed profile for a real system. To address this problem, this paper proposes a new power distribution strategy using a neural network. The average speed and driving range are used as input parameters to train the neural network system. The strategy determines a limit for the use of the battery and the desired power is distributed between the engine and the motor simultaneously. Its fuel economy can increase by improving the basic strategy.

• 한국항공운항학회지
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• 제16권2호
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• pp.1-11
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• 2008

Increasing demand for improved reliability and survivability of mission-critical systems is driving the development of health monitoring and Automated Contingency Management (ACM) systems. An ACM system is expected to adapt autonomously to fault conditions with the goal of still achieving mission objectives by allowing some degradation in system performance within permissible limits. ACM performance depends on supporting technologies like sensors and anomaly detection, diagnostic/prognostic and reasoning algorithms. This paper presents the development of a generic prototype test bench software framework for developing and validating ACM systems for advanced propulsion systems called the Propulsion ACM (PACM) Test Bench. The architecture has been implemented for a Monopropellant Propulsion System (MPS) to demonstrate the validity of the approach. A Simulink model of the MPS has been developed along with a fault injection module. It has been shown that the ACM system is capable of mitigating the failures by searching for an optimal strategy. Furthermore, the concepts of Validation and Verification (V&V) of such systems are introduced with relevant examples.

• 한국컴퓨터정보학회논문지
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• 제11권6호
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• pp.237-248
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• 2006

정부는 그 동안 공공부문의 문제점으로 지적되어 왔던 낮은 경영성과 저 생산성, 고비용 구조, 낮은 시장 대응력, 조직 운영의 비효율성 등의 문제를 해결하기 위하여 공공부문을 포함하는 정부 혁신을 강력하게 추진하고 있다. 이러한 혁신의 핵심은 체계적인 성과관리에 있다. 지방공기업 역시 경영효율성을 높이고 경쟁력을 강화하기 위해서는 무엇보다도 자율 경영 체제하에서 경영성과를 정확히 측정하고 그에 따른 보상체계를 마련하는 것이 필수적이다. 본 논문에서는 이러한 균형성과표(Balanced Scorecard)에 기반하여 다원화된 평가주체에 부합하는 지방공기업의 성과 지표에 대한 틀을 설계하고 이를 이용하여 실례로 광주광역시환경시설공단에 적용한 사례를 보이고자 한다.

• 산업경영시스템학회지
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• 제37권2호
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• pp.19-26
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• 2014

With the radical changes and advancements of industrial economy, it is required to secure product competitiveness through technological innovations to overcome uncertain environments and generate a driving force for sustainable growth. So the Korea government introduced the superior product selection system in 1996 and has granted such incentives as priority purchasing and contracts the products of SME whose technological capabilities have passed the screening criteria. After analyzing the ambiguity of the evaluation procurement used in designation of excellent product, this study proposed seven detailed indexes for evaluation.

• 한국항행학회논문지
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• 제15권6호
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• pp.1234-1240
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• 2011

최근 여러 분야에 걸쳐 기존의 감시시스템은 많은 문제점이 도출되고 있다. 이러한 문제점에 대해서 많은 연구가 활발히 진행 중이다. 따라서 본 논문에서는 각종 사고 예방 및 안전 운행에 도움을 주고, 위험 사항을 외부로 연계하거나 관리자에게 알려주며, 실시간 분석 및 파악이 가능한 지능형 영상감시시스템의 구성, 기술요소, 요구 기능과 이의 응용과 그 적용에 대하여 연구하였다.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2012년 춘계학술대회
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• pp.159-166
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• 2012

Recently, by the whole world paradigm shift to "Low Carbon Green Growth", it is required to renovate National Transportation and Logistics System. Transportation accounts for 21% of the total energy consumption and 20% of the total $CO_2$ emission, and also places its main reliance on fossil fuels. From green point of view, electric railway system is superior to the other transportation alternatives, but also required to develop the innovative technologies for high efficiency and low energy consumption. In this paper, the concept of railway green operation system by regenerative synchronized driving is presented, including the numerical example and the estimated effect.

• 한국수소및신에너지학회논문집
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• 제32권4호
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• pp.236-244
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• 2021

Fuel cell systems for medium duty truck require high power demands under driving. Since high power demands results in significant heat generation, thermal management is crucial for the performance and durability of medium duty truck. Therefore, various configurations of dual stacks with cooling systems are investigated to understand appropriate thermal management conditions. The simulation model consists of a dynamic fuel cell stack model, a cooling system model equipped with a controller, and the mounted controller applies a feedback controller to control the operating temperature. Also, In order to minimize parasitic power, the comparison of the cooling systems involved in the arrangement was divided into three case. As a result, this study compares the reaction of fuel cells to the placement of the cooling system under a variety of load conditions to find the best placement method.

• 한국융합학회논문지
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• 제6권5호
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• pp.33-38
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• 2015

V2X 카 융합서비스 환경에서, 인포테인먼트 서비스와 운전자 관리 서비스 가운데 주요 서비스는 드라이버, 유지보수 관리자, 고객, 익명의 사용자의 중요한 정보를 중심으로 지원되어야 한다. 많은 소프트웨어 어플리케이션들이 운전 관리 프로그램과 계획의 특정 요구조건을 만족하기 위해 솔루션을 고려해오고 있다. 본 논문에서는 V2X 융합서비스 환경에서 클리닉 환경설정, 클리닉, 클리닉 페이지, 맴버십, 클리닉 요청 처리, 운전자 프로파일 데이터, 클리닉 맴버십 데이터 그리고 클리닉 인증을 포함한 운전자용 차량 진단을 위한 안전한 관리 시스템의 Data flow diagram을 설명하였다. STRIDE 모델 가운데 스푸핑, 탬퍼링, 부인방지, 노출, 서비스 거부, 권한 관리와 같은, ITS 진단 시스템의 보안 위협 이슈를 중심으로 고찰하였다.

• 한국대기환경학회지
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• 제29권6호
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• pp.745-756
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• 2013

The purpose of this study is to evaluate representativeness of fuel-based emission factors. Twelve light-duty diesel vehicles which meet Euro-3 to 5 legislative emission limits were selected for emission tests. Second-by-second modal emission rates of vehicles were measured on a standard laboratory chassis dynamometer system. An off-cycle driving cycle was developed as a representative Korean real-world on-road driving cycle. Fuel-based emission factors were developed for short trip segments that involved in the selected driving cycle. Each segment was defined to have unit travel distance, which is 1 km, and characterized by its average speed and Relative Positive Acceleration (RPA). Fuel-based $NO_x$ emission factors demonstrate relatively good representativeness in terms of vehicle operation conditions. $NO_x$ emission factors are estimated to be within ${\pm}20%$ of area-wide emission factor under more than 40% of total driving situations. This result implies that the fuel-based $NO_x$ emission factor could be practically implemented into the on-road emission management strategies, such as a remote sensing device (RSD). High emitting vehicles as well as high emitting operating conditions heavily affect on the mean values and distributions of CO and THC emission factors. Few high emitting conditions are pulling up the mean value and biasing the distributions, which weaken representativeness of fuel-based CO and THC emission factors.

• 유통과학연구
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• 제20권3호
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• pp.23-31
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• 2022

Purpose: The purpose of this study is to analyze the Safety and Logistical Distribution Management system in Thailand's Highway Work Zone based on data from Logistics drivers. Accidents in highway construction zones have caused enormous casualties in Thailand yearly. Statistical data shows evidence of correlation between numbers of accidents and drivers' recklessness. Research design, data, and methodology: In this study, we conducted an in- depth interview with 414 logistics drivers and highway construction workers in Khon Kaen province, Thailand. The data was collected based on 63 questionnaires aiming at capturing factors contributing to the risk of safety and cause of accidents in logistic infrastructures such as Highway work zone. Results: The result reveals two significant factors affecting safety in highway work zone, which includes construction environment and safety management system. Moreover, the result shows that feeling of afraid and confused while driving within the construction zones significantly affecting driver's risk of having an accident. Conclusions: The findings of this study offer that a strategic planning and evaluation of the logistics drivers' satisfaction and construction workers' participation to mitigate highway accidents at construction zones and that drivers' knowledge and perception toward construction safety management plays a significant role in preventing highway accidents at the construction areas.