• Journal of the Korean Institute of Gas
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• v.25 no.6
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• pp.92-97
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• 2021

In accordance with the revision of the Enforcement Regulations of the High-Pressure Gas Safety Management Act in February 2021, from August 27, 2021, the operation status of safety devices such as gas leak detection and alarm devices, emergency shut-off devices and flame detectors installed at hydrogen vehicle charging stations can be monitored in real time. It is transmitted and operated by the computer system managed by Korea Gas Safety Corporations. We intend to share the results of statistical analysis of abnormal signals that have occurred along with the results of the monitoring system construction so that they can be used for the safety management of hydrogen refueling stations, and to seek future safety management directions.

• Journal of Technology Innovation
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• v.26 no.4
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• pp.1-28
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• 2018

With the growing number of emerging carmakers, automotive parts manufacturers have to penetrate into emerging markets. They can provide large existing carmakers with fully customized parts because of economies scale, but cannot do this for small emerging carmakers due to their small and highly volatile volume order. Once the order by an emerging carmaker is placed, a part manufacturer is exposed to high risks both of decrease in profit margin and high opportunity cost. The platform-based mass customization can be a solution for cost reduction, but the risks of volatility in volume hard to manage. Tackling this issue, we presents a method of optimizing the product portfolio to maximize profits while managing volatility of volume order by emerging carmakers at an affordable level. It is the first robust product portfolio method to keep the scaled deviation of profits at a fixed level under volume order uncertainty. Also, the effect of on the platform-based mass customization on cost is considered. This model can be a building block of conservative market penetration as well as product development strategy while minimizing the financial risks. We conducted an empirical study of a part manufacturer targeting on eighteen automobile manufacturers in North America, Europe and Asia with it powered lift gate.

• The Journal of the Acoustical Society of Korea
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• v.26 no.7
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• pp.361-365
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• 2007

Aero-pulsation noise, generally caused by geometric asymmetry of a rotating device, is one of considerable sources of annoyance in passenger cars using the turbocharged diesel engine. Main source of this noise is the compressor wheel in the turbocharger system, and can be reduced by after-treatment devices such as silencers, but which may increase the manufacturing cost. More effective solution is to improve the geometric symmetry over all, or to control the quality of components by sorting out inferior ones. The latter is more simple and reasonable than the former in view of manufacturing. Thus, an appropriate discrimination method should be needed to evaluate aero-pulsation noise level at the production line. In this paper, we introduce the accurate method which can measure the noise level of aero-pulsation and also present its evaluation criteria. Besides verifying the reliability of a measurement system - a rig test system-, we analyze the correlation between the results from rig tests and those from vehicle tests. The gage R&R method is carried out to check the repeatability of measurements over 25 samples. From the result, we propose the standard specification which can discriminate inferior products from superior ones on the basis of aero-pulsation noise level.

• Korea Trade Review
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• v.42 no.1
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• pp.1-25
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• 2017

By applying the AHP(Analytic Hierarchy Process), we have analyzed the importance and the order for priorities to the management risk factors of Korean SMEs & Venture companies in China. The major management risk factors of manufacturing companies were the rise in labor costs followed by fierce competition in the marketplace, problems involved with human resource management and the rise in the cost of materials. In the case of companies manufacturing electronic products, the rise of labor costs and alteration in government's tax policy were seen as the main risk factors. In the case of chemical product manufacturing companies, the reinforcement of environmental protection law and in automobile component manufacturing companies, apart from the rise in labor cost, the increase in raw materials costs were analyzed as the main risk factors. While considering the time period, the main risk factors of the companies that entered China in the 1990's were fierce competition and alteration in government's tax policy and for the companies that entered China in the 2000's, increase in raw material cost, the rise in labor cost etc were analyzed to be the main risk management factors.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.4
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• pp.1-6
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• 2006

The tunnel is the place where brightness changes abruptly. It is important to grasp the road situation and the traffic situation of the tunnel accurately for safe and secure driving, and tunnel lighting installation should be well maintained. Luminance and illuminance of the tunnel inside should be measured periodically to maintain enough brightness. But traditional manual measurement could not guarantee the fastness and trustworthy of the measured values. In this paper, a mobile measuring system for tunnel lighting luminance and illuminance was developed and a result regarding the propriety of the system was derived.

• Transportation Technology and Policy
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• v.5 no.1
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• pp.161-171
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• 2008

아시아의 도시교통사고는 빠른 인구증가와 경제성장으로 인한 자동차 보급 확대로 인해 OECD 국가에 비해 2${\sim}$3배 높은 수준으로 교통사고절감을 위한 대안 마련이 시급한 실정이다. 이에 본고에서는 ITS기반 도로교통 안전시스템의 정착을 통해서 아시아 도시의 공통된 교통안전문제를 해소하기 위한 공동대응방안을 제시하고 있다. 이를 요약하면, 첫째, 도로사고와 ITS관계를 규명하고 사고요인을 도로상에서 제거할 수 있는 ITS기술을 소개하였다. 교통사고원인의 95%가 운전자관련인자로 나타나 운전자관련 ITS요소기술(HMI 등)의 개발이 시급한 것으로 나타났다. 또한 현재 도로 안전분야에서 적용 가능한 실용기술로는 돌발상황관리시스템, 충돌경고시스템, 비상연락시스템, 단속시스템 등인 것으로 판단된다. 둘째, ITS기반 도로교통 안전시스템의 조기 정착을 위해서는 기존 조직 법 제도의 정비가 필요하다. 아시아 도시에서는 ITS 도입 초기 정부주도형으로 추진하는 것이 바람직한데, 이를 위해서는 정부조직 내 ITS 전담기구 (Headquarter)를 신설하고, 도로안전 ITS관련 법령 및 ITS Master Plan에 근거한 권한과 사업, 예산을 확보해야한다. 또한 인프라 및 ITS 구축 운영과 함께 RSA(Road Safety Audit)와 같은 선진안전제도 시스템을 벤치마킹하여 국내 현실에 맞도록 접목시켜 나가야한다. 셋째, 교통관제 (광역)정보센터, 버스센터, 구간속도단속 등 혁신적인 도로안전사업을 지속적으로 발굴 확충하여 노하우를 축적해야 한다. 넷째, 아시아 도시의 공통된 교통문제를 해소하기 위한 공동대응방안을 마련하기 위하여 각국의 노하우를 전파하고 공유하는 창구로 아시아 태평양지역 ITS포럼을 더욱 육성해야 하겠다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.10
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• pp.1987-1996
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• 2009

Recently, the color of vehicle license plate has been changed from green to white. Thus the vehicle plate recognition system used for parking management systems, speed and signal violation detection systems should be robust to the both colors. This paper presents a vehicle license plate recognition system, which works on both of green and white plate at the same time. In the proposed system, the image of license plate is taken from a captured vehicle image by using morphological information. In the next, each character region in the license plate image is extracted based on the vertical and horizontal projection of plate image and the relative position of individual characters. Finally, for the recognition process of extracted characters, PCA(Principal Component Analysis) and LDA(Linear Discriminant Analysis) are sequentially utilized. In the experiment, vehicle license plates of both green background and white background captured under irregular illumination conditions have been tested, and the relatively high extraction and recognition rates are observed.

• Journal of Korea Port Economic Association
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• v.39 no.3
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• pp.47-60
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• 2023

A thorough inventory of ship emissions, particularly ship's emission of in-port area is necessary to identify significant sources of exhaust gases such as NOx, SOx, PM, and CO₂ and trends in emission levels over time, and reduce their serious effects on the environment and human health. Therefore, the goal of this study is to assess the volume of emissions from ships in Mokpo port, which serves as a gateway to the southwest coast of Korea, using a bottom-up methodology and data from the automatic identification system (AIS) and the Korean Port Management Information System (Port-MIS). In this work, an analysis of ship movement utilizing AIS data and an actual set of data on ship specification were gathered. By examining ship movement using AIS data, We also proposed a new approach for identifying cruising/maneuvering mode. Finally, the results were classified by ship operating mode, by exhaust gas, by ship type, and by berth, which provides a thorough and in-depth analysis of the air pollution caused by ships in Mokpo port.

• Journal of Energy Engineering
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• v.25 no.4
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• pp.93-102
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• 2016

Vehicle-to-Grid (V2G) system, bi-direction power trading technology, enables drivers possessing electric vehicle to sell the spare electricity charged in the vehicle to power distribution company. The drivers gain profit by charging electricity in the day time of high electricity rate. In this regard, the government is preparing the policies of building and supporting V2G infrastructure and demanding the potential consumers' preference for the V2G system. This paper attempts to analyze the consumers' preference using the data from obtained a survey of randomly selected 1,000 individuals. To this end, choice experiment, an economic technique, is employed here. The attributes considered in the study are residual amount of electricity, electricity trading hours, required plug-in time, and price measured as an amount additional to current gasoline vehicle price. The multinomial logit model, which requires the assumption of 'independence of irrelevant alternatives', is applied but the assumption could not be satisfied in our data. Thus, we finally utilized nested logit model which does not require the assumption. All the parameter estimates in the utility function are statistically significant at the 10% level. The estimation results show that the marginal willingness to pay (MWTP) for one hour increase in electricity trading hours is estimated to be KRW 1,601,057. On the other hand, a one percent reduction in residual amount of electricity and one hour reduction in required plug-in time in V2G system are computed to be KRW -91,911 and -470,619, respectively. The findings can provide policy makers with useful information for decision-making about introducing and managing V2G system.

• Journal of Adhesion and Interface
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• v.10 no.3
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• pp.127-133
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• 2009

Acrylic pressure sensitive adhesives (PSAs) are used in various field of high-technology industries such as semiconductor, display, mobile, automobile, and so on. Because of they have high durabilities and can be easily introduced functional groups in their molecular structures. PSA perfomances has an effect on their applications in industry process operation, reliability of final products. In this study, PSA performances as a function of fim thickness which is one of the impact factors effects on PSA performances will be investigated using combinatorial methods. Acrylic PSAs are synthesized using 2-ethylhexyl acrylate and acrylic acid. Thickness-gradient of acrylic PSA sample is made by a micro applicator. We compare general coating method with thickness-gradient coating method and evaluate the reappearance of combinatorial methods compared with existing coating method. Thickness-gradient of acrylic PSA sample shows rough and broad data tendency.