• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.5D
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• pp.705-717
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• 2011

The number of horizontal tower cranes, major hoisting machineries for lifting approximately 50% of entire materials in construction projects, is rapidly increasing, but a number of accidents related to the tower cranes are being continuously occurred in construction sites as well. In particular, telescoping works in the horizontal tower cranes have showed the greatest safety concerns such as falls and collapses. It is due to the fact that tasks inserting a new mast in the space made after raising telescoping cage by fluid pressure and ascending it to the required height in the telescoping works include a series of dangerous factors in safety aspects, and might cause very serious and unexpected accidents in construction sites. The primary objective of this research is to propose two conceptual models for automating the telescoping work in horizontal tower crane and conduct their technical feasibility analyses. In this study, a design concept, a position control system using hydraulic cylinders is suggested as a better alternative for automating the telescoping work. Its potential safety improvement rate compared to the conventional method is also analyzed and presented in this study.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.832-835
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• 2008

An information-oriented basis in today's society has been changing fast, and the desire for connectivity has caused an exponential growth in wireless communication and sensor network. Sensor networks using RFID, in particular, have led this trend due to the increasing exchange of data in Ubiquitous such as the home RF, access control system, U-Healthcare, and Logistics information Systems. Also, the RFID when it applies a technique, is able to raise the stability of shipping as controling the mobile course and an entrance and exit of the crews an well as previously preventing an accident from shipping. In this paper, we designed and implemented personnel control system using UHF-RFID in vessels which shows through host PC reading and writing tag.

• The Transactions of the Korean Institute of Power Electronics
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• v.6 no.2
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• pp.173-179
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• 2001

This paper represents the control algorithm of the instantaneous voltage sag corrector for the power quality enhancement in distribution line. Especially, a novel detection technique of the symmetrical components is proposed for the analysis of the three-phase unbalanced and asymmetrical problems caused by the single line ground fault which is he most frequent event. This proposed method is based on the simple calculation and the control references of the symmetrical components for voltage compensation can be described as dc value without any other phase detection procedure. And also, for the generation of the reference voltages, the UF and MF defined by IEC is considered. Using this proposed control algorithm, the compensator has the fast dynamic characteristics and the THD of the compensated voltage waveform is very low. Finally, the validity of the proposed algorithm is proved by the PSCAD/EMTDC simulation and experimental results.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.82.1-82.1
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• 2011

최근 국내에서 발생된 대규모 정전사태로 인해 안정적인 전력공급에 대한 국민들의 요구가 커져, 지난 3월 일본 후쿠시마 원전사고 이후 다시 한번 분산전원에 대한 필요성이 대두되어지고 있다. 여러 분산전원 중 연료전지는 다른 에너지원에 비해 에너지의 지속성이 우수하여 가장 안정적인 분산전원 형태의 하나이다. 이에 따라 국내의 경우 우수한 도시가스 인프라로 인해 건물용 연료전지라는 신기술에 대한 국민의 수용성은 점점 높아질 것으로 기대된다. 현재 건물용 연료전지의 경우, 주로 1kW급 연료전지가 시범보급되어 각 가정에 설치되어지고 있으나, 상가, 주유소 및 편의점 등의 상업시설과 생활관 및 소형빌라 등의 집단 주거시설 같은 1kW급 보다 용량을 더 필요로 하는 응용처에 국내에서 개발된 5kW급 연료전지시스템이 적용되어지기를 기대한다. 본 연구에서는 국내 제작된 5kW급 고분자전해질 연료전지시스템의 보급이전에 안전성능 평가를 통해 시스템의 성능 및 안전성 평가결과를 제조사에 피드백 하여 5kW급 건물용 연료전지시스템의 조기 상업화에 앞장서고자 한다. 5kW급 연료전지시스템의 기술개발은 핵심부품인 연료변환기, 스택 및 BOP 기술의 경우 1kW급 연료전지시스템에 적용된 것과는 다른 기술이 필요하고, 단순한 scale-up 과정이 아닌 새로운 기술개발로 제품에 적용시켜야 하는 난점을 가지고 있다. 특히, 연료변환기의 경우 연료 유량의 증가로 인하여 reformer, CO shift 및 Prox 반응기의 유체역학, 열교환 흐름 및 촉매반응 공학적으로 이론을 응용한 새로운 반응기 설계와 제작기술 확립이 선행되어 전체적인 시스템 제작 설계에 반영되어져야 한다. 그러므로 본 연구에서는 연료전지시스템 안전성능 평가를 위해 용량증대에 따른 안전성평가 항목을 검토하고, 5kW급 연료전지시스템평가를 수행하여 시스템의 제품성능, 작동성능 및 계통연계성능에서의 안전성을 확인하였고, 정전 유풍과 같은 이상조건 및 실외 환경에 대한 시스템의 안전성도 확인하였다. 또한 부하운전 조건을 75% 및 50%로 변화시켰을 때 빠른 응답시간과 안정적인 부하변동운전을 확인하였다.

• Proceedings of The KACE
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• 2018.01a
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• pp.83-85
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• 2018

사회가 복잡하게 변화됨에 따라 온난화 등의 해결하기 어려운 새로운 문제들이 등장하고 있다. 이를 효과적으로 해결하기 위해서는 창의력과 절차적인 사고가 요구되며 이러한 능력을 키우기 위해 소프트웨어 교육이 필요하다. 이에 따라 2015개정 교육과정에서 정보교과의 비중이 증가하였으며, 2018학년도부터는 중학교 정보교육이 의무화되었고, 그 동안 실제 생활에 접목하여 문제 해결력 및 컴퓨팅 사고력을 향상 시킬 수 있는 피지컬 컴퓨팅이 도입되었다. 하지만 고등학생의 경우 이전 교육과정에서 새롭게 도입되었기에 피지컬 컴퓨팅 수업이 진행되기가 쉽지 않다. 본 연구에서는 고등학생의 피지컬 컴퓨팅 구현 능력 향상과 이를 통해서 문제 해결력 향상에 어떠한 영향이 있는가를 알아보기 위해서 피지컬 컴퓨팅 교육 프로그램을 위한 과정으로 오래된 운영체제에서만 사용이 가능한 구형 프린터기의 드라이버를 최신 운영체제에서도 사용이 가능하도록 프린터 드라이버를 커스터마이징하여 윈도우 10에서도 사용이 가능하도록 하는 소프트웨어 교육을 설계하였고 이를 고등학생에게 적용하기 위하여 학생들의 사전 사후 검사를 실시하고자 한다. 자원의 재활용과 환경적인 측면에서 그 동안에는 신제품 구입 후 빠른 IT환경의 발전 및 변화로 멀쩡한 하드웨어를 폐기하고, 최신 운영체제에 대응하는 하드웨어를 새롭게 구입해야 했으나, 본 교육과정을 통해 각 가정에 있는 구형 프린터의 재사용을 위한 프린터 드라이버 제작이라는 선순환적인 교육목적을 추구하며 소프트웨어 교육이라는 본질 측면에 좀 더 가까이 다가가며, 해당 하드웨어 제품에 대한 소프트웨어의 저작권 교육도 함께 진행할 수 있으며, 잘 만들어진 소프트웨어의 경우 새로운 시장을 창출할 수 있도록 하는 계기가 될 것이다. 학생들의 흥미에서는 좋은 반응을 보였으나 실제 문제 해결력을 위해서는 저변 확대가 필요함을 알 수 있었다. 오래된 구형 하드웨어를 최신 운영체제에서도 사용할 수 있도록 하는 과정에서의 실생활에 적용되는 유용한 피지컬 컴퓨팅을 보다 효과적으로 사용하기 위해서는 프로그램의 설계에 대한 지속적인 연구가 필요할 것이다.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.49 no.1
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• pp.94-102
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• 2012

Recently entered into an aging socity as the number of elderly drivers is increasing. Traffic accidents of elderly drivers are caused by driver inattentions such as poor vehicle control due to aging, visual information retrieval problems caused by presbyopia, and objects identifying problems caused by low contrast sensitivity. In this paper, detection method of ROIs on the road is proposed. The proposed method creates the saliency map to detect the candidate ROIs from the input image. And, the input image is segmented to obtain the ROIs boundary. Finally, selective visual attention regions are detected according to the presence or absence of a segmented region with saliency pixels. Experimental results from a variety of outdoor environmental conditions, the proposed method presented a fast object detection and a high detection rate.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.7
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• pp.1554-1560
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• 2015

802.11p WAVE is the next-generation wireless communication that can make Ad-hoc network communication possible for Vehicle-to-Vehicle. GBSR protocol, one of the 802.11p WAVE protocols, mainly focuses on improvements in networks that have a tendency to disconnect. However, it does not consider the transmission time and velocity of a packet thus, there is a disadvantage of there being a delay in the transmission velocity, in urgent situations like car accidents, emergency patients transportation and crimes. In this paper, we proposed A-GBSR protocol for transmission of a packet to mobile node which has a high speed through the improved beacon message and Adaptive Neighbor list Management that are considering of the GBSR protocol transmission velocity.

• The KIPS Transactions:PartC
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• v.18C no.4
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• pp.199-206
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• 2011

Removable Storage provides the excellent portability with light weight and small size which fits in one's hand, many users have recently turned attention to the high-capacity products. However, due to the easy of portability for Removable Storage, Removable Storage are frequently lost and stolen and then many problems have been occurred such as the leaking of private information to the public. The advent of remote storage services where data is stored throughout the network, has allowed an increasing number of users to access data. The main data of many users is stored together on remote storage, but this has the problem of disclosure by an unethical administrator or attacker. To solve this problem, the encryption of data stored on the server has become necessary, and a searchable encryption system is needed for efficient retrieval of encrypted data. However, the existing searchable encryption system has the problem of low efficiency of document insert/delete operations and multi-keyword search. In this paper, an efficient searchable encryption system is proposed.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.3
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• pp.196-200
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• 2010

The number of railway tunnels has been increasing rapidly. Although fires in long railway tunnels are rare, the consequences can be devastating. Prior to this study, there were no adequate time-temperature curves for the fire safety assessment of Korean railway tunnels. We studied a standard foreign time-temperature curve for which the heat rate is based on the traffic and the types of vehicles. We then proposed a hydrocarbon curve as a fire design model for railway tunnels in Korea. We examined the implications of this proposed model on railway tunnel structures using numerical analysis.

• Journal of Korean Society of Transportation
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• v.23 no.2
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• pp.61-74
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• 2005

This study is to investigate the effects of driving anger and traffic congestion on drivers' behaviors. Driving anger is the propensity to become angry while driving, and people differ in the tendency to get angry when encountering frustration and provocation on the road. Individual differences of the propensity contribute to anger on the road and aggressive driving leading traffic vaiolations and accidents. In the experiment three traffic conditions (an open road condition, a bumper-to-bumper traffic condition and a being stuck behind a slower driver condition) were simulated and driving behaviors were collected with RTSA-DS(Road Traffic Safety Authority-Driving Simulator). The results were as follows: Most of high anger drives drove at higher speeds in an open road condition, and in the bumper-to-bumper condition they drove faster and had an higher crash rate, which suggests they did aggressive driving, and risky and unsafe behaviors.