• 대한건축학회논문집:구조계
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• 제34권5호
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• pp.35-42
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• 2018

In order to seek out methods to reduce safety accidents caused by construction machinery and equipment, this study collects data about safety accidents and draws main risk factors by construction from the data, through SNA. It aimed to suggest safety management points to be used in future construction fields, by analyzing risk index of such factors. The finding can be summarized: First, Backhoe Bucket is the risk factor for crash accidents of average workers in earth works; boring machines-maintenance is the risk factor for fall accidents of construction machinery operators in foundation works; bending machine-reinforcing rod processing is the risk factor for jamming accidents of reinforcing rod engineers in frame works; and mobile crane-hook is the risk factor for crash accidents of average workers in lifting works. Second, works can be arranged in turn, according to the risk index: earth, lifting, frame and foundation works. Risk factors can be also arranged according to the risk index: Backhoe in earth works, pile drivers in foundation works, bending machines in frame works and mobile cranes in lifting works. This study has some limits, in that it only analyzed main machinery/equipment, among various kinds of them, for earth, foundation, frame and temporary works (lifting works) and used data collected over three years. Therefore, it is necessary to conduct an analysis using big data, by collecting additional data about a lot of machinery/equipment in future construction fields.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.673-673
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• 2015

Earthwork is an operation that provides space for structures, and it takes up a large portion of the construction costs in a construction project. In large-scale earthwork, numerous types of construction equipment are used in the operation. The types of equipment should be selected based on the field conditions and the construction methods. These construction vehicles are constantly changing positions during the earthwork operation. Therefore, the equipment operators require effective communication to ensure the efficiency of the earthwork operation. All equipment operators should exchange information with the other equipment operators. Information should be exchanged continuously to support decision making and increase productivity during the earthwork operation at the construction site. This paper investigates the attributes required for an information interface between construction vehicles during an earthwork operation. This paper 1) discusses the importance of an information interface for construction vehicles in order to increase productivity during an earthwork operation, 2) analyses the types of attributes that need to be communicated between construction vehicles, and 3) provides a database that has been built for attribute control. The database built for the information interface between construction vehicles will enhance communication between vehicle operators. Table I shows the typical attributes that should be shared between the excavator operator and the dump truck operator. This information needs to be shared among the operators, as it helps them to plan the earthwork operation in a more efficient manner. A database has been developed to store this information in an entity relation diagram. A user-interface display environment is also developed to provide this information to the operators in the construction vehicles. The proposed interface can help exchange information effectively and facilitate a common understanding during the earthwork operation. For example, the vehicle operators will be aware of the planned volume, excavated volume, transportation time, and transportation numbers. As a part of this study, mobile devices, such as mobile phones and google glasses, will be used as hands-on communication tools.

• 대한전자공학회논문지TC
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• 제41권11호
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• pp.87-91
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• 2004

모바일 단말기는 터치패드 방식의 문자 입력을 한다. 따라서 사용자에게 긴 입력을 요구할 때 불편한 환경을 제공한다. 따라서 이미지의 특정 지점을 마우스로 선택함으로 문자입력을 대신하여 인증을 함으로써 편리한 환경을 제공한다. 보안을 제공하기 위하여 초기 이미지에 따른 이미지의 배열 정보 및 입력된 값을 해시코드화 하여 인증 및 키교환이 안전하게 이루어진다. HASH와 SEED 암호화 알고리즘을 적용하여 효율적이고, 전송 메시지의 무결성을 보장하며 내부 참여자에 의한 정보 유출이 있더라도 안전한 전자지불 프로토콜 시스템을 설계 및 구현하였다.

• 한국콘텐츠학회논문지
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• 제17권10호
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• pp.334-342
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• 2017

정보통신기술의 발달로 방송중계 방식은 급격히 변화하고 있다. 무선통신망중계방송(DMNG) 방식의 도입은 일인중계를 가능케 함으로써 장비와 인력 측면에서 절대적인 감축 효과를 낳았다. 하지만 방송안정성과 화질과 같은 방송의 기본적인 부분에 대한 완성도는 떨어지고 있는 것이 현실이다. 이에 본 논문은 '백팩'이라고 불리는 무선이동통신중계 장비와 방송 시스템에 대해 분석하고 향후 발전 방안에 대해 논의한다. 이를 위해 백팩 중계방송의 성공과 실패 사례를 분석함으로 현장중계 개선에 대한 구체적 방안을 제시한다. 현장을 신속하게 중계하는 방식의 방송은 향후 지속적으로 증가할 것이다. 본 논문은 가까운 미래에 기술적으로 무선통신이 발전하고 이에 대한 방송의 활용이 더욱 중요해지는 시점에서 무선이동통신을 활용한 중계방송에 대한 연구로 가치를 가진다.

• Journal of information and communication convergence engineering
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• 제7권3호
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• pp.404-411
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• 2009

In this paper, in order to increase system capacity and reduce the transmitting power of the user's equipment, we propose an efficient power estimation consisting of a modified open-loop power control (OLPC) and closed-loop power control (CLPC) schemes for mobile/satellite communications systems. The OLPC works well if the forward and reverse links are perfectly correlated and the CLPC is sensitive to round-trip delay (RTD). Therefore, it is not effective in mobile/satellite system. In order to solve the above problem, we added monitoring equipment to both the OLPC and CLPC to use information about transmitting power that has not yet been received by the receiver over the satellite/ATC channel. Moreover, we adapted an efficient pilot diversity of both OLPC and CLPC in order to get a better signal to interference plus noise ratio (SIR) estimation of the received signal.

• 한국가스학회지
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• 제25권6호
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• pp.80-84
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• 2021

수소법이 제정됨에 따라 수소용품 4종이 검사대상제품으로 지정되었다. 수소용품의 종류는 수전해설비, 수소추출설비, 고정형 연료전지, 이동형 연료전지이다. 수소용품 검사를 위한 안전기준 제정은 각 수소용품별 위험요소를 정의하였고 위험요소를 예방하기 위한 안전기준을 수소용품 기준에 규정하였다. 각 수소용품 별 주요 안전기준은 수전해설비는 수소품질 및 안전제어, 수소추출설비는 독성물질 배출 방지 및 일산화탄소 배출 방지, 고정형 연료전지는 배출가스 규제 및 버너 안전성능, 이동형 연료전지는 진동안전성이 안전기준에 규정하여 안전성을 강화하였다.

• 한국수소및신에너지학회논문집
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• 제33권6호
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• pp.769-775
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• 2022

Global efforts to reduce carbon emissions have focused attention on the development of hydrogen energy and the development of various hydrogen mobility requires mobile hydrogen charging stations. In this study, the flow characteristics of the flow control hydrogen valve for mobile hydrogen charging equipment were studied according to the temperature change of hydrogen gas. The inlet pressure was 100 MPa, the outlet pressure to 70 MPa, and temperature condition was set -40℃ to 85℃. As a result, the difference in the valve flow coefficient, which determines the capacity of the valve, showed a difference within 5% depending on the temperature.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.766-771
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• 2004

In this paper, new exploration mobile robot is presented. This mobile robot, called Robhaz-6W, is able to overcome hazardous terrains, recognize three dimensional terrain information and generate a path toward the destination by itself. We develop the passive four bar linkage mechanism adoptable to such terrain without any active control and the real time stereo vision system for obstacle avoidance, a remote control and a path planning method. And the geometrical information is transmitted to the operator in the remote site via wireless LAN equipment. And finally, experimental results for the passive mechanism, the real time stereo vision system, the path planning are reported, which show the versatility of the proposed mobile robot system to carry out some tasks.

• Journal of Construction Engineering and Project Management
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• 제2권3호
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• pp.48-57
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• 2012

With increasing number of serious construction disasters such as death, a safety management in real-time is more required recently. One of the ways to support the needs, a convergence with Information Technology (IT) has been noticed. Although number of inefficiencies including a limitation of IT equipment (weight, control inconveniences) has been concerned, data exchanging and processing fields have been improved at a wide range with an advance of mobile communication and an introduction of smart mobiles that are simple and convenient. In this research, a framework is realized in connection with smart mobile to find the problems of current safety management and derive demands in order to support effective safety management. Two smart mobile applications, Safety Management application and Safety Guideline application, enable a real-time safety management and less re-work by provided safety information.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.1136-1139
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• 2009

Recently, various Ni doping systems and thermal annealing systems have been developed for fabrication of polycrystalline silicon film using SGS (super grain silicon) for medium and largesize AMOLED panels. In this study, we compare the potential of Ni doping systems including ALD (atomic layer deposition), AMD (atmospheric metal deposition), in-line sputter, and crystallization annealing systems including batch type furnace, inline furnace, and RTA (rapid thermal annealing) developed for the SGS method. Additional requirements for those systems to be used for mass production of large AMOLED TVs are suggested based on evaluation results for both poly-Si films and TFT backplanes.