• 한국안전학회지
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• 제28권5호
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• pp.71-77
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• 2013

This Study aims at investigating actual condition on attending school road of children and analyzing empirically the characteristics of cognition and the influence of safety on school road. This study findings are as follows : 1) Walking alone to go to school is the highest rates among Commuting Mode, and Commuting distance to school is nearly doubles than range of school zone(300 m). 2) Among characteristics of urban spatial structure affecting on influence classify safety of school road, 'Commuting Distance' has been drawn to most influential variable. Especially, there are 4 types classified by commuting distance and it became obvious that the longer the distance, the lower the safety score(under 127 m=76.9 points, Over 451 m=58.3 points). 3) As a result of investigating the influence of Safety on attending school road, Vehicle commuting speed urder 127 m as internal of school zone, and Walking and crossing convenience over 451 m as external of school zone have a lot of influence on safety cognition on school road. Therefore Safety on school road should be considering the commuting distance to school among surrounding characteristics, needed for improvement plan and program based on real safety cognition of children.

• 한국안전학회지
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• 제26권5호
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• pp.17-22
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• 2011

This study proposes feature extraction method of pattern recognition by evaluation of weld defects in weld zone of titanium. For this purpose, analysis objectives in this study are features of attractor quadrant and fractal dimension. Trajectory changes in the attractor indicated a substantial difference in fractal characteristics resulting from distance shifts such as porosity of weld zone. These differences in characteristics of weld defects enables the evaluation of unique characteristics of defects in the weld zone. In quantitative fractal feature extraction, feature values of 0.87 and 1.00 in the case of part of 0.5 skip distance and 0.72 and 0.93 in the case of part of 1.0 skip distance were proposed on the basis of fractal dimensions. Attractor quadrant point, feature values of 1.322 and 1.172 in the case of ${\phi}1{\times}3mm$ porosity and 2.264 and 307 in the case of ${\phi}3{\times}3mm$ porosity were proposed on the basis of distribution value. The Proposed feature extraction of pattern recognition in this study can be used for safety evaluation of weld zone in titanium.

• Geomechanics and Engineering
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• 제13권6호
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• pp.997-1010
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• 2017

The black box model is a relatively new option for nonlinear dynamic system identification. It can be used for prediction problems just based on analyzing the input and output data without considering the changes of the internal structure. In this paper, a black box model was presented to solve unconstrained overlying strata movement problems in coal mine production. Based on the black box theory, the overlying strata regional system was viewed as a "black box", and the black box model on overburden strata movement was established. Then, the rock mechanical properties and the mining thickness and mined-out section area were selected as the subject and object respectively, and the influences of coal mining on the overburden regional system were discussed. Finally, a corrected method for height prediction of the fractured zone was obtained. According to actual mine geological conditions, the measured geological data were introduced into the black box model of overlying strata movement for height calculation, and the fractured zone height was determined as 40.36 m, which was comparable to the actual height value (43.91 m) of the fractured zone detected by Double-block Leak Hunting in Drill. By comparing the calculation result and actual surface subsidence value, it can be concluded that the proposed model is adaptable for height prediction of the fractured zone.

• 한국안전학회지
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• 제31권6호
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• pp.12-18
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• 2016

This paper describes an optimal design of electric snow melting mat on vulnerable walk zone. In order to design an optimal electric power of snow melting mat and protect pedestrians with a nonslip mat, with considering protection of environmental pollution from abusing of the de-icing salts added calcium chloride. We analyzed nine snow melting mats through verification experiment in the condition of $-5^{\circ}C$, depending on three different kinds of heating material, electric heating cable, carbon heating film and carbon textile film. As a consequence, the $150W/m^2$ carbon textile film mat for snow melting was identified as an optimal power input and functional performance for pedestrians' safety on vulnerable walk zone. It is expected that the $150W/m^2$ carbon textile film mat would be useful to reduce slip down accidents by human error.

• 융합보안논문지
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• 제9권1호
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• pp.19-27
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• 2009

본 연구에서는 최근 학교 주변에서 발생하는 범죄 사고의 관리 및 예방을 위한 센서 네트워크 기반의 스쿨존 안전관리 시스템을 제안한다. 어린이들에게 부착되는 센서들과 학교 주변의 일정 공간에 펼쳐진 고정된 센서 네트워크 망을 통하여 어린이들의 환경 및 위치 센싱 정보들을 공간 지식화하여 어린이들의 상태를 모니터링 할 수 있는 안전과 관련된 서비스를 제공한다. 또한 학교 주변의 스쿨존 망을 벗어나는 경우 기회주의적 네트워크를 통한 전략적 안전관리 방안을 제안한다. 이러한 시스템이 구축된다면 현재 GPS를 통하여 개개인이 서비스를 받는 시스템에서 발전하여 많은 학생들이 적은 비용으로 쉽게 서비스를 받을 수 있을 것으로 기대한다.

• 한국산학기술학회논문지
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• 제12권12호
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• pp.5873-5877
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• 2011

본 논문은 안전관리 지역 내에서 아이와 같은 객체의 움직임에 대한 분석 연구이다. 안전관리 지역 내의 객체의 이상상황을 감지하여, 만일 비정상적인 상황이 감지되면 사전에 정해진 업무를 수행하도록 설계되어진다. 인적자원을 통하여 안전관리가 필요한 지역에 대해서 지속적으로 이상상황에 대한 감지업무를 수행한다는 것은 불가능한 사항이므로 이러한 감지 시스템의 도입을 통하여 안정적으로 지역의 신뢰도를 높일 수 있다. 따라서 본 논문에서는 객체의 검지를 통하여 현재의 상황을 인식하여 그에 대한 대응을 위한 것이다. 본 논문에서 제안한 방안을 통하여 센서 기반 분석시스템을 이용하여 객체의 이동상황 및 이상상황 감지를 수행한다.

• 한국안전학회지
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• 제18권1호
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• pp.8-13
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• 2003

This study proposes integrity evaluation method of weld zone in rails using high precision distance amplitude characteristics curve(DACC) and ultrasonic signals. For these purposes, the ultrasonic signals for defects(porosity and crack) of weld zone in rails are acquired in the type of time series data and echo strength. 6 lines in the DACC indicated damage evaluation standard of weld zone in rails. The aquired ultrasonic signals agree fairly well with the mesured results of reference block and sensitivity block(defect location, beam propagation distance, echo strength, etc). The proposed high precision DACC in this study can be used for integrity evaluation of weld zone in rails.

• 해양환경안전학회지
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• 제7권1호
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• pp.25-40
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• 2001

The coastal waters and the adjacent coastal lands strongly influenced by each other and includes islands, transitional and intertidal ares, salt marshes wetlands and beaches. We focus on the coastal zone because of its unique geographical characteristics, Its ecological and economic importance, and the increasing pressures on its integrity. Our coastal zone have been controlled individually about 50 of a different kind of laws, as a result, to reach an individual purpose of the laws, people have developed the coastal zone without considering environmental condition, which brought about ecological destruction, pollution and devastation of the coastal areas. Finally, In 1999, the Coastal Management Act and the Wetlands Conservation Act were established and hereafter the environmental concern has been increased. They will be an important role to preserve our environment of coastal zone. Here I will examine the Laws concerned with environmental management of coastal zone and indicate immanent problems of it. So, I expect that problems will be improved one by one through this paper.

• 한국안전학회지
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• 제20권1호
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• pp.30-35
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• 2005

This study proposes construction of through transmission for weld defects detection of rail weld zone from ultrasonic signals. For these purposes, the ultrasonic signals for defects(porosity and crack) of weld zone in rails are acquired in the type of time series data and echo strength. 6 lines in the distance amplitude characteristics curve(DACC) indicated damage evaluation standard of weld zone in rails. The acquired ultrasonic signals agree flirty well with the mesured results of reference block and sensitivity block(defect location beam propagation distance, echo strength, etc). The proposed construction of through transmission in this study can be used for weld defects detection of rail weld zone.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2009년도 추계학술대회
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• pp.639-643
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• 2009

세계 각국은 새로운 유비쿼터스 환경변화에 맞추어 전략적 차원에서 u-IT에 대한 연구와 다양한 프로젝트를 추진 중이다. 특히 유비쿼터스를 지역수준으로 적용 시 지역 구성원들의 삶의 질이 향상되고 편익을 직접적으로 체감할 수 있는 효과가 있다. 유비쿼터스 환경의 중심 기술 중 하나인 RFID는 대역별로 다른 특징을 가지고 있어 단일 대역 RFID는 제약조건이 있으며, 이를 극복하고 보다 입체적인 정보와 서비스를 제공하기 위하여 여러 대역의 RFID를 통합하는 기술이 필요하다. 따라서 본 연구에서는 새로운 u-City 서비스 모델로써 u-Zone 서비스 구축 시에 필요한 13.56MHz와 2.45GHz 주파수 대역의 듀얼밴드 RFID Manager를 개발한다. RFID Manager는 u-Zone 서비스의 임베디드 하드웨어인 Base Station에 탑재하는 응용 소프트웨어로서 리더에서 입력되는 정보를 u-Zone 통합 서버 시스템에 전달하는 역할을 한다.