• 가정과삶의질연구
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• 제26권5호
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• pp.75-89
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• 2008

The purpose of this study is to understand the physical accessibility of the child care centers for disabled children in Japan. Fifteen centers located in Tokyo, Japan were surveyed through sketching, measuring, taking pictures, and observation. To understand the user's needs. the directors of the centers were interviewed. As a result,the followings suggestions were proposed. First, when the entrance of the center is close to the road, careful design for the entrance area is required to secure the safety of children using wheelchairs. If possible, a fence or door between the corridor and entrance is necessary. Second, most aspects of accessibility are pretty well designed. But a canopy over the entrance area is required to escape the rain. Third, a wider corridor space is desirable for storing and driving wheelchairs and for special equipment for the disabled. Forth, because the emergency exits were installed but not used, the new and safer emergency exits should be installed. These results will be a good case reference for developing Korean design guidelines for the children with disabilities.

• 국제초고층학회논문집
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• 제5권4호
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• pp.319-326
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• 2016

The ingenuity of structural engineers in the field of tall and super-tall buildings has led to some of the most remarkable inventions. During this evolution of structural engineering concepts in the last 100 years, the technical challenges that engineers encountered were extraordinary and the advances were unprecedented. However, as the accomplishments of structural engineers are progressing, the desire for taller and safer structures is also increasing. The diagrid structural system is part of this evolving process as it develops a new paradigm for tall building design combining engineering efficiency and new architectural expression. The first appearances of this type of tall buildings have already been constructed and the interest of both engineering and architectural communities is growing mainly due to the many advantages compared to other structural systems. This paper presents a simple approach on optimizing member sizes for the diagonals of steel diagrid tall buildings. The optimizing method is based on minimizing the volume of the diagonal elements of a diagrid structure. The constraints are coming from the stiffness-based design, limiting the tip deflection of the building to widely accepted regulative limits. In addition, the current paper attempts to open the discussion on the important topic of optimization and robustness for tall buildings and also studies the future of the diagrid structural system.

• 한국도로학회논문집
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• 제14권1호
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• pp.73-83
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• 2012

본 연구에서는 하이패스 차로의 속도감소를 유도하기 위한 적절한 노면표시를 도출하기 위하여 감성공학적 분석방법을 활용하여 연구를 수행하였다. 현재 고속도로 영업소에서는 감속유도를 위하여 하이패스 차로에 갈매기 노면표시를 설치하여 운영하고 있다. 본 연구에서는 하이패스 차로의 감속유도를 위하여 갈매기 노면표시 및 Peripheral Transverse Bar(PT bar)에 대한 효과평가를 실시하고, 두 가지 노면표시를 조합하여 6가지 시나리오를 도출하였다. 도출된 시나리오에 대하여 이용자의 Perception 측정 및 분석을 통한 노면표시 설계 시 Human Factor를 반영할 수 있는 방법론을 제시하였다. 분석결과 빗살무늬의 PT bar 및 $60^{\circ}$ 각도의 갈매기 노면표시의 조합시나리오가 가장 적절한 노면표시로 선정되었다. 본 연구의 결과는 하이패스 차량들의 통과속도를 감소시켜 고속도로의 안전성을 높일 수 있을 것으로 기대된다.

• Structural Engineering and Mechanics
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• 제91권2호
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• pp.211-225
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• 2024

Soft bending actuators have gained significant interest in robotic applications due to their compliance and lightweight nature. Their compliance allows for safer and more natural interactions with humans or other objects, reducing the risk of injury or damage. However, the nonlinear behaviour of soft actuators presents challenges in accurately predicting their bending motion and force exertion. In this research, a new comprehensive study has been conducted by employing a developed 3D finite element model (FEM) to investigate the effect of geometrical and material parameters on the bending behaviour of a soft pneumatic actuator reinforced with Kevlar fibres. A series of experiments are designed to validate the FE model, and the FE model investigates the improvement of actuator performance. The material used for fabricating the actuator is RTV-2 silicone rubber. In this study, the Cauchy stress was expanded for hyperelastic models and the best model to express the stress-strain behaviour based on ASTM D412 Type C tensile test for this material has been obtained. The results show that the greatest bending angle was achieved for the semi-elliptical actuator made of RTV2 material with a pitch of 1.5 mm and second layer thickness of 1 mm. In comparison, the maximum response force was obtained for the semi-elliptical actuator made of RTV2 material with a pitch of 6 mm and a second layer thickness of 2 mm. Additionally, this research opens up new possibilities for development of safer and more efficient robotic systems that can interact seamlessly with humans and their environment.

• 대한조선학회 특별논문집
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• 대한조선학회 2007년도 특별논문집
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• pp.99-106
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• 2007

The IACS Common Structural Rules are to be applied for double hull tanker of more than 150m length with contracted after 1 April 2006. The objectives of the rules are to make more robust, safer ship and to ensure transparency of the technical background. In compliance of CSR, we had carried out prescriptive rules scantling determination and 3-D hold FE analysis of AFRAMAX TANKER. Prescriptive rules scantling determines the minimum required scantling, hull-girder longitudinal bending and shear strength, hull girder ultimate strength, local strength of plate and stiffener, strength of primary supporting member and fatigue assessment of the longitudinal stiffener end connections to the transverse bulkhead. 3-D hold FE analysis assesses the structural adequacy of the vessel's primary hull structure and major supporting members using yielding and buckling failure modes. So we could verify the strength assessment of AFRAMAX TANKER applied CSR.

• 대한조선학회 특별논문집
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• 대한조선학회 2007년도 특별논문집
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• pp.89-93
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• 2007

The Boil-off gas (BOG) generation during the voyage is inevitable since Natural Gas (NG) in normally liquefied below -160 degree C in atmosphere condition and small heat ingress due to relatively hot outside keeps evaporating continuously. The one of major issue in LNG carriers is to handle generated BOG from cargo tank. The generated BOG affects to increase the cargo tank pressure and Gas Management System (GMS) for LNG carriers is closely related to cargo tank pressure maintenance. Economically, BOG is generally used as fuel in LNG carrier. Newly developed GMS for LNG carrier in boiler propulsion system, VaCo System, not only accomplish automatic control in GMS but also ensure safer operation.

• Journal of Chest Surgery
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• 제19권1호
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• pp.18-24
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• 1986

The mean perfusion pressure produced by 20 different design and size of disposable aortic perfusion cannulas [size range: 18F to 20F] at flow rates of 1 to 5 L/min was compared. A roller pump with perfusion tubing 10mm in inner diameter was used with a mixture of 0.9% normal saline and 100% glycerin [mixing ratio of 6.72:13.28] to make the viscosity as normal blood in 20oC as the test solution. Line pressure in these cannulas at a flow rate of 3L/min ranged from 13.2$\pm$4.47 to 157$\pm$1 34 mmHg in a case of absence of resistance, and from 11.4$\pm$1.14 to 227.2$\pm$4.47 mmHg in a case of presence of resistances 14 cannulas had gradients of less than 100Hg at a flow rate of 3L/min and 9 cannulas less than 100mmHg at 4L/min. The following results were obtained from this experimental study: .1] A wide range of line pressure was observed in disposable aortic perfusion cannulas currently in clinical use; 2] Some cannulas currently used for cardiopulmonary bypass in adults generated excessive line pressure; 3] Both the material and design affect function, with some designs safer than others. Cardiac surgeons should base the choice of aortic perfusion cannula on the best performance and safest design available to avoid cannula-related problems during operation.

• 한국구조물진단유지관리공학회 논문집
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• 제6권4호
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• pp.189-199
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• 2002

This study is intended to propose a systematic procedure for the development of the conditional assessment based on the safety of structures and the cost effective performance criteria for designing and upgrading of bridge structures. As a result, a set of cost function models for a life cycle cost analysis of bridge structures is proposed and thus the expected total life cycle costs (ETLCC) including initial (design, testing and construction) costs and direct/indirect damage costs considering repair and replacement costs, human losses and property damage costs, road user costs, and indirect regional economic losses costs. Also, the optimum safety indices are presented based on the expected total cost minimization function using only three parameters of the failure cost to the initial cost (${\tau}$), the extent of increased initial cost by improvement of safety (${\nu}$) and the order of an initial cost function (n). Through the enough numerical invetigations, we can positively conclude that the proposed optimum design procedure for bridge structures based on the ETLCC will lead to more rational, economical and safer design.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.1085-1092
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• 2022

Travel distance is a parameter mainly used in the objective function of Construction Site Layout Planning (CSLP) automation models. To obtain travel distance, common approaches, such as linear distance, shortest-distance algorithm, visibility graph, and access road path, concentrate only on identifying the shortest path. However, humans do not necessarily follow one shortest path but can choose a safer and more comfortable path according to their situation within a reasonable range. Thus, paths generated by these approaches may be different from the actual paths of the workers, which may cause a decrease in the reliability of the optimized construction site layout. To solve this problem, this paper adopts reinforcement learning (RL) inspired by various concepts of cognitive science and behavioral psychology to generate a realistic path that mimics the decision-making and behavioral processes of wayfinding of workers on the construction site. To do so, in this paper, the collection of human wayfinding tendencies and the characteristics of the walking environment of construction sites are investigated and the importance of taking these into account in simulating the actual path of workers is emphasized. Furthermore, a simulation developed by mapping the identified tendencies to the reward design shows that the RL agent behaves like a real construction worker. Based on the research findings, some opportunities and challenges were proposed. This study contributes to simulating the potential path of workers based on deep RL, which can be utilized to calculate the travel distance of CSLP automation models, contributing to providing more reliable solutions.

• 대한수사과학회지
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• 제2권1호
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• pp.23-31
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• 2007

우리나라는 좁은 국토에 비하여 인구밀도가 높아 광복 이후 도시에는 아파트에 많은 인구가 살아 왔고, 최근 재개발 및 재건축으로 도시를 재정비함에 있어서도 아파트가 주된 건설 형식으로 진행 중이다. 그러나 도시화와 산업화로 이웃 간에 온정이 사라지고, 개인주의와 사생활 보호, 익명성 등으로 아파트 거주민들은 이미 범죄에 노출되어 있고, 이러한 현상이 사회적으로 큰 문제시 되었다. 미국과 영국에서는 1960년대 말부터 도시의 환경에 대한 연구를 시작하여 방어공간(Defensible Space)이론, 환경설계를 통한 범죄예방이론(CPTED)을 통하여 환경과 범죄간의 연구를 발전시켜 왔다. 우리나라에서도 최근 판교신도시 건설 및 부천시의 도시개발 계획 등에서 환경과 범죄의 관계를 반영하여 범죄가 발생하기 어려운 도시환경을 만들고자 민(民), 관(官), 학(學), 경찰(警察) 등 여러 분야에서 머리를 맞대고 연구하고 있다. 이번 연구에서는 기존의 연구와는 다른 시각으로 아파트의 형태별 범죄유형을 분석하였다. 아파트의 분류 방법 중 평면의 형식에 따른 분류로 계단실형 아파트와 편복도형 아파트를 기준으로 하고, 거주민들이 발생면(發生面)이나 빈도면(頻度面)에서 가장 많이 체감(體感)한다고 볼 수 있는 절도사건의 유형별로 비교 분석하였다. 창원시내에서 발생하여 경찰에 신고된 절도사건을 중심으로 주거침입절도, 오토바이 및 차량 등 절도, 노상에서 발생하는 날치기, 기타 등으로 분류를 하였고 창원시내 아파트 중 서로 인접하여 비슷한 지역에 위치하고 있는 비교대상 아파트 12개를 선정하여 계단실형 아파트와 편복도형 아파트를 분류하여 서로 비교, 분석하였다. 주거침입절도는 계단실형과 편복도형 아파트에서 비슷한 비율로 발생하였고, 오토바이 및 차량 등 절도는 편복 도형에서, 날치기는 계단실형 아파트에서 높은 비율로 나타났다. 특히, 다양한 여러 세대가 함께 거주하는 아파트에서는 다른 지역과 달리 오토바이 및 차량 등 절도가 많이 발생하고 있어 지상 및 지하 주차장에 대한 방범대책이 요구된다.