• 한국재난정보학회 논문집
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• 제13권2호
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• pp.191-198
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• 2017

레고식 차도블록 시스템은 시설물의 설치 및 유지보수를 위한 도로굴착공사지에서 조립된 구조블록을 사용한 임시포장면을 형성하여 차량 및 보행자의 안전한 통행이 가능하도록 개발된 시스템이다. 레고식 차도블록 시스템의 재료적 품질시험, 미끄럼저항시험 및 압축시험을 통해 기초성능에 대한 연구를 수행하였으며, 현장시험을 통해 레고식 차도블록 시스템의 도로지반 다짐성능을 검토하고 평가하였다. 그 결과, 도로복구를 위한 레고식 차도블록 시스템의 성능 및 다짐 효과는 우수한 것으로 나타났다.

• Nuclear Engineering and Technology
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• 제56권4호
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• pp.1472-1479
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• 2024

Cyber-Physical Energy Systems (CPESs) integrate cyber and hardware components to ensure a reliable and safe physical power production and supply. Renewable Energy Sources (RESs) add uncertainty to energy demand that can be dealt with flexible operation (e.g., load-following) of CPES; at the same time, scenarios that could result in severe consequences due to both component stochastic failures and aging of the cyber system of CPES (commonly overlooked) must be accounted for Operation & Maintenance (O&M) planning. In this paper, we make use of Deep Reinforcement Learning (DRL) to search for the optimal O&M strategy that, not only considers the actual system hardware components health conditions and their Remaining Useful Life (RUL), but also the possible accident scenarios caused by the failures and the aging of the hardware and the cyber components, respectively. The novelty of the work lies in embedding the cyber aging model into the CPES model of production planning and failure process; this model is used to help the RL agent, trained with Proximal Policy Optimization (PPO) and Imitation Learning (IL), finding the proper rejuvenation timing for the cyber system accounting for the uncertainty of the cyber system aging process. An application is provided, with regards to the Advanced Lead-cooled Fast Reactor European Demonstrator (ALFRED).

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.768-773
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• 2011

Today's urban transit system is regarded as the important public transportation service which saves passengers' time and provides the safety. Many researches focus on the rapid and protective responses that minimize the losses when dangerous situation occurs. In this paper we proposed the early fire detection and corresponding rapid response method in urban transit system by combining automatic fire detection for video input and the sensor system. The fire detection method consists of two parts, spark detection and smoke detection. At the spark detection, the RGB color of input video is converted into HSV color and the frame difference is obtained in temporal direction. The region with high R values is considered as fire region candidate and stepwise fire detection rule is applied to calculate its size. At the smoke detection stage, we used the smoke sensor network to secure the credibility of spark detection. The proposed system can be implemented at low prices. In the future work, we would improve the detection algorithm and the accuracy of sensor location in the network.

• 한국정보전자통신기술학회논문지
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• 제13권6호
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• pp.556-561
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• 2020

현대 사회의 농업 인구의 고령화 및 감소로 농업 환경 개선이 필요한 실정이고 대표적인 문제 중 하나이다. 그리고 대부분의 작업체계에서 항상 운반 작업이 필요하기 때문에 운반 작업에 사용되는 시간과 노동력의 비율이 매우 높다. 이에 따라 많은 종류의 운반차들이 개발되고 판매되고 있으며, 초기에는 대부분 화석연료를 사용하는 동력운반차가 주종을 이루고 있다. 그러나 최근에는 지구온난화와 기후변화협약 등 국제 환경규제의 강화 및 화석연료의 고갈로 인한 수소, 연료전지, 태양광, 바이오 등 차세대 친환경에너지를 주목하고 있다. 그래서 본 연구에서는 화석연료를 대체하는 친환경적이며 누구나 쉽게 조작이 가능하고 안전한 농업용 전기운반차를 개발하는 것을 최종목표로 한다. 농업용 전기운반차의 광범위한 차속 조절 및 안정성 확보에 초점을 두고 설계하였으며, 성능 및 디자인을 고려하여 프레임, 주행부, 조향부, 컨트롤러 시스템 등으로 구성되어 각 부분별 검토하였다. 본 연구의 농업용 전기운반차가 젊은 인력이 부족한 농경사회에서 고령노동자나 여성들이 쉽고 편하게 작업을 할 수 있고 높은 효율성을 통해서 농경사회에 도움이 될 수 있을 것이다.

• Safety and Health at Work
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• 제15권1호
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• pp.87-95
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• 2024

Background: This study focuses on assessing occupational risk for the health hazards encountered during maintenance works (MW) in semiconductor fabrication (FAB) facilities. Objectives: The objectives of this study include: 1) identifying the primary health hazards during MW in semiconductor FAB facilities; 2) reviewing the methods used in evaluating the likelihood and severity of health hazards through occupational health risk assessment (OHRA); and 3) suggesting variables for the categorization of likelihood of exposures to health hazards and the severity of health effects associated with MW in FAB facilities. Methods: A literature review was undertaken on OHRA methodology and health hazards resulting from MW in FAB facilities. Based on this review, approaches for categorizing the exposure to health hazards and the severity of health effects related to MW were recommended. Results: Maintenance workers in FAB facilities face exposure to hazards such as debris, machinery entanglement, and airborne particles laden with various chemical components. The level of engineering and administrative control measures is suggested to assess the likelihood of simultaneous chemical and dust exposure. Qualitative key factors for mixed exposure estimation during MW include the presence of safe operational protocols, the use of air-jet machines, the presence and effectiveness of local exhaust ventilation system, chamber post-purge and cooling, and proper respirator use. Using the risk (R) and hazard (H) codes of the Globally Harmonized System alongside carcinogenic, mutagenic, or reprotoxic classifications aid in categorizing health effect severity for OHRA. Conclusion: Further research is needed to apply our proposed variables in OHRA for MW in FAB facilities and subsequently validate the findings.

• 한국융합학회논문지
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• 제11권3호
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• pp.61-66
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• 2020

산업과 IT기술의 융합으로 현대사회는 급속하게 발전하고 있으며, 그 이면에는 기본 인프라를 제공해 주는 건설 공사의 역할이 매우 크다고 할 수 있다. 최근 들어 건설공사의 복잡화 및 대형화, 첨단화에 따라 품질향상을 위한 제도 개선 등 관리의 중요성이 더욱 높아지고 있다. 그러나 건설현장에서 품질관리의 이슈가 발생할 경우 이를 해결하기 위하여 많은 시간이 소요되고 있는 것이 현실로서, 건설 프로젝트를 성공적으로 수행하기 위해서는 다양한 시스템이 유기적으로 연결되어 최적의 의사결정을 관리할 수 있는 시스템이 필요하다. 본 논문에서는 RESTful_API 기반의 GCM 푸쉬 알람 서비스를 이용한 품질관리 모델을 제안한다. 제안 모델은 건설 회사의 품질관리실과 프로젝트 매니저가 의사결정에 이용할 수 있는 모델로서, 건설현장의 프로젝트 관리에 적용할 경우 더욱 효율적이고 안전한 건설공사 관리가 가능할 것으로 기대된다.

• 한국안전학회지
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• 제33권5호
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• pp.109-119
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• 2018

This study has performed to identify the effect of safety behavior, safety climate and its satisfaction through the Behavior Based Safety Program for 5 sites of the same Company. The study result indicated that the level of recognized safety behavior, climate and its satisfaction improved by conducting observation of worker behavior, jobsite feedback, displaying feedback chart, safety training, behavior modification committee. Additionally, the participation level of safety activity and conformity level of safety rule improved. The recognized level of safety climate improved together with recognized safety value by management, safety participation of direct boss, communication with each other to be dealt with safety matter, safety training material to be contained unsafe behavior and practical hazard, understanding and conducting safety standard. In addition, The recognized level of satisfaction improved together with safety behavior and climate. As a result, this program provided an opportunities to correct worker's unsafe behavior to safe behavior in conjunction with increasing number of observation, providing additional time to have a safety check, safety suggestion to improve work situation and a permit to work rule. It will be integrated into health and safety management system to be able to reduce industrial accident.

• 한국항해항만학회지
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• 제30권9호
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• pp.755-762
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• 2006

When we consider to develop a new harbor, the most important factor, we think, is the lowest water depth of waterway and approaching channel for safe navigation of vessel. The existing harbors have been being dredged to meet the international trend of jumbo sized vessels by adopting the new design criteria. As the dredged materials over the expected at the design level were common and there are still lack of land based reclamation area, we have no choice to discharge the dredged materials in open sea area In this study, we analysed the behavior of discharged materials at the dumping area of offshore, which were collected from the dredging work at the waterway in Busan New Port. We measured the tidal currents and analyzed the waters of dumping site after the dumping work. These were used to evaluate the numerical models. Suspended Solids(SS) were introduced to the diffusion model. Because of the characteristic of the dumping site, the speed of initial diffusion and settle down of the discharged materials was so fast. Therefore, we believe that the dumped materials do not cause a significant impact to the marine environment.

• Geomechanics and Engineering
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• 제16권3호
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• pp.321-329
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• 2018

Classic braced walls use struts and wales to minimize ground movements induced by deep excavation. However, the installation of struts and wales is a time-consuming process and confines the work space. To secure a work space around the retaining structure, an anchoring system works in conjunction with a braced wall. However, anchoring cannot perform well when the shear strength of soil is low. In such a case, innovative retaining systems are required in excavation. This study proposes an innovative earth-retaining wall that uses in situ soil confined in dual sheet piles as a structural component. A numerical study was conducted to evaluate the stability of the proposed structure in cohesionless dry soil and establish a design chart. The displacement and factor of safety of the structural member were monitored and evaluated. According to the results, an increase in the clearance distance increases the depth of safe excavation. For a conservative design to secure the stability of the earth-retaining structure in cohesionless dry soil, the clearance distance should exceed 2 m, and the embedded depth should exceed 40% of the wall height. The results suggest that the proposed method can be used for 14 m of excavation without any internal support structure. The design chart can be used for the preliminary design of an earth-retaining structure using in situ soil with dual steel sheet piles in cohesionless dry soil.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.1285-1293
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• 2008

Locking sheet is to display the contents of interlocking equipment for safe train drive in stations. It is being used as a basic information for interlocking equipment and for route control condition and the discussion for train operation between related parties. In spite of importance of this, there was no other way except depending on the work by hands from each stage(drawing, examination, discussion, approval) due to non-existing any tool. It is written it takes 30days from drawing to approval by procedures. However, it is required over the days in real time due to argument of each party. Furthermore on drawing of locking sheet, special conditions applied in accordance with situations of each station occasionally are different depending on the person in charge. Therefore, it is urgent to make up Logic Tree to accept special conditions of all stations. Automation Program for Drawing and Examination of Locking Sheet is to improve inefficient interlocking operation which was operated by hands in accordance with custom as automated system. The target of this program is to minimize the processing time and potential errors by personal work and set up standards for Logic Tree of special condition.