• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권1호
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• pp.216-238
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• 2023

In intelligent transportation systems, traffic management is an important task. The accurate forecasting of traffic characteristics like flow, congestion, and density is still active research because of the non-linear nature and uncertainty of the spatiotemporal data. Inclement weather, such as rain and snow, and other special events such as holidays, accidents, and road closures have a significant impact on driving and the average speed of vehicles on the road, which lowers traffic capacity and causes congestion in a widespread manner. This work designs a model for multivariate short-term traffic congestion prediction using SLSTM_AE-BiLSTM. The proposed design consists of a Bidirectional Long Short Term Memory(BiLSTM) network to predict traffic flow value and a Convolutional Neural network (CNN) model for detecting the congestion status. This model uses spatial static temporal dynamic data. The stacked Long Short Term Memory Autoencoder (SLSTM AE) is used to encode the weather features into a reduced and more informative feature space. BiLSTM model is used to capture the features from the past and present traffic data simultaneously and also to identify the long-term dependencies. It uses the traffic data and encoded weather data to perform the traffic flow prediction. The CNN model is used to predict the recurring congestion status based on the predicted traffic flow value at a particular urban traffic network. In this work, a publicly available Caltrans PEMS dataset with traffic parameters is used. The proposed model generates the congestion prediction with an accuracy rate of 92.74% which is slightly better when compared with other deep learning models for congestion prediction.

• 한국건설관리학회논문집
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• 제25권1호
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• pp.13-22
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• 2024

2021년 1월 8일, 「중대재해처벌 등에 관한 법률」이 법사위를 통과하고 2022년 1월부터 본격적으로 시행되고 있다. 하지만 여전히 건설현장에서의 안전사고는 끊이지 않고 있으며, 이에 건설현장 근로자들의 안전의식을 향상시킬 수 있는 방안을 논의할 필요성이 있다. 이에 본 연구에서는 건설현장 근로자들을 대상으로 한 설문조사를 통해 자료를 수집하고, 작업장의 조직풍토가 근로자들의 안전의식 수준에 미치는 영향을 연구하였다. 연구결과, 작업장의 조직풍토 중 조직의 구조성, 자율성 보장과 감독자의 배려 요인이 근로자의 안전의식 향상에 정적 영향을 미치고 있었다. 이를 토대로 본 연구자는 현장작업 진행시에 작업의 상황, 내용 등에 따라 일부 작업수행에 대한 권한을 근로자에게 위임하며, 성과에 따른 인센티브 보상제를 겸비할 것 등의 제언을 제시하였다.

• Nuclear Engineering and Technology
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• 제39권5호
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• pp.603-616
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• 2007

Roy Huddle, having invented the coated particle in Harwell 1957, stated in the early 1970s that we know now everything about particles and coatings and should be going over to deal with other problems. This was on the occasion of the Dragon fuel performance information meeting London 1973: How wrong a genius be! It took until 1978 that really good particles were made in Germany, then during the Japanese HTTR production in the 1990s and finally the Chinese 2000-2001 campaign for HTR-10. Here, we present a review of history and present status. Today, good fuel is measured by different standards from the seventies: where $9*10^{-4}$ initial free heavy metal fraction was typical for early AVR carbide fuel and $3*10^{-4}$ initial free heavy metal fraction was acceptable for oxide fuel in THTR, we insist on values more than an order of magnitude below this value today. Half a percent of particle failure at the end-of-irradiation, another ancient standard, is not even acceptable today, even for the most severe accidents. While legislation and licensing has not changed, one of the reasons we insist on these improvements is the preference for passive systems rather than active controls of earlier times. After renewed HTGR interest, we are reporting about the start of new or reactivated coated particle work in several parts of the world, considering the aspects of designs/ traditional and new materials, manufacturing technologies/ quality control quality assurance, irradiation and accident performance, modeling and performance predictions, and fuel cycle aspects and spent fuel treatment. In very general terms, the coated particle should be strong, reliable, retentive, and affordable. These properties have to be quantified and will be eventually optimized for a specific application system. Results obtained so far indicate that the same particle can be used for steam cycle applications with $700-750^{\circ}C$ helium coolant gas exit, for gas turbine applications at $850-900^{\circ}C$ and for process heat/hydrogen generation applications with $950^{\circ}C$ outlet temperatures. There is a clear set of standards for modem high quality fuel in terms of low levels of heavy metal contamination, manufacture-induced particle defects during fuel body and fuel element making, irradiation/accident induced particle failures and limits on fission product release from intact particles. While gas-cooled reactor design is still open-ended with blocks for the prismatic and spherical fuel elements for the pebble-bed design, there is near worldwide agreement on high quality fuel: a $500{\mu}m$ diameter $UO_2$ kernel of 10% enrichment is surrounded by a $100{\mu}m$ thick sacrificial buffer layer to be followed by a dense inner pyrocarbon layer, a high quality silicon carbide layer of $35{\mu}m$ thickness and theoretical density and another outer pyrocarbon layer. Good performance has been demonstrated both under operational and under accident conditions, i.e. to 10% FIMA and maximum $1600^{\circ}C$ afterwards. And it is the wide-ranging demonstration experience that makes this particle superior. Recommendations are made for further work: 1. Generation of data for presently manufactured materials, e.g. SiC strength and strength distribution, PyC creep and shrinkage and many more material data sets. 2. Renewed start of irradiation and accident testing of modem coated particle fuel. 3. Analysis of existing and newly created data with a view to demonstrate satisfactory performance at burnups beyond 10% FIMA and complete fission product retention even in accidents that go beyond $1600^{\circ}C$ for a short period of time. This work should proceed at both national and international level.

• 산업진흥연구
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• 제9권2호
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• pp.69-75
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• 2024

한국은 경제 규모, 기술경쟁력 등 다수의 주요 지표에서 선진국 대열에 진입하였으나, 산업재해 재해율은 여전히 OECD 국가 중 최하위권 수준이며, 최근에도 각종 건물 붕괴 등으로 다수의 근로자 또는 시민이 사망하는 후진국형 재해가 발생하고 있다. 고용노동부의 2022년 산업재해 현황분석에 따르면 2022년 전산업 업무상 사고사망자 874명 중 건설업 업무상 사고사망자는 402명이며 이는 전체 사고사망자의 약 46%를 차지한다. 특히, 건설업 사고사망만인율은 1.61로 전산업 사고사망만인율인 0.43이 비해 월등히 높은 수준이며, 건설업은 광업 12.18, 어업 1.80 다음으로 사고사망만인율이 높아 그 심각성을 나타내고 있다. 건설공사를 유형에 따라 민간공사와 공공공사로 나누어 볼 때 민간공사가 수주 및 기성 금액면에서나 사고 건수, 사망자수에서 공공공사보다 월등히 높은 수치를 기록하고 있다. 하지만 공공기관에 비해 대다수의 민간 발주자는 안전보건 활동이 미비하고 안전보건체계 구축이 되지 않은 곳이 많다. 본 연구는 민간 발주자의 안전보건 체계 구축과 안전보건활동 강화의 필요성에 대한 제언을 통하여 민간 발주자에 경각심을 알리고 앞으로 선진적인 민간 발주자의 안전보건 발전 방향에 대해 고찰해 보고자 한다.

• 한국경제지리학회지
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• 제13권4호
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• pp.681-696
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• 2010

본 연구는 부동산 개발사업 각 단계별로 발생 가능한 위험요인의 중요도를 평가하고, 이에 대한 관리방안을 제시하는데 목적이 있다. 이를 위해 부동산 개발사업에 영향을 미칠 것으로 예상되는 단계별 위험요인을 선행연구를 통해 사전적으로 도출한 다음, 부동산 개발사업 전문가들을 대상으로 설문조사를 실시하여, 단계별 위험요인들의 중요도를 AHP 기법을 이용하여 평가했다. 본 연구결과를 요약하면 다음과 같다. 첫째, 부동산 개발사업의 대분류별 위험요인을 분석한 결과, 개발 전 단계에서는 기획 위험, 개발준비 단계에서는 개발사업 인허가 위험, 개발 단계에서는 현금흐름 위험이 가장 중요한 것으로 평가되었다. 둘째, 부동산 개발사업의 소분류별 위험요인을 분석한 결과, 개발 전 단계에서는 소비자 선호도의 변화, 개발준비 단계에서는 계약 및 인허가 관련업무, 개발 단계에서는 시행사 및 건설사의 부도, 관리 및 운영 단계에서는 사고 및 재해의 발생에 의한 시설보상이 가장 중요한 위험요인으로 평가되었다. 셋째, 이러한 위험요인의 중요도 평가결과에 따라 단계별 위험관리 방안을 제시했다.

• Safety and Health at Work
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• 제6권3호
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• pp.227-232
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• 2015

Background: In comparison with other industries, the construction industry still has a higher rate of fatal injuries, and thus, there is a need to apply new and innovative approaches for preventing accidents and promoting safe conditions at construction sites. Methods: In this study, the effectiveness of a new incentive system-the surprising incentive system-was assessed. One year after the implementation of this new incentive system, behavioral changes of employees with respect to seven types of activities were observed. Results: The results of this study showed that there is a significant relationship between the new incentive system and the safety performance of frontline employees. The new incentive system had a greater positive impact in the first 6 months since its implementation. In the long term, however, safety performance experienced a gradual reduction. Based on previous studies, all activities selected in this study are important indicators of the safety conditions at workplaces. However, there is a need for a comprehensive and simple-to-apply tool for assessing frontline employees' safety performance. Shortening the intervals between incentives is more effective in promoting safety performance. Conclusion: The results of this study proved that the surprising incentive would improve the employees' safety performance just in the short term because the surprising value of the incentives dwindle over time. For this reason and to maintain the surprising value of the incentive system, the amount and types of incentives need to be evaluated and modified annually or biannually.

• Safety and Health at Work
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• 제9권1호
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• pp.53-58
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• 2018

Background: Since the Republic of Korea became a labor-force-importing country, the number of foreign workers has increased gradually, especially in the construction industry. The main objective of this study was to examine the differences in safety perception between domestic and foreign workers at Korean construction sites. Methods: A total of 891 Korean and foreign workers were surveyed: 140 foreign and 751 Korean workers. The general characteristics and 25 factors influencing safety perception were considered in the questionnaire. Regression and correlation analyses were conducted to examine the variables of workers' safety perception. Results: Differences of nationality (F = 7.379, p < 0.001) and workplace accidents were statistically significant for both domestic (F = 1.503, p < 0.05) and foreign workers (F = 7.868, p < 0.05). In contrast, age, education, and Korean language level were significant variables only for foreign workers. Correlation coefficients of $0.428^{**}$ for Korean and 0.148 for foreign workers between two items - namely, "management's commitment to safety" and "blaming staff when they make mistakes" - support the conclusion that foreign workers do not trust management's commitment to safety, while Korean workers have confidence in these commitments. Conclusion: Foreign workers' level of safety perception should rise to the same level as Korean workers, especially in terms of obeying safety rules, safety education performance, and safety beliefs. Therefore, an improvement plan for the Korean construction industry is suggested in order to have a better safety level at construction sites with foreign workers.

• Safety and Health at Work
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• 제13권2호
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• pp.170-179
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• 2022

Background: The vulnerability of international migrant workers is on the rise, affecting the frequency of occupational accidents at workplaces worldwide. If migrant workers are managed in the same way as native workers, the consequences on safety assurance and risk management will be significant. This study aimed to develop the vulnerability factor model for migrant workers in seafood processing industries because of significant risk-laden labor of Thailand, which could be a solution to control the risk effectively. Methods: A total of 569 migrant workers were surveyed (432 Burmese and 137 Cambodian), beginning with 40 initial vulnerability factors identified in the questionnaire established from experts. The data were analyzed through descriptive analysis; exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were used to ascertain the model. Results: The result of content validity >0.67 and the Cronbach's alpha of 0.957 specified the high reliability of 40 factors. The EFA indicated a total variance of 65.49%. The final CFA validated the model and had an empirical fitting; chi-square = 85.34, Adjust Goodness-of-Fit Index = 0.96, and root mean square error of approximation = 0.016. The structure concluded with three dimensions and 18 factors. Dimension 1 of the structure, "multicultural safety operation," contained 12 factors; Dimension 2, "wellbeing," contained four factors; and Dimension 3, "communication technology," contained two factors. Conclusion: The vulnerability factor structure developed in this study included three dimensions and 18 factors that were significantly empirical. The knowledge enhanced safety management in the context of vulnerability factor structure for migrant workers at the workplace.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.353-360
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• 2022

Due to the dense and complicated working environment, the construction industry is susceptible to many accidents. Worker's fall is a severe problem at the construction site, including falling into holes or openings because of the inadequate coverings as per the safety rules. During the construction or demolition of a building, openings and holes are formed in the floors and roofs. Many workers neglect to cover openings for ease of work while being aware of the risks of holes, openings, and gaps at heights. However, there are safety rules for worker safety; the holes and openings must be covered to prevent falls. The safety inspector typically examines it by visiting the construction site, which is time-consuming and requires safety manager efforts. Therefore, this study presented a worker-driven approach (the worker is involved in the reporting process) to facilitate safety managers by developing integrated computer vision and inertia sensors-based mobile applications to identify openings. The TensorFlow framework is used to design Convolutional Neural Network (CNN); the designed CNN is trained on a custom dataset for binary class openings and covered and deployed on an android smartphone. When an application captures an image, the device also extracts the accelerometer values to determine the inclination in parallel with the classification task of the device to predict the final output as floor (openings/ covered), wall (openings/covered), and roof (openings / covered). The proposed worker-driven approach will be extended with other case scenarios at the construction site.

• 환경정책연구
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• 제7권3호
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• pp.89-120
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• 2008

한국은 주된 에너지원이 석유이므로 석유의 꾸준한 소비증가와 더불어 유류의 해상운송량도 증가추세에 있으며, 이에 따른 오염사고도 매년 300여건이상이 발생되고 있다. 특히 심각한 것은 사고발생건수도 동반해서 증가추세에 있다는 점이다. 폐유나 기름찌꺼기의 고의적 투기행위를 제외하면, 유류사고의 원인은 운항상의 인적 과실이나 선박의 하자로 인한 경우라는 점에서 대부분의 사고가 인재(人災)에 해당된다. 따라서 선원의 질향상 및 단일선체선박을 포함한 노후선박의 대체는 사고발생을 사전에 예방할 수 있는 가장 기본적 사항이다. 이것은 단기간에 그 개선을 기대하기 어렵지만 그 개선을 위한 장 단기적 제도적 방안도 마련되어야 한다. 그리고 아직도 한국의 인근해상에서 대형 유류오염피해가 발생될 가능성이 상존하고 있다는 점에서 92FC의 보상한도를 초과하는 피해에 대해서는 일정 범위내에서 피해를 보전할 수 있는 제도를 마련할 필요가 있다. 그러나 현행 특별법에 따른 피해보전은 전적으로 국민세금으로 충당되고 있다는 점에서 문제가 있으며, 따라서 2003보충기금(supplementary fund)협약에 가입하는 것보다는 '국내 Fund'를 창설하는 경우에 대하여 보다 적극적으로 검토할 필요가 있다. 즉 유류운송에 따른 위험도 '수익자부담의 원칙'이라는 관점에서 정유사들의 부담금을 기초로 하여 마련되는 '국내 Fund'의 창설 및 도입을 고려할 필요가 있다고 본다. 그리고 더 나아가 유류오염에 따른 대규모 생태계 파괴 등 환경피해에 대해서는 주민피해와 구별하여 환경피해복구를 위한 공적기금마련에 대해서도 논의할 시점이 되지 않았나 생각한다. 여하튼 대형 유류오염사고에 대한 사후대응책은 항시 만족스럽지 못하다. 그 이유는 대형유류오염이 내포하고 있는 재앙의 상징성 때문이다. 대형유류오염은 사전에 예방할 수 있는 인재임에도 불구하고, 그 피해는 끝을 파악하기 힘들 정도로 인간의 삶과 자연생태계에 심각한 손상을 가져온다. 그런 점에서 대형유류오염사고에 대한 가장 최선의 대응책은 사전예방이다.