• 산경연구논집
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• 제12권3호
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• pp.31-41
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• 2021

Purpose: The purpose of this paper is to analyze the impact of the minimum wage policy and the employment labor force in Myanmar by exploring firms' actions such as installing supplementary machines to substitute for labor resources and by addressing gender issues in employment. Research design, data, and methodology: This paper applies a fixed-effect estimation method by using the World Bank's enterprise panel data set surveyed in Myanmar. Results: Findings suggest that the minimum wage reduces both full-time and part-time employment, while the first minimum wage policy increases overall female employment. The adverse impacts are more pronounced for female employees of Joint Venture enterprises and enterprises located in the less-populated regions. Investment in capital such as equipment and machinery increase to substitute for labor after the minimum wage policy implementation; as a result, full-time employment slightly decreases. Conclusions: Appropriate measures concerning the minimum wage policy must be prepared by the government and institutions related to the labor union to serve the well-being of employees. Government of Myanmar should fix the minimum wage in a reasonable period based on the fiscal year for both employers and employees to prevent possible issues and losses resulting from the minimum wage being set.

• 한국안전학회지
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• 제36권2호
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• pp.111-119
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• 2021

Multi-dimensional analysis of reactor safety-KINS standard (MARS-KS) is a thermal-hydraulic code to simulate multiple design basis accidents in reactors. The code has been essential to assess nuclear safety, but has mainly focused on light water reactors, which are in the majority in South Korea. Few previous studies considered pressurized heavy water reactor (PHWR) applications. To verify the code applicability for PHWRs, it is necessary to develop MARS-KS input decks under various transient conditions. This study proposes an input model to simulate small-break loss of coolant accidents for PHWRs. The input model includes major equipment and experimental conditions for test B9802. Calculation results for selected variables during steady-state closely follow test data within ±4%. We adopted the Henry-Fauske model to simulate break flow, with coefficients having similar trends to integrated break mass and trip time for the power supply. Transient calculation results for major thermal-hydraulic factors showed good agreement with experimental data, but further study is required to analyze heat transfer and void condensation inside steam generator u-tubes.

• 드라이브 ㆍ 컨트롤
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• 제18권4호
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• pp.28-34
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• 2021

Among the currently available types of fuel, LNG emits a relatively small amount of nitrogen oxide and carbon dioxide when it burns in the engine. However, since LNG is a flammable material, leakage during bunkering can lead to accidents, such as fires. Therefore, it is necessary to install a remote operation emergency shut-down (ESD) valve to block the flow and leakage of LNG in an emergency situation that occurs during bunkering. The ESD valve uses a hydraulic driving device consisting of a hydraulic control valve and a hydraulic motor to control globe valve disc displacement, which regulates the flow path for LNG transfer. At this time, there are various nonlinearities in hydraulic driving devices; hence, it is necessary to design a controller with robust control performance against these uncertainties. In this study, modeling of the ESD valve was carried out, and a sliding mode controller to control the displacement of the globe valve disc was designed. As a result, it was confirmed that the designed control performance could be achieved by overcoming nonlinearity characteristics using the designed controller.

• 한국안전학회지
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• 제37권4호
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• pp.63-72
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• 2022

The number of deaths caused by power crane accidents continues to decline. Nevertheless, more than 50 people die each year due to these accidents. Various types of slings, such as wire rope sling, chain sling, belt sling, and grommet, are used in industries, depending on the characteristics of the work involved. To reduce the number of accidents involving these slings, the formulation of technical measures and education of workers are necessary. This study compares and analyzes local and international guidelines as well as those found in manufacturer manuals in relation to grommets, which are widely used in shipyards and construction sites. Moreover, measures for improving the safety of work using grommet are reviewed. This paper further proposes the revision of the technical guidelines of the Korea Occupational Safety and Health Agency such that the information directly affecting the safety of work involving grommets is included. By clarifying the guidelines that manufacturers provide in their manuals, accident prevention through worker awareness is anticipated in the future.

• 방송공학회논문지
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• 제28권2호
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• pp.230-237
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• 2023

자율주행은 4차 산업의 핵심 기술로 차, 드론, 자동차, 로봇 등 다양한 곳에 응용 가능하다. 그 중 위치 추정 기술은 GPS, 센서, 지도 등을 활용하여, 객체나 사용자의 위치를 파악하는 기술로 자율주행을 구현하기 위한 핵심적인 기술 중 하나이다. GPS나 LIDAR 등의 센서를 이용하여 위치 추정이 가능하지만, 이는 매우 고가이고 무거운 장비를 탑재해야 하며 지하 혹은 터널 등 전파 방해가 있는 곳의 경우 정밀한 위치 추정이 어렵다는 단점이 있다. 본 논문에서는 이를 보완하기 위해 저가의 비전 카메라로 획득한 컬러 영상을 입력으로 하여 관심 영역 추출 네트워크와 영상 분할 지도를 이용한 영상 검색 기술을 제안한다.

• 한국안전학회지
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• 제38권4호
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• pp.60-67
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• 2023

Various lifting slings are used in domestic industrial sites depending on the purpose, form, and environment. Each sling has its characteristics, and safe lifting work is possible when its performance meets the regulations. Therefore, this study analyzed domestic and foreign regulations and guidelines related to chain slings. It identified significant problems by analyzing the chain-sling-related disaster cases. The current status of chain slings used by various industries and the ways to improve chain sling safety were studied. The major chain sling issues were: 1) employing improper components to chains, 2) having different safety coefficients between the regulation and industrial standards, and 3) using chains unsuitable for lifting purposes. Based on these issues, the following measures were proposed to improve chain sling work safety: 1) revise the safety coefficient requirements under the Regulations on Occupational Safety and Health Standards, 2) disseminate specialized sling courses, and 3) strengthen on-site chain slings-related training. In the future, this study is expected to minimize chain use mistakes by unifying the safety coefficient related to chain slings and recognizing the importance of correctly selecting components employed in the chain.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.539-543
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• 2005

The research presented in this paper enables real-time 3D modeling to help make construction processes ultimately faster, more predictable and safer. Initial research efforts used an emerging sensor technology and proved its usefulness in the acquisition of range information for the detection and efficient representation of static and moving objects. Based on the time-of-flight principle, the sensor acquires range and intensity information of each image pixel within the entire sensor's field-of-view in real-time with frequencies of up to 30 Hz. However, real-time working range data processing algorithms need to be developed to rapidly process range information into meaningful 3D computer models. This research ultimately focuses on the application of safer heavy equipment operation. The paper compares (a) a previous research effort in convex hull modeling using sparse range point clouds from a single laser beam range finder, to (b) high-frame rate update Flash LADAR (Laser Detection and Ranging) scanning for complete scene modeling. The presented research will demonstrate if the FlashLADAR technology can play an important role in real-time modeling of infrastructure assets in the near future.

• 한국항만학회지
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• 제4권1호
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• pp.45-57
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• 1990

Today, about 95% of totoal import import and export container cargo in Korea is being transported through the Busan Port. The 59% of these cargos is being handled at BCTOC and the rest is at the existing piers. As the Off-Dock Container Yards(ODCY) within Busna City are located at 33 different places, it causes serious problems in the container cargo transport and inland traffic near Busan district. The container carriers to the inland market or other terminals cause heavy traffics to the Busan Traffic System. Hence, this impacts to the cost of the cargo handling equipment and cargo storage, the usage of labor resources, the control of natural environment etc. To solve those problems, it is required to build Inland Container Depot(ICD) in the Southeastern Economic Area. In this study therefore, we try to calculate the required area of Inland Container Depot(ICD) for Busan Port which deals which deals with the container cargo. We also investigate the sites for ICD being suggested outside of Busan City. We use the Analytic Hierarchy Process(AHP) Method to decide the best one. The result shows that the best is the Site B(Dong Myen, Yangsan Kun).

• Wind and Structures
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• 제36권6호
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• pp.423-434
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• 2023

Aerodynamic force coefficients are generally obtained from traditional wind tunnel tests or computational fluid dynamics (CFD). Unfortunately, the techniques mentioned above can sometimes be cumbersome because of the cost involved, such as the computational cost and the use of heavy equipment, to name only two examples. This study proposed to build a deep neural network model to predict the aerodynamic force coefficients based on data collected from CFD simulations to overcome these drawbacks. Therefore, a series of CFD simulations were conducted using different geometric parameters to obtain the aerodynamic force coefficients, validated with wind tunnel tests. The results obtained from CFD simulations were used to create a dataset to train a multilayer perceptron artificial neural network (ANN) model. The models were obtained using three optimization algorithms: scaled conjugate gradient (SCG), Bayesian regularization (BR), and Levenberg-Marquardt algorithms (LM). Furthermore, the performance of each neural network was verified using two performance metrics, including the mean square error and the R-squared coefficient of determination. Finally, the ANN model proved to be highly accurate in predicting the force coefficients of similar bridge sections, thus circumventing the computational burden associated with CFD simulation and the cost of traditional wind tunnel tests.

• 대한안전경영과학회지
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• 제25권2호
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• pp.113-120
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• 2023

Occupational safety and health management expenses in the construction industry are statutory and separately included in the cost statement to prevent occupational accidents and health problems. The expenses are determined by multiplying the standard amount by the rate decided according to construction types and scales. However, the current expense appropriation method does not properly reflect the recent changes in the construction industry such as industry size, industry diversification, and social atmosphere about safety reinforcement. This study surveyed 1579 questionnaires in total and analyzed expense execution rate and proportion of each expense category. The expense execution rate was relative higher in complex construction (e.g., heavy construction = 126%, civil engineering = 125%) and long-period project (equal to or over 48 months construction = 133%) compared to general construction (98~116%) and short-period project (less than 48 months construction = 115%). The proportion of spending expenses was higher in the category of safety manager labor costs (25~52%), safety facility costs (22~40%), and personal protective equipment costs (10~25%). The analysis results of the study can be utilized in revising the standard expense appropriation method by reflecting the current usages of the occupational safety and health management expenses in the construction industry.