• Safety and Health at Work
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• 제8권2호
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• pp.226-230
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• 2017

The performance of sound barriers was evaluated to determine their technical effectiveness and practicality in reducing noise exposures to operating engineers in construction. Commercially purchased sound dampening mats (SDMats) were installed inside three heavy-equipment engine compartments. Sound pressure levels (SPLs) were measured before and after installing the SDMats while the equipment was on idle and full-throttle settings where it normally operates. SPLs inside the heavy-equipment operator cabs were significantly reduced by 5.6-7.6 dBA on the full-throttle setting following installation of the SDMats (p < 0.01). The evaluated engineering control intervention was simple to install, affordable, and substantially reduced the engine noise reaching the heavy-equipment operator, potentially reducing reliance on hearing-protection devices to protect construction workers from noise exposures.

• 기본간호학회지
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• 제15권4호
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• pp.566-577
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• 2008

Purpose: Developing a curriculum(DACUM) is a method of analyzing job focused competency, which is obtained from the data of an expert belonging to a certain career. In this study the DACUM method was used to analyze the jobs of operating room nurses. Method: Through the DACUM workshop which was arranged by two DACUM facillitators, a definition of the role of operating room nurses was developed and then duties and tasks of operating room nurses' were identified. For the workshop, a DACUM committee with 10 operating room nurses was organized. Finally, the duties and tasks which were identified were validated by 422 nurses for importance, difficulty and frequency. Results: Thirteen duties and 105 tasks were identified on the DACUM chart, where importance, difficulty, and frequency of tasks were represented by alphabet letters A, B, and C as higher degree of importance. The determinant coefficient(DC) showed that the most important duty was assisting with operations(DC=6.61), and the least, managing operating materials(DC=4.22). For tasks, the most important ones were assisting in orthostatic surgery(DC=7.60), and assisting in thoracic surgery(DC=7.38), and the least important making gauze ball(DC=2.39), and saving of operation site((DC=3.27). Conclusion: The results suggest a need to develop an education program using the DACUM chart as a basis for the development and as a clinical career ladder and for curriculum of operating room nursing.

• 산업공학
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• 제24권4호
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• pp.274-280
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• 2011

Delayed access to surgery may lead to deterioration in the patient condition, poor clinical outcomes, increase in the probability of emergency admission, or even death. The purpose of this work is to decide the number of patients selected from a waiting list and to schedule them in accordance with the operating room capacity in the next period. We formulate the problem as an infinite horizon Markov Decision Process (MDP), which attempts to strike a balance between the patient waiting times and overtime works. Structural properties of the proposed model are investigated to facilitate the solution procedure. The proposed procedure modifies the conventional value iteration method along with the binary search technique. An example of the optimal policy is provided, and computational results are given to show that the proposed procedure improves computational efficiency.

• 전자공학회논문지D
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• 제35D권4호
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• pp.71-77
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• 1998

In this paper, algeration of electical characteristics is analyzed when the operating temperature of MOSFET, BJT and CMOS/BiCMOS inverter is lowered from 300K to 77K. As the operating temperature is lowered, electric characteristics of MOSFET are enhanced generally but, those of bipolar transistor are degraded because current gain is reduced by BGN(Band Gap Narrowing) effect. For the inverter considered in this work, switching characteristics of PSA-BiCMOS inverter are enhanced by the electrical characteristics enhancement of MOSFET when the operating temperature is reduced to 200K, while under 200K, those of PSA-BiCMOS inverter are degraded because the degradation of BJT impacts on the inverter circuit.

• 대한임베디드공학회논문지
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• 제2권4호
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• pp.242-250
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• 2007

Wireless sensor networks are subject to highly heterogeneous system requirements in terms of their functionality and performance due to their broad application areas. Though the heterogeneity hinders the opportunity of developing a single universal platform for sensor networks, efforts to provide uniform, inter-operable and scalable ones for sensor networks are still essential for the growth of the industry as well as their technological advance. As a part of our work to develop such a robust platform, this paper presents the software architecture for sensor nodes with focus on our sensor node operating system and its configuration methodology. Addressing principle issues in its design space which includes programming, execution, task scheduling and software layer models, our architecture is highly reconfigurable with respect to system resources and functional requirements and also highly efficient in supporting multi-threading under small system resources.

• 수산해양교육연구
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• 제25권4호
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• pp.998-1007
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• 2013

At container terminals, a major measurement of productivity can be work efficiency. For improving the productivity of container crane, the more efficient container yard operation method is necessary in container terminals. Recently, container terminal operators make an experiment on the dual cycle operation, which ship loading/unloading were carried out simultaneously, for increasing the productivity of container crane. In this paper, propose a system operating efficient dual cycle methods as utilize Ad-hoc technology in distributed port operation system. The dual cycle methods that proposed recognizes position information of Y/T during an action in Ad-hoc networks in case of container transfer works by real time as load an Ad-hoc module to Y/T taking charge of a container transfer with quay and yard. Utilize Ad-hoc networks technology in an operating system of container yard, and efficiently distributed processing done Y/T to container crane compare with operation systems of the existing dedicated method, and an improvement can do an operating system of an yard.

• International Journal of Automotive Technology
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• 제3권2호
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• pp.57-62
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• 2002

It is well known that the entrained air in oil causes appreciable reduction in the stiffness of hydraulic systems. It makes the response delay of the systems and sometimes destroys the stability. Because the hydraulic systems of automatic transmissions are operated in relatively low pressure and high temperature, it is very important to analyze the effects of the air included in automatic transmission fluid. However, it is difficult to derive the generalized model to describe the effective bulk modulus theoretically or measure it in actual operating conditions of automatic transmissions. This paper reviews previous studies of the air effects in hydraulic systems and the measurement techniques of the effective bulk modulus in operating conditions. Based on this work, the theoretical model with moderate complexity and the measurement technique of the effective bulk modulus considering entrained air effect at real operating conditions are suggested. Our paper also shows that the quantity of the entrained air in the automatic transmission fluid can be estimated from the experimental results.

• 한국항해학회지
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• 제23권4호
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• pp.29-42
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• 1999

In the recent past, maritime safety research has been applied primarily to technological requirements and progression of regulations on standards of safety from which the ISM Code has resulted. Despite the engineering and technological innovations, significant marine casualties continue to occur, which indicates that human factors are an area requiring more focused attention. This paper aims to study the clear concept and its details of human factors in ship operating system through the investigation of researches presented so far. The purpose of studying human factors is to identify how the crew, the owners, the classification societies, and the regulatory bodies can work together to sever the chain of errors which are associated with every marine casualty. The human factors in ship operating system may be defined as the study and analysis of the interaction between the operator and system variables composing the system, most importantly the procedures and the crew and management follow.

• 대한안전경영과학회지
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• 제13권4호
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• pp.25-33
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• 2011

Workers in logistics centers also are exposed to serious musculoskeletal disorders the same as workers in general manufacturing due to operating forklifts and other labor duties. The frequency of these work related injuries decreases, workers' job satisfaction In addition, it causes many employees questioning a job change, which is regarded as the primary factor which drops the productivity. In this paper, we conducted a survey ti perceive the correlation between work related injuries in the fields of distribution centers and job satisfaction. Furthermore we made statistical analysis with our findings. The results of our analysis showed that the frequency of work related injuries due to workers' repetitive loading and unloading work is the primary factor which lowers job satisfaction. In order to improve aforementioned problem we propose first of all loading and unloading on pallet basis, second of all automation and computerization of logistics systems, and third of all ensurinf sufficient break time.

• 한국안전학회지
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• 제38권3호
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• pp.93-101
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• 2023

The COVID-19 pandemic has significantly impacted how people work, resulting in a massive shift towards working from home or remotely. Work from home has played a critical role in reducing the transmission of COVID-19 by limiting in-person interactions and reducing the density of people in office buildings. It also enabled businesses and organizations to continue operating while keeping their employees safe and healthy. The COVID-19 pandemic accelerated the adoption of work from home in business and organizational sectors worldwide, and it is likely to continue as a preferred mode of work even after the pandemic is over. This shift towards working from home has not only impacted the way people work but also has significant implications for urban development, transportation, and the environment. This study intends to develop measures for addressing potential physical and mental health issues among remotely working employees. Additionally, it identifies the major influencing factors of home workers' health hazards and proposes improvement measures that can be applied to working from home, along with existing laws and prevention methods.