• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권10호
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• pp.3867-3886
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• 2015

This article investigates the problem of opportunistic spectrum access in dynamic environment, in which the signal-to-noise ratio (SNR) is time-varying. Different from existing work on continuous feedback, we consider more practical scenarios in which the transmitter receives an Acknowledgment (ACK) if the received SNR is larger than the required threshold, and otherwise a Non-Acknowledgment (NACK). That is, the feedback is discrete. Several applications with different threshold values are also considered in this work. The channel selection problem is formulated as a non-cooperative game, and subsequently it is proved to be a potential game, which has at least one pure strategy Nash equilibrium. Following this, a multi-agent Q-learning algorithm is proposed to converge to Nash equilibria of the game. Furthermore, opportunistic spectrum access with multiple discrete feedbacks is also investigated. Finally, the simulation results verify that the proposed multi-agent Q-learning algorithm is applicable to both situations with binary feedback and multiple discrete feedbacks.

• 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.

• 대한간호학회지
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• 제51권4호
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• pp.454-464
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• 2021

Purpose: This study aimed to identify the level of complete knowledge about hand hygiene indications among nurses working at integrated nursing care service wards. Methods: A total of 127 nurses in eight integrated nursing care service wards completed structured sheets while observing a video based on six scenarios developed by the research team. Complete knowledge level was calculated as the percentage (%) of participants who responded correctly to all questions among participants. Complete knowledge levels according to the scenarios were calculated and compared according to general characteristics using the chi-squared test or Wilcoxon rank-sum test. Results: The complete knowledge level for each scenario ranged from 7.9% (scenario 6) to 42.5% (scenarios 4 and 5), and no one had complete knowledge of all scenarios. Only 3.1% of participants demonstrated complete knowledge in more than four scenarios, and 26.0% had complete knowledge of four or more hand hygiene moments. Complete knowledge level per scenario did not differ depending on work experience at hospitals and study wards, or prior hand hygiene training in the last year. Conclusion: As the complete knowledge level regarding hand hygiene moment is very low, it is suggested that regular hand hygiene training should be provided to nurses using video media that reflect real nursing tasks. Thus, they can acquire complete knowledge of when hand hygiene is needed or not during complex nursing work situations.

• 동남아시아연구
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• 제21권1호
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• pp.185-216
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• 2011

This work shows dynamism of empathy which Thailand experienced while its monarchy was replaced by democracy with conflicts and harmony. In this work, two imaginary protagonists are put into the most important period in Thai history, from the political reform of the absolute monarchy in 1932 up to Black May in 1992, for 60 years. With the writer's imagination, they are actualized into the historically important situations with reality. One of them is Yeoy, a dissident and the other is a police officer, a concenter, who chases after him. In this dissertation, empathy is analyzed which the characters feel about real incidents in their country through trust and doubt, hope and anger. This research on emotional circumstance is all about figuring out the direction for harmony and coexistance. Thailand needs a powerful leader who deals with swiftly changing worldwide affairs and domestically economic matters. Even if their leader has the same destination to get to, their approach to it is different from each other. Therefore, conflicts come out and misunderstanding makes situation worse. Public sympathy among Thai is that Thailand contribute to global mutual prosperity, by which Thailand becomes a powerful and influential state in making the world harmonious and prosperous.

• 한국환경복원기술학회지
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• 제23권6호
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• pp.57-73
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• 2020

A study was conducted to present the criteria for evaluating the revegetation method of the slope of the expressway. The results of comparative analysis between 2019-2020 field survey and existing research data (2015-2016) are as follows. Soil is a very important factor at the beginning of revegetation work. However, after the plant has settled, the importance of the soil composition diminishes. Among the plants used, the number of plants sown at the beginning gradually decreases. And it changes as it competes with invading plants. Among the plants used for sowing, it was found to affect the vegetation composition in the order of exotic grass > native herb and wildflower > native tree. Plant coverage is continuously evaluated as an important factor regardless of the time. The vegetation structure on the slope will change continuously over time. New items need to be evaluated in situations where a lot of time has elapsed since the application of revegetation work. It is desirable to use the current evaluation standard only to perform the evaluation within 1 to 2 years. In the long run, it is necessary to establish a new evaluation standard that adjusts the weights of each item.

• Safety and Health at Work
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• 제12권1호
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• pp.10-19
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• 2021

Background: Traditional safety concept, which is called Safety-I, and its relevant methods and models have much contributed toward enhancing the safety of industrial systems. However, they have proved insufficient to be applied to complex socio-technical systems. As an alternative, Safety-II and resilience engineering have emerged and gained much attention for the last two decades. However, it seems that safety professionals have still difficulty understanding their fundamental concepts and methods. Accordingly, it is necessary to offer an introductory guide to them that helps safety professionals grasp them correctly in consideration of their current practices. Methods: This article firstly explains the limitations of Safety-I and how Safety-II can resolve them from the four points of view. Next, the core concepts of resilience engineering and Functional Resonance Analysis Method are described. Results: Workers' performance adjustment and performance variability due to it should be the basis for understanding human-related accidents in socio-technical systems. It should be acknowledged that successful and failed work performance have the same causes. However, they are not well considered in the traditional safety concept; in contrast, Safety-II and resilience engineering have conceptual bases and practical approaches to reflect them systematically. Conclusion: It is necessary to move from a find-and-fix and reactive approach to a proactive approach to safety management. Safety-II and resilience engineering give a set of useful concepts and methods for proactive safety management. However, if necessary, Safety-I methods need to be properly used for situations where they can still be useful as well.

• 한국도서관정보학회지
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• 제53권4호
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• pp.163-188
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• 2022

본 연구는 제주지역 내 21개관의 작은도서관 실무자들을 대상으로 운영실태를 파악하고, 이를 기반으로 활성화할 수 있는 방안이 무엇인지 알아보고자 하였다. 이를 위해 작은도서관의 운영시간, 프로그램 운영, 자원봉사자의 활동, 시설확충, 작은도서관 및 일반 공공도서관과의 교류, 업무관련교육, 업무 우선순위, 홍보활동, 활성화를 위한 서비스 등 작은도서관의 운영 및 근무상황 전반에 대한 실태조사를 실시하였다. 그 결과, 지역주민의 작은도서관에 대한 관심 유도, 독서문화프로그램 확대운영, 운영인력의 전문성 확보, 운영인력 충원, 예산 확대 및 운영인력의 인건비 기준마련, 작은도서관지원센터 설립 등의 활성화방안을 제시하였다.

• Nuclear Engineering and Technology
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• 제56권6호
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• pp.1959-1974
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• 2024

Nuclear energy plays a crucial role in energy supply in the 21st century, and more and more Nuclear Power Plants (NPPs) will be in operation to contribute to the development of human society. However, as a typical complex system engineering, the operation and development of NPPs require efficient and stable control methods to ensure the safety and efficiency of nuclear power generation. Reinforcement learning (RL) aims at learning optimal control policies via maximizing discounted long-term rewards. The reward-oriented learning paradigm has witnessed remarkable success in many complex systems, such as wind power systems, electric power systems, coal fire power plants, robotics, etc. In this work, we try to present a systematic review of the applications of RL on these complex systems, from which we believe NPPs can borrow experience and insights. We then conduct a block-by-block investigation on the application scenarios of specific tasks in NPPs and carried out algorithmic research for different situations such as power startup, collaborative control, and emergency handling. Moreover, we discuss the possibilities of further application of RL methods on NPPs and detail the challenges when applying RL methods on NPPs. We hope this work can boost the realization of intelligent NPPs, and contribute to more and more research on how to better integrate RL algorithms into NPPs.

• 실천공학교육논문지
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• 제16권2호
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• pp.241-249
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• 2024

본 연구는 COVID-19 거점 전담병원의 간호사를 대상으로 직무스트레스와 간호업무환경, 이직의도를 파악하고 이직의도에 미치는 영향요인을 확인하고자 수행되었다. 2022년 9월 1일부터 9월 27일까지 I지역의 일 개 COVID-19 거점 전담병원 간호사 144명을 대상으로 자료를 수집하였으며, 수집된 자료는 SPSS Statistics 23.0 프로그램을 이용하여 분석하였다. 연구결과, 이직 의도는 근무경력(F=11.20, p<.001)과 직급(F=4.09, p=.009)에 따라 유의한 차이를 보였다. 또한 이직의도는 직무스트레스(r=.561, p<.001), 간호업무환경(r=-.382, p<.001)과 유의한 상관관계를 나타냈다. 이직의도의 영향요인은 직무스트레스(β=.46, p<.001), 11년 이상의 근무경력(β=.34, p<.001), 3~10년의 근무경력(β=.20, p=.022), 간호업무환경(β=-.22, p=.001)이며 43.9%의 설명력을 보였다. 이에 COVID 19 거점 전담병원 간호사의 이직의도를 감소시키기 위해 감염병 상황에서는 경력별 업무 특성을 고려한 직무 스트레스 감소 방안과 효율적인 간호업무환경을 조성해야 하겠다.

• 한국환경보건학회지
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• 제43권1호
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• pp.42-54
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• 2017

Objectives: The present study was conducted to investigate farm work environments among farmers and examine the level of management of safety and health, and to subsequently produce study result to serve as foundational data for the development of guidelines on safety and health as part of the improvement of farming work environments among farmers raising Korean native cattle. Methods: The present study conducted a survey on farm work environments and the management of safety and health with 407 farmers engaged in Korean native cattle farming in selected regions in eight provinces. It also visited 10 farmers to verify the current status of farm work. Results: The survey results showed that 16.4% of the respondents experienced safety-related accidents due to farm work. The locations of the accidents were inside the cattle shed (71.4%) and facilities outside the cattle shed (19.6%). The types of accident showed collision with animals (35.7%), collision or contact with obstacles (27.1%), and musculoskeletal accidents due to heavy object handling (12.9%). The causes of the accidents were cattle (38.3%), cultivators and tractors (25.4%), facility tools in cattle sheds (9.0%), and slippery floors (6.0%). The damaged areas were hand (21.0%), spine (19.8%), lower limb (18.5%), and foot (17.3%). A self-diagnostic survey on respiratory diseases showed that 11.5% of the respondents experienced respiratory-related symptoms. The survey on safety and health during farm work showed that wearing personal protective equipment and response to emergency situations, which were needed to prevent safety-related accidents, were relatively low compared to the level of recognition of the need and awareness of safety issues. Furthermore, the field survey identified the current status of safety and health issues such as prevention management of collision accidents with cattle, how to handle heavy objects, and wearing of personal protective equipment. Conclusions: The present study identified safety-related accidents and problems in the management of safety and health among Korean native cattle farmers. In order to address the problem, it is necessary to not only provide guidelines on safety and health management which are appropriate to the characteristics of Korean native cattle farming work, but also to study the development of personal protective equipment.