• Journal of information and communication convergence engineering
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• 제20권3호
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• pp.181-188
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• 2022

An intelligent distributed multi-agent system (IDMS) using reinforcement learning (RL) is a challenging and intricate problem in which single or multiple agent(s) aim to achieve their specific goals (sub-goal and final goal), where they move their states in a complex and cluttered environment. The environment provided by the IDMS provides a cumulative optimal reward for each action based on the policy of the learning process. Most actions involve interacting with a given IDMS environment; therefore, it can provide the following elements: a starting agent state, multiple obstacles, agent goals, and a cluttered index. The reward in the environment is also reflected by RL-based agents, in which agents can move randomly or intelligently to reach their respective goals, to improve the agent learning performance. We extend different cases of intelligent multi-agent systems from our previous works: (a) a proposed environment-clutter-based-index for agent sub-goal selection and analysis of its effect, and (b) a newly proposed RL reward scheme based on the environmental clutter-index to identify and analyze the prerequisites and conditions for improving the overall system.

• Journal of Medicine and Life Science
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• 제18권3호
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• pp.49-55
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• 2021

Atypical antipsychotics are more effective than typical antipsychotics and have fewer side effects such as tardive dyskinesia and extrapyramidal symptoms; therefore, prescriptions of atypical antipsychotics are increasing. However, recently, it has been reported that atypical antipsychotics have a higher incidence of diabetes, hyperglycemia, and obesity than typical antipsychotics. Atypical antipsychotics induce obesity-inhibiting appetite-related receptors such as serotonin and dopamine. Decreased exercise due to improving psychotic symptoms, and genetic characterictics can also cause weight gain. Hyperglycemia and hypoglycemia were another metabolic problem related to treatment with atypical antipsychotics. The mechanisms of hyperglycemia were mainly related obesity, decreased anorexigenic hormones, and increased insulin resistance in multiple organs. There are also reports that genes related to diabetes have an effect on the incidence of diabetes mellitus treated with atypical antipsychotics. On the other hand, although it is not clear why hypoglycemia occurs, it documented in case reports all over the world. There are more reports of atypical antipsychotics than typical antipsychotics and these are frequently reported in Asians. Further research on the mechanism of hypoglycemia related to atypical antipsychotics is strongly recommended.

• Computers and Concrete
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• 제34권1호
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• pp.123-135
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• 2024

Strain-hardening cement-based composites (SHCC) under cracked condition exhibits remarkable capillary absorption due to water ingress from multiple cracks. Surface treatment using water repellent agents is an effective way for improving water resistance of SHCC, but the water resistance may remarkably decrease when cracks penetrate impregnation depth. Another way is to add water repellent agents directly into the mixture, offering SHCC integral water repellency even if cracks form later. However, although integral water repellent treatment has been proved feasible by previous studies, there is still lack of simulation work on the treated SHCC for evaluating its durability. This study presents a simulation method for capillary absorption of cracked SHCC with integral treatment based on a multi-scale approach proposed in the authors' previous work. The approach deals with water flows in bulk matrix and multiple cracks using two individual transport equations, respectively, whereas water absorbed from a crack to its adjacent matrix is treated as the mass exchange of the two equations. In this study, the approach is enhanced for the treated SHCC by integrating the influencing of water repellency into the two transport equations as well as the mass exchange term. Using the enhanced approach, capillary absorption of water repellent SHCC under cracked condition is simulated, showing much more reduced water ingress than the untreated concrete, which is consistent with total absorption data from previous tests. This approach is also capable of simulating water spatial distribution with time in treated SHCC reasonably.

• 한국미생물·생명공학회지
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• 제38권3호
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• pp.308-314
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• 2010

축산 악취물질인 암모니아가스를 대상으로 하여 환경개선제 사용시 자돈의 돈분뇨에서 발생되는 암모니아가스의 발생특성에 대한 연구를 수행하였다. 이 실험을 위하여 96 L의 부피를 가지는 아크릴 악취발생기를 제작하였다. 돈분으로부터 악취를 발생한지 한시간이 경과되면, 대략 평균 24.3ppmv의 암모니아가 발생되고, 범위는 16~40 ppmv였다. 실험결과 분무용 제제의 경우 분무 직후에 50~90%의 저감효과를 보였고, 1차 분무 시 지속성은 약 2일 정도로 나타났다. 천연탈취제의 지속성이 타 제품과 비교할 때 가장 우수하였다. 본 연구에서는 6구획의 실험구를 설정하였고, 5종류의 사료용 제제 첨가구와 일반 사료구에서 모두 항생제를 제외한 사료를 자돈에 급이하였다. 실험구엔 자돈($6.3{\pm}0.2\;kg$) 60마리를 대상으로 하여 각 구획당 10마리였으며, 총 35일간 실험이 진행되어 각 제제가 암모니아 방출에 미치는 영향을 일주일에 한번씩 살펴보았다. 사료용 제제를 급여한 자돈의 돈분에서의 암모니아 발생량은 일반사료만을 먹은 자돈의 돈분에서의 암모니아 발생량보다 낮았다. 사료용 제품중 효율이 우수한 제품은 7주 전 기간에 걸쳐 71~99%의 지속적 암모니아 저감효율을 보여주었으며, 일부 제품의 경우 초기 저감효율이 일시적이고 전기간에 걸쳐 전혀 암모니아 저감효율을 보여주지 않은 제품도 있었다.

• 한국산업보건학회지
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• 제4권1호
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• pp.117-126
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• 1994

Some of the important and vital roles performed by the Health Care Center of Pohang Iron & Steel Co., Ltd.(POSCO) are the periodic monitoring of the work sites as well as regular medical check-ups for each workers to ensure both pleasant and safe working conditions and to protect employees' health. Pohang Steel Works, which has 42 plants, 26 facilities and 12,000 employees, has an annual crude steel production capacity of 9,670,000 using 24,500,000 ton of raw materials. We have measured lots of areal and personal working environment according to Occupational Safety and Health Law semiannually. All data collected on industrial hygiene is stored and managed by personal computer. The developed of a computerized industrial hygiene control system linked to the company's main computer system will provide efficient evaluation of the working environment as well as critical informations on employees' health. Development of this system had begun in May, 1992 and was completed in March, 1994. The computerized industrial hygiene control system can; 1. store industrial hygiene data, providing key pertinent to the diagnosis of occupational related illnesses, and if necessary, the basis for improving the working environment, 2. decide type and time of medical examination of each work for exposure to specific agents, and supply proper protection periodically, 3. prevent occupational related illnesses through evaluation of environmental and biological monitoring, and performance of epidemiological surveillance, 4. facilitate proper job placement through linking of industrial hygiene control and personnel information systems, 5. monitor job processes. levels of chemical agents used, and new agents introduced, 6. and increase productivity by saving time resulting from the implementation of the computerized sysyte,

• 한국식품영양학회지
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• 제30권1호
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• pp.139-147
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• 2017

The objective of this study was to develop anti-browning agents for commercial ready-to-eat pear products, which are preferred not only to maintain the flavor, color and texture of pears, but also to increase consumers' preference. The sliced 'Shin-go (Niitaka)' pears were immersed in 5% and 10% oxidized starch, 1% citric acid, and 5% and 10% oxidized starch with addition of 0.1% sucralose for 3 minutes, and then they were packaged in vacuum sealed bags at $1^{\circ}C$ for 9 days. In order to evaluate the quality of packaged sliced pears, the quality index was determined in terms of color, firmness, soluble solids, and sensory quality. With the passage of storage time, no specific variation in firmness and soluble solids was observed. However, the ${\Delta}E$ value of the sliced pears treated with 5% oxidized starch solution was significantly lower than that of the other pears. Also, the Hunter L and b values of the sliced pears treated with 5% oxidized starch solution remained nearly constant from the beginning of storage. This observation shows that 5% oxidized starch solution was effective in reducing surface browning of sliced pears. Moreover, sliced pears treated with oxidized starch solution with addition of 0.1% sucralose were given an overall liking score which was slightly higher than that given to the other pears because of the sweetness of sucralose. In conclusion, 5% oxidized starch solution with addition of 0.1% sucralose was effective in reducing browning of sliced pears and in improving the taste of sliced pears.

• 한국정보과학회논문지:시스템및이론
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• 제35권12호
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• pp.552-559
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• 2008

인터넷 기술이 발달하고 다양한 온라인 서비스들이 생겨남에 따라 사람들 간의 인터넷 커뮤니케이션 방식도 크게 변하고 있다. 특히 최근 유행하고 있는 3차원 가상현실 세계를 이용한 다양한 채팅서비스들은 사용자가 대화 내용을 이해하기 쉽고 흥미를 느낄 수 있는 방향으로 현재도 꾸준히 발달하고 있으며, 현실성과 흥미를 더하기 위한 많은 기법들을 도입하고 있다. 하지만 3차원 가상현실 세계는 점점 더 발달하고 있는데 비해 채팅 방식은 2차원의 대화창이나 말풍선을 이용하고 있어 현실성을 떨어뜨릴 뿐만 아니라 다양한 변화를 주는데 그 한계를 가지고 있다. 본 논문은 실제 세계에서의 대화 방식에 기반을 둔 가상 세계 커뮤니케이션 프레임워크를 제안한다. 제안하는 커뮤니케이션 프레임워크는 사용자들 간의 시점과 거리 등 3차원의 공간 정보를 고려하여 현실세계와 유사한 대화방식을 제공할 수 있으며, 인공적인 채팅 기법이나 사용자의 입력을 최소화하면서 가상현실 세계에서의 커뮤니케이션 효과를 높일 수 있다. 또한 기존의 대화 내용 기록 방식에서 사용된 시간 정보와 함께 아바타의 공간 정보까지 고려함으로써 대화간의 질문/답변 관계를 그래프의 형태로 기록할 수 있으며, 이를 통하여 가상 세계 내의 대화 내용을 효율적으로 관리하는데 도움이 된다.

• 한국산업보건학회지
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• 제9권1호
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• pp.73-86
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• 1999

This study was performed to find out factors affecting degree of satisfaction with workers' working environment. The study subjects were 165 workers who were working at painting process of twelve furniture manufacturing factories in Incheon area. We used self-administered questionnaire containing general characteristics, working conditions, the degree of satisfaction with working environment, and the degree of satisfaction with working condition. In addition, we measured the exposure levels of occupational hazardous agents. The results were as follows; 1. Correlations between the degree of satisfaction with workers' working environment and the measured of occupational hazardous agents did not affect the degree of satisfaction with workers' working environment. 2. Factors affecting the degree of satisfaction with workers' working environment were not the exposure levels of occupational hazardous agents, but the degree of satisfaction with working condition, size of industry, health status, and types of ventilation system. As the degree of satisfaction with working condition was increased, the degree of satisfaction with working environment was increased. Also, for the workers who had good health status, the degree of satisfaction with work environment was appeared to be high. To increase the degree of satisfaction, with workers' working environment, firstly, effective work management and production control are required. Also, the worker's effort to negotiate continuously with top manager on improving working conditions is required. Secondly, developing heath promotion program to be appropriate for the characteristics of worksite is required. Moreover, leading worker's participation in health promotion program is very important to increase the degree of satisfaction with workers' working environment.

• 한국토양비료학회지
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• 제45권6호
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• pp.949-954
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• 2012

시설재배지 토양의 축적양분인 염류를 활용하기 위해 EC가 높은 토양에 여러 킬레이트제를 처리하여 토양의 화학성과 작물의 무기성분 흡수량을 비교 분석하였다. DTPA와 EDTA를 처리한 구에서 킬레이트제는 Ca, Mg, K, P등의 다량원소 뿐만 아니라 Fe, Cu, Mn, Zn 등의 미량원소와 킬레이트 하는 능력이 뛰어났다. 그러나, 토양의 ECDTPA를 처리한 는 EDTA를 처리한 토양보다 낮아졌다. 킬레이트제가 처리된 토양에서 생육한 배추의 무기성분 흡수량을 살펴본 결과 DTPA 0.5 mM 처리한 구에서 배추의 T-N, $P_2O_5$, $K_2O$, 그리고 Fe의 흡수량은 다른 처리구보다 높았다. 이로부터 시설재배지의 집적된 양분을 킬레이트화하여 작물의 양분 이용성을 증대하는 데 효과적인 킬레이트제는 DTPA이며, 적정한 농도는 0.5 mM로 나타났다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제39권2호
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• pp.43-54
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• 2013

In an attempt to regain function and aesthetics in the craniofacial region, different biomaterials, including titanium, hydroxyapatite, biodegradable polymers and composites, have been widely used as a result of the loss of craniofacial bone. Although these materials presented favorable success rates, osseointegration and antibacterial properties are often hard to achieve. Although bone-implant interactions are highly dependent on the implant's surface characteristics, infections following traumatic craniofacial injuries are common. As such, poor osseointegration and infections are two of the many causes of implant failure. Further, as increasingly complex dental repairs are attempted, the likelihood of infection in these implants has also been on the rise. For these reasons, the treatment of craniofacial bone defects and dental repairs for long-term success remains a challenge. Various approaches to reduce the rate of infection and improve osseointegration have been investigated. Furthermore, recent and planned tissue engineering developments are aimed at improving the implants' physical and biological properties by improving their surfaces in order to develop craniofacial bone substitutes that will restore, maintain and improve tissue function. In this review, the commonly used biomaterials for craniofacial bone restoration and dental repair, as well as surface modification techniques, antibacterial surfaces and coatings are discussed.