• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권4호
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• pp.1419-1436
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• 2020

For an energy harvesting sensor network, when the network lifetime is not the only primary goal, maximizing the network performance under environmental energy harvesting becomes a more critical issue. However, clustering protocols that aim at providing maximum information throughput have not been thoroughly explored in Energy Harvesting Wireless Sensor Networks (EH-WSNs). In this paper, clustering protocols are studied for maximizing the data transmission in the whole network. Based on a long short-term memory (LSTM) energy predictor and node energy consumption and supplement models, an uneven clustering protocol is proposed where the cluster head selection and cluster size control are thoroughly designed for this purpose. Simulations and results verify that the proposed scheme can outperform some classic schemes by having more data packets received by the cluster heads (CHs) and the base station (BS) under these energy constraints. The outcomes of this paper also provide some insights for choosing clustering routing protocols in EH-WSNs, by exploiting the factors such as uneven clustering size, number of clusters, multiple CHs, multihop routing strategy, and energy supplementing period.

• 한국수소및신에너지학회논문집
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• 제19권4호
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• pp.313-321
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• 2008

Dynamics of the proton exchange membrane fuel cell is specially important when the system is frequently working on transient conditions. Even though the dynamics of proton exchange membrane fuel cell for residential power generation is less critical than that of PEMFC for transportation application, the system dynamics of PEMFC for RPG can be very important for daily start-up and stop. In particular, thermal management of the PEMFC for RPG is very important because the heat generation from electrochemical reaction is delivered to the home for hot water usages. Additionally, the thermal management is also very important for heat balance of the system and temperature control of the fuel cell. The objective of this study is to develop a dynamic system model for the study of PEMFC performance over various BOP options. Basic simulation results will be presented.

• 대한치과의사협회지
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• 제53권6호
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• pp.418-426
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• 2015

The appropriate occlusion is one of the most important factors for the long-term success of implant and its restorations. The purpose of this review is to investigate and define occlusal considerations to reduce failure of implant prostheses. The physiological movement of implants is markedly lower than that of natural teeth and they also lack in occlusal sensitivity. Proper occlusal pattern may be assigned to compensate for the biological disadvantages and occlusal contacts must be formed where the cantilever effect is minimized. Moreover, the long-term success of implants after osseointegration can be assured by reducing early occlusal loading to avoid implant overloading and selecting appropriate occlusion material. Occlusal overload was brought by the number and location of occlusal contacts, which are under the clinician's control. The concept of implant occlusion is based on the concepts derived from traditional prosthetics. Moreover, there are few evidence on the concept or design of implant occlusion. Several occlusal design was recommended for implant prosthesis. Mutually protected occlusion, group function occlusion and bilateral balance occlusion was recommended for the specific types of implant restorations. This article reviews proper design of occlusion for implant restoration and offers occlusion strategy clinically.

• Journal of Electrical Engineering and Technology
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• 제13권5호
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• pp.1986-1995
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• 2018

In this paper, a novel neutral-point voltage balancing scheme for NPC three-level inverters using carrier-based sinusoidal pulse width modulation (SPWM) method is developed. The new modulation approach, based on the obtained expressions of zero sequence voltage in all six sectors, can significantly suppress the low-frequency voltage oscillation in the neutral point at high modulation index and achieve a fast voltage-balancing dynamic performance. The implementation of the proposed method is very simple. Another attractive feature is that the scheme can stably control any voltage difference between the two dc-link capacitors within a certain range without using any extra hardware. Furthermore, the presented scheme is also applicable to the single-phase NPC three-level inverter. It can maintain the neutral-point voltage balance at full modulation index and improve the voltage-balancing dynamic performance of the single-phase NPC three-level inverter. The performance of the proposed strategy and its benefits over other previous techniques are verified experimentally.

• Journal of Microbiology and Biotechnology
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• 제32권6호
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• pp.681-698
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• 2022

The Nile tilapia Oreochromis niloticus, Atlantic salmon Salmo salar, rainbow trout Oncorhynchus mykiss, olive flounder Paralichthys olivaceus, common carp Cyprinus carpio, grass carp Ctenopharyngodon idella and rohu carp Labeo rohita are farmed commercially worldwide. Production of these important finfishes is rapidly expanding, and intensive culture practices can lead to stress in fish, often reducing resistance to infectious diseases. Antibiotics and other drugs are routinely used for the treatment of diseases and sometimes applied preventatively to combat microbial pathogens. This strategy is responsible for the emergence and spread of antimicrobial resistance, mass killing of environmental/beneficial bacteria, and residual effects in humans. As an alternative, the administration of probiotics has gained acceptance for disease control in aquaculture. Probiotics have been found to improve growth, feed utilization, immunological status, disease resistance, and to promote transcriptomic profiles and internal microbial balance of host organisms. The present review discusses the effects of single and multi-strain probiotics on growth, immunity, heamato-biochemical parameters, and disease resistance of the above-mentioned finfishes. The application and outcome of probiotics in the field or open pond system, gaps in existing knowledge, and issues worthy of further research are also highlighted.

• 한국ITS학회 논문지
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• 제19권3호
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• pp.38-51
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• 2020

고속도로에서 공사로 인한 차로폐쇄가 발생하면 병목이 형성되어 혼잡이 발생한다. 따라서 공사구간의 도로 운영효율을 개선하기 위해 다양한 교통관리전략이 개발되었으며, 대표적으로 공사구간 상류에 운영하는 합류제어가 있다. 일반차 환경에서는 혼잡시 운전자가 합류에 어려움을 겪어 전략 운영에 한계가 존재하나, 자율협력주행차는 통신기능을 활용하여 고도화된 교통관리전략의 운영이 가능하다. 이에 본 연구는 자율협력주행차 환경에서 동적합류제어와 차로변경제어를 통합한 교통관리전략을 개발하였다. 통합제어전략은 공사구간 상류의 점유율을 기준으로 조기합류 또는 지연합류를 운영하며, 비공사차로의 차로별 교통량을 균형화 하기 위해 차로를 변경할 차량수를 결정한다. 미시교통시뮬레이션에 자율협력주행차와 전략을 구현하고 분석한 결과 누적 통과교통량, 공사구간 상류의 평균속도 및 네트워크 평균통행시간이 개선되어 도로 운영성이 향상된 것을 확인하였다.

• 마케팅과학연구
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• 제18권4호
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• pp.61-118
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• 2008

본 연구는 국내외 프랜차이즈의 해외진출에 대한 연구들을 바탕으로 국제프랜차이징연구의 전체적인 연구체계를 세워보고, 연구체계를 형성하고 있는 연구요인들을 확인하여 각 연구요소별로 이루어지는 연구주제와 내용을 살펴보고, 앞으로의 연구주제들을 제안하고자 한다. 주요한 연구요소들은 국제프랜차이징의 동기 및 환경 요소과 진출의사결정, 국제프랜차이징의 진입양식 및 발전전략, 국제프랜차이징의 운영전략 및 국제프랜차이징의 성과이다. 이외에도 국제프랜차이징 연구에 적용할 수 있는 대리인이론, 자원기반이론, 거래비용이론, 조직학습이론 및 해외진출이론들을 설명하였다. 또한 국제프랜차이징연구에서 보다 중점적으로 개발해야 할 질적, 양적 방법론을 소개하였으며, 마지막으로 국내연구의 동향을 정리하여 추후의 연구방향을 종합적으로 정리하였다.

• 해양안보
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• 제8권1호
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• pp.41-71
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• 2024

국제적 무력충돌 상황에서 교전국의 교전권과 중립국의 무역 활동을 통한 경제적 이익의 이해 균형을 맞추고자 발달한 중립법상 '전시금제품 제도'는 19세기 해상무역의 발달에 따라 제도의 변천과 발전이 이루어지기 시작했다. 특히, 제1, 2차 세계대전을 거치면서 물자 통제의 범위가 확대되어 오늘날까지 지속되고 있으며, 군사용과 민간용으로 모두 사용될 수 있는 '조건부 금제품'의 군사적 사용을 막기 위한 추세로 발전했다. 이 과정에서 전시금제품 제도는 개념적으로 평시까지 확대되어, 국제기구를 중심으로 하는 '국제 수출통제 체제'가 형성되기도 하였다. 오늘날에도 여전히 전시금제품 제도는 유효하다. 하지만, 우리나라에는 한반도 유사시를 대비한 전시금제품 제도 관련 법령이나 지침은 부재한 실정으로 보인다. 전시금제품 목록 작성과 대외적 공표가 국제적 실행임을 고려하면, 우리나라도 이를 대비할 필요가 있다. 이에 본 논문에서는 중립법상 전시금제품 제도의 역사적 연원과 발전을 확인하고, 전시금제품 통제에 대한 국가실행을 시대 흐름에 따라 살펴 보고자 한다. 이를 통해 전시금제품 제도의 변천과 국가실행 변화가 한반도에 주는 함의를 도출하고자 한다.

• 한국전산구조공학회논문집
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• 제23권4호
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• pp.435-443
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• 2010

본 연구에서는 MR(Magneto-Reological)제어기가 설치된 단자유도 구조물의 응답을 예측하기 위하여 구조물의 운동방정식을 해석적으로 분석하고 주요변수를 파악하였다. MR제어기의 수치 모델로는 마찰 및 점성감쇠로 단순모델한 Bingham모델을 사용하였다. 자유진동과 조화진동일때의 응답감쇠를 결정짓는 주요변수가 각각 마찰력과 최대정적복원력의 비 $R_f$, 마찰력과 최대조화가진력의 비 $R_h$ 임을 파악하였다. 비선형 미분방정식을 등가의 선형 미분방정식으로 변환하기 위하여 마찰력에 의한 에너지 소산을 등가의 점성에너지로 치환하여 등가점성감쇠와 등가점성감쇠비를 유도하였다. 마지막으로 등가선형화과정을 검증하기 위하여 실제 지진에 대한 구조물의 응답을 비선형 미분방정식의 해와 비교하였다.

• 동의생리병리학회지
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• 제24권5호
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• pp.807-813
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• 2010

Impairment of balance between bone-resorbing osteoclasts and bone-forming osteoblasts result in bone disease. Especially, increased osteoclast formation and activity are responsible for bone diseases such as osteoporosis, rheumatoid arthritis, periodontal disease. Natural metabolites of plants have recently received much attention as an alternative tools for the development of novel therapeutic strategy. The aim of this study was to search the natural products to inhibit osteoclast differentiation and was to evaluate of its mechanism. Water extract of Gastrodia elata Blune significantly inhibited receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation in bone marrow macrophages (BMMs) in a dose dependent manner. However, water extract of Gastrodia elata Blune did not affect cytotoxicity when compared with control. The mRNA expression of c-Fos, NFATc1, and TRAP induced by RANKL was inhibited by water extract of Gastrodia elata Blune treatment. Also, water extract of Gastrodia elata Blune inhibited the protein expression of c-Fos and NFATc1 expression in BMMs treated with RANKL. Water extract of Gastrodia elata Blune suppressed the phosphorylation of p38 induced by RANKL. In general, RANKL considerably inhibited the expression level of Id2 and MafB known as negative regulators of osteoclastogenesis, but RANKL did not inhibit Id2 and MafB expression in BMMs when it was co-treated with Gastrodia elata Blune. Taken together, these results suggest that Gastrodia elata Blune may be a useful drug in the treatment of bone-related disease.