• 해양환경안전학회지
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• 제15권2호
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• pp.143-149
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• 2009

경제 사회적 발전과 주 5일 근무제의 시행으로 국민들 삶의 질이 향상되고 좀 더 다양한 삶을 추구하고자 하는 가치관이 형성됨으로써 다양한 유형의 레저활동이 급격하게 증가하고 활성화되고 있는데 특히, 해양에서의 레저활동이 지속적으로 증가하고 있다. 그 중에서도 스킨스쿠버다이빙은 해양레저활동의 높은 비율을 차지하고 있지만, 동 활동의 안전에 관한 법규는 배우 미비하다. 이에 본 논문은 스킨스쿠버다이빙의 안전성을 향상시키고 또한 활성화시키기 위하여, 동 활동과 관련한 여러 법적 쟁점을 논의하고 고찰하여 문제점을 확인하고 개선방안을 도출하고자 한다.

• Smart Structures and Systems
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• 제19권5호
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• pp.553-565
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• 2017

Structural modeling of unencapsulated ionic polymer metal composite (u-IPMC) actuators that are used for flapping the insect scale-flapping wing of micro air vehicles (FMAV) in dry environmental conditions is carried out. Structural modeling for optimization of design parameters for retention of water, maximize actuation performance and to study the influence of water activity on the actuation characteristics of u-IPMC is explored for use in FMAV. The influence of equivalent weight of Nafion polymer, cations, concentration of cations, pre-treatment procedures on retention of water of u-IPMCs and on actuation parameters, flapping angle, flexural stiffness and actuation displacement are investigated. IPMC designed with Nafion having equivalent weight 900-1100, pre-heated at $30^{\circ}C$ and with sodium as the cations is promising for optimum retention of water and actuation performance. The actuation parameters while in operation in dry and humid environment with varying water activity can be tuned to desirable frequency, deflection, flap angle and flexural stiffness by changing the water activity and operational temperature of the environment.

• 한국수학교육학회지시리즈A:수학교육
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• 제55권1호
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• pp.41-71
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• 2016

The purpose of this study is to investigate elementary students' communication in process of applying mathematical modeling. For this study, 22 fifth graders in an elementary school were observed by applying mathematical modeling process (presentation of problem ${\rightarrow}$ model inducement activity ${\rightarrow}$ model exploration activity ${\rightarrow}$ model application activity). And the level of their communication with their activity sheets and outputs, observation records and interviews were also analyzed. Additionally, by analyzing the activity cases of and , this study researched that what is a positive influence on students' communication skills. Whereas showed significant advance in the level of communication, who communicated actively on speaking area but not on every areas showed insensible changes. To improve communication abilities, cognitive tension and debate situation are needed. This means, mathematical education should continuously provide students with mathematical communication learning, and a class which contains mathematical communication experiences (such as mathematical modeling) will be needed.

• 한국전자거래학회지
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• 제19권1호
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• pp.63-78
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• 2014

본 논문에서는 정보보호 거버넌스를 강조한 선행연구들을 바탕으로, 거버넌스 측면에서 가장 첫 번째에 해당하는 최고경영층의 정보보호에 대한 리더십이 정보보호 정책수립, 정보보호 조직과 인력 구성, 정보보호 교육 및 훈련, 기술적 대책 활동, 모니터링 및 감사활동 등과 같은 정보보호 통제활동에 어떤 영향을 주는 지에 대해 실증적으로 분석하고자 한다. 뿐만 아니라 최고경영층의 리더십과 비교되는 요인으로 조직 내에서 발생한 인터넷 침해사고 피해에 의해 정보보호 통제활동에 얼마나 차이가 있는지를 분석하여 시사점을 찾고자 한다.

• 한국환경보건학회지
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• 제33권4호
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• pp.338-343
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• 2007

Chlorine inhibition on the denitrifing activity of activated sludge treating dairy wastewater was investigated in this study. Filamentous bulking was caused artificially by a sudden load of feed and monitored by measuring sludge volume index. In cases of the activated sludge and bulking sludge which were contacted with chlorine as $7.5\;mgCl_2/gVSS/day$ for bulking control, the decreases of specific denitrification of $32.2{\sim}40.4%\;and\;43.5{\sim}46.5%$ were shown in comparison to the control group which was not reacted with chlorine, respectively. In continuous operation, it was observed that the removal efficiency of total nitrogen was more susceptible to chlorine than the removal efficiency of total phosphorus.

• 미생물학회지
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• 제18권2호
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• pp.59-66
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• 1980

Two strains S-P and S-P-2, both Streptomyces sp., have been isolated and were found to have relatively high specific enzyme activity compared to other organisms reported. The specific activity of the enzyme produced from these two strains were 0.25 and 0.2 international units respectively. The productivity of the enzyme achieved was about 50 IU/l/hr. Glucose isomerase form these strains was found to be stable under the temperature of heat treatment (at $65^{\circ}C$) for fixation of enzyme inside the dell. This organism has an advantage in that it did not require toxic metalic ion for enzyme activity and could utilize xylan in leu of xylose as an inducer. The optimal temperature and pH of enzymatic reaction purpose of using these data for the optimal operation and designing of enzyme reactor system. The reaction mechanism was found to follow the single substrate reversible reaction kinetics. The kinetic constants determined experimentally are : $K_{mf}=0.33M,\;K_{mb}=1.0M,\;V_{mf}=0.88{\mu}mole\;per\;min.,\;V_{mb}= 2.96{\mu}mole\;per\;min.\;and\;K_{eq}=0.74.

• 전기학회논문지
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• 제57권12호
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• pp.2336-2344
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• 2008

In this paper, muscular activity and muscle fatigue of FDI(first dorsal interosseous muscle) and thenar muscle of hand was analyzed with surface EMG signal based on four kinds of attitudes(grip, tip, key and palmar) to measure grip strength and pinch strength after hand operation and rehabilitation treatment. The normative data are needed to interpret evaluation data to assess a patient's ability to return to labor environment. The preceding researchers proposed the standard data only by studying on maximum grip strength and the maximum pinch strength followed by each attitude of subjects' hands. But in this study, the muscle activity and muscle fatigue were considered under the various attitude to propose normative data. As a results, the muscle fatigue may be used only for presentation of normative data in labor environment.

• 한국정보통신학회논문지
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• 제11권12호
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• pp.2280-2286
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• 2007

정보시스템은 다양한 구성요소들을 포함하고 있으며, 이들 구성요소들은 몇 개의 유형으로 구분될 수 있다. 보안수준관리활동을 준비 할 때, 관리활동의 대상을 정의하는 것이 가장 중요하며, 이들 대상을 정의한 이후 보안수준 관리활동이 시작될 수 있다. 본 논문에서는 정보시스템을 몇 개의 부분으로 나눔으로써 관리대상을 정의하고, 이들 대상은 운영 환경과 특성에 따라 다양하게 관리될 수 있음을 보여준다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(1)
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• pp.97-100
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• 2004

Our country has depended on fossil fuel very much according to the Increasing of the demand of the electric power. For instance, if the reduction and freezing caused by the warm gas in earth by the regulation of international environment happen in Korea it will bring about the result of weakness in industrial activity. As a result, it will cause many problems to compete an advanced country which wants to connect environment with the activity of industrial product in their country. The photovoltaic system outputs have peak about a half past 13 o'clock(before and after) mainly in a good weather. The output decreases rapidly from a half past 17 o'clock and PV output doesn't work at six o'clock before the sun rises. The outputs of PV system stops at that time. The frequent degree of harmonics in dwelling house which lots of people live has peak from 19 o'clock to 22 o'clock Harmonics mainly happens at least at night. In recent, many researches about power quality has been studying very hard in order to solve the question, the voltage fluctuating and harmonics as one compensator. In this paper, I suggest the algorithm which can increase the power quality as a rate of operation of this system. This algorithm proves to have effectiveness through computer simulation.

• Industrial Engineering and Management Systems
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• 제14권3호
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• pp.248-274
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• 2015

This study discusses a contract to promote collection and recycling of used products in a green supply chain (GSC). A collection incentive contract is combined with a reward-penalty contract. The collection incentive contract for used products is made between a retailer and a manufacturer. The reward-penalty contract for recycling used products is made between a manufacturer and an external institution. A retailer pays an incentive for collecting used products from customers and delivers them to a manufacturer with a product order quantity under uncertainty in product demand. A manufacturer remanufactures products using recyclable parts with acceptable quality levels and covers a part of the retailer's incentive from the recycled parts by sharing the reward from an external institution. Product demand information is assumed as (i) the distribution is known (ii) mean and variance are known. Besides, the optimal decisions for product quantity, collection incentive of used products and lower limit of quality level for recyclable parts under decentralized integrated GSCs. The analysis numerically investigates how (1) contract for recycling activity, (ii) product demand information and (iii) quality of recyclable parts affect the optimal operation for each GSC. Supply chain coordination to shift IGSC is discussed by adopting Nash Bargaining solution.