• 전력전자학회논문지
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• 제24권3호
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• pp.201-206
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• 2019

This study presents the design and experimental result of a GaN-based DC-DC converter with an integrated gate driver. The GaN device is attractive to power electronic applications due to its superior device performance. However, the switching loss of a GaN-based power converter is susceptible to the common source inductance, and converter efficiency is severely degraded with a large loop inductance. The objective of this study is to achieve high-efficiency power conversion and the highest power density using a multiphase integrated half-bridge GaN solution with minimized loop inductance. Before designing the converter, several GaN and Si devices were compared and loss analysis was conducted. Moreover, the impact of common source inductance from layout parasitic inductance was carefully investigated. Experimental test was conducted in buck mode operation at 48 -12 V, and results showed a peak efficiency of 97.8%.

• Nuclear Engineering and Technology
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• 제54권2호
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• pp.764-769
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• 2022

The United Arab Emirates is currently building and operating four units of the APR-1400 developed by a South Korean vendor, Korea Electric Power Corporation (KEPCO). This paper attempts to perform APR-1400 reactor core analysis by using the well-known two-step method. The two-step method was applied to the APR-1400 first cycle using the open-source nodal diffusion code, KOMODO. In this study, the group constants were generated using CASMO-4 fuel transport lattice code. The simulation was performed in Hot Zero Power (HZP) at steady-state and transient conditions. Some typical parameters necessary for the Nuclear Design Report (NDR) were evaluated in this paper, such as effective neutron multiplication factor, control rod worth, and critical boron concentration for steady-state analysis. Other parameters such as reactivity insertion, power, and fuel temperature changes during the Reactivity Insertion Accident (RIA) simulation were evaluated as well. The results from KOMODO were verified using PARCS and SIMULATE-3 nodal core simulators. It was found that KOMODO gives an excellent agreement.

• International Journal of Computer Science & Network Security
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• 제22권7호
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• pp.359-365
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• 2022

Scholars are paying increasingly close attention to brain research and the creation of biological neural networks, artificial neural networks, artificial intelligence, neurochips, brain-computer interfaces, prostheses, new research instruments and methods, methods of treatment, as well as the prevention of neurodegenerative diseases based on these data. The authors of the study propose their hypothesis on the understanding of the phenomenon of consciousness that answers questions concerning the criteria of consciousness, its localization, and principles of operation. In the study of the hard problem of consciousness, the philosophical and scientific categories of consciousness, and prominent hypotheses and theories of consciousness, the authors distinguish "the area of the conscious mind", which encompasses several states of consciousness united by the phenomenon of integrated consciousness. According to the authors, consciousness is a kind of executor of the phenomenological idea of the "chalice", so the search for it should be conducted deeper than the processes in the power of thought consciousness and transconsciousness, to which integrated consciousness can act as a lever. However, integrated consciousness may have the capacity to transcend into lower states of consciousness, which requires further study.

• 비교교육연구
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• 제28권3호
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• pp.333-354
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• 2018

본 연구는 우리나라 누리과정의 수학교육과 미국의 CCSS 및 뉴저지 주 Preschool Standards 수학교육과정을 비교 분석함으로써 누리과정 수학교육내용에 필요한 것이 무엇인지 시사점을 도출하여 향후 누리과정 수학교육의 개정 및 발전을 위한 기초자료를 제공하고자 하였다. 분석준거는 선행연구를 참고하여 목표, 내용범주 및 내용, 세부 내용 및 특징으로 정하였다. 그 결과 첫째, 우리나라 누리과정은 수학적 지식을 구성하고 이를 바탕으로 일상의 문제를 해결하는 능력을 강조한 포괄적 목표를 제시한 반면 미국의 수학교육 목표는 유아들이 습득해야 할 수학적 내용 및 개념을 중심으로 구체적으로 제시하고 있다. 둘째, 한국과 미국의 내용범주 및 내용은 두 나라 모두 수와연산의 기초, 측정, 공간 및 도형 등에 대한 것을 다루고 있다. 우리나라 누리과정 수학교육은 자연탐구영역에서 1개의 내용범주를 제시하고 있고, 미국 CCSS의 내용범주는 주요 수학적 개념 5개이며 Preschool Standards 내용범주는 4개로 제시 되어있다. 셋째, 두 나라 유아수학교육은 유 초 연계를 포함한 연령 및 학년별 연계성과 기술방법에 차이점이 있다. 이를 통해 누리과정 유아수학교육 내용 개선 시 고려해야 할 점을 살펴보았다.

• Strategy21
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• 통권41호
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• pp.153-173
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• 2017

On 15 December 2015, China seized an underwater drone belonging to the U.S. in the South China Sea. The underwater drone was then about to be retrieved by the Bowditch, a U.S. naval ship.Although China returned the underwater drone to the U.S. on 20 December 2016, the incident resulted in the considerable controversy involving the use of underwater drones. The reason for this is that the seizure of the underwater drone happened in the exclusive economic zone (hereafter referred to as "EEZ") of the Philippines. Part XIII of the United Nations Convention on the Law of the Sea (hereafter referred to as "UNCLOS") governs the matters of marine scientific research (hereafter referred to as "MSR"). If a State intends to use an underwater drone in the EEZ of another coastal State for the purpose of MSR, the former has to obtain the consent of the latter in accordance with relevant provisions included in Part XIII of the UNCLOS. However, it is not obvious whether the consent of a coastal State should be required to launch an underwater drone in the EEZ of the State for the purpose of hydrographic surveying or military surveying. Maritime powers such as the U.S. regard hydrographic surveying or military surveying as part of "other internationally lawful uses of the sea related to these freedoms, such as those associated with the operation of ships, aircraft and submarine cables and pipelines" found in Article 58(1) of the UNCLOS, or part of the freedom of the high seas. This interpretation is not incompatible with the implications that the UNCLOS has. Nevertheless, Korea cannot accept this kind of interpretation that is supported by maritime powers. The freedom of hydrographic surveying or military surveying could imply that the EEZ of Korea would be full of underwater drones launched by China, Japan or even Russia. Hence, Korea should claim that the data collected for the purpose of MSR cannot be distinguished from that collected for the purpose of hydrographic surveying or military surveying. This means that hydrographic surveying or military surveying without the consent of a coastal State in the EEZ of the State should not be permitted.

• 한국사회복지학
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• 제57권3호
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• pp.277-304
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• 2005

복지국가로의 발달과정은 주로 산업화이론과 정치자원론으로 설명되어 왔다. 그러나 본고는 복지국가로의 발달과정을 비교문화 역사적 관점에서 분석하였다. 문화정향은 인류학자 Mary Douglas가 분류한 운명주의 문화, 계층주의 문화, 개인주의 문화, 평등주의 문화를 원용하였다. 비교대상국가는 영국, 미국, 독일, 일본, 스웨덴이다. 영국과 미국이 산업화 후기단계에 비교적 늦게 사회보장제도를 도입하고 복지국가 위기의 영향을 많이 받은 것은 이들 국가들의 강한 개인주의 문화에서 비롯된 것으로 보며, 독일과 일본이 산업화 초기단계에 비교적 일찍 사회보장제도를 도입하고 조합주의적이면서 보수적인 사회보장체계를 유지하는 것은 계층주의 문화의 영향으로 본다. 또한 스웨덴이 산업화가 진행되기 전에 사회보장제도를 도입하고 복지선진국으로 발전한 것은 평등주의 문화가 지배적이기 때문이다.

• Journal of Community Nutrition
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• 제4권3호
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• pp.143-150
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• 2002

The objective of this study is to establish outcome validity for three instruments that assess whether subjects met recommendations for daily servings of fruits and vegetables for“Stage of Change”research. A convenience sample of 294 college students was recruited from introductory nutrition classes at Michigan State University in the United States. To measure servings of fruits and vegetables, separately, three types of methods (self-rated intake, 24-hour recall and food frequency) were used in comparison to the servings from a three-day food record, the criterion used. The outcome validity was assessed based on whether or not at least two servings of fruits and three servings of vegetables were reported. Validity was assessed by sensitivity, to measure the ability to detect low intakes, and by specificity, to measure ability to detect adequate intakes. Cohen's kappa was used as well to examine the agreement between the three methods and a three-day food record. The results showed, for fruits, the 24-hour recall had the best agreement (recall 0.54, self-rated : 0.31, food frequency : 0.29) with a three-day food record for servings consumed by people in pre-action or post-action stages. Sensitivity for fruit was also best using a recall (0.81). For vegetables, however, all three methods had low agreement (food frequency : 0.27, recall : 0.21, self-rated : 0.17) with the results of the three-day food record. Self-rated intakes for vegetables had the best sensitivity (0.66) and the food frequency had the best specificity (0.73). Therefore, researcher can use the 24-hour recall method to identify people who consume inadequate servings of fruit. To detect adequate vegetable intake, the food frequency was best of the three methods. Accuracy may be improved by probing for vegetables in mixed dishes and on sandwiches. (J Community Nutrition 4(3)： 143∼150, 2002)

• Ecology and Resilient Infrastructure
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• 제2권4호
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• pp.265-273
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• 2015

생물다양성을 감소시키고 인간에게 경제적 손실을 불러오는 침입외래생물은 사전에 자연으로의 유입 차단이 최선이지만, 유입과 억제에 실패한 경우 적극적으로 구제하거나 퇴치해야 한다. 본 연구에서는 영국과 미국에서 실시된 뉴트리아 박멸 사례를 소개하고, 국내 뉴트리아 관리체계 개선에 기여할 수 있는 정보를 제공하고자 하였다. 영국의 박멸캠페인은 관리의 목적과 목표에 대한 완전한 이해를 바탕으로 장기적인 계획을 수립하였고 적합한 지원을 확보하였다. 뉴트리아에 대한 충분한 정보를 축적하고 관리 여건의 변화에 따라 관리전략을 수정하였으며, 현장에 반영하였다. 미국의 체사피크만 박멸 프로젝트는 장기간의 생태정보를 바탕으로 영국에 비해 발전된 포획 기술을 적용하였으며, 영국 박멸캠페인 성과를 분석하여 박멸계획과 전략, 실행방안을 도출하였다. 국내 서식하는 뉴트리아를 효과적으로 관리하기 위해서는 다음과 같은 사항을 제안할 수 있다. 첫째, 퇴치 필요성에 대하여 이해당사자간 공감으로 협의체를 구성하고 주기적으로 생태적 정보와 의견을 교환한다. 둘째, 현장의 의견을 적극 수렴하여 퇴치전략과 관리정책에 반영한다. 관리지표를 기반으로 퇴치계획을 수립하고, 성과를 평가하고, 성과에 따라 조정하는 모든 과정은 유기적으로 연계되도록 한다. 셋째, 과학적인 관리방법을 도입하고 관리성과는 객관적으로 평가하며, 실천계획은 서식실태 모니터링을 통해 가변적으로 조정한다. 넷째, 장기적인 예산과 안정적인 조직을 확보하고 퇴치 효율성이 높은 시기에 재원을 집중하여 투입한다. 이러한 시사점은 국내 뉴트리아 관리방식을 효율적으로 개선하고 체계적이고 장기적인 관리를 지속하는데 도움이 될 수 있다.

• 한국노년학
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• 제31권3호
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• pp.505-526
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• 2011

이 연구는 한국과 미국 대학생의 노인에 대한 지식 및 태도를 측정하고, 관련 변인들이 그 지식 및 태도 수준과 어떠한 관계가 있으며, 양국 간 어떠한 차이가 있는지를 비교하였다. 이를 위하여 한국과 미국의 10개 대학 학생 1129명(한국은 서울, 경기, 충청지역 소재 5개 대학 학생 840명, 미국은 뉴욕지역 소재 5개 대학 학생 289명)으로부터 수집된 설문조사 결과를 SPSS 15.0을 사용해 분석하였다. 조사도구는 노인에 대한 지식을 측정하기 위한 Palmore(1998)의 Fact on Aging Quiz Part 1(FAQ 1), 노인에 대한 태도를 측정하기 위한 Sanders 등(1984)의 의미분별척도(Semantic Differential Scale), 그리고 몇 가지 인구사회적 및 노인관련경험을 측정하기 위한 문항으로 구성하였다. 연구결과, 첫째, 노인에 대한 지식수준을 비교한 결과 25점 만점에 한국대학생은 12.51점, 미국대학생은 11.57점으로 한국대학생의 노인에 대한 지식이 미국대학생에 비해 높게 나타났다. 한국과 미국대학생의 노인에 대한 지식의 문항별 차이를 보면 한국은 9개 문항에서 높은 정답률을 보여 준 반면 미국은 4개 문항에서만 높은 정답률을 보여주어 역시 한국학생의 노인에 대한 지식이 미국 학생에 비해 높음을 뒷받침했다. 둘째, 노인에 대한 태도의 차이를 비교한 결과 20점-140점 구간에서 한국대학생은 77.54점, 미국대학생은 70.07점으로 미국대학생의 노인에 대한 태도점수가 낮아 한국대학생에 비해 더 긍정적인 것으로 나타났다. 한국과 미국대학생의 노인에 대한 태도의 문항별 차이를 보면 한국대학생은 오직 한 문항에서 미국 학생들보다 긍정적으로 답변한 반면 미국대학생은 14문항에서 한국학생들에 비해 긍정적인 태도를 보여 역시 미국학생의 노인에 대한 태도가 한국학생에 비해 긍정적임을 뒷받침했다. 셋째, 한국과 미국 대학생 모두 노인에 대한 지식이 높을수록 노인에 대한 태도가 긍정적으로 나타났고, 특히 양국 학생 간 그 강도에 있어서 다소의 차이는 있지만 노인에 대한 심리적 지식과 가족/사회적 지식은 대학생의 노인에 대한 태도와 유의미한 관련이 있음을 확인하였다. 위의 결과를 바탕으로 향후 관련 정책과 실천 및 후속연구에의 함의를 제시하였다.

• 항공우주정책ㆍ법학회지
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• 제5권
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• pp.101-118
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• 1993

Generally there is no law and liability system which applies particulary to commercial space ventures. There are several international treaties and national statutes which deal with space ventures, but their impact on the liability of commercial space ventures has not been significant. Every state law in the United States will impose both tort and contract liability on those responsible for injuries or losses caused by defective products or by services performed negligently. As with the providers of other products and services, those who participate in commercial space ventures have exposure to liability in both tort and contract which is limited to the extent of the resulting damage The manufacturer of a small and cheap component which caused a satellite to fail to reach orbit or to operate nominally has the same exposure to liability as the provider of launch vehicle or the manufacturer of satellite into which the component was incorporaded. Considering the enormity of losses which may result from launch failure or satellite failure, those participated in commercial space ventures will do their best to limit their exposure to liability by contract to the extent permitted by law. In most states of the United States, contracts which limit or disclaim the liability are enforceable with respect to claims for losses or damage to property if they are drafted in compliance with the requirements of the applicable law. In California an attempt to disclaim the liability for one's own negligence will be enforceable only if the contract states explicitly that the parties intend to have the disclaimer apply to negligence claims. Most state laws of the United States will refuse to enforce contracts which attempt to disclaim the liability for gross negligence on public policy grounds. However, the public policy which favoured disclaiming the liability as to gross negligence for providers of launch services was pronounced by the United States Congress in the 1988 Amendments to the 1984 Commercial Space Launch Act. To extend the disclaimer of liability to remote purchasers, the contract of resale should state expressly that the disclaimer applies for the benefit of all contractors and subcontractors who participated in producing the product. This situation may occur when the purchaser of a satellite which has failed to reach orbit has not contracted directly with the provider of launch services. Contracts for launch services usually contain cross-waiver of liability clauses by which each participant in the launch agrees to be responsible for it's own loss and to waive any claims which it may have against other participants. The crosswaiver of liability clause may apply to the participants in the launch who are parties to the launch services agreement, but not apply to their subcontractors. The role of insurance in responding to many risks has been critical in assisting commercial space ventures grow. Today traditional property and liability insurance, such as pre-launch, launch and in-orbit insurance and third party liability insurance, have become mandatory parts of most space projects. The manufacture and pre-launch insurance covers direct physical loss or damage to the satellite, its apogee kick moter and including its related launch equipment from commencement of loading operations at the manufacture's plant until lift off. The launch and early orbit insurance covers the satellite for physical loss or damage from attachment of risk through to commissioning and for some period of initial operation between 180 days and 12 months after launch. The in-orbit insurance covers physical loss of or damage to the satellite occuring during or caused by an event during the policy period. The third party liability insurance covers the satellite owner' s liability exposure at the launch site and liability arising out of the launch and operation in orbit. In conclusion, the liability in commercial space ventures extends to any organization which participates in providing products and services used in the venture. Accordingly, it is essential for any organization participating in commercial space ventures to contractually disclaim its liability to the extent permitted by law. To achieve the effective disclaimers, it is necessary to determine the applicable law and to understand the requirements of the law which will govern the terms of the contract. A great deal of funds have been used in R&D for commercial space ventures to increase reliability, safety and success. However, the historical reliability of launches and success for commercial space ventures have proved to be slightly lower than we would have wished for. Space insurance has played an important role in reducing the high risks present in commercial space ventures.