• Transactions on Electrical and Electronic Materials
• /
• 제18권4호
• /
• pp.199-202
• /
• 2017

Silicon carbide (SiC) is being spotlighted as a next-generation power semiconductor material owing to the characteristic limitations of the existing silicon materials. SiC has a wider band gap, higher breakdown voltage, higher thermal conductivity, and higher saturation electron mobility than those of Si. When using this material to implement Schottky barrier diode (SBD) devices, SBD-state operation loss and switching loss can be greatly reduced as compared to that of traditional Si. However, actual SiC SBDs exhibit a lower dielectric breakdown voltage than the theoretical breakdown voltage that causes the electric field concentration, a phenomenon that occurs on the edge of the contact surface as in conventional power semiconductor devices. Therefore in order to obtain a high breakdown voltage, it is necessary to distribute the electric field concentration using the edge termination structure. In this paper, we designed an edge termination structure using a field plate structure through oxide etch angle control, and optimized the structure to obtain a high breakdown voltage. We designed the edge termination structure for a 650 V breakdown voltage using Sentaurus Workbench provided by IDEC. We conducted field plate experiments. under the following conditions: $15^{\circ}$, $30^{\circ}$, $45^{\circ}$, $60^{\circ}$, and $75^{\circ}$. The experimental results indicated that the oxide etch angle was $45^{\circ}$ when the breakdown voltage characteristics of the SiC SBD were optimized and a breakdown voltage of 681 V was obtained.

• 디지털콘텐츠학회 논문지
• /
• 제18권8호
• /
• pp.1577-1584
• /
• 2017

최근 전국적으로 많은 지자체들이 '도시재생특별법' 개정과 '도시재생 선도지역', '도시재생 뉴딜정책'의 추진으로 도시재생 사업을 추진하고 있지만, 공모사업 중심의 도시재생사업은 '도시재생특별법'에 의한 도시재생 계획체계에 맞게 추진하기에는 한계가 있다. 이처럼 공모사업 중심의 획일적인 계획과 비 계획체계에 의한 도시재생사업 추진되고 있어 많은 전략계획과 활성화계획 등 계획수립 소요시간 증가와 이에 따른 사회적 비용증가 등 많은 문제점을 야기하였다. 이에 본 연구에서는 도시재생 계획체계 정립 및 유연화 등의 방법론을 모색하고자 함을 목적으로 도시재생 계획체계의 운영 실태를 분석하여 문제점을 분석하고 개선 방안을 제시하여 우리나라의 도시재생 계획체계 재정립 등의 방안을 연구하고자 한다.

• 한국정보통신학회논문지
• /
• 제18권9호
• /
• pp.2251-2258
• /
• 2014

본 논문에서는 이동식 복지용구 소독을 위한 통합제어시스템을 개발하였다. 통합제어시스템은 과산화수소 증기 공급 제어회로와 저 진공을 이용한 살균 소독챔버 제어회로 및 마이크로버블을 이용한 세탁 제어회로 구성된다. 개발한 통합제어시스템에 대한 동작상태 및 통신 상태 등을 측정하기 위하여 스마트 기반의 원격 제어 및 모니터링 시스템을 구현하였다. 개발한 통합제어시스템 에 대한 성능을 평가하기 위해 실험 장치를 구현하였다. 제어회로에 대한 동작상태 및 신호 송수신 등을 측정해본 결과, 정상적으로 동작함을 알 수 있었다. 그리고 스마트 기반의 원격 제어 및 모니터링 시스템과의 연동 테스트에서 개발한 통합제어시스템이 통신상태, 센서 인터페이스 및 제어 면에서 좋은 동작성능을 보였다. 향 후 개발한 제어시스템을 실 시스템에 적용하여 그 성능을 증명하는 것이 필요하다.

• 인터넷정보학회논문지
• /
• 제23권3호
• /
• pp.97-110
• /
• 2022

연합학습은 학습데이터의 전송없이 모델의 학습을 수행할 수 있는 학습방법이다. IoT 혹은 헬스케어 분야는 사용자의 개인정보를 다루는 만큼 정보유출에 민감하여 시스템 디자인에 많은 주의를 기울여야 하지만 연합학습을 사용하는 경우 데이터가 수집되는 디바이스에서 데이터가 이동하지 않기 때문에 개인정보 유출에 자유로운 학습방법으로 각광받고 있다. 이에 따라 많은 연합학습 구현체가 개발되었으나 연합학습을 사용하는 시스템의 개발과 운영을 위한 시스템 설계에 관한 구체적인 연구가 부족하다. 본 연구에서는 연합학습을 실제 프로젝트에 적용하여 IoT 디바이스에 배포하고자 할 때 연합학습의 수명주기, 코드 버전 관리, model serving, 디바이스 모니터링에 대한 대책이 필요함을 보이고 이러한 점을 보완해주는 개발환경에 대한 설계를 제안하고자 한다. 본 논문에서 제안하는 시스템은 중단 없는 model-serving을 고려하였고 소스코드 및 모델 버전 관리와 디바이스 상태 모니터링, 서버-클라이언트 학습 스케쥴 관리기능을 포함한다.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2005년도 ICCAS
• /
• pp.1066-1071
• /
• 2005

This paper presents the two lossless auxiliary inductors-assisted voltage source type half bridge (single ended push pull: SEPP) series resonant high frequency inverter for induction heated fixing roller in copy and printing machines. The simple high-frequency inverter treated here can completely achieve stable zero current soft switching (ZCS) commutation for wide its output power regulation ranges and load variations under its constant high frequency pulse density modulation (PDM) scheme. Its transient and steady state operating principle is originally described and discussed for a constant high-frequency PDM control strategy under a stable ZCS operation commutation, together with its output effective power regulation characteristics-based on the high frequency PDM strategy. The experimental operating performances of this voltage source SEPP ZCS-PDM series resonant high frequency inverter using IGBTs are illustrated as compared with computer simulation results and experimental ones. Its power losses analysis and actual efficiency are evaluated and discussed on the basis of simulation and experimental results. The feasible effectiveness of this high frequency inverter appliance implemented here is proved from the practical point of view.

• Composites Research
• /
• 제23권1호
• /
• pp.1-7
• /
• 2010

본 논문에서는 상용 유한요소해석 프로그램인 ABAQUS 6.71을 이용하여 수술 직후 골절부 거동을 예측할 수 있는 해석을 수행하였다. 스테인리스 고정판과 적층순서를 달리한 복합재료 고정판을 대상으로 대퇴골의 골절치료에 대한 효과를 비교 분석 하였다. 실제 상태를 모사하기 위해 고정판과 골절뼈 및 골절부간 접촉조건을 부여하였으며, 스크류 체결과정과 하중부가 과정을 두 단계로 나누어 해석을 수행하였다. 유한요소해석을 통하여 스테인리스 고정판과 복합재료 고정판이 체결된 경우에 대한 골절부 틈새의 변화 및 응력분포 등을 계산하고 그 차이를 비교하였다. 복합재료 고정판은 골절뼈와의 접촉에 의한 불필요한 응력 증가를 감소시키고 골절부위의 응력은 증가시켜 골절치료에 더 효과적인 것으로 나타났다.

• 한국공간정보시스템학회 논문지
• /
• 제3권2호
• /
• pp.45-51
• /
• 2001

기존의 건설지원시스템은 주로 문자정보를 대상으로 구축되어 지형이나 공간정보와 같은 실 세계에 대한 정보를 제공하는데 취약점이 있으나, GIS(Geographic Information System)는 이러한 문제에 대해 공간정보의 제공뿐만 아니라 설계지원시스템과 연계하여 효율적이고 체계적인 정보의 분석 및 지원 기능을 제공해 줄 수 있을 것으로 기대된다. 이에 대하여 다양한 네트워크의 구축 및 이를 통한 정보서비스의 발전은 GIS의 제공방식과 내용을 변모시키고 있으며 네트워크 상에서 즉각적으로 사용자에게 다양하고 동적인 GIS 솔루션을 제공할 수 있는 Web GIS의 활용이 확산되고 있다. 본 연구에서는 건설진행상황을 즉각적으로 확인하고 실시간으로 업무보고 및 업무지시를 수행함으로써 원격공정관리를 가능하게 하고, 나아가 단지 문서적인 업무보고에만 의존하여 보고자의 의도에 따라 수동적으로 의사결정을 내리던 관행에서 벗어나 Web GIS에 기반한 건설공사 정보관리시스템을 개발함으로써 건설공사 현황을 직관적으로 판단하고 의사결정을 내릴 수 있는 시스템을 구축하였다.

• 한국관광식음료학회지:관광식음료경영연구
• /
• 제8권
• /
• pp.123-144
• /
• 1997

This study, by setting the systems of room sale promotion, analyzing the actual status and the present working state with its center on the 'RHotel' that is a special grade-two hotel and the sales promotion activities of each type, intends to understand the presentstatus of the hotel and present its problems and the method for improvement. The strategy of salespromotion and the ineffectivenessof the system organization were found to be imminent in the sales promotion activities as its problems, and the importanceis being not attached to the actual substance rather than to the actualresults, such as the advertisement and publicity strategies, the irrationality of sales personnel controland its evaluation method, and therefore, the goal-oriented control is not being takenad its problems are emerging. Therefore, as an improvement plan, we ought to put the plan of the hotel merchandising into action for customers to buy what they want, the establishment of the customer-oriented sales promotionservice and the communication channel using the brand-new managerial skills, systemaizesales promotion method sand strategies, develop the organizational and systematic strategies develop the organizatinal and systemactic strategies and goods for the sake of the image-making and room sales promotion of hotels, develop the activation ways of flexible operation, and also need to develop the skills of sales promotion. Accordingly, by doing irrationalsales activities in the system and the promotion with its center on the sales promotion department, and it sis urgently required that we streng then the comodity developments fitting the hotel's traits, such as uniformpolicy of cost, mass-communicationactivities for sales promotion, the improvement of non-effectiveness, and advertisement of hotel items, and the publishing of public relation books. Therefore, the best weapon for hotels before other purchaseis to be discriminatized from other competitive hotel with theunderstanding of the psychology and activities of customers, and the communicatin with customers, and to set up organicprograms of sales promotionstrategies. Also we must promote our sales in accordance with the desire of new customers, gater the market information of customers, all the time, and systematize the facility improvement, managerial policy, business strategiescorresponding with the desire of customers. By doing so, we are able to seek, at the same time, both the satis faction of customers and the sales maximization of the hotels that will perfrom the activities of sales promotion and management.

• 한국농촌건축학회논문집
• /
• 제19권1호
• /
• pp.11-22
• /
• 2017

The purpose of this study is to analyze the actual situation of residents' participation in rural development projects, to identify their performance and problems, and suggest ways to develop desirable villages in rural areas. From reviewing relevant pre-studies, this study was done by interview, questionnaire, and observation targeting 140 leaders and residents of exampled village of the project in Jeollanam-do, as well as by listening opinions of relative experts. This study is largely classified into 4 parts, review of character and appearing background of village development project, review of theoretical discussion about residents' participation, evaluation of accomplishments and analysis of participation, and establishing a model for habitants-participating village development project and how to improve it. As a result of questionnaire, it was found urgent for habitants to convert their thinking about village development and their participation in it, to realize a model of this project, as well as political stimulus to promote that. Therefore, measures must be required to improve current village development projects and to promote them. First of all, a preparation period is required to sufficiently provide the village where habitants are willing to participate in, from the state of place selection. Besides, it is required to run away from profit-making businesses aiming at foreign people, to improvement of residents' welfare in a long term, and enhanced resources management in a broad view. Waste of working expenses seems to be solved through direct operation by a corporation in charge of profit-making businesses, under superstition of residents' community. Finally conclusion, expansion and practicalization of education to residents are essential, to promote their participation in rural development projects. Especially it must be practical education for habitants such as 'community-ship' or 'technology education in each interesting part,' rather than tour of other villages and unilateral lectures from experts. Along with this, a long term plan and systematic participation is more essential. Since planning itself can be mutual learning to enhance residents' capacity, a chance must be established to discuss and plan each part including resources-research, by making them participate in.

• 한국환경복원기술학회지
• /
• 제23권6호
• /
• pp.109-123
• /
• 2020

The purpose of this study is to provide basic data for the establishment of future countermeasures by diagnosing the growth status and actual condition of undesignated old trees distributed in Hyeongok-myeon, Gyeongju, Gyeongsangbuk-do. The number of old trees surveyed was 2 weeks in Gajeong-ri, 2 weeks in Haguri, 3 weeks in Nae-Tae-ri, 1 week in Nawon-ri, 6 weeks in Oryu-ri, 3 weeks in Sangguri, and 2 weeks in Sohyeon-ri, The trees species composition was 6 trees Celtis sinensis Pers., 1 Diospyros lotus L. trees, 4 trees Salix chaenomeloides Kimura trees, 2 Styphnolobium japonicum L. trees, and 7 Zelkova serrata (Thunb.) Makino trees. Growth status is 7.1~22.0m in height, 14.6~25.1m in long axis, 10.2~19.2m in short axis, root diameter is 76.0~236.4cm, diamter at breast height is 67.0~220.0cm, soil acidity is pH4.9~7.0, soil The hardness was measured to be 4.0-27.0mm. The result grade of the scoring data of health information is represented by monitoring generally, monitoring critically, and absolute monitoring, and it was confirmed that out of the 20 trees population in Hyeongok-myeon, the general monitoring grade was 7 weeks, the major monitoring grade was 13 weeks, and there was no absolute monitoring grade. Accordingly, the number of old trees of the general surveillance level was maintained at the current level, and ecological surgical operations were introduced for the major surveillance level, but the case of village forests should be different, and sequential treatments were the old tree urgently needed. The level and bark of the target tree, the state of the crown, the root exposure, the presence of pests and pests, the vitality and the ground condition, the degree of pollution are normal, poor, or very poor, operation and protection management, soil improvement, removal of cover, and disinfection were urgently needed for the old trees with the surveyed data. In order to compensate for these matters, continuous monitoring and management measures for the old number should be sought.