• Title/Summary/Keyword: 기술적 요소

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A study on selecting of Light Cutoff Panel depending on the installation condition using the lighting simulation (조명 시뮬레이션을 이용한 설치 환경별 차광판 선정에 관한 연구)

  • Park, Hyung-Kyu;Gu, Jin-Hoi;Lee, Kyu-Mok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.2
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    • pp.246-251
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    • 2016
  • The use of security lighting that emits spill light is considered a cause of light trespass problems in the residential areas. Therefore, a cutoff panel was installed as an alternative way to reduce light trespass. On the other hand, it has another problem in that it is less effective and is not good enough for aesthetics and safety. In this study, a light cutoff panel was designed and manufactured to reduce the light trespass, and the structure of a proper light cutoff panel was studied. Using a goniophotometer, the light distribution file (IES file) was extracted and the characteristics of light distribution were analyzed using the RELUX program. The results showed that the reduction of spilt light in the backward direction was decreased significantly for all types of light cutoff panels except the coated globe. In the case of a black powder coated light cutoff panel, the forward light caused by light reflected from the surface of the light cutoff panel was also reduced, which means that the black powder coated light cutoff panel is effective in the performance of light cutoff in the forward and backward directions. In addition, the coated glove increased the spilt light in the forward and backward directions because it reflects the upward light to go down. A 90 % accuracy between the measurement value of light trespass and the expected value of the light trespass was obtained from a simulation.

Analytical and Experimental Study on the Quality Stability of Multi Roll Forming Process (멀티 롤 포밍 공정의 품질 안정성에 대한 해석 및 실험적 연구)

  • Son, Jae-Hwan;Han, Chang-Woo;Ryu, Kyung-Jin;Kang, Hae-Dong;Kim, Chul-Hong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.10
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    • pp.6977-6984
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    • 2015
  • It is faced with the necessity of multi roll forming process of the ball slide rail which is made by adding the separate manufacturing processes, piercing, bending, trimming, to the roll forming process of a continuous plastic deformation, to improve the quality. However, the vibration and noise of the press machine in this process leads to the quality degradation of slide rail manufactured in this process. In this study, the roll was designed considering the optimal strain rates by the roll forming program with finite element method. And to estimate the static stability of the multi process the Von-Mises stress and deformation on the press was calculated with a structural analysis program. Also, to avoid driving systems in the resonance region their natural frequencies in the 1st and 2nd mode were calculated through the modal analysis. To verify its dynamic stability improvement the magnitudes of noise and vibration in the existing and studied system were compared using a microphone and accelerometers. And the widths and surface roughnesses of the rails which had been produced in the existing and studied process were measured. Therefore, it is known that multi roll forming process is stable in the analytical and experimental study.

Determining Relative Weights of Criteria for Evaluating National Quarantine Station by the Analytic Hierarchy Process (AHP방법을 적용한 국립검역소 평가 준거의 가중치 결정)

  • Jeong, Mun-Yong;Lee, Moo-Sik;Kim, Dae-Kyung;Yoo, In-Sook
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.1
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    • pp.335-340
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    • 2010
  • In accordance with the increasing possibility that the new and reoccurring epidemics continuously appearing abroad flow into Korea, it is very important to evaluate the efficiency of quarantine management projects of National Quarantine Station. This study adopted the pairwise comparison approach using the analytical hierarchy process(AHP) that has been recognized with its scientific adequacy for allocating the weight, the relative importance of evaluation components. AHP technique is evaluated to be distinguished in measuring the impact by making hierarchy of, simplifying and systemizing the complicated multi-criteria decision making problems. The weights by evaluation indexes were 0.2 in the organization evaluation field and 0.8 in the service and program field. The quarantine business showed the highest value, 0.45, in the service and program field. The indexes were classified into the upper category (organization evaluation field, service and program evaluation field) and lower category (input/process/result/quarantine field, inspection field, hygiene management field, pathogenic organ investigation and monitoring field, epidemics prevention promotion/education field). The evaluation indexes that were finally selected were applied to the actual businesses in National Quarantine Station. Next, the minimum evaluation indexes were selected and so the evaluation system on the businesses in National Quarantine Station was more systemized.

Case Study on Engineering Camp Program involving Engineering Design Activity and Intra-/Inter-Team Works for High School Students: Plant factory as main theme (공학설계활동과 팀 내, 팀 간 협력 기반 고등학생 공학 캠프 프로그램 운영 사례: 식물공장을 주제로)

  • Cho, Kyung-Suk
    • Journal of Engineering Education Research
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    • v.18 no.3
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    • pp.46-58
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    • 2015
  • Informal engineering education program for high school students was developed to cultivate engineering literacy using the human resources and facilities of university. Plant factory, a smart farming technology, was selected as a main theme, and the novel engineering camp program involving engineering design activities and intra-linter-team works was planned. The camp program was applied to 38 high school students in an active learning classroom. Five teams were constructed according to elemental technologies such as biotechnology, information-communication technology, energy engineering, mechanical engineering and architectural engineering, and the students were participated in intra- and inter-team activities to achieve the final goal of 'the construction of a plant factory in school'. The team works were conducted according to the eight steps of engineering design process (identifying the problem and need, identifying criteria and constraints, brainstorming possible solutions, selecting the best possible solution, constructing a prototype, testing and evaluating the solution, communicating the solution, and refining design). Participants' satisfaction survey showed that the satisfaction on the contents of engineering design was 4.48 on 5-point Likert scale. The participants' satisfaction on creative activity and systematic methodology was 4.43 on 5-point Likert scale. 97% of participants responded positively to team works, and 92% of participants were satisfied with career mentoring activity supplied by undergraduate/graduate students. These results indicates that the engineering camp program involving engineering design activity and intra-/inter-team works can contribute to cultivate engineering literacy such as creativity, problem solving ability, collaboration, communication skills for high school students, and to increase their interests in engineering fields.

The Analysis of Elasto-Plastic Thermal Stresses for Welding Part in Double Capstan Drum (더블 캡스턴 드럼의 용접부에 대한 탄소성 열응력해석)

  • 김옥삼
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.36 no.4
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    • pp.329-336
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    • 2000
  • Welding is a important technological method in mechanical engineering. $CO_2$MAG(metal active gas) welding means that metal part in double capstan drum for the inshore and costal vessels are joined by melting(with or without a filler material) or that new material is added to a metal part by melting. The thermal stresses appear due to a non-uniform temperature field, inhomogeneous material properties, external restraint and volume changes during phase transformations. In this study analysis the elasto-plastic thermal stresses distribution of welding part in double capstan drum for the inshore and costal vessels using finite element method (FBM). Therefore it calculates the numerical value that can be applied to the optimum design of welding parts and the shapes. The significant results obtained in this study are summarized as fellows. At early stage of the cooling after welding process, the abrupt thermal stresses gradient has been shown in the vicinity of welding part. In the thermal stresses analysis due to temperature gradient and heat shocking maximum stress was occurred of welding part and stresses were distributed from 54MPa~48MPa.

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A Policy-driven RFID Data Management Event Definition Language (정책기반 RFID 데이터 관리 이벤트 정의 언어)

  • Song, Ji-Hye;Kim, Kwang-Hoon
    • Journal of Internet Computing and Services
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    • v.12 no.1
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    • pp.55-70
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    • 2011
  • In this paper, we propose a policy-driven RFID data management event definition language, which is possibly applicable as a partial standard for SSI (Software System Infrastructure) Part 4 (Application Interface, 24791-4) defined by ISO/IEC JTC 1/SC 31/WG 4 (RFID for Item Management). The SSI's RFID application interface part is originally defined for providing a unified interface of the RFID middleware functionality―data management, device management, device interface and security functions. However, the current specifications are too circumstantial to be understood by the application developers who used to lack the professional and technological backgrounds of the RFID middleware functionality. As an impeccable solution, we use the concept of event-constraint policy that is not only representing semantic contents of RFID domains but also providing transparencies with higher level abstractions to RFID applications, and that is able to provide a means of specifying event-constraints for filtering a huge number of raw data caught from the associated RF readers. Conclusively, we try to embody the proposed concept by newly defining an XML-based RFID event policy definition language, which is abbreviated to rXPDL. Additionally, we expect that the specification of rXPDL proposed in the paper becomes a technological basis for the domestic as well as the international standards that are able to be extensively applied to RFID and ubiquitous sensor networks.

Business Model of Data Service in Broadcasting and Communication Convergence (유비쿼터스시대 방송과 통신의 컨버전스 데이터 서비스 비즈니스 모델)

  • Jung, Chang-Duk;Lee, Ji-Eun
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2006.11a
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    • pp.245-249
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    • 2006
  • 디지털 컨버전스와 유비쿼터스 시대의 시작은 디지털 미디어 기술의 발전과 방송 통신 사업의 컨버전스를 가속화 시켰으며, 그 결과로DMB, WCDHA, Wibro, IP-TV, HSDPA 등의 새로운 형태의 차세대 제품과 서비스들이 뉴미디어 매체의 핵심으로 등장하고 있다. 국내에서 방송 통신의 컨버전스의 빠른 진행은 세계 최초로 디지털 멀티미디어 방송(DMB) 서비스 시작을 가능하게 하였다. DMB 서비스는 멀티미디어 서비스가 핵심이다. DMB 데이터 서비스인 Broadcasting Website Service(BWS)는 현재 지상파 DMB방송 사업자인 KBS, MBC, SBS, YTNDMB가 본방송 준비 막바지 단계이며, 삼성 전자와 LG전자를 비롯한 단말기 개발사들도 데이터 서비스를 위한 제품 출시에 서두르고 있는 등 DMB 산업의 활성화의 주역이 될 것으로 예상된다. DMB의 데이터 서비스는 뉴스, 날씨, 프로그램 정보 등의 단순 정보보기 수준에 그치지 않고, 리턴 채널을 이용한 양방향 서비스와, SMS, 전화걸기 등 휴대전화 단말의 고유기능과의 연계를 통한 다양한 서비스도 선보일 것이다. 더 나아가 향후 T-Commerce와 개인 광고 등 새로운 비즈니스 모델과 사업영역으로 확산시켜 나갈 수 있을 것이다. 그러나, 아직까지 DMB와 데이터 서비스는 초기단계로서, 표준 기술의 규격 작업, 이론적 논의들, 관련 사업자들의 비즈니스 준비 등에서 검토되어, 실제 사용자들을 대상으로한 연구 분석이 이루어 지지 않았다는 연구의 한계를 가지고 있다. 본격적으로 방송, 통신 컨버전스 데이터 서비스가 시작되면서, 사용자들에 초점을 맞춘 많은 연구가 이루어지길 바라며, 이러한 연구의 분석를 통해 또 다른 새로운 서비스와 비즈니스 기회의 창출을 기대해 본다.여 RD(Rate Distortion) 최적화 기반 모드 결정을 빨리 완료함으로써 고속 프레임간 모드 결정을 가능하게 한다. 제안된 방법은 프레임 간 모드 결정을 고속화함으로써 스케일러블 비디오 부호화기의 연산량과 복잡도를 최대 57%감소시킨다. 그러나 연산량 감소에 따른 비트율의 증가나 화질의 열화는 최대 1.74% 비트율 증가 및 0.08dB PSNR 감소로 무시할 정도로 작다., 반드시 이에 대한 검증이 필요함을 알 수 있었다. 현지관측에 비해 막대한 비용과 시간을 절약할 수 있는 위성영상해석방법을 이용한 방법은 해양수질파악이 가능할 것으로 판단되며, GIS를 이용하여 다양하고 복잡한 자료를 데이터베이스화함으로써 가시화하고, 이를 기초로 공간분석을 실시함으로써 환경요소별 공간분포에 대한 파악을 통해 수치모형실험을 이용한 각종 환경영향의 평가 및 예측을 위한 기초자료로 이용이 가능할 것으로 사료된다.염총량관리 기본계획 시 구축된 모형 매개변수를 바탕으로 분석을 수행하였다. 일차오차분석을 이용하여 수리매개변수와 수질매개변수의 수질항목별 상대적 기여도를 파악해 본 결과, 수리매개변수는 DO, BOD, 유기질소, 유기인 모든 항목에 일정 정도의 상대적 기여도를 가지고 있는 것을 알 수 있었다. 이로부터 수질 모형의 적용 시 수리 매개변수 또한 수질 매개변수의 추정 시와 같이 보다 세심한 주의를 기울여 추정할 필요가 있을 것으로 판단된다.변화와 기흉 발생과의 인과관계를 확인하고 좀 더 구체화하기 위한 연구가 필요할 것이다.게 이루어질 수 있을 것으로 기대된다.는 초과수익률이 상승하지만, 이후로는 감소하므로, 반전거래전략을 활용하는 경우 주식투자기간은 24개월이하의 중단기가 적합함을 발견하였다. 이상의 행태적 측면과 투자성과측면의 실증결과를 통하여 한국주식시장에

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Analysis on the Temperature of 3D Multi-core Processors according to Vertical Placement of Core and L2 Cache (코어와 L2 캐쉬의 수직적 배치 관계에 따른 3차원 멀티코어 프로세서의 온도 분석)

  • Son, Dong-Oh;Ahn, Jin-Woo;Park, Jae-Hyung;Kim, Jong-Myon;Kim, Cheol-Hong
    • Journal of the Korea Society of Computer and Information
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    • v.16 no.6
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    • pp.1-10
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    • 2011
  • In designing multi-core processors, interconnection delay is one of the major constraints in performance improvement. To solve this problem, the 3-dimensional integration technology has been adopted in designing multi-core processors. The 3D multi-core architecture can reduce the physical wire length by stacking cores vertically, leading to reduced interconnection delay and reduced power consumption. However, the power density of 3D multi-core architecture is increased significantly compared to the traditional 2D multi-core architecture, resulting in the increased temperature of the processor. In this paper, the floorplan methods which change the forms of vertical placement of the core and the level-2 cache are analyzed to solve the thermal problems in 3D multi-core processors. According to the experimental results, it is an effective way to reduce the temperature in the processor that the core and the level-2 cache are stacked adjacently. Compared to the floorplan where cores are stacked adjacently to each other, the floorplan where the core is stacked adjacently to the level-2 cache can reduce the temperature by 22% in the case of 4-layers, and by 13% in the case of 2-layers.

Power efficiency research for application of IoT technology (사물인터넷 기술 적용을 위한 소비전력 효율화 연구)

  • Seo, Younghoon;Park, Eun-Cheol;Kang, Sunghwan;Hwang, Jae-Mun;Yun, Junghwan;Eom, Junyoung;Gwon, Hyeong-Jun
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2015.10a
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    • pp.669-672
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    • 2015
  • Recent Internet of Things (IoT, Internet of Things) that can be applied to various fields as the development of technology has been developed a lot of service and has been developed with the service also for crop management. To manage the essential elements of soil moisture in the crop growth but existing a direct person measuring the fluid point to carry the measuring instrument, if you take advantage of the WPAN (Wireless Personal Area Network) in this paper to manage sensor data, a fixed 3 points (30, 60, 90 cm) and can be managed can be scientifically analyzed the state of growth of the crop. Open field environment is utilized as it is less disturbance of the interference and the frequency of the radio frequency signal of the structure provides a relatively comfortable environment. Therefore, WPAN building and data transmission scheme of the minimum cost is to be developed. In addition, the operation to enter low power mode, the algorithm is necessary because a lot of restrictions on the power supply applied to the sensor nodes and the gateway is constructed in the open field. In the experiment, verifying the effectiveness by using a network configuration of each of the sensor nodes and the gateway, and provides a method for time synchronization of the operation and a low power mode. The study protocol for the RF communication with the LoRa and to enhance communication efficiency is needed in the future.

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Analysis of Seismic Performance of Modular Containment Structure for Small Modular Reactor (소형 원자로용 모듈화 격납구조의 내진성능 분석)

  • Park, Woo-Ryong;Yhim, Sung-Soon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.1
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    • pp.409-416
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    • 2020
  • The seismic performance of a containment structure should be secured to maintain the structural soundness of a containment structure under various earthquakes that occur globally. Therefore, an analysis of the seismic performance of a modular containment structure for a small modular reactor is also required. To analyze the seismic performance of modular containment, FEM models with contact surfaces between the modules and tendon were prepared and the modal and seismic analyses were performed. The displacement, stress, and gap size of modular containment under earthquake wave were analyzed. The effects of the tendon force, friction coefficient, and earthquake wave on the seismic performance were analyzed. The seismic performance of monolithic containment was also analyzed for comparison. In the 1st and 2nd natural modes, which most likely affect, the modular containment showed horizontal dynamic behavior, which is similar to monolithic containment, because of the combined effects of the tendon force and friction force between modules. When the combined effect is sufficient, the seismic performance of the modular containment is secured over a certain level. An additional increase in seismic performance is expected when some material with a larger friction coefficient is adopted on the contact surface.