• 대한전기학회논문지:시스템및제어부문D
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• 제51권12호
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• pp.596-603
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• 2002

New layout methods for implementing MOS switches of ultra low channel resistance are presented. These area-effective layout methods include the waffle structure, zipper structure, star zag structure and fingered waffle structure. The design equations for these new layout structures are analyzed. The area-effectiveness of these structures is compared with that of the conventional alternating bar structure. MOS switches of the waffle structure were fabricated using a standard 0.25um CMOS process. The experimental characterization results of the fabricated MOS switches are presented. The analytical comparison and experimental results show that area reductions over 40% are achievable with the new structures.

• Nuclear Engineering and Technology
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• 제53권4호
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• pp.1259-1265
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• 2021

In the present study, a large-area hybrid gamma imaging system was designed by adopting coded aperture imaging on the basis of a large-area Compton camera to achieve high imaging performance throughout a broad energy range (100-2000 keV). The system consisting of a tungsten coded aperture mask and monolithic NaI(Tl) scintillation detectors was designed through a series of Geant4 Monte Carlo radiation transport simulations, in consideration of both imaging sensitivity and imaging resolution. Then, the performance of the system was predicted by Geant4 Monte Carlo simulations for point sources under various conditions. Our simulation results show that the system provides very high imaging sensitivity (i.e., low values for minimum detectable activity, MDA), thus allowing for imaging of low-activity sources at distances impossible with coded aperture imaging or Compton imaging alone. In addition, the imaging resolution of the system was found to be high (i.e., around 6°) over the broad energy range of 59.5-1330 keV.

• Spatial Information Research
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• 제21권2호
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• pp.99-106
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• 2013

현대사회가 산업화 되고 고도성장을 이룩하며 자연환경이 훼손됨에 따라 기후변화 대응 및 저탄소 녹색성장을 위한 도시차원의 구체적인 실천대안의 필요성이 증대되고 있다. 국내에서 많은 저탄소도시 및 녹색도시 관련 연구가 진행 중에 있으나 대부분의 관련 연구들에서는 저탄소도시 혹은 녹색도시 구축을 위한 연구를 진행함에 있어 건축, 교통, 에너지 등 각 분야별로 연구를 진행하고 있기에 각 분야별 연구 결과들이 통합적으로 이용되지 않고 있다. 본 논문에서는 이러한 문제점을 해결하기 위하여 저탄소도시 혹은 녹색도시를 위한 시스템을 구축하는 관련 연구들의 현황을 조사하고, 각 분야별로 도출된 결과물을 통합적으로 이용할 수 있는 방안을 정의하고자 한다. 논문에서 정의된 '탄소저감 도시계획 통합시스템'의 통합 모델로서 각 개별 시스템을 분석 시 데이터 로드 등에 대한 문제로 인하여 C/S 시스템으로 개발하고, 통합 시스템에 분석된 DB를 조회/활용할 수 있도록 개발하며, 통합 시스템은 Web으로 개발하는 방향으로 결정하였다. 본 연구 결과를 바탕으로 차후 연구개발 사업들에서는 경제적이고 효율적인 통합 모델이 도출될 수 있을 것이며, 현장에서 실제로 각 개발 성과물들이 활용될 수 있을 것이다.

• 한국주거학회:학술대회논문집
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• 한국주거학회 1994년도 학술발표대회논문집 상
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• pp.29-36
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• 1994

The purpose of this study is to suggest the basic design elements for dwelling environment planning of downtown in Taegu.The evaluation of the dwelling environment should be approached from the satisfaction and the cognitive of the residents, that are based on their desire and various values on the conditions of residential area. This paper concerns the satisfaction and the congnitive image structure of the residents in the various dwelling types, from which design elements for dwelling environments can be derived. The results are as folIows: 1) The analysis on the satisfaction of dwell ins environment shows lots of displeasure about the lack of open-spaces and the housing low-quality, neighborhood in Mun-hwa, Korean style housing and the low-rise apartment areas. In order to make the variety types of dowelling in downtown district, the improvement of housing qualities and the expantion of the urban facilities for the open-spaces and communities are need. 2) The design elements of dwelling environments in downtown find out the important planning elements for urban design. The evaluation of the cognitive image structures about the safety and affection should be considered in design for urban dwelling areas.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.197-202
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• 2004

In order to design accurately sand compaction pile (SCP) method with low replacement area ratio, it is important to understand the mechanical interaction between sand piles and clays and its mechanism during consolidation process of the composition ground. In this paper, a series of numerical analyses on composition ground improved by SCP with low replacement area ratio were carried out, in order to investigate the mechanical interaction between sand piles and clays. The applicability of numerical analyses, in which an elasto-viscoplastic consolidation finite element method was applied, could be confirmed comparing with results of a series of model tests on consolidation behaviors of composition ground improved by SCP. And, through the results of the numerical analyses, each mechanical behaviors of sand piles and clays in the composition ground during consolidation was elucidated, together with stress sharing mechanism between sand piles and clays.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.373-378
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• 2004

Recently the electrostatic 2-axis MEMS stages have been fabricated for the purpose of an application to PSD (Probebased Storage Device). However, most of them have low area efficiency, which is undesirable as data storage devices, since all of the components (springs, comb electrodes, anchors, platform, etc.) are placed in-plane. In this paper, we present a novel structure of electrostatic 2-axis MEMS stage that is characterized by having large area platform. For large area efficiency, the actuator part consisting of mainly comb electrodes and springs is placed right below the platform. In this article, the structures and operational principle of the MEMS stages are described, followed by design procedure, structural and modal analysis using FEM(Finite Element Method). The area efficiency of the MEMS stage was designed to be about 55％, that is very large compared with conventional ones having a few percentage.

• 한국컴퓨터정보학회논문지
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• 제17권10호
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• pp.99-105
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• 2012

지그비는 저 전력, 저 비용, 낮은 데이터 전송 속도의 특징을 가지는 무선 개인 망(Low Rate Wireless Personal Area Networ: LR-WPAN)의 표준이다. 방향성 메시징 기법은 방송을 사용하는 무선 센서 네트워크에서 방향정보를 가지는 메시지를 특정 영역으로 전송함으로써 중복 메시지 전송을 줄이는 것을 통하여 에너지 효율성을 높이는 프로토콜이다. 본 논문에서는 에너지 효율성 향상을 위하여 방향성 메시징을 지원하도록 수정한 지그비를 사용하는 실험용 격자형 센서 네트워크를 설계하고 구현한다. 본 논문의 실험용 센서 네트워크는 방향성 정보를 사용하도록 수정한 ADV 메시지와 라우팅 관리 모듈을 지원하는 Nano-24 노드로 구성한다. 실험용 센서 네트워크의 에너지 효율 향상성은 실제 ADV 메시지 전송에 따른 실험 결과 분석울 통하여 나타내 보인다.

• 설비공학논문집
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• 제19권11호
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• pp.776-781
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• 2007

Optimized capacity of equipments are essential for energy saving and low cost construction and operation. So we must use proper design data for HVAC system design. We investigated for architectural data, equipment capacity, cooling and heating load design criteria of 52 office buildings. Following research results were obtained by carrying out each task. Office building effective area rate is 63%. The average building cooling load of South Korea is $140W/m^2$ and average heating loads in Seoul and Pusan area are $120{\sim}130W/m^2$ and $70{\sim}80W/m^2$. We also analysised HVAC design criteria. Person ratio in effective building area is $0.2person/m^2$, sensitive and latent heat loads of a person are 60W and 65W, light and equipment loads of office buildings are $25W/m^2$ and $20W/m^2$.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제13권4호
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• pp.231-239
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• 2007

본 논문에서는 국내 표준 128비트 블록 암호화 알고리즘인 SEED를 하드웨어로 설계할 경우 면적-성능간의 trade-off 관계를 보여준다. 본 논문에서 다음 4가지 유형의 설계 구조를 비교한다. (1) Design 1 : 16 라운드 완전 파이프라인 방식, (2) Design 2 : 단일 라운드의 반복 사용 방식 (3) Design 3 : G 함수 공유 및 반복 사용 방식 (4) Design 4 : 단일 라운드 내부 파이프라인 방식. (1),(2),(3)의 방식은 기존의 논문들에서 제안한 각기 다른 설계 방식이며 (4)번 설계 방식이 본 논문에서 새롭게 제안한 설계 방식이다. 본 논문에서 새롭게 제안한 방식은, F 함수 내의 G 함수들을 파이프라인 방식으로 연결하여 면적 요구량을 (2)번에 비해서 늘이지 않으면서도 파이프라인과 공유블록 사용의 효과로 성능을 Design 2와 Design 3보다 높인 설계 방식이다. 본 논문에서 4가지 각기 다른 방식을 각각 실제 하드웨어로 설계하고 FPGA로 구현하여 성능 및 면적 요구량을 비교 분석한다. 실험 분석 결과, 본 논문에서 새로 제안한 F 함수 내부 3단 파이프라인 방식이 Design 1 방식을 제외하고 가장 throughput 이 높다. 제안된 Design 4 가 단위 면적당 출력성능(throughput)면에서 다른 모든 설계 방식에 비해서 최대 2.8배 우수하다. 따라서, 새로이 제안된 SEED 설계가 기존의 설계 방식들에 비해서 면적대비 성능이 가장 효율적이라고 할 수 있다.

• 한국IT서비스학회지
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• 제14권1호
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• pp.159-173
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• 2015

This paper presents a study on the Internet of Things based low-power wireless sensor networks for remote monitoring of wildlife ecosystem due to climate change. Especially, it is targeting the wild vegetation communities ecological monitoring. First, we performed a pre-test and analysis for selecting the appropriate frequency for the sensor network to collect and deliver information reliably in harsh propagation environment of the forest area, and selected for sensors for monitoring wild vegetation communities on the basis of considerations for selecting the best sensor. In addition, we have presented the platform concept and hierarchical function structures for effectively monitoring, analyzing and predicting of ecosystem changes, to apply the Internet of Things in the ecological monitoring area. Based on this, this paper presents the system architecture and design of the Internet of Things based low-power wireless sensor networks for monitoring the ecosystem of the wild vegetation communities. Finally, we constructed and operated the test-bed applied to real wild trees, using the developed prototype based on the design.