• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 통신소사이어티 추계학술대회논문집
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• pp.121-124
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• 2003

Passive optical networks (PONs) will be the pervasive choice in the design of next-generation access networks. One possible solution to implementing Passive optical access network is to rely on wavelength-division multiplexing (WDM). In this paper, we solve the problem of providing real-time service to both hard and soft real-time messages in conjunction with a conventional vest-effort service in WDM. we propose an adaptive scheduling algorithm to schedule and manage the message transmissions in the optical access network. Proposed algorithm is MLF-MQF. Also, we suggest dynamic bandwidth algorithm(DBA) in Loop-back WDM-PON (LPB-PON).our mechanism based on bandwidth reservation protocol.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.359-362
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• 2000

The purpose of this study is to research and develop graphene composite for lithium polymer battery. VO(graphene) composite is one of the promising material as a electrode active material for lithium polymer battery(LPB). We investigated AC impedance response and charge/discharge cycling of VO(graphene)/SPE/Li cells. The first discharge capacity of VO(graphene) cathode with 50wt.% V$_2$O$\sub$5/ was 150mAh/g, while that of VO(graphene) cathode with 85wt.% V$_2$O$\sub$5/ was 248mAh/g. The Ah efficiency was above 98% after the 2nd cycle. The discharge capacity of VO(graphene) anode with 3wt.% V$_2$O$\sub$5/ was 718 and 266mAh/g at cycle 1 and 10 at room temperature, respectively. The VO(graphene) anode with 3wt.% V$_2$O$\sub$5/ in PVDF-PAN-PC-EC-LiC1O$_4$ electrolyte showed good capacity with cycling.

• 반도체디스플레이기술학회지
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• 제8권3호
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• pp.39-44
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• 2009

Local Binary Pattern (LBP) is becoming a popular tool for various machine vision applications such as face recognition, classification and background subtraction. In this paper, we propose a new extension of LBP, called the Diagonal LBP (DLBP), to handle the image-based gender classification problem arise in interactive display systems. Instead of comparing neighbor pixels with the center pixel, DLBP generates codes by comparing a neighbor pixel with the diagonal pixel (the neighbor pixel in the opposite side). It can reduce by half the code length of LBP and consequently, can improve the computation complexity. The Support Vector Machine is utilized as the gender classifier, and the texture profile based on DLBP is adopted as the feature vector. Experimental results revealed that our approach based on the diagonal LPB is very efficient and can be utilized in various real-time pattern classification applications.

• Earthquakes and Structures
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• 제16권4호
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• pp.401-413
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• 2019

The concept of base isolation for equipment is well known. Its application in buildings and structures is rather challenging. Introduction of horizontal flexibility at the base helps in proper energy dissipation at the base level thus reducing the seismic demand of the super structure to be considered during design. The present study shows the results of a series of numerical simulation studies on seismic responses of secondary system (SS) housed in non-isolated and base-isolated primary structures (PS) including equipment-structure interactions. For this study the primary structure consists of two similar single bay three-store reinforced cement concrete (RCC) Frame building, one non-isolated with conventional foundation and another base isolated with Lead plug bearings (LPB) constructed at IIT Guwahati, while the secondary system is modeled as a steel frame. Time period of the base isolated building is higher than the fixed building. Due to the presence of isolator, Acceleration response is significantly reduced in both (X and Y) direction of Building. It have been found that when compared to fixed base building, the base isolated building gives better performance in high seismic prone areas.

• 멤브레인
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• 제14권4호
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• pp.263-274
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• 2004

고분자 분리막 기술은 리튬이온전지나 리튬폴리머전지와 같은 리튬이차전지의 성능을 좌우할 정도로 중요한 요소기술이다. 본 논문에서는 지금까지 개발되어 사용되고 있는 다양한 고분자 분리막의 특징 및 기술동향에 대하여 기술하고, 보다 적합한 분리막의 요건을 만족시키기 위한 고분자물질의 판단기준을, 특히 안정성 측면에서 살펴보고자 한다. 또한 실제 리튬이온전지용 분리막을 제조하기 위한 제조공정을 통해 고분자재질의 특징과 관련한 적용성의 여부를 판단코자 하며, 제조된 분리막에 대한 실용화 가능성을 판단하기 위한 분리막의 물리적 요구치 및 측정법에 대하여 기술코자 한다.

• 인터넷정보학회논문지
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• 제18권6호
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• pp.15-23
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• 2017

Wireless power transmission (WPT) for wireless charging is currently attracting much attention as a promising approach to miniaturize batteries and increase the maximum total range of an electric vehicle. The main advantage of the laser power beam (LPB) approach is its high power transmission efficiency (PTE) over long distance. In this paper, we present the design of a laser power beam based WPT system, which has a best WPT channel selection technique at the receiver end when multiple power transmitters and single power receiver are operated simultaneously. The transmitters send their transmission channel information via optically modulated laser pulses. The receiver uses the received signal strength indicator and digitized data to choose an optimum power transmission path. We modeled a vertical multi-junction photovoltaic cell array, and conducted an experiment and simulation to test the feasibility of this system. From the experimental result, the standard deviation between the mathematical model and the measured values of normalized energy distribution is 0.0052. The error between the mathematical model and measured values are acceptable, thus the validity of the model is verified.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 C
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• pp.1034-1038
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• 1995

The purpose of this study is to research and develop $TiS_2$ composite cathode for lithium polymer battery(LPB). $TiS_2$ electrode represent a class of insertion positive electrode used in Li secondary batteries. In this study, we investigated preparation of $TiS_2$ composite cathode and AC impedance response of $TiS_2$ composite/SPE/Li cells as a function of state of charge(SOC) and cycling. The resistance of B type cell using $TiS_2PEO_8LiClO_4PC_5EC_5$ composite cathode was lower than that of A type cell using $TiS_2PEO$ composite cathode. The cell resistance of B type cell is high for the first few percent discharge, decreases for midium discharge and then increases again toward the end of discharge. We believe the magnitude of the cell resistance is dominated by passivation layer impedance and small cathode resistance. AC impedance results indicate that the cell internal resistance increase with cycling, and this is attributed to change of passivation layer impedance with cycling. The passivation layer resistance($R_f$) of B type cell decreases for the 2nd cycling and then increases again with cycling. Redox coulombic efficiency of B type cell was about 141% at 1st cycle and 100% at 12th cycle. Also, $TiS_2$ specific capacity was 115 mAh/g at 12 cycle.

• Journal of Periodontal and Implant Science
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• 제25권2호
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• pp.222-238
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• 1995

Inflammatory cells may produce active species of oxygen in antimicrobial defense. While such species can directly damage surrounding tissue, their major secondary role may be to mediate important components of the inflammatory response. Superoxide dismutase, antioxidant, have significant anti-inflammatory properties in rheumatoid arthritis, ischemic tissue injury and gastrointestinal disease. Increased oxidative product formation diseases. And superoxide dismutase produced by Porphyromonas Gingivalis is resistant to killing by polymorphonuclear leukocyte. The purpose of this study was to investigate on the effects of superoxide dismutase in 3T3 fibroblast and in experimental gingivitis in the rats. The effect of superoxide dismutase(SOD) to cell morphology and cell activity was measured in cultured mouse 3T3 fibroblast. After experimental gingivitis were induced by lipopolysaccharide(LPb) and bovine serum albumin(BSA), injection of SOD were done. WBC count and histologic findings were observed at 1, 2, 3, and 7 days. The results were as follows; 1. There was a little difference between LPS treated groups and SOD treated groups in 3T3 fibroblast morpholoy. 2. There was no difference between only SOD treated groups (except SOD 150U at 3days) and control in 3T3 fibroblast activity. 3. LPS $0.5{\mu}g/ml$ and SOD treated groups (except 150U) had decreased 3T3 fibroblast activity and no significant difference at 3 days. 4. LPS $5.0{\mu}g/ml$ and SOD treated groups were significantly increased cell activity of 3T3 fibroblast than control group at 1 day(P<0.05). 5. In LPS induced gingivitis, the number of leukocytes in SOD treated was significantly decreased than in saline treated at 1 day(P<0.05). 6. In histopathologic findings of LPS or BSA induced gingivitis, inflammatorycell infiltration in SOD treated groups were less than in saline treated group at 1, 2 and 3 days.

• 한국콘텐츠학회논문지
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• 제13권1호
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• pp.1-8
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• 2013

얼굴 영상 데이터베이스에서 제공하는 눈 좌표에 의존해서 부분 자동 얼굴 인식 알고리즘을 설계 구현하면 실 환경 얼굴 인식 시스템에서는 눈 좌표 추출 알고리즘의 정확도에 따라 인식 성능이 달라질 수 있다. 본 논문에서는 얼굴의 눈, 코, 입 및 윤곽선 정보를 바탕으로 설정한 특징점 기반의 얼굴 모델 그래프를 생성하여 얼굴 영상에 정합시키고 각 특징점에서 Gabor 및 LBP 피쳐를 추출해서 결합하는 방식의 완전 자동 얼굴 인식 알고리즘을 제안하였다. 본 알고리즘에서는 완전 자동으로 얼굴 영상에 얼굴 모델 그래프를 맞출 뿐만 아니라 기존의 Gabor 피쳐에 LBP 피쳐를 추가함으로써 인식 성능을 극대화 시킬 수 있도록 하였다. 제안한 알고리즘을 FERET 데이터베이스에 적용해 본 결과 1,000명 이상의 얼굴을 실시간으로 인식할 수 있었고 각 데이터 집합에 대해서 우수한 인식 성능을 얻을 수 있었다.

• 한국방재안전학회논문집
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• 제14권1호
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• pp.61-72
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• 2021

최근 기후변화로 인한 가뭄발생으로 국지적인 물부족 문제 해결을 위해 안정적인 지하수를 활용한 물공급 방안의 필요성이 증가하고 있으며 이에 대한 대안으로 지하수 인공함양 기술이 대두되고 있다. 본 연구에서는 기상조건 및 목표취수량, 함양정의 주입량, 주입기간 등을 고려한 함양 시나리오를 반영하여 수치모델링을 통해 인공함양-취수 시스템의 함양능력 평가와 최적 운영조건을 도출하여 가뭄발생에 대비한 농업용수의 효율적인 공급과 안정적인 용수확보를 위한 정량적인 평가기법을 도출하고자 하였다. 이에 함양정의 함양능력을 평가하기 위해 물수지 분석으로부터 도출된 목표취수량을 고려한 총 주입량 10,000 ton의 조건하에서 주입 시나리오별(Case 1~4)로 주입정 및 관측정별 지하수위 변화를 모사한 결과 주입 후 유역 내 지하수위는 약 25~42일간 유지되는 것으로 나타났다. 이 중 Case 3의 경우 지표하 1 m 미만으로 지하수위가 상승하여 적정 주입량은 50 m³/day가 적절한 것으로 모사되었으며 함양수 주입에 의한 지하수위 상승에 따른 영향범위는 113.5 m로 예측되었다. 또한 함양 시나리오에 따른 하류부 저투수성 벽체(LPB) 설치 전후의 유역내 함양능력 변화는 설치 전 대비 지하수 저류량은 약 6배가량 증가하였고 지하수 체류시간은 약 4배 정도 증가하는 것으로 모사되었다. 본 연구결과는 향후 가뭄대응을 위한 안정적인 농업용수 공급 및 지속적인 수자원 확보에 크게 기여할 것으로 기대된다.