• Bulletin of the Korean Chemical Society
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• 제28권12호
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• pp.2442-2444
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• 2007

CO adsorbates on the surface of Pt supported on carbon catalysts (Pt/C) were investigated by CO stripping voltammetry. Three types of CO adsorbed samples were prepared: by methanol dehydrogenation only (COm), by CO gas bubbling only (COg), and by methanol dehydrogenation followed by CO gas bubbling (COm+g). Our coverage data show that CO gas can be adsorbed on Pt/C catalyst already saturated with CO adsorbates by methanol dehydrogenation. The COm+g sample showed the properties of both COm as well as COg samples in terms of the potential although the CO adsorbed by dehydrogenation was completely exchanged with CO in the electrolyte solution. Therefore, the oxidation pathways of CO on Pt/C were observed to depend on the initial adsorption conditions of CO more strongly than on the CO coverage. Our results imply that an initial CO poisoning condition in fuel cell operation is an important factor to determine the difficulty in removing the adsorbed CO and confirm that the properties of the adsorbed CO do not change even with chemical replacement with CO in different conditions. In addition, our results indicate a low CO surface mobility on the Pt in an electrolyte solution.

• 한국ITS학회 논문지
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• 제8권1호
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• pp.30-36
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• 2009

도심지역에서 사용되는 DSRC 통신시스템은 노변기지국과 차량간 100미터의 통신거리를 갖고 있으며, 이 특성을 이용하여 DSRC시스템에서 RSE(Road Side Equipment)는 차량으로부터 교통정보를 수집하거나 차량에 교통정보를 제공한다. 그러나 고속도로상에서 100미터 통신범위를 갖는 RSE를 사용하는 것은 장비가격 및 설치비가 고가이어서 현실적으로 많은 어려움이 있다. 본 논문에서는 RSE의 표준 셀 범위를 100미터에서 300미터로 확장하고 차량단말기가 RSE와 통신할 수 없는 불감지역을 Cover 하기 위하여 Fixed Relay를 도입하였으며, 이로 인해 Fixed Relay를 사용하는 것이 RSE 만을 사용하는 것 보다 더 경제적인 것을 보인다.

• ETRI Journal
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• 제38권1호
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• pp.112-122
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• 2016

This paper presents a set of candidate regulatory requirements for TV band devices (TVBDs) in the Rep. of Korea. To guarantee the protection of incumbent services, especially digital TV (DTV) and wireless microphones, in TV frequency bands, we suggest minimum separation distances of TVBDs from the noise-limited contour according to incumbent users and TVBD types. This paper also deals with multiple sets of separation distances of a co-channel TVBD network from a DTV protected contour on the basis of the radio propagation characteristics of different geographic areas to make good use of TV white space (TVWS) and safely protect the DTV service. We present a low-power transmission mode of TVBDs and the relevant separation distances for small-cell deployment. The service coverage reduction ratio of a TVBD network is investigated in the presence of DTV interference in four geographic areas. The TVWS field verification results, conducted on the island of Jeju (Rep. of Korea), show that incumbent services operate well without harmful interference from neighboring TVBDs with the proposed separation distances.

• 대한전기학회논문지:시스템및제어부문D
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• 제52권2호
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• pp.93-101
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• 2003

Scan design is a structured design-for-testability technique in which flip-flops are re-designed so that the flip-flops are chained in shift registers. The scan design cannot be used in a design with scan design rule violations without modifying the design. The most important scan design rule is concerning clock and reset signals to pins of the flip-flops or scan cells. Clock and Reset pins of every scan cell must be controllable from top-level ports. We propose a new technique to re-design gated clocks and resets which violate the scan design rule concerning the clock and reset pins. This technique substitutes synchronous sequential circuits for gated clock and reset designs, which removes the clock and reset rule violations and improves fault coverage of the design. The fault coverage is improved from $90.48\%$ to $100.00\%$, from $92.31\%$ to $100.00\%$, from $95.45\%$ to $100.00\%$, from $97.50\%$ to $100.00\%$ in a design with gated clocks and resets.

• 제어로봇시스템학회논문지
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• 제11권9호
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• pp.789-794
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• 2005

This paper describes an algorithm for minimal turning complete coverage Path planning for cleaning robots. This algorithm divides the whole cleaning area by cellular decomposition, and then provides the path planning among the cells employing a flow network. It also provides specific path planning inside each cell guaranteeing the minimal turning of the robots. The minimal turning of the robots is directly related to the faster motion and energy saving. The proposed algorithm is compared with previous approaches in simulation and the result shows the validity of the algorithm.

• Archives of Reconstructive Microsurgery
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• 제20권2호
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• pp.113-115
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• 2011

We present our experience of reconstruction of inguinal soft tissue defect following inguinal lymphadenectomy, because of penile squamous cell carcinoma. Malignant infiltration required wide resection, producing a defect requiring complex soft tissue reconstruction. We have used a pedicled anterolateral thigh flap as our first choice flap for this case. Patient achieved reasonable esthetic coverage. Complications were few and patient achieved durable long term coverage. We found this flap to be technically easy, reliable and effective.

• 로봇학회논문지
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• 제6권3호
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• pp.255-262
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• 2011

Many intelligent robots have to be given environmental information to perform tasks. In this paper an intelligent robot, that is, a cleaning robot used a sensor fusing method of two sensors: LRF and StarGazer, and then was able to obtain the information. Throughout wall following using laser displacement sensor, LRF, the working area is built during the robot turn one cycle around the area. After the process of wall following, a path planning which is able to execute the work effectively is established using flow network algorithm. This paper describes an algorithm for minimal turning complete coverage path planning for intelligent robots. This algorithm divides the whole working area by cellular decomposition, and then provides the path planning among the cells employing flow networks. It also provides specific path planning inside each cell guaranteeing the minimal turning of the robots. The proposed algorithm is applied to two different working areas, and verified that it is an optimal path planning method.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2008년도 정보통신설비 학술대회
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• pp.229-232
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• 2008

급격한 이동통신 기술의 발전에 힘입어 음영지역 해소 및 고속 데이터 처리를 위해 댁내 기지국에 대한 개발 및 연구가 진행 중이다. 댁내 기지국은 크게 음영지역 해소를 위한 Open 방식의 기지국과 고속 데이터 처리를 위해 특정 가입자만 사용할 수 있는 Close 방식이 있다. 상기 방식들은 망의 특성에 맞게 이를 제공하는 망 사업자에 의해 선택 된다. 댁내 기지국을 관리하기 위해서는 많은 시간과 인력자원이 소요되므로 자동으로 설정 및 최적화시키는 기능이 요구 시 되고 있으며, 이를 3GPP에서 SON (Self Organizing Optimizing Networks) 이라 일컫고 연구진행 중이다. 본 논문은 댁내 기지국 관리를 위해 셀의 기본 인자인 PCI(Physical Layer Identity) 할당 방안과 댁내 기지국간 간섭을 최소화 시키기 위한 Adaptive Coverage 방안을 제시한다. 또한 계층적 셀 구성(Hierarchical Cell Structure)에 따른 이동성 제공 방안을 제시한다.

• 한국정보통신학회논문지
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• 제17권9호
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• pp.2191-2198
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• 2013

본 논문에서는 실내 위치 인식을 고려한 RFID 기반 셀 구성 방안을 제안하였다. RFID 셀 구성을 위한 4개의 목적함수 설계 및 시뮬레이션 기반 성능 평가뿐만 아니라 RFID 리더를 실내 공간에 실제 배치하여 제안한 기법의 성능평가를 수행하였다. 성능 평가는 RFID 셀 구성에 필요한 최소 RFID 리더 수, 위치 인식이 가능한 최대 셀 영역, 셀 영역 간의 최소 중첩, 그리고 셀 영역의 최대 위치 인식 정확도 측면에서 수행되었다.

• 전자통신동향분석
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• 제37권2호
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• pp.83-95
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• 2022

5G goes beyond people to serve indoor and outdoor companies and industries, as well as campuses such as halls, industrial complexes, educational institutions, stadiums, dense urban areas, rural areas, and government institutions. Therefore, a new approach to small cells is needed. Accordingly, 3GPP and Small Cell Forum are researching 5G small cell architecture; 3GPP, Small Cell Forum, and 5G Alliance for Connected Industries and Automation are also researching private networks tailored to meet the specific requirements of various companies and local governments. In particular, in the UK, a small cell-based technology is required for realizing the Joint Operator Technical Specifications-Neutral Host In-Building specification to cost-effectively secure indoor coverage. Further, the research on the SON(Self-Organizing Network) technology for small cells in 5G, where commercialization has begun, is required. The 5G-based small cell structure, private network, and Neutral Host In-Building and SON reviewed in this study are at the initial research stages; therefore, additional research is needed to secure the competitiveness of the small cell technology in 5G and Beyond 5G.