• 제목/요약/키워드: Coverage Problem

검색결과 366건 처리시간 0.021초

Verilog UDP Library의 등가 게이트수준 모델 생성 (Generation of Gate-level Models Equivalent to Verilog UDP Library)

  • 박경준;민형복
    • 전자공학회논문지SC
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    • 제40권1호
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    • pp.30-38
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    • 2003
  • Verilog HDL의 UDP(User Defined Primitive) 라이브러리는 디지털 회로 설계 과정에서 시뮬레이션을 위해 사용된다. 그러나 합성이 되지 않는 특성으로 인해 이와 등가의 게이트수준 라이브러리를 따로 만드는 데에 많은 시간과 노력이 소요된다. 등가의 게이트수준 모델이 존재하지 않을 경우 이는 테스트 과정에서 고장 검출율을 낮추는 요인이 되므로 등가 게이트수준 모델 생성은 필수적이며 이의 자동화가 필요하다. 이를 위해 매우 복잡한 알고리즘이 발표되기는 했지만 Verilog UDP library의 특성상 보다 더 간단한 알고리즘으로 구현이 가능하다. 알고리즘이 간략해짐에 따라 이를 구현하는 데에 걸리는 시간과 노력이 절약되고 프로그램 실행시간도 크게 줄일 수 있다.

A Design of Dual Frequency Bands Time Synchronization System for Synchronized-Pseudolite Navigation System

  • Seo, Seungwoo;Park, Junpyo;Suk, Jin-Young;Song, Kiwon
    • Journal of Positioning, Navigation, and Timing
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    • 제3권2호
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    • pp.71-81
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    • 2014
  • Time synchronization system using dual frequency bands is designed and the error sources are analyzed for alternative synchronized-pseudolite navigation system (S-PNS) which aims at military application. To resolve near/far problem, dual frequency band operation is proposed instead of pulsing transmission which degrades level of reception. In dual frequency operation H/W delay should be considered to eliminate errors caused by inter-frequency bias (IFB) difference between the receivers of the pseudolites and users. When time synchronization is performed across the sea, multipath error is occurred severely since the elevation angle between pseudolites is low so total reflection can be happened. To investigate the difference of multipath effects according to location, pseudolites are set up coastal area and land area and performances are compared. The error source related with tropospheric delay is becoming dominant source as the coverage of the PNS is broadening. The tropospheric delay is measured by master pseudolite receiver directly using own pseudorange and slave pseudorange. Flight test is performed near coastal area using S-PNS equipped with developed time synchronization system and test results are also presented.

Efficient Energy and Position Aware Routing Protocol for Wireless Sensor Networks

  • Shivalingagowda, Chaya;Jayasree, P.V.Y;Sah, Dinesh.K.
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제14권5호
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    • pp.1929-1950
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    • 2020
  • Reliable and secure data transmission in the application environment assisted by the wireless sensor network is one of the major challenges. Problem like blind forwarding and data inaccessibility affect the efficiency of overall infrastructure performance. This paper proposes routing protocol for forwarding and error recovery during packet loss. The same is achieved by energy and hops distance-based formulation of the routing mechanism. The reachability of the intermediate node to the source node is the major factor that helps in improving the lifetime of the network. On the other hand, intelligent hop selection increases the reliability over continuous data transmission. The number of hop count is factor of hop weight and available energy of the node. The comparison over the previous state of the art using QualNet-7.4 network simulator shows the effectiveness of proposed work in terms of overall energy conservation of network and reliable data delivery. The simulation results also show the elimination of blind forwarding and data inaccessibility.

Review of the Cervical Cancer Burden and Population-Based Cervical Cancer Screening in China

  • Di, Jiangli;Rutherford, Shannon;Chu, Cordia
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권17호
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    • pp.7401-7407
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    • 2015
  • Cervical cancer continues to be a serious public health problem in the developing world, including China. Because of its large population with geographical and socioeconomic inequities, China has a high burden of cervical cancer and important disparities among different regions. In this review, we first present an overview of the cervical cancer incidence and mortality over time, and focus on diversity and disparity in access to care for various subpopulations across geographical regions and socioeconomic strata in China. Then, we describe population-based cervical cancer screening in China, and in particular implementation of the National Cervical Cancer Screening Program in Rural Areas (NACCSPRA) and the challenges that this program faces. These include low screening coverage, shortage of qualified health care personnel and limited funds. To improve prevention of cervical cancer and obtain better cancer outcomes, the Chinese government needs to urgently consider the following key factors: reducing disparities in health care access, collecting accurate and broadly representative data in cancer registries, expanding target population size and increasing allocation of government funding for training of personnel, improving health education for women, enhancing quality control of screening services and improving a system to increase follow up for women with positive results.

An Efficient Association Control Method for Vehicular Networks with Mobile Hotspots

  • Hwang, Jae-Ryong;Choi, Jae-Hyuk;Yoo, Joon;Lee, Hwa-Ryong;Kim, Chong-Kwon
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제5권5호
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    • pp.888-908
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    • 2011
  • The increasing demand from passengers in vehicles to improve safety, traffic efficiency, and comfort has lead to the growing interest of Wi-Fi based vehicle-to-infrastructure (V2I) communications. Although the V2I system provides fast and cost-effective Internet connectivity to vehicles via roadside Wi-Fi access points (APs), it suffers from frequent handoffs due to the high mobility of vehicles and the limited coverage of Wi-Fi APs. Recently, the Mobile AP (MAP) platform has emerged as a promising solution that overcomes the problem in the V2I systems. The main advantage is that MAPs may yield longer service duration to the nearby vehicles that have similar mobility patterns, yet they provide smaller link capacities than the roadside APs. In this paper, we present a new association control technique that harnesses available connection duration as well as achievable link bandwidth in high-speed vehicular network environments. We also analyze the tradeoff between two association metrics, namely, available connection duration and achievable link bandwidth. Extensive simulation studies based on real traces demonstrate that our scheme significantly outperforms the previous methods.

유리 복직근 및 복직근피판술을 이용한 사지의 재건술 (Reconstruction of the Extremity Injury using by Free Rectus Abdoninis Muscle or Myocutaneous Flap)

  • 안기영;장경수;한동길
    • Archives of Reconstructive Microsurgery
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    • 제4권1호
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    • pp.23-32
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    • 1995
  • Severe upper and lower extremity trauma may result in soft tissue loss with exposed bone and the subsequence of risk of chronic osteomyelitis or malunion of fracture fragments. Such injuries present a major reconstructive problem. But Since the introduction of microsugical technique, free muscle and myocutaneous flaps were employed to provide coverage of severely injured defects. Since Tai and Hasegawa(1974) first reported a breast reconstruction using by rectus abdominis myocuraneous flap, the free rectus myocutaneous flap has been widely employed for breast reconstuction, head and neck reconstruction, and extremity reconstruction in these days. The authors present their successful experience with free rectus abdominis muscle and rectus abdominis myocutaneous flaps for upper and low extremity reconstruction. From Nov. 94, to May 95, Five cases of severely injured extremites due to trauma or contact burn were treated with free rectus abdominis muscle flap or free rectus abdominis myocutaneous flap. All flaps except 1 case were survived without severe complications. As free muscle or myocutaneous flap, the free rectus abdominis flap has the advantages of a reliable pedicle, easy dissection, and an acceptable donor site, so it seems logical to apply the free rectus abdominis flap to apply in upper and lower extremity reconstruction.

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원위피판술을 시행한 환자의 손가락에 수술용 고무장갑을 이용한 간단한 조형법 (Simple Molding Method for Post-distant Flap Stated Finger by Using Surgical Rubber Gloves)

  • 김호길;최환준;김미선;신호성;탁민성
    • Archives of Plastic Surgery
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    • 제33권2호
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    • pp.263-267
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    • 2006
  • In both cosmetic and functional aspects, loss of digital pulp is a common problem. Compound or composite defects of the hand and fingers with exposed denuded tendon, bone, joint, or neurovascular structures may require flap coverage. Most often these lesions can be repaired by using simple local flap, neurovascular flap, thenar flap, and cross-finger flap. But microvascular reconstruction is sometimes needed for large defects. But Authors do not recommend these procedures in case of severe crushing injuries involving multiple finger pulp losses because they have possibility of damage of the vascular network and infection. So we applied distant flaps such as chest flaps, groin flaps, abdominal flaps and etc. And then we applied surgical rubber gloves for remodeling the flap after cutaneous healing. We have acquired satisfactory results, after the simple molding method for distant flap finger by using surgical rubber gloves treatment.

전파천문 및 위성통신업무간의 주파수 공유방안 (PREFERRED SHARING METHODS BETWEEN THE RADIO ASTRONOMY AND SATELLITE TELECOMMUNICATION SERVICES)

  • 정현수;노덕규;제도흥;김효령;박종민;안도섭;오대섭
    • 천문학논총
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    • 제19권1호
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    • pp.129-133
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    • 2004
  • In the past, radio astronomers have sought isolation from man-made signals by placing their telescopes in remote locations. These measures may no longer safeguard scientific observations, since NGSO satellite systems, particularly low-Earth orbit (LEO) systems, are usually designed to provide global or wide regional coverage. Further, radio astronomers have historically made their observations in the frequency bands allocated for their use by the member countries of the International Telecommunication Union (ITU). The science of radio astronomy could be adversely impacted by the deployment of large constellations of new non-geostationary orbiting (NGSO) satellites for telecommunications, navigation and Earth observation, and the proliferation of new, high-power broadcasting and telecommunication satellites in geostationary (GSO) orbits. Radio telescopes are extremely sensitive, and, in certain situations, signals from satellites can overwhelm the signals from astronomical sources. This paper describes the problem in detail and identifies ways to mitigate it without adversely affecting the continued vigorous growth of commercial space-based telecommunications.

전신성 혈관염 환자의 족부 만성 창상의 치험례 (Treatment of Chronic Wound in a Patient with Systemic Vasculitis)

  • 임진수;김형준;주홍실;최윤석
    • Archives of Plastic Surgery
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    • 제33권1호
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    • pp.116-119
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    • 2006
  • Management of chronic wound has been a great problem to many surgeons because the wound is usually associated with an underlying disease of the patient. Without accurate diagnosis and treatment of the disease, the wound can not be healed. Systemic vasculitis is a rare systemic disease which causes inflammation and obstruction of the vessels. This autoimmune disease involves multiple organs and may inflict skin wound spontaneously without traumas. It would improve or aggravate the wound in proportion to the activities of the disease. Our experience is a case of 28-year-old female who has had chronic ulcers on her right foot, especially on the great toe for 1 year. Although she had several operations of sympathectomy, debridement and artificial dermal graft, her wound was not improved. She has been diagnosed as systemic vasculitis during the evaluation for histopathology and cause of fever and pancytopenia. After medical treatments, she had the operation of adipofascial turnover flap coverage and skin graft, and the wound was improved without any complication or relapse. The diagnosis and treatment of the underlying disease should be ahead of the management of chronic wound.

학술정보에 있어서 1차 자료와 2차 자료의 관계에 대한 연구 (The Relationship between Primary and Secondary Literature)

  • 오동우
    • 한국문헌정보학회지
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    • 제33권1호
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    • pp.145-160
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    • 1999
  • 학술정보는 1차자료와 2차자료의 2가지로 구분할 수 있다. 1차자료는 학술정보 그 자체이고 2차자료는 색인, 초록, 서지 등과 같은 1차자료를 찾아볼 수 있는 길잡이이다. 2차자료에 수록된 정기간행물의 중복된 점과 범위를 이전에 연구한 자료와 금번 조사한 자료를 비교 검토하였으며 문헌정보학분야 2차자료 Library and Information Science Abstract (LISA) : Library Literature (LL) : Information Science Abstract (ISA) 등 3가지의 주요 2차자료를 비교 분석한 결과 문헌정보학 관계 자료선정 및 장서개발 정책에 영향을 미칠 수 있음을 제시 하고있다.

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