• 제목/요약/키워드: Cell Loss Detection

검색결과 49건 처리시간 0.033초

ATM 망에서의 셀 손실 복구 기법에 관한 연구 (Cell Loss Recovery Algorithm for ATM Networks)

  • 심윤섭;천상훈;곽경섭
    • 전기전자학회논문지
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    • 제3권1호
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    • pp.22-28
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    • 1999
  • 기존의 CREG-VP는 VP상에서 FEC기법을 사용하여 트래픽 과잉으로 인한 연속적인 셀 손실을 보상하는 기법으로써, 평균 코딩/디코딩 시간이 짧고, ATM 표준 셀 형식과 호환성을 유지할 수 있다는 장점을 지니고 있으나, 복구할 수 있는 셀의 수에는 제한이 존재한다. 본 논문에서는 CREG-VP를 확장하여 버스트 특성을 갖는 트래픽에서도 효과적으로 셀 손실을 복구하는 기법을 제안하였다. 제안된 기법은 CRP를 변경하여 셀 손실의 검출 성능을 향상시켰고, 인터리브 패리티 셀을 적용하여 연속적인 셀의 복구성능을 향상시켰다. 실험 결과 제안된 기법은 CREG-VP 방식보다 셀 손실률 감소 계수를 향상 시킴을 알 수 있었다.

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Target Detection probability simulation in the homogeneous ground clutter environment

  • Kim, In-Kyu;Moon, Sang-Man;Kim, Hyoun-Kyoung;Lee, Sang-Jong;Kim, Tae-Sik;Lee, Hae-Chang
    • International Journal of Aeronautical and Space Sciences
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    • 제6권1호
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    • pp.8-16
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    • 2005
  • This paper describes target detection performance of millimeter wave radar that exits on non-stationary target detection schemes in the ground clutter conditions. The comparison of various CFAR process schemes such as CA(Cell-Average)-CFAR, GO(Greatest Of)/SO(Smallest Of)-CFAR, and OS(Order Statistics)-CFAR performance are applied. Using matlab software, we show the performance and loss between target detection probability and signal to noise ratio. This paper concludes the OS-CFAR process performance is better than any others and satisfies the optimal detection probability without loss of detection in the homogeneous clutter, When range bins increase.

The Study of CFAR(Constant False Alarm Rate) process for a helicopter mounted millimeter wave radar system

  • Kim In Kyu;Moon Sang Man;Kim Hyoun Kyoung;Lee Sang Jong;Kim Tae Sik;Lee Hae Chang
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2004년도 학술대회지
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    • pp.890-895
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    • 2004
  • This paper describes constant alarm rates process of millimeter wave radar that exits on non-stationary target detection schemes in the ground clutter conditions. The comparison of various CFAR processes such as CA(Cell-Average)-CFAR, GO(Greatest Of)/SO(Smallest Of)-CFAR and OS(Order Statistics)-CFAR performance are applied. Using matlab software, we show the performance and loss between detection probability and signal to noise ratio. When rang bins increase, this results show the OS-CFAR process performance is better than any others and satisfies the optimal detection probability without loss of detection in the homogeneous clutter.

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Apoptotic cell clearance and human diseases

  • Yoon, Kyoung Wan
    • 셀메드
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    • 제7권1호
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    • pp.3.1-3.2
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    • 2017
  • The efficient removal of dead cells is an evolutionarily conserved process essential for homeostasis in multicellular organisms. The phagocytosis involves a series of steps that ultimately leads the detection of apoptotic cell by the phagocytes and the subsequent engulfment and degradation of corpse. The uptake of apoptotic cells by phagocytes not only removes debris from tissues but also generates an anti-inflammatory signal that blocks tissue inflammation. Conversely, impaired clearance of dead cells can cause loss of immune tolerance and the development of various inflammation-associated diseases such as autoimmunity, but can also affect cancer development. This review will discuss current understanding of the molecular mechanism of apoptotic cell phagocytosis and how they may be related to human diseases.

소방 비상용 태양전지 발전시스템의 고효율 직류-교류 인버터 설계에 관한 연구 (A Study on High Efficiency DC-AC Inverter of Solar Cell Power System Used in Fire Emergency Equipment)

  • 곽동걸;이봉섭
    • 에너지공학
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    • 제15권3호
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    • pp.181-187
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    • 2006
  • 본 논문에서는 소방 비상용으로 이용되는 태양전지 발전시스템을 제안하고, 발전시스템의 효율을 증대시키기 위한 새로운 고효율의 전력변환장치(승압용 초퍼와 인버터)가 설계된다. 직류-직류(DC-DC) 승압용 초퍼와 직류-교류(DC-AC) 인버터는 사용된 제어스위치들의 스위칭 손실을 최소화하기 위해 공진회로를 이용한 새로운 소프트 스위칭 기법이 적용되고 시스템의 효율을 증대시킨다. 또한 본 논문에서는 태양전지(solar cell)의 최대전력 전송에 의한 태양전지의 효율적인 사용을 위한 태양전지 발전전력의 최대점 $P_{max}$을 손쉽게 추종하고 검출하는 새로운 제어기법과 제어회로에 대해 상세히 해석된다. 고효율의 전력변환 장치와 태양전지 최대전력 전송회로는 컴퓨터 시뮬레이션과 실험을 통하여 그 타당성이 입증된다.

ATM 멀티플렉서에서 우선순위 제어에 의한 음성전송효율 및 버퍼관리에 관한 연구 (A Study on the Voice Traffic Efficiency and Buffer Management by Priority Control in ATM Multiplexer)

  • 이동수;최창수;강준길
    • 한국통신학회논문지
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    • 제19권2호
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    • pp.354-363
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    • 1994
  • 본 논문은 광대역 ISDN에서 음성 서비스를 효율적으로 제공하는 방법에 관한 연구이다. 음성은 그 특성상 유음구간과 북음구간으로 나누어지며, 음성활성검출에 의하여 실제로 말을 하는 동안만 전송이 이루어질 수 있도록 음성 트래픽을 발생한다. 본 논문에서는 ATM통신망에서 음성을 음성활성검출과 삽입(Embedded) ADPCM으로 코딩하고, 멀티플렉서에서 셀 폐기를 통하여 트래픽을 제어하는 알고리즘에 관하여 연구하였다. 트래픽 제어는 버퍼에 임계값을 주어, 버퍼의 상태가 임계값을 초과하는 경우에 낮은 우선순위를 갖는 음성 셀을 폐기하는 셀 폐기 알고리즘을 사용하였다. 셀 손실 확률, 큐 크기, 평균지연등을 성능분석 파라메터로 설정하고, 트래픽 제어 알고리즘의 성능을 평가하기 위하여 컴퓨터 시뮬레이션하였다. 이를 통하여 센 폐기방식에 의한 트래픽 제어가 음성의 질을 많이 저하시키지 않으면서도 트래픽 제어를 하지 않을 때에 비하여 전송 대역 이득을 향상시킨다는 것을 확인하였다.

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CCN 실시간 서비스에서 이동성 탐지에 따른 중간노드의 이동성 지원 (Supporting Intermediate-node Mobility in CCN Real-time Service according to Mobility Detection)

  • 성국일;권태욱
    • 한국멀티미디어학회논문지
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    • 제22권12호
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    • pp.1438-1446
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    • 2019
  • Recently, the number of mobile users as well as high-speed Internet user has been increasing rapidly. Moreover, traffic is growing fast as services that provide real-time content such as Youtube and Netflix become popular. The problem of traffic control in real-time content services is important because many people use cell phones to receive real-time content. In this regard, the field of CCN is currently being studied. We studied the mobility of nodes among CCN research fields. Node mobility can be divided into three categories : consumer mobility, intermediate node, and provide mobility. In this paper, we propose Mobility Node Support(MD-INS) to support the intermediate-node mobility in CCN real-time services. Experimental results show that the proposed scheme shows better performance than CCN in terms of service disconnection time and packet loss.

The Dharma of Nonsense-Mediated mRNA Decay in Mammalian Cells

  • Popp, Maximilian Wei-Lin;Maquat, Lynne E.
    • Molecules and Cells
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    • 제37권1호
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    • pp.1-8
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    • 2014
  • Mammalian-cell messenger RNAs (mRNAs) are generated in the nucleus from precursor RNAs (pre-mRNAs, which often contain one or more introns) that are complexed with an array of incompletely inventoried proteins. During their biogenesis, pre-mRNAs and their derivative mRNAs are subject to extensive cis-modifications. These modifications promote the binding of distinct polypeptides that mediate a diverse array of functions needed for mRNA metabolism, including nuclear export, inspection by the nonsense-mediated mRNA decay (NMD) quality-control machinery, and synthesis of the encoded protein product. Ribonucleoprotein complex (RNP) remodeling through the loss and gain of protein constituents before and after pre-mRNA splicing, during mRNA export, and within the cytoplasm facilitates NMD, ensuring integrity of the transcriptome. Here we review the mRNP rearrangements that culminate in detection and elimination of faulty transcripts by mammalian-cell NMD.

Automatic Detection of Malfunctioning Photovoltaic Modules Using Unmanned Aerial Vehicle Thermal Infrared Images

  • Kim, Dusik;Youn, Junhee;Kim, Changyoon
    • 한국측량학회지
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    • 제34권6호
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    • pp.619-627
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    • 2016
  • Cells of a PV (photovoltaic) module can suffer defects due to various causes resulting in a loss of power output. As a malfunctioning cell has a higher temperature than adjacent normal cells, it can be easily detected with a thermal infrared sensor. A conventional method of PV cell inspection is to use a hand-held infrared sensor for visual inspection. The main disadvantages of this method, when applied to a large-scale PV power plant, are that it is time-consuming and costly. This paper presents an algorithm for automatically detecting defective PV panels using images captured with a thermal imaging camera from an UAV (unmanned aerial vehicle). The proposed algorithm uses statistical analysis of thermal intensity (surface temperature) characteristics of each PV module to verify the mean intensity and standard deviation of each panel as parameters for fault diagnosis. One of the characteristics of thermal infrared imaging is that the larger the distance between sensor and target, the lower the measured temperature of the object. Consequently, a global detection rule using the mean intensity of all panels in the fault detection algorithm is not applicable. Therefore, a local detection rule was applied to automatically detect defective panels using the mean intensity and standard deviation range of each panel by array. The performance of the proposed algorithm was tested on three sample images; this verified a detection accuracy of defective panels of 97% or higher. In addition, as the proposed algorithm can adjust the range of threshold values for judging malfunction at the array level, the local detection rule is considered better suited for highly sensitive fault detection compared to a global detection rule. In this study, we used a panel area extraction method that we previously developed; fault detection accuracy would be improved if panel area extraction from images was more precise. Furthermore, the proposed algorithm contributes to the development of a maintenance and repair system for large-scale PV power plants, in combination with a geo-referencing algorithm for accurate determination of panel locations using sensor-based orientation parameters and photogrammetry from ground control points.

Curcumin Induces Caspase Mediated Apoptosis in JURKAT Cells by Disrupting the Redox Balance

  • Gopal, Priya Kalyan;Paul, Mausumi;Paul, Santanu
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권1호
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    • pp.93-100
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    • 2014
  • Background: Curcumin has has been reported to exert anti-inflammatory, anti-oxidation and anti-angiogenic activity in various types of cancer. It has also been shown to induce apoptosis in leukemia cells. We aimed to unravel the role of the redox pathway in Curcumin mediated apoptosis with a panel of human leukemic cells. Materials and Methods: In this study in vitro cytotoxicity of Curcumin was measured by MTT assay and apoptotic effects were assessed by annexin V/PI, DAPI staining, cell cycle analysis, measurement of caspase activity and PARP cleavage. Effects of Curcumin on intracellular redox balance were assessed using fluorescent probes like $H_2DCFDA$, JC1 and an ApoGSH Glutathione Detection Kit respectively. Results: Curcumin showed differential anti-proliferative and apoptotic effects on different human leukemic cell lines in contrast to minimal effects on normal cells. Curcumin induced apoptosis was associated with the generation of intracellular ROS, loss of mitochondrial membrane potential, intracellular GSH depletion, caspase activation. Conclusions: As Curcumin induces programmed cell death specifically in leukemic cells it holds a great promise as a future therapeutic agent in the treatment of leukemia.