• Title/Summary/Keyword: Potential Interference

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독립접지방식의 전위간섭 문제 해결을 위한 연구 (A Research on the Solution of the Potential Interferences of Isolation Grounding Systems)

  • 이복희;이수봉;이태형;길형준;한운기;김효진;이형권
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 제36회 하계학술대회 논문집 전기설비
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    • pp.49-51
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    • 2005
  • This paper presents the potential interferences in various grounding electrode systems. The ground potential rise and potential interference coefficients were calculated as a function of the configuration and size of grounding electrodes and the distance between grounding electrodes. The potential rise and potential interference coefficient strongly depend on the distance between grounding electrodes, the shape and size of grounding electrodes.

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수조실험장치를 이용한 접지전극 상호간의 전위간섭 평가 (Evaluation of Potential Interferences between Grounding Electrodes using an Electrolytic Tank)

  • 이복희;이수봉;이태형;길형준
    • 조명전기설비학회논문지
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    • 제20권4호
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    • pp.29-36
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    • 2006
  • 본 논문은 여러 가지 형상의 접지시스템에서 접지전극 상호간의 전위간섭에 대해 다루었다. 접지전극의 일정한 형상과 크기, 접지전극간 이격거리에 따른 전위상승과 전위간섭계수를 수조실험장치를 이용하여 측정하고, CDEGS 프로그램으로 해석하였다. 전위상승과 전위간섭계수는 접지전극의 이격거리, 접지전극의 형상과 크기에 강하게 의존한다. 격자형 접지전극과 격자형 접지전극 사이의 전위간섭은 격자형 접지전극과 봉형 접지전극 사이의 전위간섭보다 낮은 것으로 나타났다.

Analysis of Potential Risks for Garbage Collection and Wear Leveling Interference in FTL-based NAND Flash Memory

  • Kim, Sungho;Kwak, Jong Wook
    • 한국컴퓨터정보학회논문지
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    • 제24권3호
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    • pp.1-9
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    • 2019
  • This paper presents three potential risks in an environment that simultaneously performs the garbage collection and wear leveling in NAND flash memory. These risks may not only disturb the lifespan improvement of NAND flash memory, but also impose an additional overhead of page migrations. In this paper, we analyze the interference of garbage collection and wear leveling and we also provide two theoretical considerations for lifespan prolongation of NAND flash memory. To prove two solutions of three risks, we construct a simulation, based on DiskSim 4.0 and confirm realistic impacts of three risks in NAND flash memory. In experimental results, we found negative impacts of three risks and confirmed the necessity for a coordinator module between garbage collection and wear leveling for reducing the overhead and prolonging the lifespan of NAND flash memory.

Low-Overhead Feedback Topology Design for the K-User MIMO Interference Alignment

  • Jin, Jin;Gao, Xiang-Chuan;Li, Xingwang;Cavalcante, Charles Casimiro;Li, Lihua
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제12권11호
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    • pp.5304-5322
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    • 2018
  • Since designing a feedback topology is a practical way to implement interference alignment at reduced cost of channel state information (CSI) feedback, six feedback topologies have been presented in prior works for a K-user multiple-input multiple-output interference channel. To fully reveal the potential benefits of the feedback topology in terms of the saving of CSI overhead, we propose a new feedback topology in this paper. By efficiently performing dimensionality-decreasing at the transmitter side and aligning interference signals at a subset of receivers, we show that the proposed feedback topology obtains substantial reduction of feedback cost over the existing six feedback designs under the same antenna configuration.

수조모델을 이용한 메쉬접지극의 접지저항에 관한 연구 (Study for the Grounding Resistance of the Mesh Grounding Electrode by Water Tank Model)

  • 김주찬;김성삼;최종규;이충식;고희석
    • 조명전기설비학회논문지
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    • 제20권3호
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    • pp.28-35
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    • 2006
  • 최근들어 빌딩내에 있는 많은 전기 전자 통신설비들은 기기 보호 및 안전을 위하여 반드시 접지를 필요로 하며, 고장 전류가 같은 빌딩내에 있는 어떤 접지 시스템으로 흐를 때, 이 전류에 의한 전위상승에 영향을 받아 다른 접지시스템의 전위 상승을 유도할 수 있다. 이러한 전위간섭은 접지극의 표면전위에 의해 영향을 받으며, 전각의 형상과 깊은 관련이 있다. 본 논문에서의 기본적 공식은 전위간섭을 받는 접지극과 전위간섭의 원천이 되는 두 접지극의 표면 전위에 기초하여 추론되었으며, 다중 접지극에 있어서의 전위간섭의 정도는 미리 간단한 모델을 이용하여 시뮬레이션을 실시하였다. 이는 대지위에 설치되는 건조물의 접지저항을 추정하기 위한 것이며, 실제의 현장에서 측정한 접지 저항값과 추정값과의 일치성을 입증하기 위하여 반구형 수조에서 모의 접지시스템의 축적 모델로 실험을 행한 결과, 확실한 메쉬접지극의 접지저항을 얻을 수 있었다. 따라서 수조 모델 실험을 통하여 메쉬접지각의 접지저항을 추정할 수 있음을 보여주고 있다.

Hypergraph Game Theoretic Solutions for Load Aware Dynamic Access of Ultra-dense Small Cell Networks

  • Zhu, Xucheng;Xu, Yuhua;Liu, Xin;Zhang, Yuli;Sun, Youming;Du, Zhiyong;Liu, Dianxiong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제13권2호
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    • pp.494-513
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    • 2019
  • A multi-channel access problem based on hypergraph model in ultra-dense small cell networks is studied in this paper. Due to the hyper-dense deployment of samll cells and the low-powered equipment, cumulative interference becomes an important problem besides the direct interference. The traditional binary interference model cannot capture the complicated interference relationship. In order to overcome this shortcoming, we use the hypergraph model to describe the cumulative interference relation among small cells. We formulate the multi-channel access problem based on hypergraph as two local altruistic games. The first game aims at minimizing the protocol MAC layer interference, which requires less information exchange and can converge faster. The second game aims at minimizing the physical layer interference. It needs more information interaction and converges slower, obtaining better performance. The two modeled games are both proved to be exact potential games, which admit at least one pure Nash Equilibrium (NE). To provide information exchange and reduce convergecne time, a cloud-based centralized-distributed algorithm is designed. Simulation results show that the proposed hypergraph models are both superior to the existing binary models and show the pros and cons of the two methods in different aspects.

DTV시스템과 IEEE 802.11n WLAN의 간섭분석 (Interference Analysis between DTV System and IEEE 802.11n WLAN)

  • 최재혁;김은철;양재수;김진영
    • 한국정보통신설비학회:학술대회논문집
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    • 한국정보통신설비학회 2009년도 정보통신설비 학술대회
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    • pp.104-107
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    • 2009
  • In this paper, we analyze the effect of interference between DTV system and IEEE 802.11n. We set DTV as a victim receiver and IEEE 802.11n as an interfering system. When they exist in the same area, they can make an interference effect. Therefore, we calculate a minimum coupling loss (MCL) and compare the resulting value with a path loss for determining whether there exists a potential interference or not. The minimum separation distance is determined when the path loss is larger than the MCL.

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Spatial Reuse Algorithm Using Interference Graph in Millimeter Wave Beamforming Systems

  • Jo, Ohyun;Yoon, Jungmin
    • ETRI Journal
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    • 제39권2호
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    • pp.255-263
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    • 2017
  • This paper proposes a graph-theatrical approach to optimize spatial reuse by adopting a technique that quantizes the channel information into single bit sub-messages. First, we introduce an interference graph to model the network topology. Based on the interference graph, the computational requirements of the algorithm that computes the optimal spatial reuse factor of each user are reduced to quasilinear time complexity, ideal for practical implementation. We perform a resource allocation procedure that can maximize the efficiency of spatial reuse. The proposed spatial reuse scheme provides advantages in beamforming systems, where in the interference with neighbor nodes can be mitigated by using directional beams. Based on results of system level measurements performed to illustrate the physical interference from practical millimeter wave wireless links, we conclude that the potential of the proposed algorithm is both feasible and promising.

포텐셜 에너지를 이용한 5축 NC 밀링의 공구방향 결정 (Determination of Tool Orientation in 5-Axis Milling Using Potential Energy Method)

  • 조인행;이건우
    • 한국정밀공학회지
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    • 제13권6호
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    • pp.161-167
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    • 1996
  • In five-axis milling, optimal CL-data (cutter location data) should be generated to have advantages over three-axis milling in terms of accuracy and efficiency. This paper presents an algorithm for generating collision-free CL-data for five-axis milling using potential energy method. By virtually charging the cutter and part surfaces with static electricity, global collision as wells as local interference is eliminated. Additionally, machining efficiency is improved by minimizing the curvature difference between the part surface and tool swept surface at a CC-point (cutter contact point) simultaneously.

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Quality of Service Tradeoff in Device to Device Communication Underlaid Cellular Infrastructure

  • Boabang, Francis;Hwang, Won-Joo
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2016년도 춘계학술대회
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    • pp.591-593
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    • 2016
  • Device-to-device (D2D) communications underlaid cellular infrastructure is an competitive local area services technology to promote spectrum usage for next generation cellular networks. These potential can only be tap through efficient interference coordination. Previous works only concentrated on interference from D2D pairs whiles interference from CUs to D2D pairs were neglected. This work focus on solving uplink interference problem emanating from multiple CUs sharing its resource with multiple D2D pairs. The base station (BS) acting as a supervisor selfishly institute a pricing scheme to manage the interference it experience from D2D pairs based on its Quality of service (QoS) requirement. D2D pairs following the supervisor make power allocation decisions considering the price from the BS in a non-cooperative game fashion. In order for the D2D pairs to also meet their QoS requirement, they suggest a price to the BS called discount price which reflects the interference they receive from the CUs. Finally, we analyze the proposed approach.

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