• Title/Summary/Keyword: mitigate

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Interference Mitigation by Joint Employment of Power Control and Almost Blank Subframes in Heterogeneous Networks (이종망 환경에서의 간섭완화를 위한 전력제어와 ABSF의 혼합운용 기법)

  • Kim, Hojin;Jo, Younghoon;Lim, Jaechan;Hong, Daehyoung
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39A no.1
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    • pp.62-64
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    • 2014
  • We propose joint employment of power control and almost blank subframes (ABSF) for femtocells to mitigate the interference of femto-cells to a macrocell in heterogeneous networks. We obtained improved performance in terms of both femtocells capacity and reduced interference by computer simulations while we have marginally decreased overall network capacity compared to possibly maximum capacity.

Mitigation of Transmission Line Magnetic Field by Installation of Passive Shield-Loop. (수동루프 설치에 의한 송전선로 자계 저감)

  • Kim Jeong-Boo;Shin Koo-Yong;Shin Myung Chul
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.55 no.2
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    • pp.59-61
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    • 2006
  • In our country most of transmission lines are double-circuit lines. In these lines, the combining method of increasing conductor height and installation of passive shield-loop to mitigate magnetic field near a transmission line, is a good and feasible method. The basic principle of passive shield loop is that the field from the current induced in the shield loop conductors counteracts the field from the phase conductors. This method applied to domestic transmission lines to meet the magnetic field level, 100, 30, 10 and 4 mG, respectively. In each magnetic field level, the minimum conductor height and passive loop height are presented for the implementation of the practical design.

A Cooperative Game Embedding Transmission Pricing in the Competitive Electricity Market (송전요금을 고려한 게임이론적 전력거래분석)

  • Kang, Dong-Joo;Kim, Bal-Ho
    • Proceedings of the KIEE Conference
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    • 2000.11a
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    • pp.3-5
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    • 2000
  • It has been the paradigm of game theory that more than two utilities compete and determine the price and amount of dispatch. In order for this theory to be available on real power system, it is necessary to consider the transmission costs as well as the generation costs. In addition Independent System Operator(ISO) should be able to mitigate the congestion, recover the transmission costs and provide information for long-term capacity investment by devising reasonable pricing schemes for the transmission services. Generators also have to take the transmission costs into account when building the bidding strategies. This paper proposes an approach to analyzing the profit maximizing game considering the transmission cost in a competitive electricity market.

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Using the Under Voltage Load Shedding for Stability Enhancement of Power Systems Considering Induction Motor Load (유도전동기 부하 고려 시 저전압 부하차단을 이용한 전력계통 안정도 향상 방안)

  • Lee, Yun-Hwan
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.65 no.1
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    • pp.1-6
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    • 2016
  • Recently, proportion of the induction motor load is gradually increased. When a contingency in the power systems, it has been discovered phenomenon that the voltage is delayed recover caused mechanical characteristics of the induction motor load. It can be a serious impact on the voltage stability of the power system considering induction motor load. The scheme to mitigate this phenomenon tripping off the motors to prevent voltage drop and delayed voltage recovery on the load demand side. Fault induced delayed voltage recovery phenomenon is caused by stalling of small induction motor load in transmission level contingencies. In this paper, fault induced delayed voltage recovery phenomenon mitigation method implementation under voltage load shedding on the korean power system considering induction motor load.

Cooperative Opportunistic Beamforming for OCI Mitigation in Correlated Multi-User MISO Cellular System (채널 상관도가 존재하는 다중 사용자 MISO 환경에서 인접 셀 간섭 제거를 위한 협력 기회적 빔포밍 기법)

  • Cho, Hee-Nam;Lee, Jin-Woo;Lee, Yong-Hwan
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.289-290
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    • 2008
  • We consider cooperative opportunistic beamforming that can mitigate the other cell interference (OCI) in correlated multi-user multiple-input single-output (MISO) cellular environments. By only exploiting the spatial channel information of adjacent cells, the proposed scheme generates the cooperative random beam that statistically avoids the OCI from adjacent cells. Each cell selects a user in an opportunistic manner. Thus, the proposed scheme can simultaneously achieve the multi-user diversity (MUD) gain and the OCI avoidance gain.

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Perpendicular Magnetic Recording Channel Equalization Based on Gaussian Sum Approximation of Kalman Filters (Gaussian Sum Approximation을 기반으로 한 Kalman filter의 수직자기 채널 등화기법)

  • Kong, Gyu-Yeol;Cho, Hyun-Min;Choi, Soo-Yong
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.297-298
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    • 2008
  • A new equalization method for perpendicular magnetic recording channels is proposed. The proposed equalizer incorporates the Gaussian sum approximation into a Kalman filtering framework to mitigate inter-symbol interference in perpendicular magnetic recording systems. The proposed equalizer consists of a bank of linear equalizers using the Kalman filtering algorithm and its output is obtained by combining the outputs of linear equalizers through the Gaussian sum approximation.

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Characterization and Improvement of Non-Volatile Dual In-Line Memory Module (NVDIMM의 동작 특성 분석 및 개선 방안 연구)

  • Park, Jaehyun;Lee, Hyung Gyu
    • IEMEK Journal of Embedded Systems and Applications
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    • v.12 no.3
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    • pp.177-184
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    • 2017
  • High performance non-volatile memory system can mitigate the gap between main memory and storage. However, no single memory devices fulfill the requirements. Non-volatile Dual In-line Memory Module (NVDIMM) consisted of DRAMs and NAND Flashes has been proposed to achieve the performance and non-volatility simultaneously. When power outage occurs, data in DRAM is backed up into NAND Flash using a small-size external energy storage such as a supercapacitor. Backup and restore operations of NVDIMM do not cooperate with the operating system in the NVDIMM standard, thus there is room to optimize its operation. This paper analysis the operation of NVDIMM and proposes a method to reduce backup and restore time. Particularly, data compression is introduced to reduce the amount of data that to be backed up and restored. The simulation results show that the proposed method reduces up to 72.6% of backup and restore time.

The Analysis of Indoor Thermal Environment for Air Condition System in Dome Stadium (돔경기장의 공조방식에 따른 겨울철 열환경 분석)

  • Seok, Ho-Tae;Yang, Jeong-Hoon;Chae, Mun-Byoung
    • Journal of Korean Association for Spatial Structures
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    • v.9 no.2
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    • pp.53-63
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    • 2009
  • In this study selected the domestic dome stadium, and analyzed the indoor airflow and temperature distribution application to existing or abroad air condition system in winterabWe examined the appropriateness of flow guiding fans installed to mitigate the high-temperature.

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The position servo-loop in the robot control system must be processed every sampling period by real-time

  • Ha, Young-Youl;Lee, In-Ho;Kim, Min-Soo;Kim, Jae-Hoon
    • 제어로봇시스템학회:학술대회논문집
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    • 2002.10a
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    • pp.121.1-121
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    • 2002
  • Calculation unit and peripheral units that are used to make the position controller are embedded to one chip FPGA. $\textbullet$ Feed-forward PID controller and interpolator in the calculation unit mitigate frequent context switching. $\textbullet$ The peripheral units reduce the size of the joints position control board. $\textbullet$ Because the calculation unit is designed with pipeline structure, it has the advantages to apply to the multi joints.

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Design and implementation of MPEG-4 streaming system with prioritized adaptive transport (우선순위화에 기반한 적응형 전송 기능을 가진 MPEG-4 스트리밍 시스템의 설계 및 구현)

  • 박상훈;장혜영;권영우;김종원;유웅식;권오형
    • Proceedings of the IEEK Conference
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    • 2003.11a
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    • pp.95-98
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    • 2003
  • To provide high-quality media streaming service over the best-effort Internet, an efficient streaming system with a network-adaptive transport is essential. By adopting FEC-based adaptive transport and by matching it to the priority of media packets, in this paper, an enhanced MPEG-4 streaming system is implemented. The implemented adaptive transport can complement the existing MPEG-4 streaming server with components such as elementary stream provider, sync layer and DMIF layer. Sync layer packets of each MPEG-4 elementary stream are prioritized and then selectively dropped at the sender to match the currently available bandwidth. Also, with the proposed adaptive transport module, the level of FEC protection is dynamically adjusted based on the underlying network condition. With preliminary verification over the emulated network testbed, it is shown that the proposed implementation can mitigate the impact of network fluctuation and thus improve the quality of streaming.

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