• Title/Summary/Keyword: Power Management Techniques

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A Study For Improvement of Due Date Rate by Supplementing Defects of MRP Using DBR (DBR을 이용한 MRP 단점 보완에 따른 납기 준수율 향상에 관한 연구)

  • 조중현;양광모;강경식
    • Proceedings of the Safety Management and Science Conference
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    • 2004.05a
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    • pp.299-302
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    • 2004
  • Today, several manufacture enterprises are endeavoring constantly to receive order winners of subsidiary company product. There are tendencies to occupy competitive advantage in high position in price competition and in quality etc. But, it is not easy to keep it even if price has been cheap recently. Also, it is hard to be competitive advantage element more, because production smoothing was made much even if there is in quality. To keep or improve present competitive power, the due date rate is becoming importance. Several techniques with MRP, MRP II appeared in the 1970s by method to improve the these due date rate. These techniques have some defects to due date. Therefore, in this paper, MRP wishes to receive the due date rate that is improved more by supplementing having these defect by DBR of TOC.

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Corrosion Monitoring for Offshore Wind Farm's Substructures by using Electrochemical Noise Sensors

  • Soh, Joon-Young;Lee, Min-Woo;Kim, Su-Kyung;Kim, Do Hyung
    • KEPCO Journal on Electric Power and Energy
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    • v.2 no.4
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    • pp.615-618
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    • 2016
  • Electrochemical noise(EN) has been used to analyze the deterioration of coating films of offshore wind substructures. In this study, prototype sensors using EN have been developed to detect the corrosion rate. To verify the reliability of sensors, experiments were conducted both in the laboratory and offshore using probe and standard samples. New analysis and data processing techniques show that the sensor can provide useful information about the corrosion rate.

The Application of Preventative and Diagnostic System for 765kV Substation (변전기기 예방진단 시스템의 적용 - 765kV 변전소 예방진단 시스템)

  • Hweon, D.J.;Choi, I.H.;Yoo, Y.P.;Jung, S.H.;Choi, Y.J.;Choi, D.H.;Kim, K.K.
    • Proceedings of the KIEE Conference
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    • 2000.07c
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    • pp.1885-1887
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    • 2000
  • In this paper we introduce preventative and diagnostic systems developed to prevent substations from accidental fault of electric power transmitting apparatus. We propose monitoring and diagnostic system for ultra high voltage GIS and main transformer of 765kV substations as an example of preventative and diagnostic techniques being applied in Korea. We also present a guideline to construct and manage an expert system for this purpose. Finally, an engineering solution as a substation management support system is proposed.

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Application of Adaptive Neuro-Fuzzy Inference System for Interference Management in Heterogeneous Network

  • Palanisamy, Padmaloshani;Sivaraj, Nirmala
    • ETRI Journal
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    • v.40 no.3
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    • pp.318-329
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    • 2018
  • Femtocell (FC) technology envisaged as a cost-effective approach to attain better indoor coverage of mobile voice and data service. Deployment of FCs over macrocell forms a heterogeneous network. In urban areas, the key factor limits the successful deployment of FCs is inter-cell interference (ICI), which severely affects the performance of victim users. Autonomous FC transmission power setting is one straightforward way for coordinating ICI in the downlink. Application of intelligent control using soft computing techniques has not yet explored well for wireless networks. In this work, autonomous FC transmission power setting strategy using Adaptive Neuro Fuzzy Inference System is proposed. The main advantage of the proposed method is zero signaling overhead, reduced computational complexity and bare minimum delay in performing power setting of FC base station because only the periodic channel measurement reports fed back by the user equipment are needed. System level simulation results validate the effectiveness of the proposed method by providing much better throughput, even under high interference activation scenario and cell edge users can be prevented from going outage.

A Study on the Security Management for Critical Key Infrastructure(SCADA) (중요핵심기반시설(SCADA)에 대한 보안 관리 연구)

  • Kim InJung;Chung YoonJung;Koh JaeYoung;Won Dongho
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.8C
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    • pp.838-848
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    • 2005
  • Most of the national critical key infrastructure, such as power, piped gas and water supply facilities, or the high-speed railroad, is run on the SCADA system. Recently, concerns have been raised about the possibility of these facilities being attacked by cyber terrorists, hacking, or viruses. Thus, it is time to adopt the relevant security management techniques. This paper attempts to propose such security management techniques, including information protection measures and troubleshooting, based on a risk analysis process concerning assets, threats/vulnerability, and hazards, and to examine the security management status of critical key infrastructure in the U.S. and Japan.

MODEL FOR DESIGN MANAGEMENT IN COLLABORATIVE ENVIRONMENT USING DESIGN STRUCTURE MATRIX AND DESIGN PARAMETERS' INFORMATION

  • Salman Akram;Jeonghwan Kim;Jongwon Seo
    • International conference on construction engineering and project management
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    • 2009.05a
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    • pp.1307-1312
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    • 2009
  • Design is an act based on multidisciplinary information. The involvement of various stakeholders makes it difficult to process, plan, and integrate. Iteration is frequent in most of the engineering design and development projects including construction. Design iterations cause rework, and extra efforts are required to get the optimal sequence and to manage the projects. The simple project management techniques are insufficient to fulfill the requirements of integrated design. This paper entails two things: design structure matrix and design parameters' information based model. The emphasis has been given to optimal sequence and crucial iteration using design structure matrix analysis technique. The design projects have been studied using survey data from industry. The optimal sequence and crucial iterations results have been utilized for proposed model. Model integrates two things: information about produced- required key design parameters and information of design changes during the design process. It will help to get familiar with Design management in order to fulfill contemporary needs.

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Leakage Energy Management Techniques via Shared L2 Cache Partitioning (캐시 파티션을 이용한 공유 2차 캐시 누설 에너지 관리 기법)

  • Kang, Hee-Joon;Kim, Hyun-Hee;Kim, Ji-Hong
    • Journal of KIISE:Computer Systems and Theory
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    • v.37 no.1
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    • pp.43-54
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    • 2010
  • The existing timeout based cache leakage management techniques reduce the leakage energy consumption of the cache significantly by switching off the power supply to the inactive cache line. Since these techniques were mainly proposed for single-processor systems, their efficiency is reduced significantly in multiprocessor systems with a shared L2 cache because of the cache interferences among simultaneously executing tasks. In this paper, we propose a novel cache partition strategy which partitions the shared L2 cache considering the inactive cycles of the cache line. Furthermore, we propose the adaptive task-aware timeout management technique which considers the characteristics of each task and adapts the timeout dynamically. Experimental results from the simulation show that the proposed technique reduces the leakage energy consumption of the shared L2 cache by 73% for the 2-way CMP and 56% for the 4-way CMP on average compared to the existing representative leakage management technique, respectively.

UbiFOS: A Small Real-Time Operating System for Embedded Systems

  • Ahn, Hee-Joong;Cho, Moon-Haeng;Jung, Myoung-Jo;Kim, Yong-Hee;Kim, Joo-Man;Lee, Cheol-Hoon
    • ETRI Journal
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    • v.29 no.3
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    • pp.259-269
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    • 2007
  • The ubiquitous flexible operating system (UbiFOS) is a real-time operating system designed for cost-conscious, low-power, small to medium-sized embedded systems such as cellular phones, MP3 players, and wearable computers. It offers efficient real-time operating system services like multi-task scheduling, memory management, inter-task communication and synchronization, and timers while keeping the kernel size to just a few to tens of kilobytes. For flexibility, UbiFOS uses various task scheduling policies such as cyclic time-slice (round-robin), priority-based preemption with round-robin, priority-based preemptive, and bitmap. When there are less than 64 tasks, bitmap scheduling is the best policy. The scheduling overhead is under 9 ${\mu}s$ on the ARM926EJ processor. UbiFOS also provides the flexibility for user to select from several inter-task communication techniques according to their applications. We ported UbiFOS on the ARM9-based DVD player (20 kB), the Calm16-based MP3 player (under 7 kB), and the ATmega128-based ubiquitous sensor node (under 6 kB). Also, we adopted the dynamic power management (DPM) scheme. Comparative experimental results show that UbiFOS could save energy up to 30% using DPM.

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Dynamic Power Management for Webpage Loading on Mobile Devices (모바일 웹 페이지 로딩에서 동적 관리 기법)

  • Park, Hyunjae;Choi, Youngjune
    • Journal of KIISE
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    • v.42 no.12
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    • pp.1623-1628
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    • 2015
  • As the performance of mobile devices has increased, high-end multicore CPUs have become the norm in smartphones. However, such high performance devices are exposed to the problem of battery depletion due to the energy consumption caused by software performance, and despite increases in battery capacity. The required resources are dynamic and varied, and further user interaction is highly random; thus, Linux-based power management such as DVFS is needed to fulfill requirements. In order to reduce power consumption, we propose a method to restrict the CPU frequency of data download while maintaining user reactivity. This can supplement the weakness of existing Linux-based power management techniques like DVFS in relation to webpage loading. Through the implementation of our method at the application level, we confirm that energy consumption from webpage loading is reduced.

Preparation of Reliable Measurement Data by Using State Estimation (상태추정을 이용한 고 신뢰도 측정데이터 확보방안 연구)

  • Kim, Hong-Rae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.8 no.5
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    • pp.1020-1025
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    • 2007
  • EMS(energy management system) and SCADA(supervisory control and data acquisition) systems are used for reliable and efficient operation of electrical power systems. Various functions in EMS such as power flow, contingency analysis, security analysis essentially need accurate data set for reliable operation. State estimation can be a tool for providing these data. In this paper, programs for observability analysis and bad data processing are developed. Fundamental algorithms are introduced and validity of the proposed techniques is inspected with test cases.

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