• Title/Summary/Keyword: power delivery

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An effective Supplier Selection Model for e-Business & ISO 9001 System (e-Business 환경 하에서 ISO 9001 품질경영시스템의 효율적인 공급자 선정모델)

  • 이무성;이영해
    • Journal of Korean Society for Quality Management
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    • v.30 no.4
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    • pp.15-25
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    • 2002
  • This paper considers supplier selection process for e-business & ISO 9001 quality management system environments. Determining suitable suppliers in the electronic commerce has become a key strategic consideration. However, the nature of these decisions is usually complex and unstructured. In this paper, a Quality Estimated Supplier Selection (QESS) model is proposed to deal with the supplier selection problems in the e-business(Business to Business: B to B). In the supplier selection, quality management factors will be considered for the first time, and then price, and delivery etc. In the first level, we deal with the quality management factors such as quality management audit, product test, engineering man-power, capability index and training time etc., based on the five point scale. In the second level, a QESS model determines the final solution by considering factors such as price, production lead-time and delivery time.

Reliability Assessment Considering Load Characteristics in Distribution Systems (배전계통에서 부하특성을 고려한 신뢰도평가에 관한 연구)

  • Park, Hyeon-Seok;Rho, Dae-Seok
    • Proceedings of the KAIS Fall Conference
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    • 2008.05a
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    • pp.87-90
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    • 2008
  • This paper deals with the analytical approach for the reliability assessment in radially operated distribution systems. The approach can estimate the expected reliability performance of distribution systems by a direct assessment of the configuration of the systems using the reliability indexes such as NDP(Non-Delivery Power) and NDE(Non-Delivery Energy). The indexes can consider the number and configuration of the load, but can not consider the characteristics of the load which is the one of the most important factor in the investment cost for the distribution systems. Therefore, This paper presents the new indexes considering the expected interruption cost for the load section and shows the effectiveness by simulating at the model systems.

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A Comparative Study and Analysis of LoRaWAN Performance in NS3

  • Arshad Farhad;Jae-Young Pyun
    • Smart Media Journal
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    • v.13 no.1
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    • pp.45-51
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    • 2024
  • Long Range Wide Area Network (LoRaWAN) is a widely adopted Internet of Things (IoT) protocol due to its high range and lower energy consumption. LoRaWAN utilizes Adaptive Data Rate (ADR) for efficient resource (e.g., spreading factor and transmission power) management. The ADR manages these two resource parameters on the network server side and end device side. This paper focuses on analyzing the ADR and Gaussian ADR performance of LoRaWAN. We have performed NS3 simulation under a static scenario by varying the antenna height. The simulation results showed that antenna height has a significant impact on the packet delivery ratio. Higher antenna height (e.g., 50 m) has shown an improved packet success ratio when compared with lower antenna height (e.g., 10 m) in static and mobility scenarios. Based on the results, it is suggested to use the antenna at higher allevation for successful packet delivery.

Feasible approach of contactless power transfer technology combined with HTS coils based on electromagnetic resonance coupling

  • Chung, Yoon Do;Yim, Seong Woo;Hwang, Si Dole
    • Progress in Superconductivity and Cryogenics
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    • v.15 no.1
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    • pp.40-44
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    • 2013
  • The contactless power transfer (CPT) systems have been recently gaining popularity widely since it is an available option to realize the power delivery and storage with connector-free devices across a large air gap. Especially, the CPT with electromagnetic resonance coupling method is possible to exchange energy within 2 m efficiently. However, the power transfer efficiency of CPT in commercialized products has been limited because the impedance matching of coupled coils is sensitive. As a reasonable approach, we combined the CPT system with HTS wire technology and called as, superconducting contactless power transfer (SUCPT) system. Since the superconducting coils have an enough current density, the superconducting antenna and receiver coils at CPT system have a merit to deliver and receive a mass amount of electric energy. In this paper, we present the feasibility of the SUCPT system and examine the transmission properties of SUCPT phenomenon between room temperature and very low temperature at 77 K as long as the receiver is within 1.0 m distance.

A Study on the Power Factor Correction and Harmonics Reduction of Capacitor Banks installed at Customers (수용가에 설치된 캐패시터 뱅크의 역률개선 및 고조파 저감에 관한 연구)

  • Kim, Kyung-Chul;Choi, Hyoung-Bumb
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.8
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    • pp.12-17
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    • 2008
  • Most power system loads and delivery apparatus are inductive in nature and therefore operate at a lagging power factor. Applying capacitor banks to a customer will result in a power factor correction and other benefits such as VAR support, increased voltage, reduced power losses, and reduced billing charges. Also there can be power quality problems as a result of adding capacitor banks. The most common are harmonics. This paper provides an in depth analysis on the power factor correction and harmonics reduction of capacitor bank installed at a customer. The EDSA program was used as a simulation tool for the case study.

A study on the Controller Development Depending Load Variation of a Diesel Generator for Power System Connection of Distributed-source (분산전원의 계통연계를 위한 디젤발전기의 부하변동에 따른 제어기 개발연구)

  • Han, Sang-Seok;Han, Hoo-Sek;Lee, Chang-Goo
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.5
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    • pp.53-57
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    • 2008
  • Diesel generator is most widely used for supplying of emergency electrical power. There have been extensive research efforts to develop ways to Ensure stable electrical power delivery to the loads using hybrid power sutures, such as power source, storage batteries, fuel cells and solar cells. Furthermore, as the role of these diesel generators for emergency electrical power supply has recently become very important, they should assure high reliability and flexibility according to the operation load. Therefore, in this paper, we introduce a controller to be used in diesel generator toenable tracking control of maximum power according to the load variation and suppressing high-order harmonics while maintaining stable frequency.

The Kinematic Difference According to Success and Failure of Shot-Putting - Focusing on Member of the National Team, Hwang, In-sung, Player - (남자 포환던지기 시 성공과 실패에 따른 운동학적 차이 - 국가대표 황인성 선수를 중심으로 -)

  • Ryu, Ji-Seon;Park, Jae-Myoung;Kim, Tae-Sam
    • Korean Journal of Applied Biomechanics
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    • v.21 no.2
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    • pp.161-171
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    • 2011
  • The purpose of this study was to identify biomechanical characteristics of glide and delivery motion of In-Sung Hwang, player who is a member of the national team among the finalists in the men's shot put at the 2010 National Sports Festivals. Three-Dimensional motion analysis using a system of 3 video cameras at a sampling frequency of 60 Hz was performed for this study. During the glide and delivery phase the results showed following characteristics; 1) The glide type was suitable for the short-long technique, but the trajectory of shot at the glide and delivery phase showed a different trajectory pattern with "S-shaped" type of elite players due to many deviating from central axis of the APSS(athletic-plus shot system). 2) Left knee was more flexed during failed trials compared to successful trials but COG was higher. Therefore, the player showed less stability of COG as he may not get enough breaking force at the left foot. 3) Furthermore, it would be required to have strong muscle power at the trunk, throwing arm, and the lower extremity in order to achieve maintain a low projection angle of the release.

Laser Induced Microjet Drug Delivery System: Drug Permeation Depending on Laser Wavelength and Pulse Duration (레이저 유도 마이크로젯을 활용한 약물 전달 방식: 레이저 파장 및 펄스길이에 따른 약물 침투 분석)

  • Jang, Hun jae;Ham, Hwi chan;Yoh, Jai ick
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.41 no.7
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    • pp.463-468
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    • 2017
  • For transdermal drug delivery, needless injection system is composed of laser and microjet injector. Main mechanism of microjet injector is the laser-induced bubble. Nd:YAG and Er:YAG laser are used as a power source. Laser parameters such as pulse duration and wavelength are considered, which are core parameters to control the bubble motion. The Nd:YAG laser, pulse duration is short than bubble life time making cavitation like bubble while in Er:YAG laser, long pulse duration and high absorption in water drive bubble as a boiling bubble. Detailed motion of bubble and microjet is captured by the high speed camera. So it is observed that microjet characteristics are determined by the bubble behavior. The performance of drug delivery system is evaluated by fluorescent staining of guinea pig skin.

An Efficient Load Balancing Policy in P2P Contents Delivery System for Cyber Education (사이버 교육을 위한 P2P 기반 콘텐츠 전송시스템에서 효율적인 부하 분산 정책)

  • Kim, Jin-Il;Hwang, Yoon-Cheol
    • Journal of the Korea Society of Computer and Information
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    • v.12 no.6
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    • pp.31-39
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    • 2007
  • To perform on-line cyber education, it is indispensable to delivery contents file to participant users. When users' requests occur simultaneously in a shot period, server falls into overload phase. A common to avoid overload is a software solution based on P2P, which does no cost any additional expense. But, in this solution, it yields many problems such as service delay and system failure because of peer self-control. In this paper we propose an efficient load balancing policy based on P2P system. which is the contents delivery system for cyber education system using idle computing power in the proposed solution, we present server selection scheme called P2P-Pattern method, which results in minimum service delay. we can see that our scheme outperforms previous scheme.

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Design of Power Transmission System of a Water Bike (수상 자전거의 동력전달장치 설계)

  • Choi, Jung-Kyu;Kim, Hyoung-Tae
    • Journal of the Society of Naval Architects of Korea
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    • v.50 no.3
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    • pp.153-159
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    • 2013
  • The power transmission system has always been considered critical for a human powered boat(or water bike) since it first showed up at Human Powered Vessel Festival. Mechanical problems, such as abrasions and other damages of the gear system for the power transmission, lead to poor durability and low efficiency of a boat. This paper described mechanical problems and a design process of power transmission system and then suggested the method to solve the problems. It is selected a module and a type of gears that are structurally stable thus can transmit the power durable. Especially the lower gear box is applied to CRP(contra rotating propeller) system for improving the structural stability and the propeller efficiency as well. As the results, the upper and lower gear box are designed and manufactured. And from the trial test, it is confirmed that the power transmission system is reliable.