• Title/Summary/Keyword: reliability gain

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A New Current Sharing Strategy of SRM Using Parallel Winding Method (병렬권선 방식에 의한 SRM의 부하전류분담)

  • 박성준;이동희;안진우;안영주
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.52 no.4
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    • pp.154-154
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    • 2003
  • The switched reluctance motor(SRM) has a considerable potential for industrial applications because of its high reliability as a result of the absence of rotor windings. In some applications with SRM, a parallel switching strategy is often used for cost saving, increasing of current capacity and system reliability. This paper proposes a new parallel switching strategy of SRM using parallel winding. While conventional parallel switching devices are connected in a phase winding, power devices are connected in the parallel windings wound in each pole of stator in the proposed method. Paralleling strategy for current sharing in the proposed method can be easily determined without considerations of any nonlinear characteristics of power devices such as conduction resistance, threshold voltage and gain factor. The proposed paralleling strategy is verified by the mathematical analysis and experimental results.

Effects of error terms on shear strength in BGA (BGA의 전단강도에 대한 오차 인자의 영향)

  • 구자명;정승부
    • Proceedings of the KWS Conference
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    • 2001.05a
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    • pp.283-284
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    • 2001
  • Shear test is the methode to be able to measure bondability easily. But, many papers shows their shear strength data without shear speed and force. So, It's hard to hold in common and to gain reliability. This paper shows how to change shear strength on some different conditions. Also, you are able to know the best condition of shear test.

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The Analysis of Performance for W-CDMA System using Channel Coding & Space-Time Code in Wideband Multipath Channel. (광대역 다중 경로 채널에서 채널 코딩과 시공간 부호를 적용한 W-CDMA의 성능분석)

  • 박정현;김정미;정호섭;김철성
    • Proceedings of the IEEK Conference
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    • 2003.11c
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    • pp.277-280
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    • 2003
  • In this paper, we analyze the performance of transmitter and receiver of W-CDMA system using the channel coding and space time code in downlink over ITU-R realistic channel model. We can improve the reliability of communications and increase the data rate by channel coding, and we can get a diversity gain by using the space time code over fading channels. We also apply the RAKE receiver to improve tile performance in multi-Path fading channel environment.

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A Design of Signal Processing Analog Front-End IC for Automotive Piezo-Resistive Type Pressure Sensor (Automotive Piezo-Resistive Type Pressure Sensor 신호 처리 아날로그 전단부 IC 설계)

  • Cho, Sunghun;Lee, Dongsoo;Choi, Jinwook;Choi, Seungwon;Park, Sanghyun;Lee, Juri;Lee, Kang-Yoon
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.8
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    • pp.38-48
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    • 2014
  • In this paper, a design of Signal Processing Analog Front-End IC for Automotive Piezo-Resistive Type Pressure Sensor is presented. In modern society, as the car turns to go from mechanical to electronic technology, the accuracy and reliability of electronic parts required importantly. In order to improve these points, Programmable Gain Amplifier (PGA) amplifies the received signal in accordance with gain for increasing the accuracy after PRT Sensor is operated to change physical pressure signals to electrical signals. The signal amplified from PGA is processed by Digital blocks like ADC, CMC and DAC. After going through this process, it is possible to determine the electrical signal to physical pressure signal. As processing analog signal to digital signal, reliability and accuracy in Analog Front-End IC is increased. The current consumption of IC is 5.32mA. The die area of the fabricated IC is $1.94mm{\times}1.94mm$.

Concatenated Diversity System for Bandwidth Efficient Communication of Flight Type Air Node in Unstable Channel Environments (비정형 통신 채널 환경에서 비행형 에어노드의 대역 효율적인 통신을 위한 연접 다이버시티 시스템)

  • Kang, Chul-Gyu;Park, Jin-Hee;Oh, Chang-Heon
    • Journal of Advanced Navigation Technology
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    • v.16 no.2
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    • pp.247-254
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    • 2012
  • In this paper, we propose a concatenated diversity system to assure the data transmission reliability between flight type air nodes which move according to their atypical orbit, then its performance is analyzed using computer simulation and it is designed with hdl. The proposed system cannot only improve a bandwidth efficient and coding gain from diversity TCM code but also the reliability of data transmission is high. From the computer simulation result about bit error rate(BER) of the proposed system, we confirm that its BER performance is about 11dB greater than TCM code at $10^{-2}$ and about 11dB greater than space time block code at $10^{-3}$ which has a full diversity gain. In addition, when we compare its BER performance with space time trellis code which has both a diversity gain and a coding gain, the performance of the proposed system is greater than about 1.5dB at $10^{-5}$. Lastly, after designing the proposed system with HDL, we can confirm that the operation result is correct.

Experimental and analytical studies on stochastic seismic response control of structures with MR dampers

  • Mei, Zhen;Peng, Yongbo;Li, Jie
    • Earthquakes and Structures
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    • v.5 no.4
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    • pp.395-416
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    • 2013
  • The magneto-rheological (MR) damper contributes to the new technology of structural vibration control. Its developments and applications have been paid significant attentions in earthquake engineering in recent years. Due to the shortages, however, inherent in deterministic control schemes where only several observed seismic accelerations are used as the trivial input and in classical stochastic optimal control theory with assumption of white noise process, the derived control policy cannot effectively accommodate the performance of randomly base-excited engineering structures. In this paper, the experimental and analytical studies on stochastic seismic response control of structures with specifically designed MR dampers are carried out. The random ground motion, as the base excitation posing upon the shaking table and the design load used for structural control system, is represented by the physically based stochastic ground motion model. Stochastic response analysis and reliability assessment of the tested structure are performed using the probability density evolution method and the theory of extreme value distribution. It is shown that the seismic response of the controlled structure with MR dampers gain a significant reduction compared with that of the uncontrolled structure, and the structural reliability is obviously strengthened as well.

Specification Technique of EJB-Based Application using Design by Contracts Approach (DbC 접근법을 이용한 EJB 기반 애플리케이션의 명세 기법)

  • 노혜민;유철중
    • Journal of KIISE:Software and Applications
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    • v.29 no.12
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    • pp.895-906
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    • 2002
  • Due to increased concern about the distributed web application, the interest in EJB - server-side Java component architecture that enables to make out Business Logic without writing codes related to complicated distributed framework - is also increasing. Despite of these increased interest, However, efforts for reliability of these systems have been insufficient. Thus, in this paper, we propose specification technique for applying DbC approach, which can elevate the reliability of software in the Object-Oriented system development, in writing formal specification of EJB-based application. Through this specification technique, developers can gain reliability in the EJB-based application development.

The Application of a Microwave Sensor for Traffic Signal Control on Urban Arterial (도시간선도로상에서 교통신호제어를 위한 초단파 검지기(RTMS)의 적용성에 관한 연구)

  • 오영태;오영태
    • Journal of Korean Society of Transportation
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    • v.13 no.4
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    • pp.133-151
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    • 1995
  • The collective of highly reliable traffic data is necessary for traffic signal control. This study is to test application of RTMS sensor to traffic signal control. In order to find out the possibility of its application th traffic signal control, 5 types of experiments were performed. The major findings are as follows ; -The detection are a has been changing according to degree and gain. -At the results of experiments for interference are a measure, Degree 60 is stable condition. -At the results of reliability test for volume and speed. the error rate decreases as speed increases and that of Zone 1 is lower than that of Zone 3. -Two modes are set up for reliability test of traffic volume. It founds that the detection reliability of the stopped vehicles are higher than that of the passing vehicles at sidefire-intersection mode. It founds that the results are vice-versa at sidefire-highway mode. Conclusively, this sensor cannot directly apply to colection of traffic data for traffic signal control. However, this sensor can be substituted for a loop detector which is used popularly for signal control, and freeway traffic control if above faults are made up.

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Study of Standardization and Test Certification for Wearable Smart Devices (웨어러블 스마트기기의 표준화 및 시험인증 연구)

  • Han, Tae-Su;Kim, Deok-kee;Kwon, Oh-Young;Choa, Sung-Hoon
    • Journal of the Microelectronics and Packaging Society
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    • v.23 no.4
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    • pp.11-18
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    • 2016
  • Today, wearable technology products are used in a wide range of consumer, healthcare, bio-medical, and industrial applications. The market for wearable technology products is expected to increase dramatically over the next several years. In addition, concerns for safety, performance and reliability of wearable products keep increasing and will be essential for widespread acceptance in the marketplace. Wearable smart devices, which are generally in contact with the human body and skin, are exposed to the risk of the electric shock, burn, and explosion. Therefore, the standardization of wearable devices in terms of human safety and reliability should be very important. Furthermore, the development of test method and test certification of the wearable products will be one of the key technology for mass production. Such standardization and certification will help consumers to choose the safest and best quality wearable devices and allow manufacturers to prove the safety and quality of their products, thereby helping them to gain a competitive technology. This paper discusses the current status of the wearable smart devices as well as the standardization and test certification applicable to wearable technology products.

The Impacts of Service Quality of Local Food stores on Customer Satisfaction and Revisit Intention (로컬푸드 매장의 서비스품질이 고객만족과 재방문의도에 미치는 영향)

  • Han, Jin;Han, Sang-Hyuk;Jang, Dong-Heon
    • Journal of Korean Society of Rural Planning
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    • v.22 no.1
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    • pp.81-91
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    • 2016
  • This study identified the impact of the service quality of local food stores on customer satisfaction and revisiting intention of the customers as the interest into local foods is increasing. The main outcomes are as follows: First, many of the respondents said that they use the local food stores based on the trust in the origin of the products and good quality. Second, reliability and validity were suitable for factor analysis and the correlation had a positive (+) directivity. Third, reliability, assurance, empathy and tangibles were analyzed to have a positive (+) impact among the 5 aspects of service quality except for responsiveness. Fourth, customer satisfaction had a positive (+) impact on the intention to revisit the local food stores, and reliability, assurance and empathy had a positive (+) impact on revisiting intention at the statistical significance level except for responsiveness and tangibles among the 5 service quality aspects. Therefore, it is thought to be required to keep having interests into service quality to gain a competitive edge as a sustainable management system since the service quality of local food stores has impacts on customer satisfaction and intention to revisit.