• Title/Summary/Keyword: Instrument failure

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A Study on Dynamic Characteristics of EFPCD for Electrical Fire Prevention (전기화재 예방을 위한 EFPCD동작 특성에 관한 연구)

  • 이상호;오홍석
    • Fire Science and Engineering
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    • v.16 no.3
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    • pp.8-11
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    • 2002
  • Recently, the spark and the overheat due to in the failure of pressure contacts on connecting points and the momentary short circuit have been the major causes of electrical fire because these may cause the deposition and the graphite of insulating materials in electrical wiring system. Also, because in these cases the current is a surge one, the losses and faults of a communication, a home appliances, a computer and a measuring instrument may occur. Especially, in such cases, we are very difficult to detect the failure of pressure contacts on connecting points and the momentary short circuit. In this paper, we have developed an auxiliary control device, the electrical fire prevention control device(EFPCD), of an earth leakage breaker(ELB). And we can pre-vent the electrical fire caused by the spark and the overheat occurring in the failure of pressure contacts in connecting points and the momentary short circuit with the EFPCD.

Multiple Spinal Revision Surgery in a Patient with Parkinson's Disease

  • Malla, Hridayesh Pratap;Kim, Min Ki;Kim, Tae Sung;Jo, Dae Jean
    • Journal of Korean Neurosurgical Society
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    • v.59 no.6
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    • pp.655-658
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    • 2016
  • Parkinson's disease (PD) patients frequently have several spinal deformities leading to postural instabilities including camptocormia, myopathy-induced postural deformity, Pisa syndrome, and progressive degeneration, all of which adversely affect daily life activities. To improve these postural deformities and relieve the related neurologic symptoms, patients often undergo spinal instrumentation surgery. Due to progressive degenerative changes related to PD itself and other complicating factors, patients and surgeons are faced with instrument failure-related complications, which can ultimately result in multiple revision surgeries yielding various postoperative complications and morbidities. Here, we report a representative case of a 70-year-old PD patient with flat back syndrome who had undergone several revision surgeries, including anterior and posterior decompression and fusion for a lumbosacral spinal deformity. The patient ultimately benefitted from a relatively short segment fixation and corrective fusion surgery.

Parity Space and Pattern Recognition Approach for Hardware Redundant System Signal Validation using Artificial Neural Networks (인공신경망을 이용하여 하드웨어 다중 센서 신호 검증을 위한 패리티 공간 및 패턴인식 방법)

  • 윤태섭
    • Journal of Institute of Control, Robotics and Systems
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    • v.4 no.6
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    • pp.765-771
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    • 1998
  • An artificial neural network(NN) technique is developed for hardware redundant sensor validation. Since the measurement space is a continuous space with many operating regions, it is difficult to train a NN to correctly detect failure in an accurate measurement system. A conventional backpropagation NN is modified to include an additional preprocessing layer that extracts classification features from scalar measurements. This feature extraction means transform the measurement space to parity space. The NN is independent of the state variable being measured, the instrument range, and the signal tolerance. This NN resembles the parity space approach to signal validation, except that analytical parity equations are unneeded and the NN pattern recognition capability is utilized for decision making.

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Correcting Environmental Market Failures through Environmental Fiscal Reforms in China

  • Zhong, Ma;Jian, Wu
    • Environmental and Resource Economics Review
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    • v.16 no.3
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    • pp.607-627
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    • 2007
  • By reviewing the current application of Environmental Fiscal Instruments in China, existing policy gaps and weakness, and the feasibility of using EFIs in China, this paper pointed out that the Chinese government faces an historic opportunity for promoting the development of a comprehensive environmental fiscal system. It is proposed that as far as possible the real economic and social costs of pollution and environmental degradation should be reflected in the prices charged for the use of environmental and natural resources. Chinese government should systematize existing environmental fiscal funds and policies, gradually setting up a framework for integrating environmental fiscal instruments into the public financial system.

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A Study of User Satisfaction of Contract Foodservice Information Systems (위탁급식업체 정보시스템 사용자 만족도에 관한 연구)

  • 최성경
    • The Korean Journal of Food And Nutrition
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    • v.15 no.3
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    • pp.250-256
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    • 2002
  • User satisfaction is the most critical criteria in measuring information systems success or failure. In this study, Contract Foodservice Information Systems were evaluated with user satisfaction instrument based on previous work. A total of 70 Contract Foodservice Information Systems users was surveyed. The status of building area of Contract Foodservice Information Systems was more in foodservice management (M=3.74), but less in producing (M=2.53) and pruchasing (M=3.02) management. The users recognized .accuracy of information (M=4.27), lasting educational services on systems (M=4.34) and increasing work productivity (M=4.42) as the most important factors and they also recognized it was important factors to build systems such area database management, menu management, purchasing and producing management and foodservice management (p<.01.).

Bridging the Digital Divide : The Case of Nepal Wireless

  • Pun, Mahabir
    • Journal of Information Technology Applications and Management
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    • v.20 no.3
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    • pp.105-127
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    • 2013
  • Information and Communication Technology (ICT) has become a vital instrument for delivering a number of services such as education, healthcare and public services. Community wireless networks are community-centric telecommunication infrastructure developed to provide affordable communication for those who live in remote areas. This chapter discusses the role of Nepal Wireless in achieving socio economic development of rural communities by facilitating affordable Internet access. We analyze the challenges Nepal Wireless faced and articulate on the approaches it took to address those challenges such as lack of technical skills, appropriate technology and funding, difficult geographical terrains, unstable political situation, and expensive devices. In addition, we address the success and failure factors of this community-based ICT4D approach in order to guide similar endeavors. We conclude the chapter by some suggestions for policy makers, community developers, and academicians.

A Study on the Algebraic Analysis of FDI(failure detection and isolation) in Bilinear System (쌍일차계에 대한 FDI(고장검출 및 분리)의 대수적인 해석에 관한 연구)

  • In, Don-Gi;Cho, Young-Ho;Oh, Min-Hwan;Kim, Jae-Il;Chae, Young-Mu;Ahn, Doo-Soo
    • Proceedings of the KIEE Conference
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    • 2000.07d
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    • pp.2627-2629
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    • 2000
  • This paper introduces the design of a reduced order observer with unknown inputs for the purpose of fault detection and isolation(FDI) in a class of bilinear systems. To Analyze the observer and FDI, this paper uses BPF(block-pulse functions). The operational properties of BPF are much applied to the analysis of bilinear systems. The integral operational matrix BPF converts the form of the differential equation into the algebraic problems.

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Comparison to Automobile Pilot Lamp by Accelerated Life Test (가속수명시험을 통한 자동차용 파일럿램프의 비교평가)

  • Shin, Min-Gyung;Wei, Shin-Hwan;Kim, Hyung-Min
    • Journal of Applied Reliability
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    • v.8 no.2
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    • pp.75-85
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    • 2008
  • In this paper, we compared domestic with foreign pilot lamps installed on the instrument board or electronic modules (car audio, air-conditional system, etc.) of an automotive vehicle by an accelerated life test in order to estimate the life of domestic pilot lamps. An accelerated life test method was developed and the relation of the life and voltage stress was analyzed. The main results are as follows; i) $B_{10}$ life of pilot lamp is above 5,000 hours, vehicle travel time for 10 years. ii) the life of domestic pilot lamp is longer than that of foreign thing. iii) the life distribution of domestic pilot lamp is wider than that of foreign thing. iv) it is possible to promote import replacement of automobile pilot lamp.

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RESEARCH ON CURRENT STATUS AND IMPROVEMENT METHOD FOR KOREAN NAME BRAND APARTMENT

  • Kyungsook Kim;Moojoong Kim;Jaehak Jo;Jaejun Kim
    • International conference on construction engineering and project management
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    • 2005.10a
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    • pp.1083-1088
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    • 2005
  • Current brand strategies applied for name brand apartments seem to have no product differentiation but merely function as a convenient instrument for product image change through naming only. Since proliferating brand names don't have much relevance to their brand concepts at present, long-range brand strategies are definitely needed. We'll inquire, first, the success and failure cases in the brand strategies of other industry. Next, through questionnaire survey, we'll look into the brand concepts of construction firms and their customer satisfaction. Finally we'll present the necessity of indigenous brand culture by use of macroscopic contents development.

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Pullout Strength after Expandable Polymethylmethacrylate Transpedicular Screw Augmentation for Pedicle Screw Loosening

  • Kang, Suk-Hyung;Cho, Yong Jun;Kim, Young-Baeg;Park, Seung Won
    • Journal of Korean Neurosurgical Society
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    • v.57 no.4
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    • pp.229-234
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    • 2015
  • Objective : Pedicle screw fixation for spine arthrodesis is a useful procedure for the treatment of spinal disorders. However, instrument failure often occurs, and pedicle screw loosening is the initial step of a range of complications. The authors recently used a modified transpedicular polymethylmethacrylate (PMMA) screw augmentation technique to overcome pedicle screw loosening. Here, they report on the laboratory testing of pedicle screws inserted using this modified technique. Methods : To evaluate pullout strengths three cadaveric spinal columns were used. Three pedicle screw insertion methods were utilized to compare pullout strength; the three methods used were; control (C), traditional transpedicular PMMA augmentation technique (T), and the modified transpedicular augmentation technique (M). After control screws had been pulled out, loosening with instrument was made. Screw augmentations were executed and screw pullout strength was rechecked. Results : Pedicle screws augmented using the modified technique for pedicle screw loosening had higher pullout strengths than the control ($1106.2{\pm}458.0N$ vs. $741.2{\pm}269.5N$; p=0.001). Traditional transpedicular augmentation achieved a mean pullout strength similar to that of the control group ($657.5{\pm}172.3N$ vs. $724.5{\pm}234.4N$; p=0.537). The modified technique had higher strength than the traditional PMMA augmentation technique ($1070.8{\pm}358.6N$ vs. $652.2{\pm}185.5N$; p=0.023). Conclusion : The modified PMMA transpedicular screw augmentation technique is a straightforward, effective surgical procedure for treating pedicle screw loosening, and exhibits greater pullout strength than traditional PMMA transpedicular augmentation. However, long-term clinical evaluation is required.