• Title/Summary/Keyword: line reliability

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Accuracy and reliability evaluation of basic CPR application information developed in Korean (국문으로 개발된 기본심폐소생술 애플리케이션 정보의 정확성과 신뢰성 평가)

  • Jung, Eun-Kyung;Kang, Ji-Hun
    • The Korean Journal of Emergency Medical Services
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    • v.23 no.3
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    • pp.41-51
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    • 2019
  • Purpose: This dissertation is a descriptive research study analyzing the accuracy and reliability of the cardiopulmonary resuscitation (CPR) application developed in Korea. Methods: Two faculty members from the emergency medical services department and the emergency medicine department searched applications from July 1 to July 10, 2019 and selected a total of 13 applications. Twelve questions were assessed for information accuracy and three were assessed for reliability. In accordance with application types, the number and mean ± standard deviation were analyzed. The t-test was used to compare the accuracy of CPR information in accordance with information sources. Results: The results revealed the following errors: 7 cases (53.8%) identified the chest center lining from the nipple center-line as the chest pressure point; 5 cases (38.5%) did not provide information on the depth of 6 cm that should not be exceeded; and 4 cases (30.8%) did not provide advise to check respiration. When the CPR information sources were included, the information accuracy score was high; a significant difference was observed (p=.035). Conclusion: In the case of applications providing medical information regarding CPR, it is necessary to provide at least authoritarian, sources of information, and author transparency as well as continuous effort and attention.

Reliability Assesment of 22.9kV High Temperature Superconducting Cable System (22.9kV 초전도케이블 시스템의 신뢰성 평가)

  • Sohn, Song-Ho;Lim, Ji-Hyun;Sung, Tae-Hyun;Ryoo, Hee-Suk;Yang, Hyung-Suk;Kim, Dong-Lak;Hwang, Si-Dole
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.06a
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    • pp.248-248
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    • 2007
  • Demands for electricity are growing, whereas the rate of electricity infrastructure's construction declines gradually. To keep the balance of the demand and supply, the share of underground transmission line will be increased from 8.3% to 10.5% in 2020 but it will be accompanied with enormous public expenses. A great concern in high capacity transmission is on the increase so as to maximize the spacial efficiency. High Temperature Superconducting (HTS) cable is in the lime light which has the merits of environment-friendly, low transmission loss and high transmission with low voltage, but the reliability verification as a power system is yet to be solved. KEPCO completed the installation and acceptance of $3{\phi}$, 22.9kV, 1250A class HTS cable system in 2006 and the long term test is in progress. The test results focusing on long term reliability are presented in this paper.

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A Prediction Method of the Gas Pipeline Failure Using In-line Inspection and Corrosion Defect Clustering (In-line Inspection과 부식결함 클러스터링을 이용한 가스배관의 고장예측)

  • Kim, Seong-Jun;Choe, Byung Hak;Kim, Woosik
    • Journal of the Korean Institute of Intelligent Systems
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    • v.24 no.6
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    • pp.651-656
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    • 2014
  • Corrosion has a significant influence upon the reliability assessment and the maintenance planning of gas pipeline. Corrosion defects occurred on the underground pipeline can be obtained by conducting periodic in-line inspection (ILI). However, little study has been done for practical use of ILI data. This paper deals with remaining lifetime prediction of the gas pipeline in the presence of corrosion defects. Because a pipeline parameter includes uncertainty in its operation, a probabilistic approach is adopted in this paper. A pipeline fails when its operating pressure is larger than the pipe failure pressure. In order to estimate the failure probability, this paper uses First Order Reliability Method (FORM) which is popular in the field of structural engineering. A well-known Battelle code is chosen as the computational model for the pipe failure pressure. This paper develops a Matlab GUI for illustrating failure probability predictions Our result indicates that clustering of corrosion defects is helpful for improving a prediction accuracy and preventing an unnecessary maintenance.

Durability Evaluation on Doorstep Equipments Used for Low and High Level Platforms at Railway Vehicle (철도차량의 저상 및 고상 승강장 겸용 승강문 스텝에 대한 내구성 평가)

  • Kim, Chul-Su;Park, Min-Heung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.9
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    • pp.3889-3894
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    • 2012
  • The platform of railroad station for domestic passenger train has been operated at two categories like the platforms if low level(500mm, mainline) and high level(1,135mm, metropolitan subway line). To operate both metropolitan subway line and mainline railroad safely, it is essential to develop the doorstep equipment of railway vehicle regardless of low and high level platforms. On the other hand, the domestic test standard at durability and reliability of doorstep equipment has not been existed until now. This study aims at the development on doorstep equipment of telescopic sliding type for low and high level platforms. Durability analysis with VPD(Virtual Product Development) techniques are performed and the durability standard & qualification life through the rig test during no failure test time is examined in accordance with reliability qualification test.

Effect of Impurities on Stress Induced Void Formation in Al-1% Si Conductors

  • Lee, Seong-Min
    • Transactions on Electrical and Electronic Materials
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    • v.2 no.3
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    • pp.12-17
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    • 2001
  • It is shown in the present study that during the HTS (hot temperature storage) test, the metal contamination by impure elements can be highly susceptible to the void formation, leading to the open failure of the power line in the memory device. Such a functional failure associated with the metal contamination was investigated to be dominant in the early stages of the HTS test while the formation of a stress-driven void is mainly observed in the later stages. In particular, it was found that the void formed in the contaminated metal takes on a slit-like shape which has been known to be characteristic of the stress-related voiding. The impure elements leading to the metal degradation were identified to be carbon and oxygen introduced during the metal sputtering process. The experimental works show that the device reliability was significantly improved by reducing the level of such impure elements within metal. It is shown in the present study that during the HTS (hot temperature storage) test, the metal contamination by impure elements can be highly susceptible to the void formation, leading to the open failure of the power line in the memory device. Such a functional failure associated with the metal contamination was investigated to be dominant in the early stages of the HTS test while the formation of a stress-driven void is mainly observed in the later stages. In particular, it was found that the void formed in the contaminated metal takes on a slit-like shape which has been known to be characteristic of the stress-related voiding. The impure elements leading to the metal degradation were identified to be carbon and oxygen introduced during the metal sputtering process. The experimental works show that the device reliability was significantly improved by reducing the level of such impure elements within metal.

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Determination of Maintenance Period Considering Reliability Function and Mission Reliability of Electromagnetic Valves of EMU Doors Considering Air Leakage Failure (전동차 출입문 전자변 누기고장의 신뢰도 함수와 임무 신뢰도를 고려한 정비 주기 결정)

  • Park, Heuiseop;Koo, Jeongseo;Kim, Gildong
    • Journal of the Korean Society for Railway
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    • v.20 no.5
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    • pp.569-576
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    • 2017
  • The electromagnetic valve of pneumatic doors of EMUs has a high failure rate due to air leakage because it supplies air on and off to operate the doors repeatedly. The electromagnetic valve is a very important safety component for which a very high reliability is required because failure makes it impossible to operate the passenger cars. However, domestic urban railway operators maintain electronic valves of the EMU door under a fixed cycle with a spare period according to the full overhaul cycle of the EMU. An improvement of the current maintenance cycle was suggested based on the reliability function and mission reliability. Using the statistical program MINITAB for the operational data of EMU line 6, we analyzed the characteristics of the fault distribution and derived the shape and scale parameters of the reliability function. If we limit the specific reliability probability to under a certain failure rate and calculate its statistical parameters, we can calculate the allowable inspection period with mission reliability. Through this study, we suggested a maintenance period based on RCM (reliability centered-maintenance) to improve the reliability of electromagnetic valves from 68% to 95%.

A Study on the Basic Bodice Pattern for the Fatty Body -The subject of middle-aged women- (비만체형을 위한 기본 Bodice 원형연구 -중년기 부인을 중심으로-)

  • 한애미
    • Journal of the Korean Home Economics Association
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    • v.25 no.3
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    • pp.15-26
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    • 1987
  • The purpose of this study was to develop the pattern drafting method which would be suitable to their physical characteristics for the fatty body of 40∼55 aged Korean women who are more than 1.5 Rohrer's Index and 90㎝ bust girth. The study was composed as follows; 1. Body measurement and statistical analysis: One hundred and thirty women were measured on 29 items. Thirty-four items including 29 measured items and 5 calcutated items were analyzed statistically. 1) Mean, standard deviation, variance, maximum, minimum, range were computed. 2) Correlation coefficients between each items were computed. 2. Development of new bodice pattern drafting method: Measurement items necessary to draft new bodice pattern were bust girth, center back waist length, shoulder width, back width, chest and neck base girth. The new pattern was examined through three wearing tests for completion. 3. Evaluation of the new pattern drafting method: The new pattern was objectively evaluated by the sensory test. The sensory evaluation was applied to evaluate the new pattern for the fatty body women by comparint it with the conventional patterns. The results of sensory tests of the new pattern are as follows: 1) The composite reliability coefficient is 0.7698, and the reliability of sensory test shows high. 2) According to a statistical analysis of the result of the 23 items on the questionaire, all the items showed significant differences(α 0.01) between the two, with the new pattern having higher scores. The new pattern is better conventional pattern as the average mark of the former is 3.901 but that of latter is 2.926. The new pattern drafting method proved to be superior to the conventional one especially in the fitness at the center front neck point, shoulder point, side line, armscye depth, position of bust point, chest width line, under arm dart and the shoulder line.

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Face detection system for the degree of concentration checking and analysis of learning attitude of learners in online learning (온라인 학습에서 학습자 학습태도 분석 및 집중도 체크를 위한 얼굴 검출 시스템)

  • Kim, Geun-Ho;Chung, Jung-In;Kim, Eui-Jeong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2016.05a
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    • pp.420-424
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    • 2016
  • Recently, with the development of Internet technology and multi-media technology, the Internet is going to develop in many areas, a new application areas. In particular, in the area of education, has made a Epoch-making development in the Internet applications, it has presented the instructional methods of the new paradigm. Study using the online learning, instructional method of a conventional traditional new proposal that deviates from the off-line teaching, Unlike the existing off-line learning, without being bound by time and space, in terms of anytime, anywhere it is possible to attend the lecture, is a very efficient learning. Online lectures Despite many advantages, and containing a number of problems. In terms of space of the learning is performed on-line, there is a disadvantage that the student management and learning, the reliability of evaluation missing number. In this study, out of such a variety of problems, concentration to induce an active learning attitude of learners, learners of learning who attempt to increase the reliability and using the face detection system of attendance learning It proposed a degree system.

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Modern Paper Quality Control

  • Komppa, Olavi
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.32 no.5
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    • pp.72-79
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    • 2000
  • On the other hand, the fiber orientation at the surface and middle layer of the sheet controls the bending stiffness of paperboard. Therefore, a reliable measurement of paper surface fiber orientation gives us a magnificent tool to investigate and predict paper curling and cockling tendency, and provides the necessary information to fine-tune the manufacturing process for optimum quality. Many papers, especially heavily calendered and coated grades, do resist liquid and gas penetration very much, being beyond the measurement range of the traditional instruments or resulting inconveniently long measuring time per sample. The increased surface hardness and use of filler minerals and mechanical pulp make a reliable, non-leaking sample contact to the measurement head a challenge of its own. Paper surface coating causes, as expected, a layer which has completely different permeability characteristics compared to the other layers of the sheet. The latest developments in sensor technologies have made it possible to reliably measure gas flow n well controlled conditions, allowing us to investigate the gas penetration of open structures, such as cigarette paper, tissue or sack paper, and in the low permeability range analyze even fully greaseproof papers, silicon papers, heavily coated papers and boards or even detect defects in barrier coatings! Even nitrogen or helium may be used as the gas, giving us completely new possibilities to rank the products or to find correlation to critical process or converting parameters. All the modern paper machines include many on-line measuring instruments which are used to give the necessary information for automatic process control systems. Hence, the reliability of this information obtained from different sensors is vital for good optimizing and process stability. If any of these on-line sensors do not operate perfectly as planned (having even small measurement error or malfunction), the process control will set the machine to operate away from the optimum, resulting loss of profit or eventual problems in quality or runnability. To assure optimum operation of the paper machines, a novel quality assurance policy for the on-line measurements has been developed, including control procedures utilizing traceable, accredited standards for the best reliability and performance.

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Stability Index Based Voltage Collapse Prediction and Contingency Analysis

  • Subramani, C.;Dash, Subhransu Sekhar;Jagdeeshkumar, M.;Bhaskar, M. Arun
    • Journal of Electrical Engineering and Technology
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    • v.4 no.4
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    • pp.438-442
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    • 2009
  • Voltage instability is a phenomenon that could occur in power systems due to stressed conditions. The result would be an occurrence of voltage collapse leading to total blackout of the system. Therefore, voltage collapse prediction is an important part of power system planning and operation, and can help ensure that voltage collapse due to voltage instability is avoided. Line outages in power systems may also cause voltage collapse, thereby implying the contingency in the system. Contingency problems caused by line outages have been identified as one of the main causes of voltage instability in power systems. This paper presents a new technique for contingency ranking based on voltage stability conditions in power systems. A new line stability index was formulated and used to identify the critical line outages and sensitive lines in the system. Line outage contingency ranking was performed on several loading conditions in order to identify the effect of an increase in loading to critical line outages. Correlation studies on the results obtained from contingency ranking and voltage stability analysis were also conducted, and it was found that line outages in weak lines would cause voltage instability conditions in a system. Subsequently, using the results from the contingency ranking, weak areas in the system can be identified. The proposed contingency ranking technique was tested on the IEEE reliability test system.