• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.12
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• pp.1712-1720
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• 2017

In South Korea, minimum reserve rate, which is to satisfy reliability standard, has been determined by simulation result using WASP. But, it is still controversial whether the level of minimum reserve rate is adequate. Thus, in this study, various analyses of minimum reserve rate are being conducted. WASP uses the probabilistic simulation technique to evaluate whether reliability standard is satisfied. In this process, forced outage rate and maintenance periods of each generator play important roles. Especially, the long-term plan can be varied depending on how maintenance periods deal with. In order to model maintenance periods in the probabilistic simulation technique, WASP uses derating method. However, broad analyses have to be conducted because there are various ways including derating method to model maintenance periods which result in different results. Therefore, in this paper, 3 different maintenance outage rate modeling methods are applied to arbitrarily modeled system based on the basic plan for long-term electricity supply and demand of South Korea. Results show impact of each modeling method on minimum reserve rate.

• Journal of the Korea Safety Management & Science
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• v.12 no.4
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• pp.223-228
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• 2010

Recently, the various information according to the company management is originated in the change of the rapid company environment. And the necessity of the administration,that is systematic and efficient toward the various document of a form, is gradually increased. At the same time, the efficient management ability of the various standard document obtained the specialized quality authentication system including the ISO/TS16949, ISO14001, quality 5 star, and etc., it maintains occupies the very important part as to the company management. This research suggests the standard business process of the auto part supplier for the efficient management of the standard document. In addition, by building and managing the standard management system will be able to expect the more efficient document management and the product reliability insurance.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.11
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• pp.752-759
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• 2008

This paper is to make up the climograph using standard weather data of the region of Seoul. It is made up by existed standard weather data of which the subjected region is Seoul in order to easily use work. The factors of weather data are outside air temperature and its absolute humidity, total solar radiation, amount of clouds, wind direction, and wind velocity. The standard weather data are verified by comparing with values of the existed degree day method. As the result of their verification, the difference of the data showed less than 3% each other. And, reliability of standard weather data is thought to be same as those of degree day.

• Journal of the Korean Society of Safety
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• v.23 no.2
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• pp.37-44
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• 2008

The safety assessment for facility industry is now being periodically performed. For the purpose of scientific safety management, QRA(Quantitative Risk Assessment) is also being performed, and reliability data of the facilities is essential to perform the assessment. Generally, the existing safety assessment is performed by using the values announced in other industry processes, which result in the drop of reliability. In order to solve this problem, there is an urgent need to establish reliability database for the facilities. The most appropriate method is to perform a direct reliability analysis towards the facilities undergoing safety assessment. In this study, in compliance with the assessment method and procedure of OREDA-2002 handbook, the facility reliability data are collected, which include the calendar time and operational time in terms of different facility items, the number of failures in terms of different failure mode, the mean, standard deviation, lower limit and upper limit of failure rate, and the failure rate. And the data process method for this special occasion is also proposed when the number of failure is 0.

• Physical Therapy Korea
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• v.20 no.3
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• pp.74-80
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• 2013

The purpose of this study was to determine the reliability of distance measurements from the medial border of the scapula to the spinous process of the thoracic vertebrae when obtained using tape and photography measurements. The study included 20 healthy subjects (10 males, 10 females); for a total of 40 scapula measurements. The distance measurements made using tape or photography methods were conducted with the subject in a standing position. Repeated tape and photography measurements were conducted in two sessions on different days by two examiners to assess the inter-rater and intra-rater reliability of the two methods. The reliability of scapular distance measured using tape and photography methods was tested using intraclass correlation coefficients (ICC(3,1)) and the standard error of measurement (SEM). The inter-rater reliability of the tape measurement method was excellent (ICC=.77) and the intra-rater reliability was fair to good (ICC=.74). The inter-rater and intra-rater reliabilities of the photography measurement method were excellent (ICC=.76 and .76 respectively). Our results suggest that photography measurement is an objective and qualitative measurement tool for scapular distance measurements.

• The Journal of Korean Physical Therapy
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• v.21 no.1
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• pp.41-48
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• 2009

Purpose: The examine the Reliability and Validity of the modified Emory Functional Ambulation Profile (mEFAP), Tinetti. Gait (TG), Timed Up & Go Tes t (TUG), Comfortable Gait Speed (CGS), Berg Balance Scale (BBS) in assessing gait function and balance in elderly person. Methods: The 45 community-dwelling subjects were participated in this study. Reliability was determined by intra-class correlation coefficient (ICC$_{3,1}$), Bland and Altman method (Standard Error of Measurement (SEM), Smallest Real Difference (SRD)). Results: Validity was examined by correlation the mEFAP, TG, TUG, CGS, BBS. The intra-rater reliability were High (ICC$_{3,1}$ : mEFAP=0.95, TG=0.96, TUG=0.94, CGS=0.96, BBS=0.92) and Absolute reliability were excellent (SEM: mEFAP=1.90, TG=0.21, TUG=0.28 CGS=0.25, BBS=0.52), (SRD: mEFAP=5.26, TG=0.58, TUG=0.77, CGS=0.69, BBS=1.44). There were significant correlations between assessment tool (r=.0.58$\sim$0.78, p<0.01) indicating good validity. Our results provide strong evidence that the assessment tool has good reliability, validity for assessing elderly person undergoing rehabilitation. Conclusion: The gait assessment tool is a useful scale for measuring walking function and recovery in elderly person.

• 한국정보통신설비학회:학술대회논문집
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• 2006.08a
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• pp.39-42
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• 2006

There are various analysis functions(including prediction of path loss, analyzing of capacity and coverage, etc.) of simulation tool to design and optimize the mobile communication network. Its reliability absolutely effects the performance of mobile communication network. Especially as the wireless network highly advancing focused on data service, it more needs to research and develop on the standard establishment of reliability of the simulation tool. Also it is important the systematic research how to improve the reliability of simulation tool. In this paper, to give the concrete process and skill about how to improve reliability, we define the kinds of reliability at first. And then we explain the comparison results between real field measurement data and theoretic simulation data.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.11
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• pp.1535-1542
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• 2015

An increasing number of electric vehicles (EVs) in power system affects its reliability in various aspects. Especially under high EV penetration level, new generating units are required to satisfy system's adequacy criterion. Wind power generation is expected to take the major portion of the new units due to environmental and economic issues. In this paper, the system reliability is analyzed using Loss of Load Expectation (LOLE) and Expected Energy Not Served (EENS) under each and both cases of increasing wind power generation and EVs. A probabilistic multi-state modeling method of wind turbine generator under various power output for adequate reliability evaluation is presented as well. EVs are modeled as loads under charging algorithm with Time-Of-Use (TOU) rates in order to incorporate EVs into hour-to-hour yearly load curve. With the expected load curve, the impact of EVs on the system adequacy is analyzed. Simulations show the reliability evaluation of increasing wind power capacity and number of EVs. With this method, system operator becomes capable of measuring appropriate wind power capacity to meet system reliability standard.

• Structural Engineering and Mechanics
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• v.59 no.5
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• pp.853-866
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• 2016

This paper examines a methodology for computing the probability of structural failure of reinforced concrete beams subjected to fire. The significant load variables considered are dead load, sustained live load and fire temperature. Resistance is expressed in terms of moment capacity with random variables taken as yield strength of steel, concrete class (or grade of concrete), beam width and depth. The flexural capacity is determined based on the design equations recommended in Indian standard IS456:2000. Simplified method named $500^{\circ}C$ isotherm method detailed in Eurocode 2 is incorporated for fire design. A transient thermal analysis is conducted using finite element software ANSYS$^{(R)}$ Release15. Reliability is evaluated from the initial state to 4h of fire exposure based on the first order reliability method (FORM). A procedure is coded in MATLAB for finding the reliability index. This procedure is validated with available literature. The effect of various parameters like effective cover, yield strength of steel, grade of concrete, distribution of reinforcement bars and aggregate type on reliability indices are studied. Parameters like effective cover of concrete, yield strength of steel has a significant effect on reliability of beams. Different failure modes like limit state of flexure and limit state of shear are checked.

• Journal of the Korea Society of Computer and Information
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• v.17 no.12
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• pp.187-198
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• 2012

International standard for software quality evaluation, ISO/IEC 9126 defines the quality characteristics and sub-characteristics consisting of quality of the software. Also, in this standard, the quality assessment items are presented in metrics based on maturity, fault tolerance, recoverability and compliance which are sub-characteristics of reliability. However, this reliability assessment items which are presented are not applied now due to the mathematical difficulties and the problems caused by collection of data. In order to resolve these problems, this study introduces measures to develop a specific test technique by quality attributes and to measure the quality. In other words, the detailed guidelines are presented to be utilized as a standard by summarizing test activities and techniques by each development life the most commonly used. The SW quality results are derived by assigning weights to software in order of the most important quality characteristics of respective software using checklist that can be easily utilized and applying test technique that can be utilized for detailed evaluation items and checklist. This improves problems that include reliability assessment item of ISO/IEC 9126 as the measures to measure new reliability quality of software.