• Title/Summary/Keyword: Reliability Indicators

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Analysis on Reliabilities of Seoul's Trunk Bus Lines Using BMS Data (through Data Envelopment Analysis) (BMS 자료를 이용한 서울시 간선버스의 정시성 분석(자료포락분석기법을 적용하여))

  • O, Mi-Yeong;Jeong, Chang-Yong;Son, Ui-Yeong
    • Journal of Korean Society of Transportation
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    • v.27 no.1
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    • pp.63-71
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    • 2009
  • The purpose of this paper is to identify unreliable routes in the view of users. After headway error ratio per route and travel time error ratio per route were calculated by using BMS data, reliability which incorporated two indicators each route was calculated through data envelopment analysis. Reliability among routes and among traffic zones was compared through the results, the needs to improve severely unreliable routes and to show passengers adjusted bus schedule information considering current reliability were suggested. As a future study, reliability evaluation framework of each route needs to be developed considering operation environment by analyzing bus card data (passengers and operation speed etc.) and pooly unreliable route should be managed strictly and reformed.

Control strategies of energy storage limiting intermittent output of solar power generation: Planning and evaluation for participation in electricity market

  • Sewan Heo;Jinsoo Han;Wan-Ki Park
    • ETRI Journal
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    • v.45 no.4
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    • pp.636-649
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    • 2023
  • Renewable energy generation cannot be consistently predicted or controlled. Therefore, it is currently not widely used in the electricity market, which requires dependable production. In this study, reliability- and variance-based controls of energy storage strategies are proposed to utilize renewable energy as a steady contributor to the electricity market. For reliability-based control, photovoltaic (PV) generation is assumed to be registered in the power generation plan. PV generation yields a reliable output using energy storage units to compensate for PV prediction errors. We also propose a runtime state-ofcharge management method for sustainable operations. With variance-based controls, changes in rapid power generation are limited through ramp rate control. This study introduces new reliability and variance indices as indicators for evaluating these strategies. The reliability index quantifies the degree to which the actual generation realizes the plan, and the variance index quantifies the degree of power change. The two strategies are verified based on simulations and experiments. The reliability index improved by 3.1 times on average over 21 days at a real power plant.

Development of a Premature Infant Pain Scale (PIPS) (미숙아 통증지표(Premature Infant Pain Scale) 개발)

  • Kim, Mi-Soon;Kim, Mi-Jin;Ham, Eun-Ha;Kim, Kyoung-Mi
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.13 no.3
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    • pp.510-519
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    • 2006
  • Purpose: To develop and validate a scale suitable and efficient scale for use in clinical practice as to assess pain in premature infants. Method: Pain indicators identified by observation of preform infants. A cohort of preform infants was studied prospectively to determine the construct validity, inter-rater reliability, and internal consistency of the scale. The PIPS uses four indicators of pain: corrected gestational age, heart rate, oxygen saturation, behavioral state. The validation study included 45 premature infants with gestational age of 37 weeks or less. Results: The inter-rater reliability of the PIPS was acceptable, with Pearson correlations ranging from.720 to.970. Internal consistency was high: Cronbach's alpha coefficients ranged from.551 to.653. There was a strong correlation between the PIPS and PIPP scores (each researcher's r=.743, each indicator's r=.914). Although gestational age showed no association between these factors and the sum, the other variables were positively associated with the sum. Time needed to calculate PIPS scores is was less than Premature Infant Pain Profile (PIPP) scores(p<.000). Conclusion: The validation data suggest that the PIPS is appropriate and efficient for assessing pain in premature infants. Further studies are required about to determine appropriate interventions for each pain score on the PIPS.

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Development of a Survey Table for Measurement Regional Community Capacity on Rural Development Project of Region Unit (권역단위 농촌지역개발사업의 주민역량 측정을 위한 설문도구개발)

  • Rhee, Shinho;Min, Heung Gi;Yoon, Sung Soo;Jung, Nam Su;Chang, Woo Seok
    • Journal of Korean Society of Rural Planning
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    • v.20 no.4
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    • pp.165-182
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    • 2014
  • The purpose of this study was to develop survey tools for diagnosis of capacity levels in business promotion of rural residents when performing a rural development project of a regional unit. The cases of previous studies were analyzed to select community capacity indicators related to a rural development project. Five indicators were derived : social capital, consciousness of participation, community spirit, and leadership. Based on the five indicators, measurement items of various capacities were selected and 54 survey items were selected through evaluation of experts twice. The pilot tests were conducted and targeted at Jeonnam song ho-jung village and Gyeongnam Haegeumgang village to identify derived survey items. In addition, descriptive statistic analysis and reliability analysis were conducted. As a result, survey items were corrected by reducing 10 items of the total 54 items. This results showed that using this tool could help us understand capacity levels of rural residents.

A Study on the Development of Diagnostic Tools for Sasang Constitutional Patterns (사상체질병증 진단도구 개발 연구)

  • Lee, Hyeri;Lee, Jun-Hee
    • Journal of Sasang Constitutional Medicine
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    • v.33 no.3
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    • pp.95-126
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    • 2021
  • Objectives The purpose of this study was to develop diagnostic tools for Sasang Constitutional patterns based on the middle classification of the Sasang Constitutional patterns. Methods Diagnosis and assessment indicators of Soeumin, Soyangin, Taeeumin, and Taeyangin patterns were extracted based on the 『Clinical Practice Guideline for Sasang Constitutional Medicine Symptomatology』 and 『Donguisusebowon』. An online survey was conducted on the 'importance of diagnosis and assessment indicators' by the Sasang Constitutional Medicine expert group. Results Based on the expert consultation results, the importance weight for each diagnosis and assessment indicators symptom was calculated, and the importance was ranked to develop diagnostic tools for Soeumin, Soyangin, Taeeumin, and Taeyangin patterns. Diagnostic tool consisted of 58 questions for Soeumin patterns, 68 questions for Soyangin patterns, 81 questions for Taeeumin patterns, and 42 questions for Taeyangin patterns. The final total score was calculated by reflecting each response score and the weight of each question. Conclusions The developed 'Diagnostic Tools for Sasang Constitutional patterns' can be used to make an effective and objective diagnosis in the clinical site. In the future, if the reliability and validity of these diagnostic tools are tested through clinical study, it will be possible to improve clinical applicability and contribute to standardization of diagnosis.

Proposal an Alternative Data Pipeline to Secure the Timeliness for Official Statistical Indicators (공식발표 통계지표의 적시성 확보를 위한 대안 데이터 파이프라인 구축제안)

  • Yongbok Cho;Dowan Kim
    • Journal of Korea Society of Industrial Information Systems
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    • v.28 no.5
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    • pp.89-108
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    • 2023
  • This study provides a comprehensive analysis of recent studies conducted on the topic of nowcasting in order to enhance the accuracy and promptness of official statistical data. Furthermore, we propose an alternative approach involving the utilization of real-time data and its corresponding collection methods to effectively operate a real-time nowcasting model capable of accurately capturing the current economic condition. We explore high-frequency real-time data that can predict economic indicators in both the public and private sectors and propose a pipeline for data collection processing and modeling that is based on cloud platforms. Furthermore we validate the essential elements required for the implementation of real-time nowcasting, as well as their data management protocols to ensure the reliability and consistency needed for accurate forecasting of official statistical indicators.

Experimental Study on Transmission Errors of a Single-Stage Planetary Gear Train: Influence of Torque and Speed Variations (1단 유성기어의 전달오차 특성에 대한 실험적 연구 - 토크 및 속도 변화의 영향)

  • Song, Jinseop;Lee, Geun-Ho;Park, Young-Jun;Nam, Yong-Yun
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.24 no.3
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    • pp.320-326
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    • 2015
  • Despite the wide industrial applications of planetary gear trains, the relationship between the design parameters (tooth profile, carrier mass, etc.) and performance (strength, vibration, noise, etc.) remains poorly understood. A significant amount of research has focused on transmission errors, which are measurable performance indicators directly related to the design parameters. Herein, an experimental test rig for a single-stage planetary gear set built using digital angular encoders and gap sensors is described. To study the static and dynamic characteristics of this planetary gear train, the transmission errors and sun gear orbit are analyzed from the data measured under various levels of torque and speed. The transmission errors of the gear train decrease 40% when the speed increases from 30 to 600 rpm with an output torque of 39.2 Nm, and increase 22% when the output torque increases from 19.6 to 39.2 Nm with an input speed of 30 rpm.

A Study for Maintenance Period Extension based on Reliability of Korea Trainer (국산훈련기 신뢰성기반 정비주기 연장방안 연구)

  • Jo, Intak;Park, Jong Hun
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.43 no.4
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    • pp.123-132
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    • 2020
  • Currently, there are two types of trainer in Korea : basic and advanced. Both models have been in operation for more than 10 years, and compared to the early stage of operation, reliability has gradually improved and failure rates have also entered a trend of stabilization. Therefore, it is necessary to extend the maintenance period considering economic feasibility. This study investigates the three maintenance period calculation methods: NAVAIR 00-25-403 [17], DOD, U.S. [4], CERL and US Army [3], with intention to extend the maintenance period of the trainer from current 200 hours to 400 hours. In addition, the maintenance period was calculated by the three methods with actual operational data. Common standards and procedures were established to apply operational data to the existing maintenance period calculation methods, the required reliability indicators were derived, and the maintenance periods was calculated based on the results, additionally, a review on the field applicability of the three maintenance cycles was conducted. An on-site interviews were conducted with the calculation results, and 11 out of the 15 items were expected to be extended by 400 hours. It was suggested that the remaining 4 items could be extended to 400 hours by supplementing the inspection method through additional analysis such as functional analysis, inspection content verification, and site connection.

Reliability analysis of nuclear safety-class DCS based on T-S fuzzy fault tree and Bayesian network

  • Xu Zhang;Zhiguang Deng;Yifan Jian;Qichang Huang;Hao Peng;Quan Ma
    • Nuclear Engineering and Technology
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    • v.55 no.5
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    • pp.1901-1910
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    • 2023
  • The safety-class (1E) digital control system (DCS) of nuclear power plant characterized structural multiple redundancies, therefore, it is important to quantitatively evaluate the reliability of DCS in different degree of backup loss. In this paper, a reliability evaluation model based on T-S fuzzy fault tree (FT) is proposed for 1E DCS of nuclear power plant, in which the connection relationship between components is described by T-S fuzzy gates. Specifically, an output rejection control system is chosen as an example, based on the T-S fuzzy FT model, the key indicators such as probabilistic importance are calculated, and for a further discussion, the T-S fuzzy FT model is transformed into Bayesian Network(BN) equivalently, and the fault diagnosis based on probabilistic analysis is accomplished. Combined with the analysis of actual objects, the effectiveness of proposed method is proved.

Development of an evaluation tool for the quality of nursing care in abdominal surgery patients (복부수술 환자간호의 질평가 도구 개발)

  • Lee, Byoung-Sook
    • Journal of Korean Academy of Nursing Administration
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    • v.4 no.1
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    • pp.107-127
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    • 1998
  • The purpose of this study was to develop an evaluation tool for the quality of nursing care in abdominal surgery patient. The target subjects of the tool were adult patients having abdominal surgery under general anesthesia. Process-outcome framework was selected for the development of the tool in this study. The results were as follows. 1. Nine standards. 40 criteria and 88 indicators were developed. A standard was summary statement of the ideal level of excellencein a dimension of quality of nursing care. which could be evaluated by criteria. Several criteria indicated a specific standard and each criterion could be measured by observable and measurable indicators. 2. The standards were divided into two dimensions. One was process dimension which contained four standards(23 criteria), the other was outcome dimension which contatined five standards(17 criteria). 3. Average CVI was .985 at 9 standards. .947 at 40 criteria. and .987 at 88 indicators. 4. The evaluation tool for the quality of nursing care in abdminal surgery patients was a criterion-referenced tool. And data collection methods of the tool were investigation of patient's record and interview( or questionnaire) with the patients. 5. Interrater reliabilities of the tool were ; r= .7572 (agreement between two raters), and pI=.8487 (intraclass correlation between five raters who rated the 84 patients). 6. Internal consistency reliability ${\alpha}$ was .6194, which was obtained from 32 criteria. Eight criteria were missed in the analyzing process because of data omission. 7. Scores of the process and the outcome dimensions showed significant. but low correlation(r= .3759, p < .001). 8. There were significant differences in total scores between the hospitals and the departments of surgery(F = 15.233. p .0001). There was also significant interaction effect between hospitals and departments to total score(F = 8.396. p = .0001). Construct validity of the toool was verified by the known-group method. these kinds of difference were expected by the nursing experts participated in the study. From these results, more specific patient classification is suggested for the development of evaluation tool of the quallity of nursing care. And indicators to be used for objective measurement for the quality of nursing care must be developed.

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