• 제목/요약/키워드: reliability gain

검색결과 211건 처리시간 0.029초

The effectiveness of genomic selection for milk production traits of Holstein dairy cattle

  • Lee, Yun-Mi;Dang, Chang-Gwon;Alam, Mohammad Z.;Kim, You-Sam;Cho, Kwang-Hyeon;Park, Kyung-Do;Kim, Jong-Joo
    • Asian-Australasian Journal of Animal Sciences
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    • 제33권3호
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    • pp.382-389
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    • 2020
  • Objective: This study was conducted to test the efficiency of genomic selection for milk production traits in a Korean Holstein cattle population. Methods: A total of 506,481 milk production records from 293,855 animals (2,090 heads with single nucleotide polymorphism information) were used to estimate breeding value by single step best linear unbiased prediction. Results: The heritability estimates for milk, fat, and protein yields in the first parity were 0.28, 0.26, and 0.23, respectively. As the parity increased, the heritability decreased for all milk production traits. The estimated generation intervals of sire for the production of bulls (LSB) and that for the production of cows (LSC) were 7.9 and 8.1 years, respectively, and the estimated generation intervals of dams for the production of bulls (LDB) and cows (LDC) were 4.9 and 4.2 years, respectively. In the overall data set, the reliability of genomic estimated breeding value (GEBV) increased by 9% on average over that of estimated breeding value (EBV), and increased by 7% in cows with test records, about 4% in bulls with progeny records, and 13% in heifers without test records. The difference in the reliability between GEBV and EBV was especially significant for the data from young bulls, i.e. 17% on average for milk (39% vs 22%), fat (39% vs 22%), and protein (37% vs 22%) yields, respectively. When selected for the milk yield using GEBV, the genetic gain increased about 7.1% over the gain with the EBV in the cows with test records, and by 2.9% in bulls with progeny records, while the genetic gain increased by about 24.2% in heifers without test records and by 35% in young bulls without progeny records. Conclusion: More genetic gains can be expected through the use of GEBV than EBV, and genomic selection was more effective in the selection of young bulls and heifers without test records.

Reliability-based combined high and low cycle fatigue analysis of turbine blade using adaptive least squares support vector machines

  • Ma, Juan;Yue, Peng;Du, Wenyi;Dai, Changping;Wriggers, Peter
    • Structural Engineering and Mechanics
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    • 제83권3호
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    • pp.293-304
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    • 2022
  • In this work, a novel reliability approach for combined high and low cycle fatigue (CCF) estimation is developed by combining active learning strategy with least squares support vector machines (LS-SVM) (named as ALS-SVM) surrogate model to address the multi-resources uncertainties, including working loads, material properties and model itself. Initially, a new active learner function combining LS-SVM approach with Monte Carlo simulation (MCS) is presented to improve computational efficiency with fewer calls to the performance function. To consider the uncertainty of surrogate model at candidate sample points, the learning function employs k-fold cross validation method and introduces the predicted variance to sequentially select sampling. Following that, low cycle fatigue (LCF) loads and high cycle fatigue (HCF) loads are firstly estimated based on the training samples extracted from finite element (FE) simulations, and their simulated responses together with the sample points of model parameters in Coffin-Manson formula are selected as the MC samples to establish ALS-SVM model. In this analysis, the MC samples are substituted to predict the CCF reliability of turbine blades by using the built ALS-SVM model. Through the comparison of the two approaches, it is indicated that the reliability model by linear cumulative damage rule provides a non-conservative result compared with that by the proposed one. In addition, the results demonstrate that ALS-SVM is an effective analysis method holding high computational efficiency with small training samples to gain accurate fatigue reliability.

제품안전경영프로그램으로서의 리스크 관리규격 (Risk Management Standards As a Product Safety Management Program)

  • 이동하
    • 한국신뢰성학회:학술대회논문집
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    • 한국신뢰성학회 2001년도 정기학술대회
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    • pp.376-383
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    • 2001
  • This study reviewed the national standards for risk management to judge whether they are suitable for a product safety management program. Among the standards issued from Australia, New Zealand, Canada, Japan, and UK, the risk management guideline (AS/NZS 4360: 2000) issued jointly from both Australia and New Zealand have better features of product safety management program such as a broad definition of risk concept including opportunities of loss and gain, stepwise composition of processes applicable iteratively, and integrable composition of processes for the existing other management practice. Comparing the three product safety management programs suggested by several authors yielded common features of product safety management program model: (1) organization for product safety, (2) risk identification, (3) risk evaluation, (4) risk treatment, (5) monitoring/communication, and (6) documentation. All of these activities can be performed within risk management framework.

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철도안전법의 제작자 승인 기술기준에 대한 연구 (Technical Specifications for Manufacturer Approval in Railway Safety Law)

  • 이환덕;정원
    • 한국신뢰성학회지:신뢰성응용연구
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    • 제15권1호
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    • pp.19-26
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    • 2015
  • The amended law of railway safety in Korea has recently come into effect in order to strengthen the railway safety management system. The new law, which took effect March 1, 2014, will implement stricter oversight of railway companies. As a result, a company that manufactures railroad system or components for domestic use must obtain an approval in accordance with the technical specifications of manufacturer approval. Although Korea had established the legal system in enforcing railway safety, the government wants the companies continue to develop the more improved safety systems until they gain competitive edge on the world class railway manufacturers. This paper presents an in-depth analysis of the technical specifications for manufacturer approval in International Railway Industry Standard (IRIS), which is the global standard. This paper also proposes measures and guidelines that would help Korean manufacturers those who want further develop their safety management systems, as a prerequisite for them to obtain the manufacturer approval.

영성(Spirituality) 체험 - 기독교인 중심의 현상학적 접근 - (The Experience of Spirituality)

  • 오복자;강경아
    • 대한간호학회지
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    • 제31권6호
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    • pp.967-977
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    • 2001
  • This study explored and described the living spiritual experience and was attempted to gain an understanding of spirituality. This was done by eliciting participants′ verbal descriptions of their experiences. Method: Data was obtained from in-depth interviews with one cancer patient, one pastor, and three missionaries after obtaining informed consent from each. Interviews were tape recorded and transcribed verbatim. The transcripts were analyzed using Colaizzi′s phenomenological method. Sandelowski′s evaluation criteria for qualitative research, such as reliability, suitability and auditability, were also used to establish reliability and validity of this study. Result: The five major theme clusters that designated the essence of the spiritual experience, "spiritual awareness," "interconnectedness," "love," "tran- scendent energy," "purpose and meaning in life," emerged from the analysis. Conclusion: This study revealed that spirituality was activated by awareness through introspection and interconnectedness with a Supreme Being. The interconnectedness with a Supreme Being played an important role in harmonious relationships with others and self. It also resulted in revealing the other beneticial attributes of spirituality. Love, the core concept of the interconnectedness, worked as a transcendent energy. Also, the ability to see beyond reality and resulted in finding meaning in life and accomplishing well being.

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리스크 관리규격의 제품안전경영프로그램에 대한 적용 (Application of Risk Management Standards for Product Safety Management Program)

  • 이동하;나윤균;김명수
    • 한국신뢰성학회지:신뢰성응용연구
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    • 제1권2호
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    • pp.109-120
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    • 2001
  • This study reviewed the national standards for risk management to judge whether they are suitable for a product safety management program. Among the standards issued from Australia, New Zealand, Canada, Japan, and UK, the risk management guideline (AS/NZS 4360: 2000) issued jointly from both Australia and New Zealand have better features for product safety management program than any other risk management standards in view point of broad definition of risk concept including opportunities of loss and gain, stepwise composition of management processes applicable iteratively, and integrable form of structure addible to existing management practice. Comparing the three product safety management programs suggested by several authors yielded common features of product safety management program model: (1) organization for product safety, (2) risk identification, (3) risk evaluation, (4) risk treatment, (5) monitoring/communication, and (6) documentation. All of these activities can be performed within risk management framework proposed by AS/NZS 4360.

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

  • 박성준;이동희;안진우;안영주
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • 제52권4호
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    • pp.154-160
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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.

비가략(非可略) 구조를 갖는 네트워크의 단점간 가용도 평가 (Terminal-Pair Availability Evaluation in Irreducible Structure Communication Networks)

  • 이준혁;김경목;오영환
    • 한국신뢰성학회지:신뢰성응용연구
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    • 제8권4호
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    • pp.181-192
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    • 2008
  • In this paper, we proposed effective algorithm that do Availability of communication network account using total probability formula. Use path tracing method about PSTN linked with MSC in WCDMA considering occasion that do not consider mobility of terminal and Availability did account. First, express minimum path series gathering by structure function after network that do modeling by stochastic graph for communication network saves all minimal path sets between particular two abutments and we gain Availability value in angular variable after express structure function by Boolean operation form and Availability between two abutments did account.

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Improved Reliability-Based Iterative Decoding of LDPC Codes Based on Dynamic Threshold

  • Ma, Zhuo;Du, Shuanyi
    • ETRI Journal
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    • 제37권4호
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    • pp.736-742
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    • 2015
  • A serial concatenated decoding algorithm with dynamic threshold is proposed for low-density parity-check codes with short and medium code lengths. The proposed approach uses a dynamic threshold to select a decoding result from belief propagation decoding and order statistic decoding, which improves the performance of the decoder at a negligible cost. Simulation results show that, under a high SNR region, the proposed concatenated decoder performs better than a serial concatenated decoder without threshold with an Eb/N0 gain of above 0.1 dB.

KALMAN FILTER를 이용한 원자로 열출력측정 방법개선에 관한 고찰 (The Study of Improvement in Reactor Thermal Power Measurement Method using KALMAN FILTER)

  • 정남교
    • 기술사
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    • 제30권5호
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    • pp.82-95
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    • 1997
  • A Study of Improvement in Reactor Thermal Power Measurement Method using Kalman Filter. The objectives of the safety analysis of nuclear power plants are to maintain the surface temperature of fuel and fuel cladding within limit value in case of Loss of Coolant accident (LOCA) so that it ensures the safety and reliability of nuclear power plants. The new technique evaluating the reactor power and improvement of existing plant system increase the safety margin of nuclear power plant operation, and accordingly, economic effect will be anticipated. Hereby, 1 would like to introduce reactor power measurement method using Kalman filter that enables to calculate the reactor power more precisely combining the parameters, for example, turbine output as the 1 st stage pressure of high pressure turbine, and reactor power using energy equilibrium relation. It is expected that the new technique will enhance the accuracy of measurement of reactor power and maintain the reliability of nuclear power operation by increasing operational safety margin, and gain the economic benefit

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