• Title/Summary/Keyword: Reliability growth

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Industrialization Trend of Remanufacturing and Recycling Technology in Korea and Overseas (재(再)제조.자원순환기술의 국내외 산업화 동향)

  • Jung, Won;Lee, Hee-Jung
    • Journal of Applied Reliability
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    • v.10 no.3
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    • pp.199-211
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    • 2010
  • Recycling involves processing used materials into new products and remanufacturing is an industrial process in which worn-out products are restored to like-new condition. Recycling and remanufacturing industry is environmentally and economically important industry and provides significant benefits to prevent waste of potentially useful materials and reduce energy usage. The purpose of this research is to investigate the trend of recycling and remanufacturing industry in Korea and other countries like Germany, Japan and America. The yield information is generally quite valuable to promote green growth industry as an important alternative in the 21st century.

Root Cause Analysis on Delamination Failure between Coating Film and Paper (코팅지 박리파손에 대한 근본원인분석)

  • Lee, D.B.
    • Journal of Power System Engineering
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    • v.9 no.1
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    • pp.57-63
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    • 2005
  • In the calendar and the advertising catalog, the surface is usually coated by coating polypropylene film. The delamination failure of coating film depends on surface roughness and quality of the substrate paper. In this paper, the mechanisms of delamination failure between the coating film and the paper is investigated by using the root cause analysis as one of techniques of reliability evaluation. The papers used in failure analysis are three kind products made by two domestic and one foreign companies. It found that the main causes of delamination failure between the coating film and the paper were the creation of microvoids caused by shape of filler and their growth caused by contraction of paper.

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Evaluating Some Influential Factors on Consumers' Purchasing Decisions of Environment-friendly Agricultural Products (EAP) Using Importance-Performance Analysis (IPA) (중요도-성취도 분석을 이용한 소비자의 친환경농산물 구매 결정요소 평가)

  • Kim, Sang-Oh;An, Ki-Wan;Kim, Min-Hee;Shim, Jae-Han
    • Korean Journal of Organic Agriculture
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    • v.15 no.4
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    • pp.339-353
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    • 2007
  • It is important to facilitate consumers' purchases of EAP (Environment-friendly Agricultural Products) for establishing the successful Environment-friendly Agriculture (EA). This study was conducted to evaluate the present state of some potentially influential factors on consumers' purchasing decisions of EAP using Importance- Performance Analysis (IPA). A total of 299 Gwangju citizens participated in the questionnaire survey during September and October, 2007. Urgent improvement efforts are needed for "reliability about the safety of the EAP", "reliability on EAP certification mark", "credibility of EAP producers", and "growth of EA". Respondents also seem to have positive attitudes to EA activation.

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Comparative Study on the Quality of Sintered Zirconia Block Fabricated by Using Domestic Powder and Global-Brand Powder (국산 지르코니아 분말 소결체 품질의 글로벌 제품과의 비교 연구)

  • Kim, Yong-In;Lee, Seung-Mi;Byeon, Jai-Won
    • Journal of Applied Reliability
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    • v.15 no.3
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    • pp.216-221
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    • 2015
  • Sintering behavior of 3%yttria-stabilized zirconia was comparatively studied using a spray-dried powder produced by a domestic and global company. Quality of the sintered block was analysed in terms of relative density, shrinkage rate, grain growth, hardness, and fracture toughness. Relative density, shrinkage rate, and hardness value of the finally sintered block was similar between domestic and global zirconia powder, respectively. But, flexural strength of the domestic powder specimen was about 70% of the sintered block produced by using a global powder. The poor sintering quality of the domestic powder was discussed in relation with compressibility of the spray-dried granule-type powder and the amount of monoclinic phase in the as-received powder.

Optimal capacity and allocation of distributed generation by minimum operation cost of distribution system (배전계통 운영비용의 최소화에 의한 분산전원의 최적용량과 위치결정)

  • Park, Jung-Hoon;Bae, In-Su;Kim, Jin-O;Shim, Hun
    • Proceedings of the KIEE Conference
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    • 2003.07a
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    • pp.360-362
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    • 2003
  • In operation of distribution system, DGs(Distributed Generations) are installed as an alternative of extension and establishment of substations, transmission and distribution lines according to increasing power demand. Optimal capacity and allocation of DGs improve power quality and reliability. This paper proposes a method for determining the optimal number, size and allocation of DGs needed to minimize operation cost of distribution system. Capacity of DGs for economic operation of distribution system can be estimated by the load growth and line capacity during operation planning duration. DG allocations are determined to minimize total cost with failure rate and annual reliability cost of each load point using GA(Genetic Algorithm).

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Forensic Study about Hair Analysis as Legal Evidence of Drug Abuse Crime (모발에서 마약류 분석의 법과학적 고찰 - 마약류 범죄수사에서 모발 감정결과의 증거사용에 대해서 -)

  • Park, Yong-Hoon;Han, Eun-Young;Lee, Soo-Yeun
    • YAKHAK HOEJI
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    • v.52 no.6
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    • pp.452-465
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    • 2008
  • Hair analysis for drugs of abuse offers the crucial potential advantage when compared to urine, such as the longer time window of drug intake, which makes retrospective investigation of chronic and/or past consumption. This paper reviews the physiological basis of hair growth, mechanism of drug incorporation, analytical methods, result interpretation and practical application of hair analysis. Moreover, to facilitate the court's decision regarding specific circumstances surrounding the crime, this review demonstrated that the results of hair analysis not only should be admitted as scientific evidence of drug use but also could legally improve reliability of the evidence.

Optimal Software Release Policies under Increasing Error Correction Cost (증가(増加)하는 오류수정비용하(誤謬修正費用下)에서의 최적(最適) 소프트웨어 방출정책(放出政策))

  • Bae, Do-Seon;Yun, Won-Yeong;Lee, Yeong-Bong
    • Journal of Korean Institute of Industrial Engineers
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    • v.15 no.1
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    • pp.51-63
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    • 1989
  • This paper considers software release problems based on Goel-Okumoto and S-shaped reliability growth models. Test of the software system is terminated after a preassigned time T, and it is released to the operational phase. It is assumed that correction cost of an error is increasing with test or operation time. Optimum software release time is obtained using total expected cost on the software life time as a criterion for optimization. In addition, optimal software release policies under the constraint of a software reliability requirement are discussed.

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Life Prediction by Retardation Behavior of Fatigue Crack and its Nondestructive Evaluation (피로균열의 지연거동에 따른 수명예측 및 비파괴평가)

  • Nam, Ki-Woo;Kim, Seon-Jin
    • Journal of Ocean Engineering and Technology
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    • v.13 no.3 s.33
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    • pp.36-48
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    • 1999
  • Fatigue life and crack retardation behavior after penetration were experimentally examined using surface pre-cracked specimens of aluminium alloy 5083. The Wheeler model retardation parameter was used successfully to predict crack growth behavior after penetration. By using a crack propagation rule, the change in crack shape after penetration can be evaluated quantitatively. Advanced, waveform-based acoustic emission (AE) techniques have been successfully used to evaluate signal characteristics obtained form fatigue crack propagation and penetratin behavior in 6061 aluminum plate with surface crack under fatigue stress. Surface defects in the structural members are apt to be origins of fatigue crack growth, which may cause serious failure of the whole structure. The nondestructive analysis on the crack growth and penetration from these defects may, therefore, be one of the most important subjects on the reliability of the leak before break (LBB) design. The goal of the present study is to determine if different sources of the AE could be identified by characteristics of the waveforms produced from the crack growth and penetration. AE signals detected in four stages were found to have different signal per stage. With analysis of waveform and power spectrum in 6061 aluminum alloys with a surface crack, it is found to be capabilities on real-time monitoring for the crack propagation and penetration behavior of various damages and defects in structural members.

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An Empirical Analysis on the Relationship Between Income Inequality and Economic Growth (소득불평등과 경제성장의 상호영향력 분석)

  • Yoon, Jai-Hyung
    • Asia-Pacific Journal of Business
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    • v.8 no.2
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    • pp.15-30
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    • 2017
  • This study analyzes the relationship between income inequality and economic growth. Gini coefficient (market income), the deciles income inequality index and per capita real GDP were analyzed. Furthermore, various cointegration tests were tried to improve the reliability of the test results. From the weak exogeniety test of between per capita real GDP and the Gini coefficient (market income), per capita real GDP has a weak exogeneity while the Gini coefficient is endogenous. From the various cointegration tests, we found out that there is a cointegration between Gini coefficient and per capita real GDP. Moreover, it is estimated that per capita real GDP has a positive effect on the Gini coefficient (market income). In the VAR Granger causal analysis, per capita real GDP affects the Gini coefficient (market income), but it is difficult to say that the Gini coefficient (market income) always has an effect on per capita real GDP. Also, the impulse-response function of the VAR model shows that per capita real GDP temporarily reduces the Gini coefficient (market income), and then increases it over time. Accordingly, it is necessary for the policies to improve not only the distribution structure but also income distribution through economic growth.

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Experimental and numerical simulation study on fracture properties of self-compacting rubberized concrete slabs

  • Wang, Jiajia;Chen, Xudong;Bu, Jingwu;Guo, Shengshan
    • Computers and Concrete
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    • v.24 no.4
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    • pp.283-293
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    • 2019
  • The limited availability of raw materials and increasing service demands for pavements pose a unique challenge in terms of pavement design and concrete material selection. The self-compacting rubberized concrete (SCRC) can be used in pavement design. The SCRC pavement slab has advantages of excellent toughness, anti-fatigue and convenient construction. On the premise of satisfying the strength, the SCRC can increase the ductility of pavement slab. The aim of this investigation is proposing a new method to predict the crack growth and flexural capacity of large-scale SCRC slabs. The mechanical properties of SCRC are obtained from experiments on small-scale SCRC specimens. With the increasing of the specimen depth, the bearing capacity of SCRC beams decreases at the same initial crack-depth ratio. By constructing extended finite element method (XFEM) models, crack growth and flexural capacity of large-scale SCRC slabs with different fracture types and force conditions can be predicted. Considering the diversity of fracture types and force conditions of the concrete pavement slab, the corresponding test was used to verify the reliability of the prediction model. The crack growth and flexural capacity of SCRC slabs can be obtained from XFEM models. It is convenient to conduct the experiment and can save cost.