• Title/Summary/Keyword: Two-Factor

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Propose to new Method determining level of Noise Factor of Taguchi Method (다구찌 기법의 잡음인자 수준 정하는 기법 제안)

  • Ree, Sang-Bok
    • Proceedings of the Korean Society for Quality Management Conference
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    • 2009.10a
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    • pp.317-323
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    • 2009
  • In this paper, we propose new methods which is to determine level of noise factor. Even Taguchi give level of noise factor which is best(or maximum) and worst(or minimum) condition, we give level of noise factor which is representative value by observing noise factor frequency. Sometimes level of noise factor is given one, two and three. We know this method is more fit in real fields.

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Method determining level of Noise Factor of Taguchi Method under various probability distribution (다양한 확률분포 하에서 다구찌 기법의 잡음인자 수준 정하는 기법)

  • Ree, Sang-Bok
    • Journal of Korean Society for Quality Management
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    • v.37 no.4
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    • pp.10-15
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    • 2009
  • In this paper, we propose new methods which is to determine level of noise factor. Even Taguchi give level of noise factor which is best(or maximum) and worst(or minimum) condition, we give level of noise factor which is representative value by observing noise factor frequency. Sometimes level of noise factor is given one, two and three. We know this method is more fit in real fields.

On the Numerical Stability of Dynamic Reliability Analysis Method (동적 신뢰성 해석 기법의 수치 안정성에 관하여)

  • Lee, Do-Geun;Ok, Seung-Yong
    • Journal of the Korean Society of Safety
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    • v.35 no.3
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    • pp.49-57
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    • 2020
  • In comparison with the existing static reliability analysis methods, the dynamic reliability analysis(DyRA) method is more suitable for estimating the failure probability of a structure subjected to earthquake excitations because it can take into account the frequency characteristics and damping capacity of the structure. However, the DyRA is known to have an issue of numerical stability due to the uncertainty in random sampling of the earthquake excitations. In order to solve this numerical stability issue in the DyRA approach, this study proposed two earthquake-scale factors. The first factor is defined as the ratio of the first earthquake excitation over the maximum value of the remaining excitations, and the second factor is defined as the condition number of the matrix consisting of the earthquake excitations. Then, we have performed parametric studies of two factors on numerical stability of the DyRA method. In illustrative example, it was clearly confirmed that the two factors can be used to verify the numerical stability of the proposed DyRA method. However, there exists a difference between the two factors. The first factor showed some overlapping region between the stable results and the unstable results so that it requires some additional reliability analysis to guarantee the stability of the DyRA method. On the contrary, the second factor clearly distinguished the stable and unstable results of the DyRA method without any overlapping region. Therefore, the second factor can be said to be better than the first factor as the criterion to determine whether or not the proposed DyRA method guarantees its numerical stability. In addition, the accuracy of the numerical analysis results of the proposed DyRA has been verified in comparison with those of the existing first-order reliability method(FORM), Monte Carlo simulation(MCS) method and subset simulation method(SSM). The comparative results confirmed that the proposed DyRA method can provide accurate and reliable estimation of the structural failure probability while maintaining the superior numerical efficiency over the existing methods.

Moderate Effect of JIT and Workforce Management on Infra and Process Factor in Quality Management Practices (품질경영 실행방식 요인과 성과 간 관계에 대한 JIT와 인력관리의 조절 효과)

  • Park, Jeong-Soo;Chang, Deok-Shin;Kim, Soo-Wook
    • Korean Management Science Review
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    • v.27 no.3
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    • pp.99-115
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    • 2010
  • We classified quality management practices of manufacturing companies into 'Infra' factor and 'Process' factor which were introduced based on existing literatures and previous studies related to quality management. It was our first objective to confirm its conformance in Korean manufacturing industry, and to examine the two factors effect positively on production performance. Moreover, we tried to examine whether JIT and workforce management have an moderate effect on 'Infra and Process factors-performance' relationship, using moderate regression. As the result of empirical study on nationwide manufacturing companies, we had the results that the classification between Infra factor and Process factor in quality management practices was valid in Korean manufacturing companies, and that the two factors gave performances positive effect. Moreover, our secondary analysis showed that JIT had an positive moderate effect on the Infra factor while workforce management on the Process factor. With these results, we have an interpretation that manufacturing companies which aim to enhance short term performances have to concentrate their effort and investment on Process factor and, on the other hand, ones which aims to improve long term performances on Infra factor.

Forecasting the Grid Parity of Solar Photovoltaic Energy Using Two Factor Learning Curve Model (2요인 학습곡선 모형을 이용한 한국의 태양광 발전 그리드패리티 예측)

  • Park, Sung-Joon;Lee, Deok Joo;Kim, Kyung-Taek
    • IE interfaces
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    • v.25 no.4
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    • pp.441-449
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    • 2012
  • Solar PV(photovoltaic) is paid great attention to as a possible renewable energy source to overcome recent global energy crisis. However to be a viable alternative energy source compared with fossil fuel, its market competitiveness should be attained. Grid parity is one of effective measure of market competitiveness of renewable energy. In this paper, we forecast the grid parity timing of solar PV energy in Korea using two factor learning curve model. Two factors considered in the present model are production capacity and technological improvement. As a result, it is forecasted that the grid parity will be achieved in 2019 in Korea.

A Study on Two Group Comparison in Gene Expression Data

  • Seok, Kyung-Ha;Lee, Sangfeel;Bae, Whasoo
    • Communications for Statistical Applications and Methods
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    • v.11 no.2
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    • pp.247-254
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    • 2004
  • Tusher, Tibshirani and Chu (2001) suggested SAM (Significance Analysis of Microarrays) to compare two groups under different conditions for each gene, using microarray data. They used two sample t-statistic adding fudge factor in the denominator to prevent the value of statistic from being inflated by large sample variance, which might result in significant difference despite of a small value in the numerator. This paper aims at finding robust fudge factor and replacing it in two-sample t-statistic used in SAM, which we call Modified SAM (MSAM). Using the simulated data and data used in Dudoit et al.(2002), it is shown that MSAM find significant genes better and has less error rate than SAM.

Psychological Well-being Measurement: A Comparative Study of Korean and American Adults

  • An Jeong-shin;Lambert Michael C.;Han Gyoung-hae;Cha Seung-eun
    • International Journal of Human Ecology
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    • v.5 no.2
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    • pp.13-29
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    • 2004
  • Ryff's(1989) psychological well-being measure is used to assess and sometimes compare Korean and American adults, however, there is no information regarding whether its dimensions are psychometrically invariant across, whether its items provide sufficient information for, and whether each item measures identical trait levels in, the two nations. Confirmatory factor analysis on response 1,696 Korean and 3,669 American adults, gave to the measure revealed lack of fit and absence of factorial invariance across the two nations. Item response theory revealed significant variance for items on each factor across two countries that most items yielded limited psychometric information. And that each item measure different trait levels, suggesting that in its present form, the measure might lead to misleading results for, and across the two nations.

AEffects of Impeller Blade Thickness on Performance of a Turbo Blower (임펠러 블레이드 두께가 터보블로워 성능에 미치는 영향)

  • Park, Jun-Young;Park, Moo-Ryong;Hwang, Soon-Chan;Ahn, Kook-Young
    • The KSFM Journal of Fluid Machinery
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    • v.13 no.4
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    • pp.5-10
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    • 2010
  • This study is concerned with effects of impeller blade thickness on performance of a turbo blower. This turbo blower is developed as an air supply system in 250 kW MCFC system. The turbo blower consists of an impeller, two vaneless diffusers, a vaned diffuser and a volute. The three dimensional, steady state numerical analysis is simultaneously conducted for the impeller, diffuser and volute to investigate the performance of total system. To consider the non-uniform condition in volute inlet due to volute tongue, full diffuser passages are included in the calculation. The results of numerical analysis are validated with experimental results of thin blade thickness. Total pressure ratio, efficiency, slip factor and blade loading are compared in two cases. The slip factor is different in two cases and the comparison of two cases shows a good performance in thin blade thickness in all aspects.

A Study on Two Stage PFC Full-Bridge Converter with a Single PWM Controller (단일 PWM 제어기에 의한 역률보상 이단 풀 브리지 컨버터에 관한 연구)

  • Jeon, Joon-Sang;Kim, Yong;Kwon, Soon-Do;Kim, Pil-Soo;Yoon, Suk-Ho
    • Proceedings of the KIEE Conference
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    • 2000.11b
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    • pp.368-371
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    • 2000
  • Two-stage power factor correction (PFC) converter with a single PWM controller is proposed. It consists of a power factor pre-regulator cascaded by an isolated DC/DC converter as in a conventional two-stage approach. However, a single PWM controller is used as in a single-stage, single-switch PFC approach. This converter gives the goof power factor correction, low line current harmonic distortions, and tight output voltage regulations. This converter also has a high efficiency by employing an soft switching method. The proposed approach has advantages such as high performance over the single-stage approach and low cost over two-stage approach. The experimental results obtained on a 300W (30V/10A) prototype PFC converter are given to verify the effectiveness of the proposed control method.

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