• Title, Summary, Keyword: 분산분석(ANOVA)

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The analysis of random effects model by projections (사영에 의한 확률효과모형의 분석)

  • Choi, Jaesung
    • Journal of the Korean Data and Information Science Society
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    • v.26 no.1
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    • pp.31-39
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    • 2015
  • This paper deals with a method for estimating variance components on the basis of projections under the assumption of random effects model. It discusses how to use projections for getting sums of squares to estimate variance components. The use of projections makes the vector subspace generated by the model matrix to be decomposed into subspaces that are orthogonal each other. To partition the vector space by the model matrix stepwise procedure is used. It is shown that the suggested method is useful for obtaining Type I sum of squares requisite for the ANOVA method.

Geostatistical Interpretation of Cs-137 and K-40 Result of the Lithosphere in the Vicinity of Youngkwang Nuclear Power Plant (지구통계학적 방법에 의한 영광원전주변 토층내 Cs-137 및 K-40 측정 결과의 해석)

  • 김경웅;이재석;문승현;박철승;고일원;고은정;조병옥;정철영;전수열
    • Economic and Environmental Geology
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    • v.35 no.6
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    • pp.545-552
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    • 2002
  • In order to investigate the influence of nuclear power plant operation on its nearby environment, soil, stream and marine sediment samples were collected in the vicinity of the Youngkwang Nuclear Power Plant in Korea, and analyzed for artificial and natural radionuclide radioactivity. From the analytical result, Cs-137 was detected in most soil samples. but it may have been derived fiom past nuclear weapon tests because Cs-134 having short half-live was not detected. The radioactivities of Cs-137 in the sediment samples were also detected which are within the normal range in the sediments based upon the published literature between 1997 and 1999. For the quality control of radioactivity analysis of environmental samples, sets of marine sediments in the Gamami area were analyzed using two HPGe Gamma-ray Spectroscopes (30% and 45%) according to the geostatistical sampling strategy, and Cs-137 and K-40 results were interpreted by analysis of variance (ANOVA). In the two-way ANOVA, variances derived from the geochemical variation were significant, but errors from sampling and analytical procedures are negligible. In conclusion. all the radioanalytical procedures of this study including sampling are validated to be acceptable.

A Basic Study on the Surface Roughness in Turning Process Considering Taper Angle Variation (선삭공정의 각도변화가 표면거칠기에 미치는 영향에 관한 기초 연구)

  • Kim, Dong-Hyeon;Choi, Jun-Young;Lee, Choon-Man
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.10 no.6
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    • pp.16-21
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    • 2011
  • In machining operation, the quality of surface finish is an important factor for many turned products. In this paper, surface quality in turning machining considering angle variation has been investigated. To reach this goal, surface quality turning experiments are carried out according to cutting conditions with angle variation. The variable cutting conditions are cutting speed, feed rate and taper angle of workpiece. The surface roughness was measured and the effects of cutting conditions were analyzed by the method of analysis of variance (ANOVA). From the experimental results and ANOVA, it is found that a better surface roughness can be obtained as decreasing feed rate, increasing cutting speed. Taper angle variation has been more influenced by feed rate and cutting speed.

Surface roughness evaluation in turning by an orthogonal array method (직교배열법에 의한 선삭가공시 표면거칠기 평가)

  • 배병중;박태준;양승한;이영문;김희술
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.862-865
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    • 2000
  • The object of this paper is to evaluate the surface roughness using the experimental equation of surface roughness, which is developed in turning by an orthogonal array method. $L_9{3^4}$ orthogonal array method, one of fractional factorial design has been used to study effects of main cutting parameters such as cutting speed, feed rate and depth of cut, on the surface roughness. And the analysis of variance (ANOVA)-test has been used to check the significance of cutting parameters. Using the result of ANOVA-test, the experimental equation of surface roughness, which consists of only significant cutting parameter - feed rate, has been developed. The coefficient of determination of this equation is 0.962.

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A Statistical Study on the Blasting Conditions when Micro Blasting for Rotating Aluminum Rod (회전하는 알루미늄 환봉의 미세입자 분사가공시 통계적 방법에 의한 분사조건에 대한 연구)

  • Kwon, Dae Kyu;Wang, Duck Hyun
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.16 no.2
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    • pp.135-141
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    • 2017
  • An experimental study of micro blasting for a rotating aluminum rod was conducted through the statistical analysis of ANOVA to obtain the effect of blasting conditions. The rotating equipment was designed and constructed with forward and backward moving for helical blasting, but rotation was used in this study. The blasting condition factors were the type of abrasive particle, nozzle diameter, pressure, standoff distance, injection time, etc. The width of the surface, the maximum depth of the sprayed surface, and ANOVA were analyzed by statistical analysis. The results showed that the contributions of the main factors were pressure, nozzle diameter, and injection particle.

Process Optimization for Co-based Self-flux Alloy Coating by Taguchi Method (다구찌 기법에 의한 코발트기 자융성합금 용사코팅의 최적공정 설계)

  • Lee, Jae-Hong;Kim, Yeong-Sik
    • Journal of the Korea Society For Power System Engineering
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    • v.17 no.6
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    • pp.108-114
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    • 2013
  • This paper describes process optimization for thermal-sprayed Co-based self-flux alloy coating by Taguchi method. Co-based self-flux alloy coatings were fabricated according to $L_9(3^4)$ orthogonal array using flame spray process. Hardness test and wear test were performed, the results were analyzed by analysis of variance(ANOVA) considering a multi response signal to noise ratio(MRSN). From the results of ANOVA, the optimal combination of the flame spray parameters on Co-based self-flux alloy coating could be predicted. The calculated hardness and wear rate of the coatings by ANOVA were found to be close to that of confirmation experimental result.

The Method of Results of Decision Reflections Between PI Project Valuation Groups Using AHP (AHP를 활용한 PI사업 평가그룹간 의사반영 방안)

  • Kim, Kwan-Joong;Jang, Myung-Soon
    • International Journal of Highway Engineering
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    • v.8 no.4
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    • pp.145-157
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    • 2006
  • Generally, the method of the policy analysis has been used for making a policy decision of the development project of the road through the expert interview based on AHP. According to introducing PI, the study of the method of the integrating process for various opinion of the related groups is required. On this study I evaluate what is a difference between the results of integrated process and the AHP analysis on what is major considering factor in decision-making process. From the analysis, each evaluate factor is in level of significance by ANOVA. First, there is a significance level difference between Group A, C and Group B Second, there is also a significance level difference on the result of AHP analysis for each group in order to evaluate by integrated method. Finally, the method of AHP analysis which considers priority factor is expected as to be useful tool on decision-making of various group.

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The Factors Influencing on an Yield of the Retirement Pension (퇴직연금 수익률에 영향을 미치는 요인 분석)

  • Jung, Se-Chang
    • Journal of the Korean Data Analysis Society
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    • v.20 no.5
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    • pp.2507-2518
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    • 2018
  • The purpose of this study is to suggest a useful implication to the participants based on analyzing the difference in the accumulated yield between the type of retirement pension and among the retirement pension companies. We employed the data from the Financial Supervisory Service (FSS). t-test, ANOVA and chi square test are used for the analysis. As a result of the analysis, the accumulated yield in the non-guaranteed is higher than the accumulated yield in the guaranteed. The accumulated yield of the insurance companies is better than that of banks and the securities companies in DB. On the other hand the accumulated yield of the securities companies is better than that of bank and the insurance companies in DC. With regard to the characteristic of financial companies, a company with a small reserve presents a better accumulated yield in the guaranteed DB and also the guaranteed DC. While a company with high affiliates shows a better accumulated yield in the guaranteed DC, a company with low affiliates presents a better accumulated yield in the non-guaranteed DC. In order to improve the accumulated yield, this paper suggests the non-guaranteed rather than the guaranteed, an insurance company in DB, a security company in DC.

A Comparative Review on Building Height Regulations Using GIS Simulation (GIS Simulation을 이용한 건축높이 규제 방안의 비교검토)

  • Kim, Ho-Yong;Yun, Jeong-Mi
    • Journal of the Korean Association of Geographic Information Studies
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    • v.16 no.2
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    • pp.129-140
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    • 2013
  • This study reviewed different results according to the selection of viewpoints and considerations of the neighborhood in the analysis of view to regulate the height of buildings. To do this, 4 cases were set according to the analytical methodology and a GIS simulation was performed. Characteristics of each methodology were compared and analyzed by simulated values with ANOVA(analysis of variance) and post-hoc analysis. First, the method using moving viewpoints was found to be appropriate for the regulation of building height as it could reflect basic characteristics of landscape which was sequential and it did not show big difference in analysis result according to situational setting. Second, the method using grid viewpoints showed a problem that viewpoints at left and right sides viewed ridges of other mountains than the background mountains of the target land. Additionally, the simulation method that induces three-dimensional cross-sections between multiple sight-surface and virtual construction points created at viewpoints used in this study was found to be useful in the simulation review with various settings as it induced the marginal height of the spot quantitatively.

Process Optimization for Thermal-sprayed Ni-based Hard Coating by Design of Experiments (실험계획법에 의한 니켈기 경질 용사코팅의 최적 공정 설계)

  • Kim, K.T.;Kim, Y.S.
    • Journal of the Korea Society For Power System Engineering
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    • v.13 no.5
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    • pp.89-94
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    • 2009
  • In this work, the optimal process has been designed by $L_9(3^4)$ orthogonal array and analysis of variance(ANOVA) for thermal-sprayed Ni-based hard coating. Ni-based hard coatings were fabricated by flame spray process on steel substrate. Then, the hardness test and observation of microstructure of the coatings were performed. The results of hardness test were analyzed by ANOVA. The ANOVA results demonstrated that the acetylene gas flow had the greatest effect on hardness of the coatings. The oxygen gas flow was found to have a neglecting effect. From these results, the optimal combination of the flame spray parameters could be predicted. The calculated hardness of the coatings by ANOVA was found to lie close to that of confirmation experimental result. Thus, it was considered that design of experiments design using orthogonal array and ANOVA was useful to determine optimal process of thermal-sprayed Ni-based hard coating.

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