• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.3
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• pp.273-278
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• 2016

This study makes a relative comparison of the results of tensile test and quasi-static analysis using AGL(Adjuster Guide Loop) model that plays a role in adjusting the height of shoulder belt, of the components of the vehicle seatbelt system and attempts to propose a method of reducing the error rate of the quasi-static analysis technique effectively. This study selects two major factors affecting the result of an analysis, draws the result of analysis through the method of experimental design, one of the statistical techniques and understands the contribution rate of the major factors affecting the result of the analysis through ANOVA(Analysis of Variance).

• The Journal of Fisheries Business Administration
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• v.40 no.3
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• pp.127-146
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• 2009

This study is to estimate the factor weights of the reasons for decreases in marine fishery resources using the Analytical Hierarchy Process. Furthermore, it classifies 20 fishes under a fishery resource recovery plan into various groups of fishes according to these factor weights using the non-hierarchial cluster analysis. The factors of decreases in marine fishery resources are identified as bio-ecological, technology-system, economic-business, and fishing village-society factors. Two of the most important factors of decreases in resource are turned out to be the economic-business and bio-ecological factors, estimated as 31% and 30% respectively. The technology-system and fishing village-society factors are estimated as 21% and 18% respectively. The study utilizes non-hierarchical cluster analysis in order to classify 20 fishes into 2, 3, and 4 groups. K-means cluster analysis is applied for grouping in conjunction with ANOVA to identify statistical differences in factors. Once again, the economic-business and bio-economic factors play main role in grouping 2-groups of fishes case. The third group of fishes in addition to the previous 2 groups of fishes appears as those 4 factors of decrease evenly play about the same role at a 3-groups of fishes case. Finally, the economic-business and bio-economic factors are turned out to be evenly important in the 4th group once there are 4-groups of fishes.

• Journal of The Korean Association For Science Education
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• v.20 no.2
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• pp.244-249
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• 2000

Using a sample of 83 secondary school science teachers, this study investigated the views on science and learning which they have. Questionnaires used in this study were the same that Kwon & Pak(1995) administered. Both 'Questionnaire for Perception of Nature of Science' and 'Questionnaire for Constructivistic Views of Learning' were 11-point scales. Data analyses were done by using t-test and ANOVA. The secondary science teachers showed a relativistic, deductivistic, instrumental, and process-oriented views on science. The younger age of the teachers, the more emphasis on process rather than content. Female teachers had more relativistic, instrumental, and process-oriented views than male teachers had. The teachers sampled in this study showed a constructivistic view on learning. Finally, the teachers' views of science and learning were closely related each other.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.4
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• pp.148-154
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• 2016

A study on the micro particle blasting was conducted to find the optimum conditions of the blasted surface of aluminum 6061. The particle type such as $Al_2O_3$ and SiC, nozzle diameter, pressure, standoff distance and injection time were used as blasting conditions. Statistical method of orthogonal arrays(ANOVA) was used to find optimum conditions of maximum depth and maximum diameter of blasted surface. Particle type, nozzle diameter, and pressure were found to be the main factors of maximum blasted depth and diameter. Maximum blasted diameter was affected by increasing pressure and nozzle diameter but saturated maximum diameter. Maximum blasted depth was affected by pressure and nozzle diameter when aluminum 6061 was blasted with $Al_2O_3$ particle. The value of surface roughness was increased as pressure and nozzle diameter increased when aluminum 6061 was blasted with SiC.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.2 s.179
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• pp.73-80
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• 2006

High speed machining(HSM) technique is widely used in the appliance, automobile part and mold industries, because it has many advantages such as good quality, low cost and rapid machining time. But it also has problems such as tool breakage, smooth tool path, and so on. In particular, small size end mill is easy to break, so it must be changed before interrupting operation. Generally, the tool life of small size end mill is affected by the milling conditions whose selected parameters are spindle speed, feedrate, and width of cut. The experiments were carried out by full factorial design of experiments using an orthogonal array. This paper shows optimal combination and mathematical model for tool life, Therefore, the analysis of variance(ANOVA) is employed to analyze the main effects and the interactions of these milling parameters and the second-order polynomial regression model with three independent variables is estimated to predict tool life by multiple regression analysis.

• Laser Solutions
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• v.14 no.2
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• pp.1-7
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• 2011

The latest trends of vehicle technology development are fuel efficiency improvement, body designs declining air resistance and lightweight of materials. Especially, as lightened weight of materials makes engine efficient so that vehicles keep the best performance, it is the best way to protect the environment and reduce fuel consumption. In this study, we conducted laser welding by using 3-dimension remote scanner that is 5J32 aluminium alloy. Furthermore, conduction experiment that was 3 times repeated for changing factors such as observing angle, laser power and welding speed. we observed exterior and cross section of weled part and tensile strength. When increasing laser power and decreasing laser speed, tensile strength increased. In order to evaluate factors that affect tensile strength qualitatively we conducted ANOVA. We assumed that the factors are observing angle, laser power and welding speed. Then we found that laser power and laser speed affect tensile strength. We conducted evaluation of weldability of aluminium alloy by above ways.

• Journal of Pharmaceutical Investigation
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• v.37 no.1
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• pp.27-37
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• 2007

Proficiency test is an essential tool far ensuring analytical ability of analytical chemists and analytical institutes. Usually, the standard protocol for proficiency test is focused on acceptability of reported analytical results of participants by calculating z-scores and related diagnostic parameters. The ultimate goal of this process is to reveal the sources of variability of analytical results and to find the way to reduce their influence. In this study, the method of analysis of variance (ANOVA) was applied to the analytical data collected from qualify control departments of pharmaceutical companies in KyungIn province in Korea in the year of 2000. As influencing factors of variability of analytical results, the use of internal standards for liquid and gas chromatograpy, the educational and professional background of participants, geological locations and yearly production sizes of participating companies were evaluated. To evaluate the variability in accuracy of analytical results, absolute differences from sample mean and sample median were used and to evaluate variability in precision of individual participants, the reported standard deviation of each participant was used. As a result, the use of internal standards in gas chromatographic analysis, participants' academic background and the yearly production sizes of pharmaceutical companies showed statistically significant influence to the accuracy and the precision of the reported analytical results used in this study.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.12
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• pp.110-115
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• 2001

In this paper, a multiple comparison was proposed to minimize the amount of coolant. And new coolant level, called "low level", was suggested to show usefulness of multiple comparison for experiments. The amount of this levee is about 1/4 of conventional coolant amount-called "high level", and dry cutting is called "none level". Using these coolant levels, the cutting temperatures of each coolant level in turning process were analyzed by analysis of variance(ANOYA)-test and a multiple comparison. As the result of ANOVA-test, we have just known that the average of temperature of each coolant level is not equal. However by Tukey's HSD, one of multiple comparison. it was analyzed that the average of temperature of low level is similar to that of high levee and different from that of none level.erent from that of none level.

• Journal of the Korean Solar Energy Society
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• v.30 no.2
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• pp.1-9
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• 2010

This study has intended to analyze citizen's recognition on Photovoltaic (PV) System Supply Policy in Korea. To reach this goal, this study has employed a survey method and statistical analysis. We have asked 140 citizens knowing the policy to some degree to answer questionnaires including various contents related to PV supply policy driven by central government of Korea. The contents of questionnaires consist of three parts: 1) supply policies, 2) PV system and 3) expected effect from the policy. To verify any differences among the characteristics of respondents, ANOVA (Analysis of Variance) was carried out in 95% confidence level. This study has found the following results: 1) most citizens were positive about the 'Photovoltaic System Supply Policies'; 2) most citizens anticipated the policy would be helpful to cope with the environmental problems and energy crisis and 3) there exit subtle differences between residents according to the respondent's characteristics such as sex, age, occupation, and housing type.

• Journal of the Korea Convergence Society
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• v.9 no.12
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• pp.321-330
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• 2018

The purpose of this study was to investigate the differences in the perception of directors of child-care center about parental education according to types of child-care centers. The subjects were 147 directors of child-care centers who reside in Chungbuk, Sejong, and Jeonbuk. Data were collected through questionnaires. The collected data were analyzed using SPSS 18, and frequency analysis, chi-square method and ANOVA method and Tukey test was also used for the posttest. The results of this study are as follows. There was no difference in the recognition of the director about the necessity of the parental education depending on the type of child-care center. There was a difference in the recognition of the directors in relation to subjects of parental education, the execution method, and evaluation area of parent education.