• Title/Summary/Keyword: Homogeneity test

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Proficiency Testing for the Gas-chromatographic Analysis of Procymidone, Chlorpyrifos and Metolachlor Residues in Soil (가스크로마토그래피를 이용한 토양 중 프로사이미돈과 클로르피리포스, 메톨라클로르의 잔류분석 숙련도시험)

  • Kim, Chan-Sub;Son, Kyeong-Ae;Gil, Geun-Hwan;Kim, Jin-Bae;Hong, Su-Myeong;Kwon, Hye-Young
    • The Korean Journal of Pesticide Science
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    • v.17 no.2
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    • pp.94-106
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    • 2013
  • The proficiency testing for the residue laboratories of pesticide registration was conducted in order to improve the reliability and the ability for pesticide residue analysis. On October 2011 the testing was carried out using the soil collected and kept as the moistened state for five years, which is expected to very low residue levels of pesticides. The soil was fortified with chlorpyrifos, metolachlor and procymidone in a manner similar to prepare soil sample for indoor soil degradation test, and then sub-samples were prepared for the distribution to participants. Some of them were randomly selected for confirm of homogeneity and to ensure the stability of samples at room temperature. Samples were consisted of two soil treated as different levels, one of which was used to the assesment and another used to confirm. In addition, provide three standard solutions, respectively concentration of 10 mg/L, and untreated soil. Forty seven institutions submitted results. The medians of results were used as the assigned values for pesticide residues. Fitness for purpose standard deviation of proficiency test was calculated by applying 20% RSD as the coefficient of variation allowed in the soil residue test. Z-score was applied for evaluation of individual pesticides, and the average of the absolute value of the Z-score for the overall assessment of pesticides. Laboratories evaluated the absolute value of the Z-score less than 2 to fit the case of chlorpyrifos and procymidone were 44, metolachlor 40.

Effect Assessment of Safety Education in Laboratories of Department of Dental Technology Applied of Theory of Planned Behavior (TPB) (TPB 이론을 적용한 치기공학 전공 대학생들의 실습실 안전교육 효과 평가)

  • Park, Jong-Hee;Lee, Myung-Sun
    • The Journal of Korean Society for School & Community Health Education
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    • v.9 no.2
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    • pp.15-31
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    • 2008
  • Objective: This study is a quasi-experimental study by nonequivalent control group pretest-posttest design, performed in order to identify whether the program developed on the basis of Ajzen(1988, 1991)'s theory of planned behavior (TPB) for predicting the safety behavior of students of department of dental technology affects intention toward safety behavior and general behavior. Therefore, the purpose of this study is to identify whether the safety education in laboratories in which knowledge is reinforced on the basis of the TPB theory affects safety behavior. Methodology: The theoretical framework of this study was established on the basis of the TPB by Ajzen(1988, 1991). This study was performed between May 20 and December 5, 2006, and the subjects included 101 in the experimental group and 98 in the control group, a total of 199. The experimental group was educated through six 50-minute sessions (twice a week) for three weeks. The experimental group was pretested, educated, and then asked to answer the pro-questionnaire after finishing the sixth session, but the control group was free from intervention. The research tool in this study was developed by the authors with reference to the process of tool development used in Schifter and Ajzen (1985) based on Ajzen and Fishbein(1980)'s tool development guide. Results: The data were analyzed through SPSS 14.0 version. The reliability test of attitude, subjective norm, perceived norm, intention, and behavior toward safety behavior as TPB variables was calculated of Cronbach's alpha coefficient, and general characteristics and the homogeneity test of the experimental and the control groups were analyzed through t test and $X^2$ test. According to the results of the analysis, the experiment group may be higher than the control group after the safety education in the scores of attitude, the subjective norm, the perceived norm, and the intention toward safety behavior as TPB independent variables showed no significant difference, but there was significant difference in the behavior and the knowledge. Meanwhile, according to the results of the pretest and posttest, eleven items in the experimental group and two items in the control group showed significant difference in the behaviors, and twelve in the former and four in the latter were significantly different in the knowledge. Conclusion: The safety education program developed on the basis of TPB was identified to enhance safety behavior and knowledge. Therefore, the safety education program used in this study for students of department of dental technology may be utilized as database for safety education in the department of dental technology.

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Effects of Perceived Similarity between Consumers and Product Reviewers on Consumer Behaviors (상품후기 작성자에 대해 상품후기 독자가 느끼는 유사성이 상품후기 독자에게 미치는 영향)

  • Kim, Ji-Young;Suh, Eung-Kyo;Suh, Kil-Soo
    • Asia pacific journal of information systems
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    • v.18 no.3
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    • pp.67-90
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    • 2008
  • Prior to making choices among online products and services, consumers often search online product reviews written by other consumers. Online product reviews have great influences on consumer behavior because they are believed to be more reliable than information provided by sellers. However, ever-increasing lists of product reviews make it difficult for consumers to find the right information efficiently. A customized search mechanism is a method to provide personalized information which fits the user's requirements. This study examines effects of a customized search mechanism and perceived similarity between consumers and product reviewers on consumer behaviors. More specifically, we address the following research questions: (1) Can a customized search mechanism increase perceived similarity between product review authors and readers? (2) Are product reviews perceived as more credible when product reviews were written by the authors perceived similar to them? (3) Does credibility of product reviews have a positive impact on acceptance of product reviews? (4) Does acceptance of product reviews have an influence on purchase intention of the readers? To examine these research questions, a lab experiment with a between-subject factor (whether a customized search mechanism is provided or not) design was employed. In order to enhance mundane realism and increase generalizability of the findings, the experiment sites were built based on a real online store, cherrya.com (http://www.cherrya.com/). Sixty participants were drawn from a pool that consisted of undergraduate and graduate students in a large university. Participation was voluntary; all the participants received 5,000 won to encourage their motivation and involvement in the experiment tasks. In addition, 15 participants, who selected by a random draw, received 30,000 won to actually purchase the product that he or she decided to buy during the experiment. Of the 60 participants, 25 were male and 35 were female. In examining the homogeneity between the two groups, the results of t-tests revealed no significant difference in gender, age, academic years, online shopping experience, and Internet usage. To test our research model, we completed tests of the measurement models and the structural models using PLS Graph version 3.00. The analysis confirmed individual item reliability, internal consistency, and discriminant validity of measurements. The results show that participants feel more credible when product reviews were written by the authors perceived similar to them, credibility of product reviews have a positive impact on acceptance of product reviews, and acceptance of product reviews have an influence on purchase intention of the readers. However, a customized search mechanism did not increase perceived similarity between product review authors and readers. The results imply that there is an urgent need to develop a better customized search tool in order to increase perceived similarity between product review authors and readers.

The Effect of Small Group Plastic Artistic Activities on the Emotional Intelligence of Early Young Children (소집단 소조활동이 유아의 정서지능에 미치는 효과)

  • Kim, Young Ju;Choi, Im Soo
    • Korean Journal of Childcare and Education
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    • v.3 no.1
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    • pp.17-37
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    • 2007
  • An abundant emotional experience in childhood can be a basis of success of their life. In this research, I set up a hypothesis as follows to see if a group plastic activities are effective for the improvement of children's emotional intelligence and self-emotion awareness ability, self-emotion management ability, self-motivation ability, other's emotion awareness ability and personal relationship skill ability. The research subjects were 40 children of 5 years old(experimental Group: 20, controlled group: 20) in Y kindergarten located in Ulsan. In pretest, we confirmed homogeneity between experiment and control group using child emotional checklist and then applied small group plastic artistic activities to the experiment group. Data analysis was performed with population, percentage, t-test and Cronbach a. The findings of this study were: First, the group plastic artistic activities was effective for the emotional intelligence of children. Second, the small group plastic activities was effective for the self-emotion awareness, self-emotion control and self motivation ability of children. Third, the small group plastic activities was effective for the awareness ability about other's emotion and personal relationship skill ability. The result of this study implies that the small group plastic artistic activities are effective children's emotion and we need to develop the various activity program and practice for children's emotion development.

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Microbiological Hazard Analysis for HACCP System Application to fermented milk (발효유류의 HACCP 시스템 적용을 위한 미생물학적 위해 분석)

  • Park, Seong-Bin;Kwon, Sang-Chul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.1
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    • pp.438-444
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    • 2015
  • The aim of this research was to apply a HACCP system (Hazard Analysis Critical Control Point) to fermented milk. The main ingredients of fermented milk, work facilities and workers were obtained from a company named YD, which is located in Seobuk-gu, Cheonan-si between November 5 2013 to April 13, 2014. A manufacturing process chart was prepared by referring to the manufacturing process of fermented milk manufacturers in common. The manufacturing process chart was made with raw materials; Raw milk, High Fructose Corn Syrup, Oligosaccharides, Lactic Acid bacteria and Subsidiary ingredients, Warehousing of packaging materials, Storage, Input, Preheating, Mixing, Homogeneity, Sterilization, Precooling, Culture, Filtration, In packaging, Out packaging, Storage, and Consignment, as listed Table 1. The results of the microbiological hazard analysis on the raw materials was safe after sterilization($90^{\circ}C{\pm}5^{\circ}C$, $35{\pm}3min.$) On the other hand,a microorganism test of an environment and workers suggested that the microbiological hazard should be reduced through systematic cleaning and disinfection accompanied by improved personal hygiene based on hygienic education on workers and the management of microorganisms in air.

A Meta-Analysis on the Effects of Social Skill Training for Schizophrenic Patients (정신분열병을 가진 사람들을 위한 사회기술훈련의 효과에 관한 메타분석)

  • Park, Jung-Im;Lee, Keum-Jin
    • The Journal of the Korea Contents Association
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    • v.13 no.12
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    • pp.309-320
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    • 2013
  • The purpose of this study was to examine the effectiveness of interventions for improving the social skills for people with schizophrenia by using method of meta-analysis. For the purpose of the study, master's theses, doctoral dissertations, and journal articles published in korea up to July, 2013 were systematically reviewed. As a result, a total of 22 studies were eligible for the inclusion criteria. The mean effect sizes and test for homogeneity of effect size(Q-statistic) were analyzed by using Comprehensive Meta-Analysis software 2.0. The main findings of the study were as follows. First, the average effect sizes for total social skill training programs were ES=0.838 of interpersonal capacity, ES=0.782 of social behavioral skills, ES=0.601 of self-assertiveness skills, and ES=0.293 of symptoms. Second, by analysing the moderate variables of the effect size for social skill training programs, 'a place of training', 'a major of trainer', 'running times' and 'sessions' were statistically significant. Based on the study results, the research and practice implications were discussed.

The Effects of Improvement of Interaction on Teaching and Learning in Nursing Education Using Change Laboratory Method (간호교육에서 변화실험실을 활용한 강의 상호작용 개선이 교수-학습에 미치는 효과)

  • Kim, Jong Kyung;Yang, Young Hee;Lee, Jeong Eun;Song, Hee-Seung
    • The Journal of the Korea Contents Association
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    • v.17 no.10
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    • pp.385-393
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    • 2017
  • The purpose of this study was to develop and apply the participation-centered lecture model and practice principle developed by the Change Laboratory Method to improve the lecture interaction of nursing education and verify the effect. The experimental group was 91, and control group was 83 students who studied in the 3rd and 4th grade at one College of Nursing, This study developed the detail participatory lecture method on January and February and applied it to the students in March, and April, 2017, In the pre-survey, general characteristics, class attitude, and learning strategies were examined and homogeneity test was conducted. Post-survey was conducted with participation, satisfaction, and performance, The results showed that the experimental group and the control group were homogeneous. The average participation levels of the experimental and control groups were 3.98 and 3.77 respectively(t=2.38, p<.05). However, there was no statistically significant difference in the satisfaction and achievement. Therefore, it was expected to improve the participation and performance of students through the application of the participation-centered lecture. In the future, it will be necessary to prepare and implement effective methods for improvement of teaching methods in each subject.

Evaluation Techniques for Residual Structural Performance of a Reinforced Concrete slab under Fire Damage (화재 피해를 입은 철근콘크리트 슬래브의 잔존 구조성능 평가기법)

  • Choi, Kwang-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.2
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    • pp.588-594
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    • 2020
  • This study proposes non-destructive rebound-hardness and ultrasonic testing methods to more accurately evaluate the residual structural performance of reinforced concrete structures in a fire. Techniques are also proposed to assess the stiffness used in the deflection calculation with natural frequencies obtained by vibration tests. In the compressive strength evaluation using rebound hardness, the residual compressive strength of thick specimens and a larger water/cement (W/C) ratio were shown to be large. The homogeneity of concrete at high temperature compared to ambient temperature conditions was assessed by the velocity of ultrasonic waves that penetrate the concrete, and it followed W/C or thickness of slab makes little different results. To assess the stiffness of fire-damaged slabs and increase in deflection, the natural frequency was measured by vibration tests and incorporated into the equation of the stiffness. The application of this technique to the slab experiment showed that it can be a very reasonable evaluation technique. In addition, to evaluate the residual strength of a member after fire, a test of the strength of a component was carried out during and after heating.

Adjustment of heterogeneous variance by milk production level of dairy herd (젖소군의 유생산 수준별 이질성 분산 보정)

  • Cho, Kwang-Hyun;Lee, Joon-Ho;Park, Kyung-Do
    • Journal of the Korean Data and Information Science Society
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    • v.25 no.4
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    • pp.737-743
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    • 2014
  • This experiment was conducted to compare heterogeneity for the variance in dairy cattle population and to induce homogeneity of variance using 502,228 performance test records of dairy cattle. The estimates of heritability for milk yields, fat yields and protein yields were 0.28, 0.26 and 0.24, respectively and the estimate of average breeding value by birth year was lower in HV (heterogenous variance) model than in animal model, collectively. The average breeding values of milk yields, fat yields and protein yields for 545 sire bulls applicable to the criteria of interbull MACE programme were 453.54kg, 10.75kg and 14.33kg, respectively and when the heterogeneity was adjusted they were 432.06kg, 10.15kg and 13.40kg, respectively, which were lower in all milk traits collectively. In animal model, coefficients of phenotypic correlation between dataset I and II were 0.839 in milk yields, 0.821 in fat yields, and 0.837 in protein yields, while in HV model, they were 0.841 in milk yields, 0.820 in fat yields, and 0.836 in protein yields, showing similar results in 2 models. When compared using animal model and HV model, the regression coefficient for ratio of number of daughters by calving year of milk yields increased from 15.157 to 16.105 and that of fat yields increased from =0.227 to =0.196, but that of protein yields decreased from 0.630 to 0.586.

A Study on the Behavior of Piled Raft Foundation Using Triaxial Compression Apparatus (삼축압축 시험기를 이용한 말뚝 지지 전면 기초 거동 연구)

  • 이영생;홍승현
    • Journal of the Korean Geotechnical Society
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    • v.19 no.6
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    • pp.387-395
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    • 2003
  • Model tests were conducted to study the behavior of the piled raft foundation system on sands. Especially in this study, the method using the triaxial compression apparatus was devised and used to apply the confining pressure which is considered difficult in the existing model test on the soil. Steel rods (6mm dia.) and aluminum plates (8mm thickness, 50mm dia.) were used to simulate piles and rafts respectively. Jumunjin standard sands were used to ensure the homogeneity of the sample. After the sample with the piled raft model was laid inside the triaxial cell, the confining pressure was applied and then the compressive force was applied. The increase and/or decrease ratio of the bearing capacity, the load distribution ratio between raft and piles and the effect of settlements decrease depending on the confining pressure, the number of piles and the length of piles were analyzed and the bearing capacity and skin friction of the pile was calculated. By the results of these experiments, the bearing capacity increased and the settlement decreased with this piled raft foundation system. Especially the effect was larger with the increase of the number of piles than with the increase of length of piles. Hereafter, the study of the load transfer mechanism of piles under confining pressure would be made possible using these small model tester like triaxial compression apparatus.