• 제목/요약/키워드: Difference-in-Differences

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개인차를 고려한 중학교 기하 교수-학습 방법 개발 (A Study on Teaching Methods of Geometry Based on Individual Differences in Middle School)

  • 권영인;서보억
    • 한국수학교육학회지시리즈A:수학교육
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    • 제47권2호
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    • pp.113-133
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    • 2008
  • This study is to develop the methods of specifying teaching that can consider individual differences in middle school geometry education. The purpose of this study is to decide the variations causing individual differences and to find the proper learning methods considering the variations. Through literature review, this study made it clear that the matter of individual difference is just the matter of talent and examined what factors make up mathematical talents. On the basis of the result, five important variations and fourteen subordinate factors were determined. I researched into the learning methods that consider the determined subordinate factors using the 'congruence' unit of middle school textbooks and developed specific learning methods for each of the subordinate factors through specific congruence problem solving situations. This study can be summarized as follows : I researched the studies of mathematical ability conducted by several educators and psychologists. This research is divided into the early study and the developed study of mathematical ability. Through this study five specific variations were determined. And fourteen subordinate factors have been made from the determined variations. The specific learning methods based on individual differences was developed according to the fourteen subordinate factors on the basis of middle school textbooks of Korea, Gusev's textbook, problem books of Russia, and etc.

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Scene Change Detection using the Automated Threshold Estimation Algorithm

  • Ko Kyong-Cheol;Rhee Yang-Won
    • 한국정보시스템학회지:정보시스템연구
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    • 제14권3호
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    • pp.117-122
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    • 2005
  • This paper presents a method for detecting scene changes in video sequences, in which the $chi^{2}$-test is modified by imposing weights according to NTSC standard. To automatically determine threshold values for scene change detection, the proposed method utilizes the frame differences that are obtained by the weighted $chi^{2}$-test. In the first step, the mean and the standard deviation of the difference values are calculated, and then, we subtract the mean difference value from each difference value. In the next step, the same process is performed on the remained difference values, mean-subtracted frame differences, until the stopping criterion is satisfied. Finally, the threshold value for scene change detection is determined by the proposed automatic threshold estimation algorithm. The proposed method is tested on various video sources and, in the experimental results, it is shown that the proposed method is reliably estimates the thresholds and detects scene changes.

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전문대학 체육전공자의 개인특성에 따른 직업가치관 차이 분석 (Analysis on the Differences of the Occupation Values Towards the Individual Characteristics of the Students Majoring in Sports at Junior Colleges)

  • 송강영;이태용
    • 한국콘텐츠학회논문지
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    • 제9권11호
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    • pp.399-406
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    • 2009
  • 본 연구의 목적은 전문대학 체육전공자들의 개인특성에 따라 인지하는 직업가치관 차이를 분석하는데 있다. 연구결과는 다음과 같다. 첫째, 조직관심에서의 차이는 학년에서 2학년이 1학년보다 높게 나타났고, 연령에서는 23세이상이 21-22세, 19-20세보다 높게 나타났다. 둘째, 경제적 수입에서의 차이는 학년에서 2학년이 1학년보다 높게 나타났고, 연령에서는 23세이상이, 19-20세보다 높게 나타났다. 셋째, 사회적 지지에서의 차이는 학년에서 2학년이 1학년보다 높게 나타났다. 넷째, 일 자부심에서의 차이는 성별에서 남학생이 여학생보다 높게 나타났으며, 학년에서는 1학년이 2학년보다 높게 나타났고, 23세이상이 21-22세, 19-20세보다 높게 나타났다. 다섯째, 행동 선호도에서의 차이는 성별에서 남학생이 여학생보다 높게 나타났다. 여섯째, 신분상승에서는 성별, 학년, 연령이 차이가 나타나지 않았다.

인천지역 정상아동과 장애아동간의 식습관 비교 연구 (A Study on the Differences of Dietary Habits between Normal and Handicapped Children in Incheon Area)

  • 황미경;김영아
    • 한국식품조리과학회지
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    • 제13권2호
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    • pp.192-203
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    • 1997
  • The purpose of this study is to investigate the difference of dietary habits between normal and handicapped children. This study was performed with 166 normal children and 154 handicapped children in Incheon area. There was very significant differences of dietary habits between normal and handicapped children, but there was no significant difference in disable type.

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소비자의 성격유형별 의복평가의 차이 (The Differences of Apparel Evaluation on Consumers Personality Types)

  • 오현정
    • 한국의류학회지
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    • 제25권2호
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    • pp.249-258
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    • 2001
  • The purpose of this study was to determine if personality types affect apparel evaluation. Personality types was applied using Myers-Briggs Type Indicator(MBTI). The data were collected from 101 female using questionnaire to evaluate on apparel, and were analysed with factor analysis, Mann-Whitney test. Results revealed several significant differences with apparel evaluation to personality type. Extroversion and introversion had significant difference in fashion concern. Extroversion types were significantly evaluated fashion concern more than introversion types. Sensing and intuition had significant difference in conformity. Sensing types were significantly evaluated conformity more than intuition types. Thinking and feeling had significant difference in symbolism. Thinking types were significantly evaluated symbolism more than feeling types. Judging and perceiving had significant difference in conformity. Judging types were significantly evaluated conformity more than perceiving types.

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The difference between two distribution functions

  • Hong, Chong Sun
    • Journal of the Korean Data and Information Science Society
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    • 제24권6호
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    • pp.1449-1454
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    • 2013
  • There are many methods for measuring the difference between two location parameters. In this paper, statistics are proposed in order to estimate the difference of two location parameters. The statistics are designed not using the means, variances, signs and ranks, but with the cumulative distribution functions. Hence these are measured as the differences in the area between two univariate cumulative distribution functions. It is found that the difference in the area between two empirical cumulative distribution functions is the difference of two sample means, and its integral is also the difference of two population means.

청소년 이성교제 허용수준에 대한 청소년과 부모세대간 차이 (Generational Differences in the Permissive Levels of Dating Among Youth)

  • 이창식;김용미;박미자
    • 한국지역사회생활과학회지
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    • 제17권4호
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    • pp.127-135
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    • 2006
  • This study investigated differences of opinion between youth and their parents about having permission to date. Opinions on youth dating permission was gathered from 150 adolescents and their parents. The results were as follows: first, for adolescents there were significant differences of opinion about youth dating permission depending on gender, age, scholastic record, and birth order, but for parents, the difference related to the gender and age of adolescents. Second, the result indicated that adolescents had a greater acceptance of dating permission than their parents, expressing a generational difference. Third, where the scholastic record of subjects was low, where subjects were non-eldest siblings, and where the parents' level of youth dating permission was high, the level of youth dating permission was higher. A main predictor of youth's level of dating permission was the level of the parents about youth dating.

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Evaluating Correlation between Geometrical Relationship and Dose Difference Caused by Respiratory Motion Using Statistical Analysis

  • Shin, Dong-Seok;Kang, Seong-Hee;Kim, Dong-Su;Kim, Tae-Ho;Kim, Kyeong-Hyeon;Cho, Min-Seok;Noh, Yu-Yoon;Yoon, Do-Kun;Suh, Tae Suk
    • 한국의학물리학회지:의학물리
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    • 제27권4호
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    • pp.203-212
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    • 2016
  • Dose differences between three-dimensional (3D) and four-dimensional (4D) doses could be varied according to the geometrical relationship between a planning target volume (PTV) and an organ at risk (OAR). The purpose of this study is to evaluate the correlation between the overlap volume histogram (OVH), which quantitatively shows the geometrical relationship between the PTV and OAR, and the dose differences. 4D computed tomography (4DCT) images were acquired for 10 liver cancer patients. Internal target volume-based treatment planning was performed. A 3D dose was calculated on a reference phase (end-exhalation). A 4D dose was accumulated using deformation vector fields between the reference and other phase images of 4DCT from deformable image registration, and dose differences between the 3D and 4D doses were calculated. An OVH between the PTV and selected OAR (duodenum) was calculated and quantified on the basis of specific overlap volumes that corresponded to 10%, 20%, 30%, 40%, and 50% of the OAR volume overlapped with the expanded PTV. Statistical analysis was performed to verify the correlation with the OVH and dose difference for the OAR. The minimum mean dose difference was 0.50 Gy from case 3, and the maximum mean dose difference was 4.96 Gy from case 2. The calculated range of the correlation coefficients between the OVH and dose difference was from -0.720 to -0.712, and the R-square range for regression analysis was from 0.506 to 0.518 (p-value <0.05). However, when the 10% overlap volume was applied in the six cases that had OVH value ${\leq}2$, the average percent mean dose differences were $34.80{\pm}12.42%$. Cases with quantified OVH values of 2 or more had mean dose differences of $29.16{\pm}11.36%$. In conclusion, no significant statistical correlation was found between the OVH and dose differences. However, it was confirmed that a higher difference between the 3D and 4D doses could occur in cases that have smaller OVH value.

성별에 따른 학령기 후기 아동의 자기유능감, 사회불안, 우울 (Gender Differences in Self-competence, Social Anxiety and Depression in Upper Level Primary School Children)

  • 문소현;조헌하
    • Child Health Nursing Research
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    • 제16권3호
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    • pp.230-238
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    • 2010
  • Purpose: The purpose of this study was to examine gender differences in self-competence, social anxiety and depression in upper level primary school children. Methods: In this cross-sectional study, data were collected from 180 students in grades 5 or 6 (83 boys and 97 girls). The instruments used for this study were a self-report questionnaire, the Self-Perception Profile for Children, the Revised Social Anxiety Scales for Children (SASC-R) and a Depression Instrument. For data analysis, descriptive statistics, t-test, Pearson correlation coefficients, and stepwise multiple regression were used with the SPSS/PC ver 12.0 program. Results: The only gender difference was in depression and girls reported more depression than boys. Social competence showed significantly negative correlations with depression and social anxiety. Gender differences were found in self competence in the prediction of depression and social anxiety. Conclusion: The results of this study indicate that there are gender differences in self competence which influence depression and social anxiety. Thus, enhancing self-competence could prevent social anxiety and depression in children but, differences in gender should be considered when developing programs to enhance self-competence.

유아의 건강도에 따른 사고경향예지도에 관한 연구 (A Study on the Effect of Accident-Proneness Prospect by Health Conditions in Children)

  • 방주영
    • 보건교육건강증진학회지
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    • 제13권1호
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    • pp.90-116
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    • 1996
  • The purpose of this study is to provide basic data for the children so as to avoid any accidents and to improve their health through a sound and safe living environment with safety education established through more systematic methods. For the study, the methods used include the questionnaires for collecting data which are distributed among 273 children from 3 to 6 years old. They live in three districts of Seoul (Kangnam and Kangbuk), Kyeonggido (Munsan and Ilsan) and Incheon. The children's general characteristics are investigated and the relationship between the accident-proneness prospects and their results are analyzed assuming that children's health is expected to have an effect on their safety. The findings of the study are as follows: 1. The accident-proneness prospect (for the living safety) has significant difference in sleeping habits and physically weak conditions(p<0.05). 2. The accident-proneness prospect (for the traffic safety) has no significant difference in accordance with the children's health condition. 3. Children's reasoning power has no significant difference in accordance with their health condition. 4. Children's movement speed non-significantly differs in accordance with their health condition. 5. Children's movement stability has a significant difference in accordance with their health conditions such as history of mild disease(p<0.05) and physical work capacity(p<0.05). 6. Children's attention power has no significant difference in accordance with their health condition. 7. Children's characteristic activities show a significant difference in accordance with their health history of mild disease(p<0.05). mental health(p<0.05). eating habits(p<0.05) and others (i.e. auditory abnormality and skin desease)(p<0.05). 8. General assessment of the APP test has no significant difference in accordance with their health condition. 9. The health conditions are a significant difference in the history of mild disease in accordance with sex(p<0.05) and whole family members(p<0.001). Also there are shown significant differences. in accordance with sex(p<0.05). in physical work capacity(p<0.05). Eye sight, blood circulation and skin condition show significant differences in accordance with residence(p<0.05) and whole family members(p<0.01). and the condition of eating habits appeared significant in accordance with age(p<0.05). Also, sleeping habits and physically weak conditions shows significant differences in accordance with age(p<0.001) and housing pattern(p<0.01), and others (i.e. auditory abnormality and skin desease) show significant differences in accordance with residence (p<0.001).

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