• Title/Summary/Keyword: Difference-in-differences analysis

Search Result 4,333, Processing Time 0.034 seconds

A Study on Spatial Differences in PM2.5 Concentrations According to Synoptic Meteorological Distribution (종관 기상 분포에 따른 PM2.5 농도의 공간적 차이에 관한 연구)

  • Da Eun Chae;Soon-Hwan Lee
    • Journal of Environmental Science International
    • /
    • v.31 no.12
    • /
    • pp.999-1012
    • /
    • 2022
  • To investigate the reason for the spatial difference in PM2.5 (Particulate Matter, < 2.5 ㎛) concentration despite a similar synoptic pattern, a synoptic analysis was performed. The data used for this study were the daily average PM2.5 concentration and meteorological data observed from 2016 to 2020 in Busan and Seoul metropolitan areas. Synoptic pressure patterns associated with high PM2.5 concentration episodes (greater than 35 ㎍/m3) were analyzed using K-means cluster analysis, based on the 900 hPa geopotential height of NCEP (National Centers for Environmental Prediction) FNL (Final analysis) data. The analysis identified three sub-groups related to high concentrations occurring only in Busan and Seoul metropolitan areas. Although the synoptic patterns of high PM2.5 concentration episodes that occur independently in Busan and Seoul metropolitan areas were similar, there was a difference in the intensity of pressure gradient and its direction, which tends to be an important factor determining the movement time of pollutants. The spatial difference in PM2.5 concentration in the Korean Peninsula is due to the difference and direction of the atmospheric pressure gradient that develops from southwest to northeast direction.

Hairdo Involvement.Hairdo Attitude Differences Depending on Clothing Involvement and Actual Conditions of Hairdo (의복관여에 따른 헤어관여와 헤어태도의 차이 및 헤어실태)

  • Lee, Hye-Weon;Kim, Mi-Young
    • Journal of the Korea Fashion and Costume Design Association
    • /
    • v.9 no.2
    • /
    • pp.69-83
    • /
    • 2007
  • The purpose of this study was to investigate the differences in the hairdo involvement and hairdo attitude influenced by clothing involvement. In addition, actual conditions of hairdo were investigated. The questionnaires were given to female residents in Seoul and Gyeong-gi province during September to October 2006. Four hundred and six questionnaires were used for data analysis. The collected data were analyzed by using SPSS 12.0 software with various techniques such as factor analysis, Cronbach's alpha, cluster analysis, ANOVA test, Duncan test, frequency analysis and $X^2-test$. The results of this study were as follows; 1. The factors for clothing involvement were found to be interests and pleasure in clothes, coordination of clothes, symbolic representation, fashionableness, and risk awareness. The hairdo involvement factors were found to be interests and pleasure in hairdo, fashionableness, symbolic representation, risk awareness, and coordination of hairdo. The factors for attitude toward hairdo were found to be orientations toward leader's fashion conformity, distinct individuality, constancy, and consciousness of others. 2. According to the level of clothing involvement, three types of group were defined. When difference in the hairdo involvement was analyzed, all factors showed significant differences. When difference in the hairdo attitude was analyzed, significant differences were found in orientations toward leader's fashion conformity, distinct individuality and consciousness of others. 3. Reason for choosing hair style is 'it's because they wanted the hair style', 'it's easy to groom', 'it's what they usually choose'. Average hair grooming time is less than 5 minute had higher rate, and then less than 10 minute came second. The money spend on buying consumption goods for hair treatment per month had the highest rate on spending 10,000 to 20,000won and the source of information on hairdo had the highest rate on hairdresser. The reason for choosing hair saloon had the highest rate on hairdressing skill, which shows that people choose hair saloons which they can trust on hair saloon's hairdressing skill.

  • PDF

A Study on the Perception about Engineering Convergence Competency between Industry and Engineering Students (공학 융합역량에 대한 산업체와 대학생의 인식 비교분석)

  • Huh, Ji-suk;Hwang, Yunja
    • Journal of Engineering Education Research
    • /
    • v.23 no.4
    • /
    • pp.3-13
    • /
    • 2020
  • The purpose of this study is to analyze the differences in the perception and education requirements between industry and engineering students on engineering convergence competency, and to suggest implications for fostering engineers suitable to industry demand and direction of focus improvement in the current engineering education field. To this end, 73 industrial representatives and 104 engineering students are surveyed the engineering convergence competency and educational needs. The results of this analysis are as follows: first, the difference in engineering convergence competency by background variable was significantly different in gender of engineering students. Second, it is found that there is a significant difference between the current level and the required level of engineering convergence competency from an industry perspective. In the IPA results, it shows that new knowledge generation and future-oriented vision skills are urgently needed to be improved. And it is showed that the creative thinking, knowledge utilization, communication, and cooperation capabilities skills need to be maintained continuously. Third, as a result of the analysis of the differences in recognition of the current competency levels between industry and engineering students, there is statistically significant differences in systemic thinking, communication and cooperation, understanding of other academic fields, humanities, and future-oriented perspectives. Therefore, it is necessary to specific plans and efforts to reduce this perception gap should be prepared at the university.

Effects of Different Shoe Heel Heights on the Kinematic Variables of the Lower Extremities during Walking on Slopes by healthy adult women

  • Yang, Yong-pil
    • Journal of the Korean Society of Physical Medicine
    • /
    • v.14 no.3
    • /
    • pp.21-27
    • /
    • 2019
  • PURPOSE: This study examined the changes in the kinematic variables during walking on a downhill ramp according to the shoe heel height. METHODS: The subjects were 10 adult women with no history of musculoskeletal disorders who agreed to participate in the study. Data were collected using a motion analysis system (VICON) consisting of six infrared cameras. The slope was 120 cm in width, 200 cm in length, and 15 in inclination. To confirm the change in gait parameters (stride length, gait speed) and lower extremity joint angle according to the heel heights of the shoes, flat, 5 cm, and 10 cm heel shoes were prepared and walked alternately. RESULTS: As a result, both the stride length and walking speed showed significant differences according to the heel height between flat and 10 cm (p<.05). In the sagittal plane, there was no significant difference in the hip joint and knee joint, but a significant difference was observed in all events in the ankle joint on all heel heights (p<.05). In particular, the heel strike and mid stance events showed significant differences among all height conditions (p<.05). No significant difference was observed in any of the joint angle changes in the frontal plane (p>.05). CONCLUSION: As the shoe heel height increased, the instability increased and efforts to secure the stability were made, leading to a shortened stride length, walking speed, and angle of the ankle joint.

The oral status of the elderly in some states difference between oral health-related quality of life (일부 노인의 구강내 상태에 따른 구강건강관련 삶의질 차이에 관한 연구)

  • Park, Jong-Hee
    • Journal of Technologic Dentistry
    • /
    • v.36 no.1
    • /
    • pp.51-62
    • /
    • 2014
  • Purpose: Recently our country is rapidly aging population is growing. In the oral cavity of the elderly status of oral health-related quality of life to evaluate any impact. Methods: The survey used structured self administered questionnaires from April to May in 2011 in Daejeon and Chungcheong provinces to 277 people, analysis of the general characteristics of a frequency analysis method, the difference between the quality of life T/F test, whether oral self-according to the quality of life healthy oral health effects of the multiple regression analysis. Results: Award comes on the number of residual value, lower age all the more, smaller monthly income was small, but significant difference between them was no difference between gender. Residual value according to the number of differences in the quality of life of physical pain upper, physical disability, the lower the physical pain, physical disability, psychological disability were significant differences in degradation. Depending on oral maxillary prosthesis fitted to physical pain, psychological discomfort, physical disability, the lower the functional limitation, physical pain, there was a significant difference in physical disability. Conclusion: Status of the oral cavity of the elderly factors affecting the quality of life remaining in the lower dimensions, upper and lower prosthetics, self-aware state of oral health in order to improve the quality of life of elderly oral health education to be strengthened to increase the residual value, reducing their own prosthetic perceived oral health is health, so they feel it should be for the development of health education programs for the elderly should be.

Analysis of Variables Affecting Young Children's Relational and External Aggression (유아의 관계적, 외현적 공격성에 영향을 미치는 관련변인들의 탐색)

  • Kim, Yeon
    • Journal of the Korean Home Economics Association
    • /
    • v.48 no.1
    • /
    • pp.55-66
    • /
    • 2010
  • The purpose of this study was to investigate the role of variables on young children's external aggression and relational aggression. Specifically, young children's temperaments and gender differences, parental marital conflicts, fathers' anti-social behaviors, mothers' child-rearing behaviors and psychological characteristics were studied. The findings of the study were as follows: Firstly, it was found that male children exhibited a higher level of external aggression than female children, while there was no significant difference between male and female children in terms of relational aggression. Secondly, analysis of variables such as children's temperaments and domestic environments revealed that fathers' anti-social behaviors, the adaptability of young children's temperaments and mothers' depression tendency have significant explanatory adequacies for young children's relational aggression. Furthermore, gender difference adaptability, activity and emotionality of young children's temperaments, in addition to parental marital conflicts, also have significant explanatory adequacies for young children's external aggression.

The Comparison of Consumer Characteristics according to Purchasing Experience of Secondhand Fashion Goods (중고패션제품의 구매경험에 따른 소비자 특성)

  • Park, Hyun-Hee;Choo, Tae-Gue
    • The Korean Fashion and Textile Research Journal
    • /
    • v.13 no.6
    • /
    • pp.909-916
    • /
    • 2011
  • This study explored the differences in consumer characteristics-consumer self-confidence, attitude toward, trust and purchase intention for secondhand fashion goods, self-confidence in fashion coordination, price sensitivity for fashion product, and environment conservation consciousness-according to purchasing experience of secondhand fashion goods. A set of questionnaire was administered to 400 university students in Daegu from 18 to 28 April 2011. Data were analyzed by factor analysis, Cronbach's ${\alpha}$, frequency, t-tests. Secondhand fashion goods shoppers were 135(37%) and non-shoppers were 230(63%). The difference analysis results between the two groups were as follows. First, in consumer self-confidence, shoppers showed higher than non-shoppers except persuasion knowledge, and there was no difference in marketplace interfaces between the two groups. Second, there were significant differences in attitude toward secondhand fashion goods, trust and purchase intention for secondhand fashion goods between the two groups. Third, shoppers had higher self-confidence in fashion coordination than non-shoppers, but there was no difference in environment conservation consciousness and price sensitivity for fashion product between the two groups. For future study, it is suggested to find out more general characteristics of secondhand fashion goods shoppers covering other age brackets.

Analysis on the innovation pattern by major industry in Korea

  • PARK, Kyoo-Ho
    • East Asian Journal of Business Economics (EAJBE)
    • /
    • v.7 no.4
    • /
    • pp.51-58
    • /
    • 2019
  • Purpose - This paper aims to analyze the difference of technological innovative pattern by industry. Research design and methodology - we try to identify the major factors which can exert an effective influence on actual innovation output, utilizing the result of Korean Innovation Survey. By doing so, this work can make a comparison with Pavitt (1984) and succeeding discussion on sectoral pattern of innovation Results - Analysis on major industry in Korea shows that there are substantial differences in terms of the source of innovation, organization-related factor, and appropriation mechanism among each industry, and differential strategy to be proper for the nature of each industry is needed. There is some variation within industries which deemed as same type of sector defined by Pavitt. Conclusions - This analysis call for elaborate analysis on sectoral pattern of innovation, considering the change and difference of innovative environment as well as differential business strategy and way to do innovate, which is proper considering the nature of innovative pattern in each industry for successful technological innovation in Korea. At the same time, proper policy measure considering the differential pattern of technological innovation is needed.

Familism of Undergraduates and Consciousness for Supporting Their Parents (남녀대학생의 가족주의 가치관과 부모부양의식)

  • 한경순
    • Journal of the Korean Home Economics Association
    • /
    • v.37 no.9
    • /
    • pp.13-24
    • /
    • 1999
  • The aim of this study was to investigate the relationship between familism and consciousness for supporting parents. To achieve this purpose, this study examined the effects of familism on consciousness for supporting parents of the undergraduates, analyzed the differences of it. For this, the subjects were 711 undergraduates living in Kwangju. Statistical analysis used were one-way ANOVA, Duncan-test, Pearson correlation analysis, and simple regression. Results were as follows. 1) The male undergraduates’familism level was higher than that of females. But there was no significant difference in their consciousness for supporting parents related to sex. 2) The familism showed signigicant differences by grade, major, and household income. Parent supporting consciousness of the subjects showed significant differences by age, grade, and major. 3) The differences between familism and parents supporting consciousness were significant. The higher the undergraduates’familism was, the higher the undergraduates’consciousness for supporting parent was. In particular, for male, familism was shown to be the most important factor predicting their consciousness for supporting parents.

  • PDF

A study on reflective spectrum between In-Ceram alumina core and IPS Empress 2 core (In-Ceram Alumina Core와 IPS Empress 2 core의 분광반사율 연구)

  • Park, Myung-Ja;Kim, Joo-Won
    • Journal of Technologic Dentistry
    • /
    • v.23 no.2
    • /
    • pp.189-202
    • /
    • 2002
  • A study on reflective spectrum between In-Ceram alumina plate(IAP) and IPS empress 2 plate were carried out in order to determine the difference of reflective spectrum rates between materials and between thicknesses of materials(0.8mm, 1.0mm, 1.2mm) by visible wave. The rates are measured by spectrophotometer(Top scan model TC-1800). And an analysis of ANOVA and paired sample t-test were carried out. The results are summarized as follows. 1. The reflective rates of IAP and IPS increased slowly as visible wave spectrum increased. 2. The difference of reflective rates of IAP between 0.8mm and 1.0mm is significant but a little(less than 1%). The differences of reflective rates of IAP between 0.8mm and l.2mm and between 1.0mm and l.2mm are significant(8%, 10% ). 3. The differences of reflective rates of IPS between 0.8mm and 1.0mm and between 0.8mm and 1.2mm and between 1.0mm and 1.2mm are significant(0.06 %, 0.01 %, 2 %). 4. The differences of reflective rates of 0.8mm, 1.0mm between IAP and IPS are significant but a little(less than 0.9%, 0.5%). The difference of reflective rates of l.2mm between IAP and IPS is significant and larger than the other thicknesses relatively(7 %).

  • PDF