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

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Perceived Differences in Brands of Jeans; Classification and Characteristics of Brand-Switching (청바지제품의 지각된 상표간 차이에 따른 상표전환의 유형과 특성)

  • 이선재
    • Journal of the Korean Society of Costume
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    • v.49
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    • pp.113-124
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    • 1999
  • The purpose of this study was to categorize brand-switching behaviors into subdivided groups by variety seeking and perceived differences between brands and to compare and to analyze brand-switching motive perceived differences between brands clothing-involvement and buying price among the subdivided groups. The subjects were 343 female and male to have jean pants-buying experience in their age of 20-29 living in Seoul and Kyunggi province. For the analysis of the data mean frequency t-test $\chi^2$-Test Factor analysis MANOVA Duncan-test were conducted and the cronbach's $\alpha$ has been calculated to measure the reliability The results are as follows: 1. brand-switching behaviors are categorized into 4 groups by strength of variety-seeking and perceived differences between brands that are small or large which are habitual brand switchers internal derived brand-switchers external derived brand-switchers and combined derived brand-switchers. 2. Among the 4 sub-groups there were significant difference in brand-switching motive according to factors such as change-seeking needs and price & promotion. And there were significant differences in perceived differences between brands according to factors such as apparel design clothing -symbolism fitness except apparel shop. 3. According to strength of variety-seeking levels of clothing-involvement and buying price have increased Combined derived brand-switchers have totally the strongest variety-seeking and the highest clothin-involvement and they purchase the highest priced jean-pants of the other types of consumers.

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Analysis about Stress Index and Resistance of Workers by Heart Rate Variability (근로자들의 스트레스에 대한 심박변이도 검사를 통한 분석)

  • Jang, Woo-Seok
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.25 no.4
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    • pp.728-733
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    • 2011
  • This study was designed to analyze the results of stress index by heart rate variability test. The subjects were workers in the automobile manufacturing industry. The subjects consisted of 23,767 workers who had answered about questionnaires of a job position, age, smoking, drinking, exercise state and sex. The stress index(SI) and stress resistance(SR) were examined by SA3000P. We analyzed the differences of SI and SR according to job positions, ages, the state of smoking, drinking, exercise and sex by T-test or ANOVA with SPSS ver. 17.0. Regarding the differences of SI among job positions, the SI was highest in sales positions. Among ages, the SI was highest in 30s. In smoking, the SI was lower in non-smoking group. In drinking, there was no significant differences in SI. In exercise, the SI was lower in exercise group. In sex, there was no significant difference. The case of SR, SR was lowest in sales positions. Among ages, the SR was lowest in 40s. In smoking, the SR was lower in smoking group. In drinking, there was no significant differences in SR. In exercise, there was no significant difference. In sex, the SR was lowest in male. According to these results, we should establish the methods of controlling stress from the perspective of Korean traditional medicine.

Analysis of Minimum Airflow Differences between Supply and Exhaust Air according to Airtightness of Rapidly Converted Temporary Negative Pressure Isolation Rooms (긴급전환형 임시음압격리병실의 기밀도에 따른 최소 급배기 유량차 평가)

  • Shin, Hee Won;Kim, Dong Wook;Kim, Ji Min;Jung, Hyo Beom;Kang, Dong Hwa
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.29 no.4
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    • pp.69-77
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    • 2023
  • Purpose: During the COVID-19 pandemic, there have been many cases of converting regular hospital wards into temporary negative pressure isolation wards. The purpose of this study is to evaluate the minimum airflow differences that satisfies the pressure difference criteria(-2.5 Pa) according to airtightness of switching type wards, in preparation for utilization of aging regular wards as negative pressure isolation wards. Methods: Visual inspection and field measurements were conducted using blower door to evaluate airtightness of 5 hospital wards. CONTAM simulation was used to assess the airflow differences when pressure difference between the corridor and wards met the criteria at various levels of airtightness. Results: The ACH50 of evaluated wards ranged from 19.3 to 50.1 h-1 with an average of 37.0 h-1, indicating more than four times leakier than other building types. The minimum airflow differences increased as the airtightness of the wards decreased and the size of the wards increased. Implications: When operating rapidly converted negative pressure isolation wards, understanding airtightness is crucial for determining the minimum airflow differences to maintain the pressure differences. The analysis of this study suggests that improving the airtightness of aging rooms is essential and the minimum airflow differences should be suggested considering both the airtightness and size of rooms.

Analysis of a Security Survey for Smartphones

  • Nam, Sang-Zo
    • International Journal of Contents
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    • v.11 no.3
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    • pp.14-23
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    • 2015
  • This paper presents the findings of a study in which students at a four-year university were surveyed in an effort to analyze and verify the differences in perceived security awareness, security-related activities, and security damage experiences when using smartphones, based on demographic variables such as gender, academic year, and college major. Moreover, the perceived security awareness items and security-related activities were tested to verify whether they affect the students' security damage experience. Based on survey data obtained from 592 participants, the findings indicate that demographic differences exist for some of the survey question items. The majority of the male students replied "affirmative" to some of the questions related to perceived security awareness and "enthusiastic" to questions about security-related activities. Some academic year differences exist in the responses to perceived security awareness and security-related activities. On the whole, freshmen had the lowest level of security awareness. Security alert seems to be very high in sophomores, but it decreases as the students become older. While the difference in perceived security awareness based on college major was not significant, the difference in some security-related activities based on that variable was significant. No significant difference was found in some items such as storing private information in smartphones and frequency of implementation of security applications based on the college major variable. However, differences among the college majors were verified in clicking hyperlinks in unknown SMS messages and in the number of security applications in smartphones. No differences were found in security damage experiences based on gender, academic year, and college major. Security awareness items had no impact on the experience of security damage in smartphones. However, some security activities, such as storing resident registration numbers in a smartphone, clicking hyperlinks in unknown SMS messages, the number of security apps in a smartphone, and the frequency of implementation of security apps did have an impact on security damage.

Analysis on the Middle School Teachers' Level of Interest of Achievement Standards-based Assessment (성취평가제에 대한 중학교 교사의 관심수준 분석)

  • Kim, Suk-Woo
    • Journal of Fisheries and Marine Sciences Education
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    • v.26 no.1
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    • pp.81-97
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    • 2014
  • The purpose of this study is to analyze the level of interest in the achievement evaluation system, under the assumption that the teacher is an important element of curriculum. For this study, surveys targeting the 150 middle school teachers from 6 schools in Pusan was conducted. A questionnaire based CBAM model was used as research tools. For data analysis, mean of relative strength by teacher's level of interest was calculated. And MANOVA was used to investigate the difference among level of interest according to teachers' background such as sex, age, career, job position, and the grade they taught. The results of the analysis are summarized as follows. First, the middle school teachers' overall interest for achievement evaluation system is low. Teachers showed a typical pattern appeared in the early stages of change. They have little interest in the achievement evaluation system. And they should try to fix and change the achievement evaluation system rather than cooperate it. Second, as a result of this analysis of the difference according to teachers' background, no significant differences were found in most of the variables. Significant differences were found only in age, career, and job position from step 0. In running the post hoc, teachers who have less careers, lower positions, and younger ages had less interest in achievement evaluation system.

A Study on the Architectural Characteristics of HaeNam Yoon clan's Residential Buildings (해남윤씨(海南尹氏) 주거건축의 건축적 특성에 관한 연구)

  • Choi, Jung-Mee;Cheon, Deuk-Youm
    • Journal of architectural history
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    • v.27 no.3
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    • pp.73-82
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    • 2018
  • Gosan(孤山) Yun Seon-do is a literary artist and poet, Nogudang House(綠雨堂) is an invisible space composition a ${\Box}$-type of arrangement in Jeollanam-do. The study of related architecture together with Gosan Yun Seon-do has been studied variously early, Mostly, the study of the life of Haenam Yun clan(海南尹氏) and the life of Gosan Yun Seon-do. In this study, HaeNam Yun compares the houses under the roof of the public house centered on buildings. In this study, we compare and analyze Nogudang House and Gongjae Historic House(恭齋古宅), Yun Cheol-ha's Historic House(尹哲夏古宅) in the Haenam Yun clan's house building. Analyze the characteristics of architecture and analyze changes in space usage and components and settlement process. The purpose of this study is to clarify differences in structural features and to analyze what structural characteristics maintain structural characteristics. In the comparative analysis process, architectural characteristics are used as variables and each correlation is investigated, and shape difference is analyzed by difference analysis. In addition, the architectural characteristics are analyzed by analyzing the relational factors influencing the morphological change, focusing on the results of the analysis of differences between the comparative analysis objects.

Usability Analysis for Designing Mobile Phones Based on Universal Design for the Elderly (노인층을 고려한 범용디자인 휴대폰 설계를 위한 사용성 분석)

  • Yim, Jang-Bin;Park, Min-Yong
    • Journal of the Ergonomics Society of Korea
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    • v.24 no.1
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    • pp.47-53
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    • 2005
  • The purpose of this study was to evaluate performance and subjective satisfaction of mobile phone's interface elements considering the elderly users. First, mobile phone's interface elements were outlined recent foreign and domestic studies. Then, final three mobile phone's interface elements were determined by expert rating, AHP analysis, and questionnaire analysis. Objective and subjective measures were then used to determine the effects of several specific design parameters and aging differences on performance of mobile phones. In this experiment, 38 subjects and 4 independent variables were used to measure task completion time and user's subjective satisfaction. The statistical analyses indicated significant aging differences between older people and younger people in terms of keypad type and bell sound level in performance. Significant aging differences were also found for user subjective satisfaction. It is suggested that some major results from this study be used to develop mobile phone design guidelines that are more usable and accessible for most users, particularly for older users.

Effects of Bridging Exercise using Vibration Stimulation and ADIMs on the Lengthening and Thickness of Transversus Abdominis in Healthy Adults

  • Kong, Kwan-Woo
    • The Journal of Korean Physical Therapy
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    • v.28 no.6
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    • pp.393-397
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    • 2016
  • Purpose: This study was conducted in an effort to determine the effects of various abdominal drawing-in maneuver (ADIM) on the thickness and length of the transversus abdominis (TrA) when using lumbar stabilization exercises on healthy adults. Methods: 72 healthy adults were divided into four groups of 18 subjects each, to which different ADIM methods were applied. 1) a simple ADIM exercise, 2) an ADIM with pressure bio-feedback units, 3) an ADIM exercise with sling, and 4) an ADIM exercise with sling and vibration. Changes in the thickness and sliding length of TrA were measured when ADIM was conducted in the supine position prior to exercise and again when beginning the exercises. Following exercise, changes in the thickness and sliding length of TrA were measured using the same methods. Differences in group measurements prior to and following exercise were compared using a one-way analysis of variance. A paired t-test was applied to compare the before and after differences within each group. Results: Differences in TrA thickness change revealed that the ADIM exercise with sling and vibration group showed a significant difference in measurements taken prior to and following exercise. Differences in TrA length change revealed that the ADIM exercise with sling and vibration group showed a significant difference in measurements taken prior to and following exercise. Conclusion: ADIM exercise with vibration stimulation conducted in the bridge posture while in a prone position using a sling can be recommended as an effective exercise to improve the function of lumbar TrA.

The Analysis of South Korea Medical Tourism Services for the Differences Perceptions by Medical Tourists and Hospital Staffs (의료관광객과 병원 종사자간의 한국 의료관광 서비스에 대한 인식차이 분석)

  • Han, Jae-Hyun;Lee, Kyun-Jick
    • Korea Journal of Hospital Management
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    • v.16 no.4
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    • pp.17-34
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    • 2011
  • Recently, medical market has been changing not for the sake of treatment of the disease but for high quality of health. Therefore, South Korea medical tourism service needs to understand and improve for the differences perceptions of medical tourists and health professionals for customer satisfaction. The purpose of this study is to understand the structure of medical tourism market through theoretical consideration and to suggest the factors which need to be taken precedence for improvement of South Korea medical tourism service through analysis differences between consumers and suppliers. To analyze the difference of awareness, we reconstructed the questionnaires focussing on evaluation factors and articles about medical tourists selection attributes and health professionals way to invigoration through previous research and precedence study. After that, we also collected the data based on reconstructed questionnaires. After we compared each collected responses from medical tourists and health professionals, also analyzed the differences of awareness by applying Johari's Window to those differences. In conclusion, there is no relation between medical tourist and health professionals about th differences of awareness in functional quality and cost that is a direct effect to transaction in current medical tourism of South Korea. In contrast, there are differences of awareness between a process which support medical tourism and technical quality. Therefor, we expect to invigorate medical tourism by innovation of supportive process and technical quality.

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A LATERAL CEPHALOMETRIC STUDY OF CRANIOFACIAL VARIATION IN KOREAN CHILD TWINS (한국인 쌍생아의 두개안면에 관한 X선학적 연구)

  • Lee Sang Rei
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.4 no.1
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    • pp.21-30
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    • 1974
  • A study was performed to investigate the degree of similarities and differences in components of craniofacial complex between Korean twins and normal children by lateral cephalometric analysis. Dimensions of S-N, S-Ba, N-Ba, Go-Me, Ar-Go and Ar-Me were against linear measurement and angles of N-S-Ba and gonial against measurement in twins and control groups. The lateral cephalograms of twin were composed of 88 twins aged from 7 to 12:44 males aged 10.65 and 44 females aged 9.55, while those of 50 normalities were composed of 25 males and 25 females aged 10.9 respectively. In order to analyze growth proportion and sexual differences, twins were divided into 3 groups according to two year age intervals and the author compared male with female in 3 groups. For the purpose of observing similarities and differences in twins and normalities by sex, total twins were compared with normalities. The obtained results were as follows: 1. There was no difference in craniofacial complex between plotted angular normalities. 2. In general, the measurements of male were larger than both twins and normalities, but there were no statistical sexual differences in both groups. 3. The growth proportion of mandible by aging was larger than that of face twins and those of female significances of in twins. 4. The growth pattern of gonial angle showed slightly reducing tendency in twins by aging. 5. There was little difference in the growth proportion of both male and female.

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