• Title/Summary/Keyword: difference-in-differences method

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Maternal Separation Anxiety on Quality of Day Care and Mother's Self-Esteem (탁아의 질과 어머니 자아존중감에 따른 어머니 격리불안)

  • 송진숙
    • Journal of the Korean Home Economics Association
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    • v.35 no.2
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    • pp.309-319
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    • 1997
  • The purpose of this study was to examine the maternal separation anxiety depending on the quality of day care and mother's self-esteem. subjects consisted of 187 mothers who had children from 60 t 36 months of age. the instruments used were the questionnaires which consisted of the Maternal separation anxiety scale(Cho and park, 1992), Self-Esteem Inventory(Coopersmith, 1967), and the checklist which consisted of the early childhood environment Rating scale(Harms & Clifford, 1980) and the Family Day Care Rating scale(Harms & Clifford, 1989). The datas were analyzed by the statistical method based o frequency, percentile, t-test, and one-way ANOVA. The main results were as follows : First, there was a significant difference in maternal separation anxiety by mothers' age and not by their educational levels. Second, there were no significant differences in maternal separation anxiety by children's age, sex, and girth order. Third, there was no significant difference in maternal separation anxiety by quality of day 2 care, size of group, and adult-child ratio. Forth, there was a significant differences in maternal separation anxiety by mother's self-esteem.

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Trellis-coded .pi./4 shift QPSK with sliding multiple symbol detection흐름 다중심벌검파를 적용한 트렐리스 부호화된 .pi./4 shift QPSK

  • 전찬우;박이홍;김종일
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.2
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    • pp.483-494
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    • 1996
  • In this paper, we proposed the receive decoder and Virterbi algorithm with sliding multiple symbol detection using MLSE. the informationis transmitted by the phase difference of the adjacent channel signal at the .pi./4 shift QPSK. In order to apply the .pi./4 shift QPSK to TCM, we use the signal set expansion and the signal set partition by the phase differences. And the Viterbi decoder containing branch mertrice of the squared Euclidean distance of the first, second and Lth order phase difference is introduced in order to extract the information in the differential detection of the Trellis-Coded .pi./4 shift QPSK. The proposed Viterbi decoder and receiver are conceptually same to the sliding multiple symbol detection method using the MLSE. By uisng this method, the study shows that the Trellis-Coded .pi./4 shift QPSK is an attractive scheme for the power and the bandimited systems while also improving the BER performance when the Viterbi decoder is employed to the Lth order phase difference metrics.

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Comparison of adhesive and non-adhesive manufacturing methods of men's jacket - Focusing on men's jacket aged 30 to 49 - (남성 재킷의 접착 제작방식과 비접착 제작방식 비교 - 30~49세 남성 재킷을 중심으로 -)

  • Dong Kuk Kwon
    • The Research Journal of the Costume Culture
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    • v.31 no.6
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    • pp.738-755
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    • 2023
  • The purpose of this study is to provide basic data for the production of jackets with high fit by comparing and analyzing the adhesive and non-adhesive production methods of men's jackets. An analysis of the manufacturing method showcased differences between the adhesive and non-adhesive manufacturing methods in the cutting and wick attachment method, the shape and attachment method of the chest reinforcing wick, the sleeve attachment method, and the shoulder pad and sleeve reinforcing cloth attachment method. In evaluating the outfit, the overall fit of the shoulder, the fit of the chest, and the fit of the armpit were found to be high in the non-adhesive production method. In evaluating appearance evaluation, the front shoulder, chest, and sleeve overall appearance showed a high non-adhesive production method. Therefore, in order to increase the wearability of the shoulder pad and the the attachment method of the upper sleeve reinforcing cloth, the non-adhesive production method should be used, and in order to increase the overall wearability and armpit wear of the chest, the difference in the attachment method, and the reinforcement method of the armhole should be used. In addition, to increase the appearance of the jacket, non-adhesive production methods such as differences in wick attachment methods, shoulder pads, sleeve reinforcing cloth, and sleeve attachment methods should be used.

Comparison of the Node Method and the Pipeline Method for the Analysis of Water Distribution Systems (배수관망해석(配水管網解析)에 있어서 절점유출법(節点流出法)과 관로유출법(管路流出法)의 비교(比較))

  • Lee, Sang Mok;Lyu, Jong Hyun;Hyun, In Hwan
    • Journal of Korean Society of Water and Wastewater
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    • v.10 no.4
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    • pp.85-93
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    • 1996
  • This study is to make a comparison between the node method and the pipeline method for the analysis of the water distribution systems. For these purposes, the two methods were applied to a pipeline system in series, an artificial distribution network and a real distribution network. The results are as follows. 1. The difference between the results of the two methods was increased with the increase of the hydraulic gradient and the length between two adjacent nodes. 2. When all pipe lengths between two adjacent nodes were larger than 200~300m and have the steep hydraulic gradient, it was found that the results of the two methods showed high differences. 3. The difference between the results of the two methods were negligible in the case of the real distribution system in which only 12% whole pipelines were longer than 30m and the longest pipe length was 850m.

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Study on Relationship Between Consumption Values of Masstige and Consumer Happiness (매스티지 브랜드의 소비가치와 소비자 행복과의 관계에 관한 연구)

  • Kim, Yu-Kyung
    • Journal of Distribution Science
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    • v.13 no.1
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    • pp.105-118
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    • 2015
  • Purpose - The objective of this study is to verify whether there are differences between Korean and Chinese consumers in the importance of the attributes such as shopping value and loyalty in social commerce. With the purpose of finding out these differences, the following questions are set up as research questions. First, will there be a difference between Korea and China in the importance of attributes of social commerce? Second, will there be a difference between Korean and Chinese consumers in shopping value? Third, will there be a difference between Korean and Chinese consumers in their loyalty? Research design, data, and methodology - The researchers collected data through self-administered questionnaires from Korean and Chinese consumers who had used social commerce within the past six months before answering the questionnaire. First, for social commerce users in Korea, comprising male and female university students in Chungcheong, a questionnaire was circulated. For social commerce users in China, university students within Beijing were surveyed. Responses to 336 questionnaires were used, excluding those with no answers or unreliable answers. Data coding and data cleaning were used. SPSS 18.0 was used. First, exploratory factor analysis is done to verify the validity of testing tools, and Cronbach's α coefficient is used to verify credibility. For factor analysis, the Varimax method is used. To verify the internal consistency reliability of each factor, the Cronbach's α coefficient is used to verify the credibility. Second, a T-test is done to verify differences between Korean and Chinese consumers for the importance of attributes. Third, ANOVA (Analysis of variance) is done to verify differences between Korean and Chinese consumers in shopping value and loyalty. Results - When Korean and Chinese consumers use social commerce, first, the importance of the attributes of social commerce is affected by four factors; playfulness and economic factors are more important to Korean consumers than Chinese consumers. As for informativeness factors, including product information and quality, and buyer comments, there was no confirmed difference between Korean and Chinese consumers. The convenience factor is more important to Chinese consumers than Korean consumers. Second, the factors affecting shopping value for Korean and Chinese consumers were hedonic shopping value and rational shopping value. To see the difference between Korean and Chinese consumers in shopping value factors, a t-test is conducted. As a result, in the rational shopping value factors of social commerce, Korean consumers scored higher than did Chinese consumers. These results were verified to be meaningful through statistics. In the hedonic shopping value factor of social commerce, Korean consumers scored higher than Chinese consumers. These results showed a significant difference. Third, loyalty in social commerce is higher for Chinese consumers than for Korean consumers. However, there is no difference in loyalty depending on sex. Conclusions - These results will hopefully be valuable and used in the future by Korean companies that wish to enter the Chinese social commerce market.

Weight Differences of Intellectual Capital Indicator Selection by Industry (산업별 지식자산 지표 선정기준의 차이에 대한 연구)

  • Han, Dong-Wook
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.30 no.4
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    • pp.118-126
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    • 2007
  • This study presents the intellectual capital (IC) indicator selection criteria based on the review of qualitative characteristics of financial accounting information and data quality of information systems. The AHP survey has been performed to verify the weight difference of the criteria to select effective IC indicators among industry. The results shows that there exists the weight differences in relevance and comparability factor by industry. To management IC effectively, different method considering industry environment should be required.

Childbirth and Socioeconomic Status Changes in Korean Women: Using Propensity Score Matching and Difference-in-Differences Method (출산과 여성의 사회경제적 상태 변화: 성향점수매칭과 이중차이를 활용한 분석)

  • Jung, Yun Sun;You, Chang Hoon;Kwon, Young Dae
    • The Journal of the Korea Contents Association
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    • v.19 no.10
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    • pp.667-676
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    • 2019
  • The purpose of this study was to assess the impact of childbirth on socioeconomic status changes of women. Data were collected from Korean Health Panel (2008-2015). A difference-in-differences model with propensity score matching was applied to assess the impact of childbirth on socioeconomic status changes. As a result, variables showing significant differences in the interaction terms indicating the impact of birth were the savings, economic activity, and occupational status. The impact of birth were significant in decreasing the amount of savings and negatively affecting women's economic activities, but in increasing the probability of full-time and regular employees in occupational status. Childbirth appears to have a negative impact on the home economics and socioeconomic status of women. The belief that home economies can be stabilized even after childbirth should be established, and a long-term and sustained support plan should be set up to realize this belief.

A Study on the Visual Evaluation according to Clothing Stimuli and the Method of Presentation (의복자재물(衣服刺載物)과 제시방법(提示方法)에 따른 시각적(視覺的) 평가(評價))

  • Kim, Hee Jung;Lee, Kyoung Hee
    • Journal of the Korean Society of Clothing and Textiles
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    • v.17 no.3
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    • pp.428-435
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    • 1993
  • The purpose of this study was to investigate the difference of the visual evaluation about clothing texture, the state of wearing and the method of presentation. The data from observation were analyzed by factor analysis, t-test, ANOVA, Scheffe test and MCA. The results of this study were as follows ; 1. 17 pairs of discriptors used for the visual evaluation of clothing stimuli were found to include four factor dimensions(total variance 65.6%) ; Attention, Appearance, Texture, Maturity. 2. For the image of clothing texture, there were significant differences in the attention and texture. 3. For the image of the state of wearing, there were significant differences in the attention and appearance. 4. For the image of the method of presentation, there were significant differences in the clothing texture and the state of wearing. 5. According to clothing texture, the state of wearing and the method of presentation, the interaction effect was significant in the attention and appearance.

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Deep Learning-Based Sound Localization Using Stereo Signals Based on Synchronized ILD

  • Hwang, Hyeon Tae;Yun, Deokgyu;Choi, Seung Ho
    • International Journal of Internet, Broadcasting and Communication
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    • v.11 no.3
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    • pp.106-110
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    • 2019
  • The interaural level difference (ILD) used for the sound localization using stereo signals is to find the difference in energy that the sound source reaches both ears. The conventional ILD does not consider the time difference of the stereo signals, which is a factor of lowering the accuracy. In this paper, we propose a synchronized ILD that obtains the ILD after synchronizing these time differences. This method uses the cross-correlation function (CCF) to calculate the time difference to reach both ears and use it to obtain synchronized ILD. In order to prove the performance of the proposed method, we conducted two sound localization experiments. In each experiment, the synchronized ILD and CCF or only the synchronized ILD were given as inputs of the deep neural networks (DNN), respectively. In this paper, we evaluate the performance of sound localization with mean error and accuracy of sound localization. Experimental results show that the proposed method has better performance than the conventional methods.

Radiation-Laminar Free Convection in a Square Duct with Specular Reflection by Absorbing-Emitting Medium

  • Byun, Ki-Hong;Im, Moon-Hyuk
    • Journal of Mechanical Science and Technology
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    • v.16 no.10
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    • pp.1346-1354
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    • 2002
  • The purpose of this work is to study the effects of specularly reflecting wall under the combined radiative and laminar free convective heat transfer in an infinite square duct. An absorbing and emitting gray medium is enclosed by the opaque and diffusely emitting walls. The walls may reflect diffusely or specularly. Boussinesq approximation is used for the buoyancy term. The radiative heat transfer is evaluated using the direct discrete ordinates method. The parameters under considerations are Rayleigh number, conduction to radiation parameter, optical thickness, wall emissivity and reflection mode. The differences caused by the reflection mode on the stream line, and temperature distribution and wall heat fluxes are studied. Some differences are observed for the categories mentioned above if the order of the conduction to radiation parameter is less than order of 10$\^$-3/ fer the range of Rayleigh number studied. The differences at the side wall heat flux distributions are observed as long as the medium is optically thin. As the top wall emissivity decreases, the differences between these two modes are increased. As the optical thickness decreases at the fixed wall emissivity, the differences also increase. The difference of the streamlines or the temperature contours is not as distinct as the side wall heat flux distributions. The specular reflection may alter the fluid motion.