• Title/Summary/Keyword: longitudinal changes

Search Result 567, Processing Time 0.021 seconds

The Longitudinal Relationship between Social Capital of North Korean Migrant Youths and School Adjustment: A Latent Growth Modeling Approach (잠재성장모형을 활용한 탈북청소년의 사회자본과 학교적응 간 종단관계 분석)

  • Yeon, Bo-Ra;KIM, Kyungkeun
    • (The)Korea Educational Review
    • /
    • v.23 no.1
    • /
    • pp.205-230
    • /
    • 2017
  • Drawing on third to fifth wave data from the Longitudinal Study of North Korean Migrant Youths' Education, we examined the longitudinal relationship between social capital of North Korean Migrant Youths and school adjustment using latent growth modeling(LGM). Specifically, we sought to answer the following research questions: Do social capital and school adjustment among North Korean Migrant Youths change over time? Is there a relationship between the changes in social capital and school adjustment among these students? Our LGM results showed that trends in social capital and school adjustment among these students were not fixed but changed over time. While the social capital developed by these students was found to influence school adjustment at the time of its development, it did not continue to influence changes in school adjustment over time. Changes in school adjustment of North Korean migrant youths were affected by changes in social capital. These results suggest that there is room for gradual improvement of school adjustment level by strengthening social capital of North Korean migrant youths.

A Case Study on Business Continuity following the Establishment of a Soho Fashion Shopping Mall: Longitudinal Research (소호패션쇼핑몰 창업 후 사업지속에 대한 사례연구: 종단적 연구를 중심으로)

  • Mi Young Son
    • Human Ecology Research
    • /
    • v.62 no.1
    • /
    • pp.1-13
    • /
    • 2024
  • This study analyzed the current operational status, business continuity, and business continuity strategies of 11 Soho fashion shopping malls through a longitudinal case study (2019/2020 and 2022/2023). The aim was to determine how Soho fashion shopping malls are continuing their business having been successfully established in the fiercely competitive current online fashion market. Regarding changes in shopping mall operation status, all cases displayed changes in items, distribution channels, marketing channels, core values, and profit structures. After establishing the businesses, a crisis arose due to the COVID-19 pandemic, leading to difficulties in creating new customers. Moreover, there was excessive business expansion, resulting in saturation of the online platform store market. This meant companies were experiencing reduced sales (5) or difficulties in maintaining their business (3). However, there were differences in the direction of overcoming the crisis and continuing or converting the business. These revealed that to continue the business after successful establishment of an online fashion shopping mall, it is essential to have the expertise of entrepreneurs, work performance, and marketing ability, as well as differentiation capabilities such as product power and management strategy and core competitiveness that provides a relative advantage over other shopping malls. Customized government support at the level of the start-up ecosystem is also essential for the survival and business continuity of a SOHO online fashion shopping mall with poor human and material resources.

Effects of Longitudinal Field in a Multiply-Twisted Superconducting Cable (초전도다중케이블에서의 축방향자계)

  • Cha, Guee-Soo;Sim, Jung-Wook;Park, Jong-Hyeon;Na, Wan-Soo;Lee, Ji-Kwang;Kim, Dong-Hun;Hahn, Song-Yop
    • Proceedings of the KIEE Conference
    • /
    • 1996.07a
    • /
    • pp.101-103
    • /
    • 1996
  • Multiply-twist cable is used for a large capacity superconducting cable because it is helpful to reduce AC losses and to increase transport current. In a multiply-twisted cable, the axis of a strand does not coincide with that of cable. Therefore, the longitudinal field is generated by the transport current. The longitudinal field changes the current distribution in the strand and generates additional AC loss. This paper calculates the longitudinal field that is applied to a strand in the multiply-twisted cable. Current distribution of a strand in the cable is also presented. 2nd level superconducting cable is chosen as an analysis model, whose current capacity is 2000A. Calculation result shows the longitudinal field cannot be neglected in low field machines such as superconducting transformer.

  • PDF

Influence of Asthma on the Longitudinal Trajectories of Cigarette Use Behaviors From Adolescence to Adulthood Using Latent Growth Curve Models

  • Bae, Jisuk
    • Journal of Preventive Medicine and Public Health
    • /
    • v.48 no.2
    • /
    • pp.111-117
    • /
    • 2015
  • Objectives: While epidemiologic research indicates that the prevalence of risk-taking behaviors including cigarette smoking among young people with asthma is substantial, the longitudinal patterns of cigarette smoking in this vulnerable population have received little attention. The aim of this study was to evaluate differences in the longitudinal trajectories of cigarette use behaviors from adolescence to adulthood between young people with and without asthma. Methods: Data from the National Longitudinal Study of Adolescent to Adult Health (Add Health) during the years 1994 to 1995 (Wave I, adolescence), 2001 to 2002 (Wave III, young adulthood), and 2007 to 2008 (Wave IV, adulthood) were analyzed (n=12 244). Latent growth curve models were used to examine the longitudinal trajectories of cigarette use behaviors during the transition to adulthood according to asthma status. Results: Regardless of asthma status, the trajectory means of cigarette use behaviors were found to increase, and then slightly decrease from adolescence to adulthood. In total participants, there were no statistically significant differences in initial levels and changes in cigarette use behaviors according to asthma status. However, in select sex and race subgroups (i.e., females and non-whites), former asthmatics showed greater escalation in cigarette use behaviors than did non-asthmatics or current asthmatics. Conclusions: This study indicated that the changing patterns of cigarette use behaviors during the transition to adulthood among young people with asthma are comparable to or even more drastic than those among young people without asthma.

Effects of partially earth-anchored cable system on dynamic wind response of cable-stayed bridges

  • Won, Jeong-Hun;Yoon, Ji-Hyun;Park, Se-Jun;Kim, Sang-Hyo
    • Wind and Structures
    • /
    • v.11 no.6
    • /
    • pp.441-453
    • /
    • 2008
  • In this study, a partially earth-anchored cable system is studied in order to reduce the dynamic wind response of cable-stayed bridges. The employment of earth-anchored cables changes the dynamic characteristics of cable-stayed bridges under wind loads. In order to estimate the changes in the member forces, the spectral analysis for wind buffeting loads are performed and the peak responses are evaluated using 3-D finite element models of the three-span cable-stayed bridges with the partially earth-anchored cable system and with the self-anchored cable system, respectively. Comparing the results for the two different models, it is found that the earth-anchored cables affect longitudinal and vertical modes of the bridge. The changes of the natural frequencies for the longitudinal modes remarkably decrease the peak bending moment in the pylon and the movements at the expansion joints. The small changes of the natural frequencies for the vertical modes slightly increase bending moments and deflections in the girder. The original effects of the partially earth-anchored cable system are also shown under wind loads; the decrement of girder axial forces and bearing uplifting forces, and the increment of cable forces in the earth-anchored cables.

Stress Evaluation by Measuring Ultrasonic Velocity (초음파 음속측정에 의한 응력평가에 관한 연구)

  • Lee, Bum-Sung
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.16 no.2 s.95
    • /
    • pp.138-144
    • /
    • 1999
  • Longitudinal wave and shear wave velocity changes of PMMA Polymer meterial under the the unidirection load were measured. The Third-order elastic modulus and acousto-elastic modulus of PMMA are obtained. The theoretical and experemental values of the velocity change of each wave by stress are compared each other and the validity of theoretical expression is examinated.

  • PDF

Evaluation of Bone Change by Digital Subtraction Radiography after Implantation of Tooth Ash-plaster Mixture (치아회분과 석고혼합제제 매식후 Digital Subtraction Radiography에 의한 골량 변화의 평가)

  • Kim Jae-Duk;Kim Kwang-Won;Cho Yaung-Gon;Kim Dong-Kie;Choi Eui-Hwan
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
    • /
    • v.29 no.2
    • /
    • pp.423-433
    • /
    • 1999
  • Purpose : To assess the methods for the clinical evaluation of the longitudinal bone changes after implantation of tooth ash-plaster mixture into the defect area of human jaws. Materials and methods : Tooth ash-plaster mixtures were implanted into the defects of 8 human jaws. 48 intraoral radiograms taken with copper step wedge as reference at soon, 1st, 2nd, 4th, and 6th week after implantation of mixture were used. X-ray taking was standardized by using Rinn XCP device customized directly to the individual dentition with resin bite block. The images inputted by Quick scanner were digitized and analyzed by NIH image program. Cu­equivalent values were measured at the implanted sites from the periodic digital images. Analysis was performed by the bidirectional subtraction with color enhancement and the surface plot of resliced contiguous image. The obtained results by the two methods were compared with Cu­equivalent value changes. Results : The average determination coefficient of Cu-equivalent equations was 0.9988 and the coefficient of variation of measured Cu values ranged from 0.08~0.10. The coefficient of variation of Cu-equivalent values measured at the areas of the mixture and the bone by the conversion equation ranged from 0.06 ~0.09. The analyzed results by the bidirectional subtraction with color enhancement were coincident with the changes of Cu-equivalent values. The surface plot of the resliced contiguous image showed the three dimensional view of the longitudinal bone changes on one image and also coincident with Cu-equivalent value changes after implantation. Conclusion : The bidirectional subtraction with color enhancement and the surface plot of the resliced contiguous image was very effective and reasonable to analyze clinically and qualitatively the longitudinal bone change. These methods are expected to be applicable to the non-destructive test in other fields.

  • PDF

Changes in the Transitional Milk Yields during the First 15 Days Postpartum (분만 첫 15일간 이행유 분비량의 변화)

  • 이정실
    • Journal of Nutrition and Health
    • /
    • v.27 no.6
    • /
    • pp.583-590
    • /
    • 1994
  • The longitudinal changes in the transitional milk yields of Korean lactating women(14 primiparae, 11 multiparae) have been studied by test-weighing method in the part of Kangwon Province form 7 day to 15 days postpartum. The transitional milk yields at 7, 10, 15 days postpartum were 531$\pm$148,598$\pm$156 and 639$\pm$169g, respectively. The mean milk yield was 589$\pm$162g from 7 to 15 days postpartum. The transitional milk yields between primiparae and multiparae appeared not significantly different but significantly different between mothers of boys and girl(p<0.05). The distribution of individual transitional milk yields were found 550-649g(28.0%), 450-549g(24.0%), 650-749g(13.3%) and 750-849g(13.3%). The transitional milk yields were not affected by mother's age, weight gain during pregnancy, gestational period and infant's weight at birth but affected by maternal height(p<0.05). Maternal weight reduction during the lactation had no correlation with the transitional milk yeilds.

  • PDF

Changes in Transitional Milk Intakes and Body Weight of Breast-Fed Infants (모유영양아의 이행유 섭취량과 체중변화)

  • 이정실
    • Journal of Nutrition and Health
    • /
    • v.27 no.6
    • /
    • pp.591-598
    • /
    • 1994
  • The longitudinal changes in transitional milk intakes and body weight of infants(18 boys, 10 girls) have been studied in the part of Kangwon Province from 7 days to 15 days postpartum. Milk intakes at 7, 10, 15 days postpartum were 474$\pm$155, 524$\pm$154 and 547$\pm$130g, respectively. The mean milk intakes were 515g from 7 to 15 days postpartum. Milk intakes of boys were significantly higher than those of girls. The transitional milk intakes per weight of infants appeared 147$\pm$41g/kg. The number of feed per day of boys were significantly higher than those of girls. Milk intakes per fed were 56$\pm$20g. The transitional milk intakes were affected by gestational period(p<0.05), maternal height(p<0.05) and mother's transitional milk yields (p<0.001). Infants transitional milk intakes were 82.6$\pm$17.0% of mothers transitional milk yields. Infants gained its weight 24.6, 40.1 and 39.0g/day at, 7, 10, 15 days postpartum, respectively.

  • PDF