• Title/Summary/Keyword: Longitudinal Relationship

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The Relationship between Korean Construction Industry and GDP in Economic Development Process (한국경제성장과정의 건설산업과 GDP의 관계 분석)

  • Choi, Dal-Sik;Le, Hoai;Lee, Young-Dai
    • Korean Journal of Construction Engineering and Management
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    • v.14 no.6
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    • pp.70-77
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    • 2013
  • Construction industry is broadly agreed as one of the most important sectors of any economy around the world. In this paper, time series data of Korean construction industry and Korean economy are examined. The Bon's proposition will be inspected for Korean context using both cross-sectional and longitudinal analyses. The analysis of the longer than four decades national account statistic of the Korean macro economy verify Bon's proposition of an inverted U-shaped relationships. The verified U-shaped relationships for Korean context exist not only in terms of the construction share in total GDP but also in terms of total construction volume as an economy develops from LDC to NIC and then to AIC eventually with time. The results of the thesis show that the contribution towards the macro economy has varied across different stages of development.

A study on the tumor induced microvasculature using hyperspectral imaging system (초분광 이미징 시스템을 이용한 암 혈관 분석에 대한 연구)

  • Choe, Se-woon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2015.05a
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    • pp.622-624
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    • 2015
  • Tumor hypoxia caused by the unique characteristics of solid tumor sites such as lowered vascular density, irregular vasculature, longitudinal oxygen gradient, and unbalanced oxygen consumption has decreased therapeutic efficacy in several clinical trials such as radiation, chemotherapy, and surgery. Hence, tumor oxygenation studies at microvascular levels are important to provide better understanding of the complexity of microvasculature oxygen transport and exchange with tissue. However, polarographic microelectodes, was employed to measure $pO_2$ at the microvasculature level, but it is difficult to perform and does not provide significant spatial and temporal information of oxygen delivery. In this research, we introduce the hyperspectral imaging system able to provide a wide range of vascular characteristics by spatial maps on hemoglobin saturation information for better understanding of the relationship between blood oxygen delivery, hypervascularity, aberrant angiogenesis at microvasculature levels during tumor growth.

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The Impact of Social Capital on Depression Trajectories in Later Life (노년기 사회자본의 차이가 우울궤적에 미치는 영향)

  • Kim, Jinhyun
    • Korean Journal of Social Welfare
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    • v.67 no.3
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    • pp.181-201
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    • 2015
  • This study conducted a longitudinal analysis to identify the impact of social capital on depression trajectories in later life. For data analysis, the Korean welfare panel data(2006-2012) was utilized and 4001 older adults aged 65 and older were included in the final sample. The results showed that social trust was significantly associated with depression scores at baseline but did not predicted the rate of change in depression over time. A higher level of reciprocity significantly predicted the faster decline in depression over time. For social participation through donation or volunteer, the percentage of participation was very low and it was not significantly related to depression trajectories. Finally as the satisfaction from social relationship becomes more positive, the rate of change in depression tended to decline faster over time. The results of this study indicates that in order to prevent or delay depression in later life, we should help older adults accumulate positive social capital such as social trust and reciprocity through active social interaction.

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Relationship between structural characteristics and hospital mortality rates on tertiary referral hospitals in Korea (우리나라 3차진료기관의 구조적인 특성과 병원사망률의 관계)

  • Sohn, Tae-Yong;Yu, Seung-Hum
    • Journal of Preventive Medicine and Public Health
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    • v.29 no.2 s.53
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    • pp.279-294
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    • 1996
  • This study was to evaluate hospital characteristics as composition of manpower and facilities to the death rate of patient; and to earmark the factors affecting the overall hospital mortality rates. The data utilized were derived from survey material conducted by the Korean Hospital Association on 32 tertiary referral hospitals in Korea between 1986 and 1994. The findings are : 1. Those hospitals having the most capacity per bed had little difference to the mortality rates than the others. 2. Those hospitals having the most daily patients per specialist had significantly higher mortality rates than the others, but the number of daily patients per nurse had little effect on the mortality rates. 3. Those hospitals which had a relatively sufficient number of quality assurance activities revealed a lower mortality, and particularly in case where such effort was directed to the clinicians, the outcome was remarkable. We concluded that the major factor affecting the hospital mortality rates seems to be the number of specialists per number of beds, the degree of quality assurance assessment of the clinicians, the quality assurance activities of each hospital as a whole, and the number of daily patient per specialist. According to the findings of this study, the composition and quality of specialist and adequate quality assurance activities seemed to be the essential for the improvement of hospital care. Therefore, in this regard e proper implementation of policy and support is highly recommended. Due to lack of available research material, the personal characteristics of specialists haven't been considered in this study. However, this longitudinal observation of 32 tertiary referral hospitals over a nine year period has significant merit alone.

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A Comparative Study of Second Language Acquisition Models: Focusing on Vowel Acquisition by Chinese Learners of Korean (중국인 학습자의 한국어 모음 습득에 대한 제2언어 습득 모델 비교 연구)

  • Kim, Jooyeon
    • Phonetics and Speech Sciences
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    • v.6 no.4
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    • pp.27-36
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    • 2014
  • This study provided longitudinal examination of the Chinese learners' acquisition of Korean vowels. Specifically, I examined the Chinese learners' Korean monophthongs /i, e, ɨ, ${\Lambda}$, a, u, o/ that were created at the time of 1 month and 12 months, tried to verify empirically how they learn by dealing with their mother tongue, and Korean vowels through dealing with pattern of the Perceptual Assimilation Model (henceforth PAM) of Best (Best, 1993; 1994; Best & Tyler, 2007) and the Speech Learning Model (henceforth SLM) of Flege (Flege, 1987; Bohn & Flege, 1992, Flege, 1995). As a result, most of the present results are shown to be similarly explained by the PAM and SLM, and the only discrepancy between these two models is found in the 'similar' category of sounds between the learners' native language and the target language. Specifically, the acquisition pattern of /u/ and /o/ in Korean is well accounted for the PAM, but not in the SLM. The SLM did not explain why the Chinese learners had difficulty in acquiring the Korean vowel /u/, because according to the SLM, the vowel /u/ in Chinese (the native language) is matched either to the vowel /u/ or /o/ in Korean (the target language). Namely, there is only a one-to-one matching relationship between the native language and the target language. In contrast, the Chinese learners' difficulty for the Korean vowel /u/ is well accounted for in the PAM in that the Chinese vowel /u/ is matched to the vowel pair /o, u/ in Korean, not the single vowel, /o/ or /u/.

An analysis of research on the determinants of exercise behavior (운동행위 결정요인에 관한 국외문헌 분석)

  • Lee, Jong Kyung
    • Korean Journal of Adult Nursing
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    • v.12 no.3
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    • pp.356-368
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    • 2000
  • The purposes of this study were 1) to identify determinants of exercise behavior 2) to determine theoretical frameworks that were used in other research 3) to investigate the limitations of exercise research. seventy six research papers, published between 1984-1999, were selected by searching Medline for this study. Research subjects, determinants of exercise behavior, exercise measurement, the design of studies, statistical method and theoretical background were examined. The results are as follows. 1. On the research subjects, most research papers studied healthy adults. 2. Thirteen variables were identified that were used more than 5 times in various researches were self efficacy, barrier, social support, benefit, physiological characteristics, habit, personality, intention, health status, motivation, subjective norm, attitude, and affect. The most frequently supported determinant was self efficacy, the second one was social support, the third was affect and so on. But few research papers found any significant relationship between subject norms or attitude and exercise. 3. On exercise measurement, only 22.4% of research papers considered intensity, duration, frequency as elements of exercise, and 64.5% of researches were assessed by self-reported questionnaires. 4. In research design, 80.3% of research papers were survey type research. The most frequently used statistcal method was Regression. 5. 44.8% of research papers were done without any theoretical basis. Based on the above findings the following suggestions are made : 1. Research which includes diverse populations with different levels of health status needs to be studied. 2. Determinants of exercise may be dynamic and varing in their influence, therefore, stages of exercise behavior and processes of change need to be studied. 3. In research design, more prospective, longitudinal studies are needed to identify determinants of exercise habits. 4. It is necessary to develop a reliable, valid exercise measurement tool. 5. Studies are needed to develop a theoretical framework for exercise behavior.

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The Conditions of Fringe Benefits and Retirement Planning among Paid Workers (임금 근로자의 복리후생 조건과 은퇴계획 수립의 관련성)

  • Kwon, Ohwi;Hong, Jin Hyuk;Kim, Ji-yeon;Noh, Young-Min;Kim, Jinseok;Noh, Jin-Won
    • The Journal of the Korea Contents Association
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    • v.19 no.11
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    • pp.22-32
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    • 2019
  • The purpose of this study was to derive association between company's fringe benefits and retirement planning. The study analyzed the 2016 Korean Longitudinal Study of Ageing(KLoSA) and a total of 1,740 participants was included. To analyze the relationship between the number of the company's employee fringe benefit and the retirement planning, multiple logistic regression was conducted. As a result, we found multiple variables affecting the retirement planning including not only the number of the fringe benefits, but also the age, marital status, residence, private health insurance status, and subjective health status. Successful retirement planning for wage workers benefits not only the individuals or government, but companies also gain benefits such as improved productivity of workers and a better corporate image, so further research is needed on the effective implementation of the system, and the role of government to support this.

The Effect of School Adjustment, Self-Esteem, and Life Satisfaction on Academic Achievement (학업성취에 영향을 미치는 학교적응, 자존감, 삶의 만족도의 구조적관계)

  • Lew, Kyoung-Hoon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.6
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    • pp.2700-2706
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    • 2013
  • The purpose of this study was to investigate the casual relationship between school adjustment, self-esteem and life satisfaction and academic achievement in elementary school students. This study utilized the NYPI's longitudinal data collected on elementary school students nationwide for 2012. Equation Modeling analysis was used to analyze 2,254 5th grade students' data. It was found that school adjustment was positively correlated with self-esteem, life satisfaction and academic achievement. School adjustment was directly associated with academic achievement. It was also confirmed that school adjustment indirectly explained academic achievement through self-esteem and life satisfaction. Future research directions and implications to teacher and institutions were discussed.

Modeling and coupling characteristics for an airframe-propulsion-integrated hypersonic vehicle

  • Lv, Chengkun;Chang, Juntao;Dong, Yilei;Ma, Jicheng;Xu, Cheng
    • Advances in aircraft and spacecraft science
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    • v.7 no.6
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    • pp.553-570
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    • 2020
  • To address the problems caused by the strong coupling of an airbreathing hypersonic vehicle's airframe and propulsion to the integrated control system design, an integrated airframe-propulsion model is established, and the coupling characteristics between the aircraft and engine are analyzed. First, the airframe-propulsion integration model is established based on the typical nonlinear longitudinal dynamical model of an air-breathing hypersonic vehicle and the one-dimensional dual-mode scramjet model. Thrust, moment, angle of attack, altitude, and velocity are used as transfer variables between the aircraft model and the engine model. The one-dimensional scramjet model can accurately reflect the working state of the engine and provide data to support the coupling analysis. Second, owing to the static instability of the aircraft model, the linear quadratic regulator (LQR) controller of the aircraft is designed to ensure attitude stability and height tracking. Finally, the coupling relationship between the aircraft and the engine is revealed through simulation examples. The interaction between vehicle attitude and engine working condition is analyzed, and the influence of vehicle attitude on engine safety is considered. When the engine is in a critical working state, the attitude change of the aircraft will not affect the engine safety without considering coupling, whereas when coupling is considered, the attitude change of the aircraft may cause the engine unstart, which demonstrates the significance of considering coupling characteristics.

Evaluation of the Effect of Coupler on the Ductility of Rebar by Uniaxial Tensile Test (1축 인장시험을 통한 커플러가 철근 연성도에 미치는 영향 평가)

  • Woo, Tae-Ryeon;Lee, Jong-Han;Cheung, Jin-Hwan;Jung, Chi-Young
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.22 no.1
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    • pp.90-98
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    • 2018
  • Recently, various reinforced concrete joints have been used in reinforced concrete structures. Therefore, it is important to grasp the tensile properties of the spliced rebar. In this study, uniaxial tensile tests were conducted on Grade 60 D22(#7), D29(#9), and two kinds of couplers manufactured according to ASTM A615 standard for evaluating ductility of coupler joints. The strain was measured using an image processing method more accurate and capable of measuring at various points freely. As the result of uniaxial tensile test, it was possible to calculate the stress-strain relationship and the longitudinal strain distribution according to the stress stages and it was founded that the average strain becomes lower as more occupying the coupler joint portions in the same gauge length. In addition, the empirical equations are proposed to account for the effect of the length of the coupler on the ultimate strain and the rupture strain.