• Title/Summary/Keyword: longitudinal studies

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The Changes in Axial and Radial Diffusivity in a Patient with Clinically Mild Encephalitis/Encephalopathy with a Reversible Splenial Lesion

  • Park, Ji Kang;Lee, Su Yun
    • Investigative Magnetic Resonance Imaging
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    • v.24 no.3
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    • pp.174-177
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    • 2020
  • Multiple studies have established that mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) exhibits reversible diffusion restriction in the white matter, including the splenium. There have been a few previous reports of the change in fractional anisotropy (FA) of MERS cases. Herein, we report the longitudinal changes in axial and radial diffusivity (AD and RD), and FA in a 15-year-old boy patient with MERS. Our case demonstrated that a MERS lesion had a significant drop of AD in the early period and gradual recovery. On the contrary, RD did not show any significant change.

Theoretical Frameworks to Predict Factors Associated With the Marital Quality and Stability (결혼생활의 질과 안정성에 관련된 이론적 모형)

  • Kim, Yeong-Hee
    • Korean Journal of Human Ecology
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    • v.5 no.2
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    • pp.53-72
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    • 1996
  • This article reviewed the research on factors associated with marital quality and stability. Three major categories of factors were described, including background and context, individual traits and behaviors, and couple interactional processes. This review highlighted findings from cross-sectional and longitudinal studies of the prediction of marital quality and stability. Particular attention was given to marital instruments and procedures that had a solid empirical foundation for understanding the concepts related to measure of marital quality and stability. Also, empirically based intervention programs that had been designed to prevent marital distress and divorce were investigated to figure out the relationship between communication factors and conflict resolution styles. Finally, three theoretical frameworks were drawn from empirical literatures, marital measurment instruments, and programs for marital strength to predict factors associated with the marital quality and stability. Recommendations for future research and implications were described.

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A New Blade Profile for Bidirectional Flow Properly Applicable to a Two-stage Jet Fan

  • Nishi, Michihiro;Liu, Shuhong;Yoshida, Kouichi;Okamoto, Minoru;Nakayama, Hiroyasu
    • International Journal of Fluid Machinery and Systems
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    • v.2 no.4
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    • pp.449-455
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    • 2009
  • A reversible axial flow fan called jet fan has been widely used for longitudinal ventilation in road tunnels to secure a safe and comfortable environment cost-effectively. As shifting the flow direction is usually made by only switching the rotational direction of an electric motor due to heavy duty, rotor blades having identical aerodynamic performance for bidirectional flow should be necessary. However, such aerodynamically desirable blades haven't been developed sufficiently, since most of the related studies have been done from the viewpoint of unidirectional flow. In the present paper, we demonstrate a method to profile the blade section suitable for bidirectional flow, which is validated by studying the aerodynamic performances of rotor blades of a two-stage jet fan experimentally and numerically.

Temperature Distribution for a Membrane type LNGC Cargo Tank (멤브레인형 LNG선의 화물창 온도분포 해석)

  • Heo, Joo Ho;Jeon, Yoon Ho
    • Journal of the Society of Naval Architects of Korea
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    • v.34 no.4
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    • pp.108-118
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    • 1997
  • For the LNG carrier, the calculation of temperature distribution of cargo tank is necessary to select the steel grade and to estimate the boil-off rate(BOR). Since the previous studies with 2-D and 3-D method ignored the effect of several primary members, the effect was included by applying the better equations for the convection coefficient that is the most important item in this kind of study. After evaluating the program considering the primary members, the results are reflected to the design of the concerned LNG carrier.

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Optimum Design of A-Pillar Trim for Occupant Protection (승원 안전을 고려한 승용차 A-Pillar Trim의 최적 설계)

  • 김형곤;강신일
    • Transactions of the Korean Society of Automotive Engineers
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    • v.9 no.2
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    • pp.99-106
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    • 2001
  • NHTSA has been conducting biomechanical studies to reduce inujuries sustained sustained during automotive collision. Furthermore, NHTSA added the regulation to the FMVSS 201, limiting the equivalent HIC(Head Injury Criterion) value under 1000. In the presont work, a methodology was developed for the optimum design of the A-pillar trim with rib-structures. The design variables for the rib-strucrures were the transverse spacing, the longitudinal spacing, and the thickness. The required sets of the design varibles were decided based on the design of experiments. The head impact simulations were carried out using the LS-DYNA3D, and the HIC(d) values were computed using the resulrs of the head impact simulation. The objective function was constructed using the response surface methed (RSM). When the obtained optimum values were not inside the region of interest, the design proceduers were repeated by changing the region of interest. Finally, an A-pillar trim with rib-structures, which resulred in HIC(d) value under 850 for 15 mph head-trim impact, was developed.

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Studies on Random Fractal and Multifractal Structures in Korean Topography (한국지형에서의 랜덤 프랙탈과 멀티프랙탈구조의 연구)

  • Kim, Kyungsik;Kong, Young Sae
    • Economic and Environmental Geology
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    • v.29 no.4
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    • pp.523-528
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    • 1996
  • In Korean topography the behaviors of random fractals and multifractality are analytically and numerically studied on the mountain heights shown between $128{\sim}129^{\circ}E$ and $37{\sim}38^{\circ}N$. The phase transitions on the fractal structure are approximately found at the critical length $N_c=2000m$ from the values of standard deviations that it varies with both the longitudinal and latitudinal lengths. In the multifractal structure we assume that the mountain heights divided by the intervals of 20 m are located on the horizontal plane in two dimensional square lattice, and estimate the values of the generalized dimension and the scaling exponents by using the the box counting method for the three cases of square area ($1{\times}1km^2$, $2{\times}2km^2$, $4{\times}4km^2$).

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Construction of an PFT database with various clinical information using optical character recognition and regular expression technique

  • Park, Man Young;Park, Rae Woong
    • Journal of Internet Computing and Services
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    • v.18 no.5
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    • pp.55-60
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    • 2017
  • The pulmonary function test (PFT) is an essential data source for evaluating the effect of drugs on the lungs or the status of lung function. However, the numeric values of PFT cannot be easily used for clinical studies without labor-intensive manual efforts, because PFTs are usually recorded as image files. This study was aimed at constructing a de-identified, open-access PFT database with various clinical information. For constructing the PFT database, optical character recognition (OCR), regular expression, and the parsing technique were used to extract alphanumeric data from the PFT images in a Korean tertiary teaching hospital. This longitudinal observational database contains 413,000 measurements of PFT from 183,000 patients.

The Impact of Elderly Caregiving on Marital Quality

  • Baek, Ju-Hee
    • International Journal of Human Ecology
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    • v.5 no.1
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    • pp.59-81
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    • 2004
  • Although the relation of caregiving burden to well-being has been frequently examined, the effect of caregiving on marital quality has been virtually ignored. The current study explores the impact of parent care on the marriages of adult children by using a nationally representative longitudinal sample. It was hypothesized that parent care would negatively influence the marital quality of adult child caregivers, the effect of parent care would differ between women and men caregivers, and the nature of marital relationship variables would moderate or mediate the impact of care on marital quality. Overall, marital quality does not appear to suffer if caregiving load is light. However, the impact of parental caregiving on some dimensions of marital quality was conditioned by gender, gender role attitudes, and congruence between attitudes and behavior.

A Study on the Review and Implication of Accounting Education Research in America (미국 회계교육연구의 동향 및 함의)

  • Roh Hyun-Sub
    • Management & Information Systems Review
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    • v.5
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    • pp.161-184
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    • 2000
  • Accounting education research addresses a wide range of topics related to students, educational processes, educational outcomes, faculty, administrative structures, and the programs and constituents of accounting education. This study examines accounting education researches for the purpose of identifying changes in this research literature and opportunities for enhancing its development. The total number of accounting articles published each year has increased. More significant is the increase in the portion of articles based on empirical research and the decrease in the portion of non-empirical articles. And the empirical studies were classified by type of study, by type of statistics used in the study, and by whether the study referred to other accounting or non-accounting literature. These analysis suggests a number of opportunities for the development of future accounting education research: (1) review relevant non-accounting literature, (2) seek empirical tests of fundamental relationships, (3) design multi-institutional and longitudinal tests, (4) provide for aptitude-treatment interactions, and (5) focus on educational outcomes.

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Elastic Bend Buckling of I-Girders Considering Interactive Effects of Flanges and Webs (플랜지-복부판의 상호작용을 고려한 I형 거더의 탄성휨좌굴)

  • 강영종;최진유;최영준;최승겸
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1997.10a
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    • pp.254-261
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    • 1997
  • In desingin plate bridges, the width-thickness ratio of flanges and webs are proportioned in such that the premature local buckling of flanges and webs prior to achievement of the full strength of plate-girders must be prevented. It is the common practive in most design codes that the flange local buckling strength and the web bend buckling strength are separately computed. In most practical plate girders, however, the flange buckles simultaneously when web bend-buckling occurs, vice versa. The primary purpose of the present study is to investigate the phenomenon, which may be called flange-web interactive buckling. Using the eight-node shell element available in the commercial multi-purpose program ABAQUS, the phenomenon was quantitatively investigated. Also presented are the effects of various factors such as the ratio of flange slenderness ratio to the web slenderness ratio, the ratio of flange width to the web depth, and the longitudinal stiffeners. A series of comparative studies with various design codes show that the present study provides more accurate and effective design basis in proportioning the flanges and webs.

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