• 한국구조물진단유지관리공학회 논문집
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• 제22권5호
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• pp.64-71
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• 2018

본 연구는 방음재를 삽입한 새로운 개념의 합성슬래브 시스템을 제안하고, T-형 바의 폭, 전단보강 철근의 설치 등을 실험의 주요변수로 한 총 7개의 실험체를 제작 Push-Down실험방법으로 수행한 수평전단성능에 대한 실험 결과를 제공하고 있다. 실험결과 T-형 바를 전단키로 적용하고 방음재를 삽입한 실험체가 기본실험체에 비해 수평전단성능에서 2배 이상 우수한 것으로 나타났다. 이는 제안한 합성슬래브상세를 실제 현장 적용하여도 기존의 합성슬래브 보다 구조적 측면에서 상당한 안전율을 확보할 것으로 생각되며, 내진동 및 방차음의 개선에도 크게 기여할 것으로 판단된다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.477-482
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• 2001

This paper is to study the effect of longitudinal reinforcement ratios and axial deformation on the frame analysis in reinforced concrete(RC) columns and to investigate the effect of confined concrete core, the length-width ratio and longitudinal steel ratios on frame analysis in Concrete-Filled steel Tubular(CFT) columns. An equation if derived to evaluate the modulus of elasticity for core concrete. The 34 reference data have been collected for the purpose and are processed by the mean of a multiple regression analysis technique. The equation and longitudinal reinforcement ratios was applied to RC columns for structural analysis. Then, the difference of beam moment was identified. In general, the results of analysis was indicated reasonable differences in beam moment, in case of longitudinal reinforcement ratios applied to RC columns when compared with the plain concrete columns. In CFT columns the equation was also applied in order to the effect of confined concrete core on structural analysis. Beam moment was increased as volumetric ratio of lateral steel was decreased. The effect of longitudinal steel ratios was investigated in CFT columns and was confirmed beam moment variety. The result was appeared reasonable difference in beam moment as longitudinal steel was increased.

• 말소리와 음성과학
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• 제10권4호
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• pp.53-66
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• 2018

This study investigated the development of English phonological awareness in preschool children based on a longitudinal study. It carried out a phonological matching task, mispronunciation task, articulation test, explicit phoneme awareness task, rhyme matching task, and initial-phoneme matching task for three-, four- and five-year-old children. A letter knowledge test was also added to the tests for the 5-year-old children. The results revealed that the development of phonological awareness follows a progression of syllable, then onset and rhyme, then phoneme. It was also revealed that language skills such as vocabulary, detection of mispronunciations, and articulation were partially related to the development of phoneme awareness. Finally, we also found that letter knowledge partially affected the children's development of phonological awareness.

• Archives of Reconstructive Microsurgery
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• 제1권1호
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• pp.51-55
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• 1992

Problems of composite tissue transfer commonly arise when a single indispensable recipient vessel receives the graft vssel, and the graft vessel must be sutured in end-to-side fashion so as not todisturb the vascularity of the recipient vessel. The triangular flap in the recipient vessel wall gives an intact endothelial surface when the flow of blood stream is presented and may reduce the chance of anastomosis. We selected mature Wistar rats weighing over 450 grams to compare the conventional longitudinal slit from the triangular flap in the recipient carotid artery over bloood pressure and blood flow when the donor carotid artery was anastomosed in end-to-side fashion. In 30 minutes after anastomosis, maximum blood pressure measured in the donor carotid arterial side when the recipient arterial wall was fasioned with the longitudinal slit was recorded 114 mmHg and with the triangular flap 100mmHg. Minimum blood pressure with the longitudinal slit was 98mmHg and with the triangular flap 88mmHg. The amount of blood collected for 30 seconds in the conventional longitudinal slit was 1.18mg and in the triangular flap 0.78mg. Histology study in 30 minutes, the conventional longitudinal slit demonstrated the more hemorrhagic features around the suture material compared to that of the triangular. flap and, in the 7th day, the conventional longitudinal slit demonstrated the more prominent granulomatous reactions and vascular proliferations around the suture material compared to that of the triangular flap.

• 자동차안전학회지
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• 제12권1호
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• pp.15-25
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• 2020

This paper presents a longitudinal control algorithm for ensuring takeover time of autonomous vehicle using V2V communication. In the autonomous driving of more than level 3, autonomous systems should control the vehicles by itself partially. However if the driver's intervention is required for functional safety, the driver should take over the control reasonably. Autonomous driving system has to be designed so that drivers can take over the control from autonomous vehicle reasonably for driving safety. In this study, control algorithm considering takeover time has been developed based on computation method of takeover time. Takeover time is analysed by conditions of longitudinal velocity of preceding vehicle in time-velocity plane. In addition, desired clearance is derived based on takeover time. The performance evaluation of the proposed algorithm in this study was conducted using 3D vehicle model with actual driving data in Matlab/Simulink environment. The results of the performance evaluation show that the longitudinal control algorithm can control while securing takeover time reasonably.

• The Journal of Korean Physical Therapy
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• 제31권4호
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• pp.222-227
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• 2019

Purpose: This study examined the influence of longitudinal arch on the strength and muscle activity of the abductor hallucis in the standing position in subjects with and without navicular drop signs. Methods: A sample of 34 subjects with and without navicular drop signs between 22 and 28 years of age were enrolled in this study. The strength and muscle activity of the abductor hallucis was measured using a tensiometer. The Smart KEMA System and electromyography device was used on the subjects with and without navicular drop signs. Two groups were classified using the navicular drop test to identify the longitudinal arch of the foot. The strength of the abductor hallucis was evaluated in standing, both with and without an external arch support condition. The two-way mixed ANOVA was used. The level of statistical significance was set to ${\alpha}=0.05$. Results: The strength and muscle activity of the abductor hallucis in standing was significantly higher with external arch support than that without the external arch support in the group with navicular drop signs. There was no significant difference in the abductor hallucis strength and muscle activity with and without external arch support in the subjects without navicular drop signs. Conclusions: The strength and muscle activity of the abductor hallucis in standing can be influenced by the external arch support in the group with navicular drop signs. The strength measurement of the abductor hallucis in standing should be separately performed in conditions with and without longitudinal arch of foot.

• 대한토목학회논문집
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• 제30권6A호
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• pp.503-512
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• 2010

하중-저항계수 설계법에서 조밀단면은 휨모멘트에 의하여 특정단면이 소성모멘트에 도달하기 전에 복부판과 플랜지에 국부좌굴 및 거더의 횡비틈좌굴이 발생하지 않는 단면으로 정의하고 있다. AASHTO LRFD(2007)에서는 수평보강재를 갖지 않는 단면에 관해서만 조밀단면을 만족하는 복부판의 세장비 규정을 제시하고 있다. 복부판에 설치하는 수평보강재의 역할은 휨 좌굴강도를 증가시키는 것이다. 비록 비보강된 복부판이 조밀단면의 기준을 만족하지 못한다고 할지라도, 적당한 수평보강재를 설치한다면 복부판의 좌굴을 방지할 수 있을 것이다. 그러므로 복부판은 소성모멘트에 도달할 수 있을 것이다. 그러나 AASHTO LRFD(2007)에서는 수평보강재를 설치한 복부판이 조밀단면을 만족하지 못하는 이유에 관하여 분명하게 설명하고 있지 않다. 본 연구에서는 수평보강재를 설치한 복부판에서의 휨에 의한 좌굴과 극한강도거동을 선형과 비선형 유한요소법을 통하여 검토하였다. 비록 조밀단면의 세장비를 만족하지 못하는 복부판이라고 할지라도, 충분한 강성과 적절한 위치에 수평보강재로 보강하면 소성모멘트에 도달할 수 있다는 것을 알아냈다. 비선형해석의 분석을 통해 수평보강재를 갖는 복부판의 조밀단면을 만족하는 새로운 세장비 조건식을 제안하였다.

• International Journal of Contents
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• 제15권3호
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• pp.7-12
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• 2019

The purpose of this study was to analyze characteristics and patterns of 'better class' by using the longitudinal text mining big data analysis technique from subjective lecture evaluation comments. First, this study classified upper 30% classes to deduce certain characteristics and patterns from every five-year subjective text data for 10 years. A total of 47,177courses (100%) from spring semester 2005 to fall semester 2014 were analyzed from a university at a metropolitan city in the mid area of South Korea. This study extracted meaningful words such as good, course, professor, appreciation, lecture, interesting, useful, know, easy, improvement, progress, teaching material, passion, and concern from the order of frequency 2005-2009. The other set of words were class, appreciation, professor, good, course, interesting, understanding, useful, help, student, effort, thinking, not difficult, explanation, lecture, hard, pleasant, easy, study, examination, like, various, fun, and knowledge 2010-2014. This study suggests that the characteristics and patterns of 'better class' at college, should be analyzed according to different academic code such as liberal arts, fine arts, social science, engineering, math and science, and etc.

• 의학교육논단
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• 제20권1호
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• pp.6-14
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• 2018

In recent years, Korean medical schools have shown a growing interest in the longitudinal integrated clerkship (LIC) as a means of improving clinical education. Some overseas medical schools have tried the LIC since the 1970s. In the 1990s, several universities in the United States, Canada, and Australia introduced LICs. A variety of studies have confirmed positive results of the LIC. Traditional block-rotation is a discipline-based, inpatient-centered practice. Instead, under the LIC system, a medical student responsible for a panel of longitudinal patients observes developments of their diseases, serving several departments simultaneously. Overseas medical schools have different LIC models depending on their affiliate hospitals' sizes and characteristics. The purpose of this study is to introduce LIC practices in Harvard Medical School and University of California San Francisco, which could be applied by Korean medical schools. This paper also aims to find out the strategies that have been able to help the two US medical schools implement the LIC successfully.

• Human Ecology Research
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• 제58권2호
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• pp.163-176
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• 2020

Longitudinal studies have shown mixed findings on the association between body image dissatisfaction and self-esteem among adolescents. This study examined the longitudinal, reciprocal influences between body image dissatisfaction and self-esteem among Korean pre- and early adolescents by using nationally representative longitudinal panel data from the Korean Youth Panel Study (KYPS). Analyses based on 2,230 participants indicated that girls' body image dissatisfaction was significantly higher than boys'. The trajectory of body image dissatisfaction increased sharply during pre- and early adolescence, but stabilized afterwards for both boys and girls. Self-esteem deteriorated rapidly initially, but began to recover as adolescent girls and boys matured. Structural equation modeling showed that reciprocal influences between body image dissatisfaction and self-esteem were detected for boys. Body image dissatisfaction among girls predicted self-esteem during the entire period, while the opposite direction from self-esteem to body image dissatisfaction emerged two years later. The present study found that, during pre- and early adolescence, body image dissatisfaction and self-esteem develop in a circular fashion by forming a vicious cycle. Implications for the development of intervention and prevention programs are discussed in consideration of age and gender.