• 한국운동역학회지
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• 제25권4호
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• pp.483-488
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• 2015

Objective : The purposes of this study was to analyze the locomotive movement of forelimbs according to changes in velocities in the quadruped cadence of horses. Methods : Horses selected as subjects consisted of Jeju pony horses (heights of withers: $1.23{\pm}0.51$). Two camcorders (HDR-HC7/HDV 1080i, Sony Corp, Japan) were used to capture the movement of the horses' forelimbs at a rate of 60 frames/sec. Additionally, raw data was collected from Kwon3D XP motion analysis package ver 4.0 program (Visol, Korea) with DARTFISH (DFKREA., Korea) video software solution. The variables analyzed consisted of 1 step lengths, 1 stride lengths, stance time, swing time, 1 stride time, velocity while walking, and trot of the horses. A two-way ANOVA and paired t-test of the variables by velocity and phase were treated at .05 level of significant difference, statistically. Results : The time elapsed of walk(stance: 0.63 sec[63.86%], swing: 0.35 sec[36.14%], 1 stride time: 0.99 sec respectively) showed significant difference with more delay than that of trot(stance: 0.29 sec[45.73%], swing: 0.34 sec[54.27% ], 1 stride time: 0.63 sec respectively), and also showed significant difference at trot in interaction (stance time>tort swing>walk swing>walk stance). The 1 step lengths and stride lengths in trot showed significant difference with longer than that of walk. Velocity of Trot showed significant difference statistically with higher than that of walk Conclusion : The horses' velocity during 1 step lengths and 1 stride lengths showed a proportional relationship, but the correlation between the horses' velocity and stance time showed a negative relationship during the quadruped cadence.

• 생명과학회지
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• 제19권2호
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• pp.271-276
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• 2009

본 연구는 여자대학생에게 복싱에어로빅 운동 후, 그 운동이 심박수변이도에 미치는 영향을 알아보기 위하여 시도되었다. 운동전 측정과 3개월 복싱에어로빅 운동 후 측정, 두 차례에 의하여 검사한 결과 다음과 같은 결론을 얻었다. (1) 심박수변이도의 결과 Mean HRT는 집단 및 시간, 집단과 시간간의 교호작용이 유의한 차이가 나타나지 않았다. (2) 심박수변이도의 결과 SDNN은 집단 및 시간, 집단과 시간간의 교호작용이 유의한 차이가 나타나지 않았다. (3) 심박수변이도의 결과 RMSSD는 집단 및 시간, 집단과 시간간의 교호작용이 유의한 차이가 나타나지 않았다. (4) 심박수변이도의 결과 TP는 집단 및 시간, 집단과 시간간의 교호작용이 유의한 차이가 나타나지 않았다. (5) 심박수변이도의 결과 LF는 집단 및 시간, 집단과 시간간의 교호작용이 유의한 차이가 나타나지 않았다. (6) 심박수변이도의 결과 HF는 집단 및 시간, 집단과 시간간의 교호작용이 유의한 차이가 나타나지 않았다. (7) 심박수변이도의 결과 LF/HF는 집단 및 시간, 집단과 시간간의 교호작용이 유의한 차이가 나타나지 않았다. (8) 심박수변이도의 결과 VLF는 집단 및 시간, 집단과 시 간간의 교호작용이 유의한 차이가 나타나지 않았다. 이상을 종합할 때 심박수변이도는 환경적인 영향을 받는 것으로 생각되어지며, 심박수변이도가 운동에 미치는 영향을 자세하기 규명하기 위해서는 비교적 동일한 집단을 더욱 세분화시키고 연령대와 성별, 운동형태 등에 따른 보다 장기적인 연구가 필요한 것으로 생각된다.

• Structural Engineering and Mechanics
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• 제17권6호
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• pp.735-749
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• 2004

This work presents a direct integration scheme, based on a fourth order finite difference approach, for elastodynamics. The proposed scheme was chosen as an alternative for attenuating the errors due to the use of the central difference method, mainly when the time-step length approaches the critical time-step. In addition to eliminating the spurious numerical oscillations, the fourth order finite difference scheme keeps the advantages of the central difference method: reduced computer storage and no requirement of factorisation of the effective stiffness matrix in the step-by-step solution. A study concerning the stability of the fourth order finite difference scheme is presented. The Finite Element Method and the Boundary Element Method are employed to solve elastodynamic problems. In order to verify the accuracy of the proposed scheme, two examples are presented and discussed at the end of this work.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2010년도 춘계 학술논문 발표대회 1부
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• pp.37-39
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• 2010

In this study, with new office construction site of S Construction company as subject, to solve all the problems according to reduced hydration heat and temperature crack of mass concrete used mat foundation and placing time difference, low heat combination of coarse particle cement and fly-ash and setting time difference applied AE water reducing agent, and to prevent the early frost damage caused by low outdoor temperature, a heat insulation method using double bubble sheet was conducted. As a result, it was found that hydration heat and setting time difference was reduced by applying a low heat combination and setting time difference construction method, and that the high insulation capability of the double bubble sheet was able to not only prevent the early frost damage but also reduce temperature difference between the central part and the upper part of mass concrete.

• Journal of Acupuncture Research
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• 제17권1호
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• pp.89-105
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• 2000

In order to obtain the clinical data on the different effects of the three different methods of indirect moxibustion, moxa-combustion time, peak temperature, average temperature, maximum gradient temperature, average gradient temperature, and moxa-combustion calorie rate of the input period in ARIRANG, JANG, PUNG were measured through this experiment. The results of the experiment were as follows : 1. In the combustion time, during the input period ARIRANG had the longest combustion time followed by PUNG, JANG in a descending order but these were not acknowledged to have significant difference each other. 2. In the peak temperature of the input period, PUNG had the highest temperature followed by ARIRANG, JANG in a descending order. ARIRANG and JANG were acknowledged to have significant difference with PUNG. ARIRANG and JANG however were not acknowledged to have difference each other. 3. In the average temperature, during the input period, PUNG had the highest temperature followed by JANG, ARIRANG in a descending order. ARIRANG and JANG were acknowledged to have significant difference with PUNG. ARIRANG and JANG however were not acknowledged to have difference each other. 4. In the maximum gradient temperature, during the input period, PUNG had the highest temperature followed by ARIRANG, JANG in a descending order. ARIRANG and JANG were acknowledged to have significant difference with PUNG. ARIRANG and JANG however were not acknowledged to have difference each other. 5. In the average gradient temperature, during the input period, PUNG had the highest temperature followed by ARIRANG, JANG in a descending order. ARIRANG and JANG were acknowledged to have significant difference with PUNG. ARIRANG and JANG however were not acknowledged to have difference each other. 6. In the moxa-combustion calorie rate, during the input period, JANG had the highest temperature followed by ARIRANG, PUNG in a descending order. ARIRANG and PUNG were acknowledged to have significant difference with JANG. ARIRANG and PUNG however were not acknowledged to have difference each other.

• 조명전기설비학회논문지
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• 제27권7호
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• pp.52-58
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• 2013

The two-dimensional finite difference time domain algorithm is used to numerically reconstruct the electron density profile in O-mode ultrashort pulse reflectometry. A Gaussian pulse is employed as the source of a probing electromagnetic wave. The Gaussian pulse duration is chosen in such a manner as to have its frequency spectrum cover the whole range of the plasma frequency. By using a number of numerical band-pass filters, it is possible to compute the time delays of the frequency components of the reflected signal from the plasma. The electron density profile is reconstructed by substituting the time delays into the Abel integral equation. As a result of simulation, the reconstructed electron density profile agrees well with the assumed profile.

• 한국통신학회논문지
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• 제32권7C호
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• pp.608-615
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• 2007

일반적으로 양방향 전송을 통한 TOA(Time Of Arrival) 정보는 두 디바이스간의 정확한 RTT(Round Trip Time) 정보로부터 도출되지만 디바이스간의 서로 다른 클럭 표류의 영향으로 인하여 RTT 측정 시 요구되는 응답 시간이 길 경우 매우 심각한 TOA 오차를 야기 시키게 된다. 이를 해결하기 위해서 본 논문에서는 비동기 시스템에서 클럭 표류의 영향을 줄이면서 TOA와 TDOA(Time Difference Of Arrival) 정보를 획득하는 방안을 제안한다. 이를 검증하기 위해서 IEEE 802.15.4a Task Group에서 제시한 단방향 전송을 통한 측위 방안과 비교하였으며 제안된 방안이 기존 방법들보다 개선된 성능을 보임을 확인하였다.

• PNF and Movement
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• 제20권3호
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• pp.331-340
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• 2022

Purpose: Thisstudy aimed to identify the effect of varying the expansibility of elastic tape on the onset time of muscle contraction during neck extension for forward head posture syndrome. Methods: Forty-five young adults with forward head posture syndrome volunteered to participate and were randomly assigned to one of three groups according to the expansibility of the elastic tape (25%, 50%, 75%). The onset time of muscle contraction for the neck extensor during neck extension was measured using an electromyographic system (Free EMG, BTS, Italy). Multivariate analysis of variance was employed to determine the effect of different expansibilities of elastic tape on the onset time of muscle contraction during neck extension for forward head posture syndrome. When there was a statistically significant difference by MANOVA, Scheffe was used as a post-hoc test. The level of significance was set at α=0.05. Results: In the comparison of the onset time of muscle contraction of varying elastic tape expansibilities and measurement times, there was a significant difference between the groups (Lt. UT, Lt. SCM, Rt. SCM) (p < 0.05), but there was no significant difference in the interaction between the measurement time and the group, between the measurement time (p > 0.05). Conclusion: In the neck extension, 75% of the tape extensibility in the Lt. UT and both SCM shortened the muscle contraction onset time.

• Smart Structures and Systems
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• 제14권6호
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• pp.1081-1103
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• 2014

Real-time hybrid simulation (RTHS) has emerged as an important tool for testing large and complex structures with a focus on rate-dependent specimen behavior. Due to the real-time constraints, accurate dynamic control of servo-hydraulic actuators is required. These actuators are necessary to realize the desired displacements of the specimen, however they introduce unwanted dynamics into the RTHS loop. Model-based actuator control strategies are based on linearized models of the servo-hydraulic system, where the controller is taken as the model inverse to effectively cancel out the servo-hydraulic dynamics (i.e., model-based feedforward control). An accurate model of a servo-hydraulic system generally contains more poles than zeros, leading to an improper inverse (i.e., more zeros than poles). Rather than introduce additional poles to create a proper inverse controller, the higher order derivatives necessary for implementing the improper inverse can be calculated from available information. The backward-difference method is proposed as an alternative to discretize an improper continuous time model for use as a feedforward controller in RTHS. This method is flexible in that derivatives of any order can be explicitly calculated such that controllers can be developed for models of any order. Using model-based feedforward control with the backward-difference method, accurate actuator control and stable RTHS are demonstrated using a nine-story steel building model implemented with an MR damper.

• 대한물리의학회지
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• 제2권2호
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• pp.161-171
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• 2007

Purpose : The purpose of this study was to evaluate the effect of footwear on gait in older adults. Methods : The footwear consists of loafer with fixation and mule and slipper without fixation. Twenty one female older adults voluntarily participated in this study. Each participant walked on the gait system GAITRite and measured temporal-spatial gait parameters. And the participants wore loafer, mule, slipper randomly. We measured stance time, swing time, heel-to-heel BOS, double support time, velocity, cadence, FAP as temporal-spatial gait parameters. Results : Three gait parameters showed significant difference statistically among 7 gait parameters. The stance time increased as loafer, mule, barefoot, slipper orderly. And there was a significant difference statistically (p<.05). The swing time increased as slipper, barefoot, mule, loafer orderly. And there was a significant difference statistically(p<.05). And the heel-to-heel BOS increased as barefoot, loafer, mule, slipper orderly. And there was a significant difference statistically(p<.05) according to footwear type. Conclusion : The footwear type with high stability like loafer is considered better than footwear type with low stability like mule and slipper for the elderly.