• 아시안잔디학회지
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• 제20권1호
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• pp.11-23
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• 2006

본 연구는 골프 코스 관리자가 관리 방법에 따른 그린 스피드를 쉽게 예측할 수 있는 정보를 제공하기 위해 롤링, 이슬제거, 그리고 롤링+이슬 제거를 각각 1회 작업 후 깎기 높이의 변화($4.0{\sim}2.5mm$)와 시간 경과($0{\sim}8hr$)에 따른 4가지 유형의 그린스피드 예측 모형을 통한 빠른 그린 관리 방법을 제시하고자 수행하였다. 공 구름 거리 측정 값은 레이크사이드 컨트리 클럽 동코스 연습용 퍼팅 그린[(Creeping bentgrass (Agrosis palustris Huds. 'Penncross')]에서 2001년 10월 18일과 2002년 5월 25일에 하였다. 자료는 SPSS for window Rel. 10.0(SPSS Inc, 2000) 통계 패키지를 이용하여 다중 회귀 분석하였다. 4가지 유형의 그린스피드 예측 모형중, 빠른 그린 관리 방법의 기준을 설명해 줄 수 있는 회귀식은 식4[($Y_4=4.171-0.225{\cdot}X_1-0.038{\cdot}X_2$(여기서 $Y_4$ : 1회 이슬 제거+1회 롤링시 그린 스피드(m), $X_1$ : 깎기 높이($4.0{\sim}2.5mm,\;X_2$) : 시간 경과($0{\sim}8hr$)]이었다. 이 식은 1회 이슬 제거(스펀지 롤러) $\rightarrow$ 3.0mm 이하의 깎기 높이(21인치 11날 보행식 그린모아, 토너먼트 밑날 장착) $\rightarrow$ 1회 롤링(경량 롤러)의 관리 작업을 할 경우 라운드 종료까지도 3.2m이상의 빠른 그린을 얻을 수 있는 것을 예측하였다. 따라서 이런 관리 시스템은 공식 골프 대회를 위한 빠른 그린의 관리의 기준이 될 것으로 기대되어 진다.

• 인터넷정보학회논문지
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• 제21권6호
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• pp.41-50
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• 2020

The consequences of wearing high heels can be different according to the heel height, gait speed, shoe design, heel base area, and shoe size. This study aimed to focus on the knee extension and flexion range of motion (ROM) during gait, which were challenged by wearing five different shoe heel types and two different self-selected gait speeds (comfortable and fast) as experimental conditions. Measurement standards of knee extension and flexion ROM were individually calibrated at the time of heel strike, mid-stance, toe-off, and stance phase based on the 2-minute video recordings of each gait condition. Seven healthy young women (20.7 ± 0.8 years) participated and they were asked to walk on a treadmill wearing the five given shoes at a self-selected comfortable speed (average of 2.4 ± 0.3 km/h) and a fast speed (average of 5.1 ± 0.2 km/h) in a random order. All of the shoes were in size 23.5 cm. Three of the given shoes were 9.0 cm in height, the other two were flat shoes and sneakers. A motion capture software (Kinovea 0.8.27) was used to measure the kinematic data; changes in the knee angles during each gait. During fast speed gait, the knee extension angles at heel strike and mid-stance were significantly decreased in all of the 3 high heels (p<0.05). The results revealed that fast gait speed causes knee flexion angle to significantly increase at toe-off in all five types of shoes. However, there was a significant difference in both the knee flexion and extension angles when the gait in stiletto heels and flat shoes were compared in fast gait condition (p<0.05). This showed that walking fast in high heels leads to abnormal knee ROM and thus can cause damages to the knee joints. The findings in this preliminary study can be a basis for future studies on the kinematic changes in the lower extremity during gait and for the analysis of causes and preventive methods for musculoskeletal injuries related to wearing high heels.

• 전기학회논문지
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• 제65권2호
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• pp.349-353
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• 2016

The purpose of this study was to investigate possible age differences in the attenuation of acceleration in the upper body (from pelvis through shoulder to head) during fast walking. Thirty young and 29 elderly subjects participated in this study. Wireless acceleration sensors were attached on head, shoulder, and pelvis. Subjects performed two trials of fast walking on a treadmill, where the fast speed was defined as 1.5 times of the comfortable speed. Root-mean-squared (RMS) accelerations of each axis were compared with age group and sensor position as independent factors. In the AP direction, the pelvis acceleration was greater in the young and the shoulder-to-head attenuation was also greater in the young (p<0.001), so that the head acceleration was comparable between age groups (p=0.581). In the ML direction, the pelvis acceleration was greater in the young and also the pelvis-to-shoulder attenuation was greater in the young (p<0.001), so that the head acceleration was greater in the elderly group (p<0.001). Insufficient attenuation ML acceleration in the elderly resulting in the greater acceleration in the head may deteriorate the balance control which utilize feedback signals from the sensory organs in head, e.g., vestibular and visual systems.

• 한국식품영양학회지
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• 제34권2호
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• pp.156-164
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• 2021

This study aimed to investigate the relationship between eating speed and nutritional status among Korean high-school students using Nutrition Quotient for Korean Adolescents (NQ-A). In this study, a questionnaire survey was conducted in 453 high-school students (227 boys and 226 girls) from September 2019 to October 2019 in Chungbuk area. Based on the self-reported speed of eating data, subjects were classified into a fast group (n=180), a medium group (n=184), and a slow group (n=89). NQ-A scores for each group were measured in each speed group. In the environment section, girls showed a significant difference in usage time of electronic devices, such as TVs and smartphones: the fast group spent significantly more time than the medium group (p=0.035). In the practice section, among boys, the slow group had significantly higher scores for washing hands before eating than the medium and the fast groups (p=0.022). This study suggested that eating speed of high school students is associated with health-related environment factor and practice factor of NQ-A, such as time spent on smart devices or washing hands before eating. The study results can provide baseline data for nutrition education on health management of high school students.

• 제어로봇시스템학회논문지
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• 제8권7호
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• pp.539-546
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• 2002

This paper presents a new direct seek control scheme that provides fast data access capability and robust performance for high-speed rotational optical disk drives (ODD). When a disk is rotating at a high speed to obtain fast data transfer in ODD, the magnitude and frequency of velocity disturbance caused by eccentric rotation of the disk increase in proportion to the rotational speed of the disk. Such disturbances make it almost impossible for the conventional seek control scheme to achieve stable and satisfactory seek performance. We analyze the problems that may arise when the conventional seek control scheme is applied to the high-speed rotational ODD and propose a new direct seek control scheme that will solve such problems. In the proposed scheme, a seek control system is designed such that its performance is guaranteed for a set of plants with parameter perturbations. The performance of the proposed seek control scheme is shown by experiments using a high-speed rotational ODD.

• Journal of Advanced Marine Engineering and Technology
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• 제32권3호
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• pp.437-445
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• 2008

This paper deals with the experimental assessment of the vibration suppression of the smart structures. First. we have presented a new high-speed active control system using the DSP320C6713 microprocessor. A peripheral system developed is composed of a data acquisition system, N/D and D/A converters, piezoelectric (PZT) actuator/sensors, and drivers for fast data processing. Next, we have tested the processing time of the peripheral devices, and provided the corresponding test results. Since fast data processing is very important in the active vibration control of the structures, we have focused on achieving the fast loop times of the control system. Finally, numerous experiments were carried out on the aluminum plate to validate the superior performance of the vibration control system at different control loop times.

• 조명전기설비학회논문지
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• 제23권8호
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• pp.21-25
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• 2009

속도와 토크의 값이 다른 5개의 동작점에서 효율이 최대가 되는 자속을 구한 후, 5개의 자속을 이용하여 효율이 최대가 되는 자속의 곡면을 구한다. 주어진 속도와 토크를 이용하여 자속곡면에서 효율이 최대가 되는 자속을 구한 후, 이 자속을 초기값으로 하여 미리 정해진 양만큼 자속을 변화시키면서 최대효율제어를 수행한다. 시뮬레이션 결과 제안한 방법에 의하여 신속히 최대효율제어를 위한 자속으로 수렴함을 보인다.

• Journal of Power Electronics
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• 제15권6호
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• pp.1559-1566
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• 2015

The brushless DC motor (BLDCM) has many advantages. As a result, it is widely used in electric vehicle (EV) drive systems. To improve the reliability of the motor control system, a position sensorless control strategy based on a sliding mode observer (SMO) is proposed. The global fast terminal sliding mode observer (GFTSMO) is proposed to enhance the control performance of the SMO control system. The advantages of the linear sliding mode and the nonsingular terminal sliding mode (NTSM) are combined in the control strategy. The convergence speed of the system state is enhanced. The motor commutation point is obtained with the observation of the back EMF, and the instantaneous torque value of the motor is calculated. Therefore, the position sensorless control of the BLDCM is realized. Experimental results show that the proposed control strategy can improve the convergence speed, dynamic characteristics and robustness of the system.

• 한국통신학회논문지
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• 제22권2호
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• pp.325-333
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• 1997

In fractral decoding procedure, the reconstructed image is obtained by iteratively applying the contractive transform to an arbitrary initial image. But this method is not suitable for the fast decoding because convergence speed depends on the selection of initial image. Therefore, the initial image to achieve fast decoding should be selected. In this paper, we propose an initial image estimation that can be applied to various decoding methods. The initial image similar to the original image is estimated by using only the compressed data so that the proposed method does not affect the compression ratio. From the simulation, the PSNR of the proposed initial image is 6dB higher han that of ones iterated output image of conventional decoding with Babaraimage. Computations in addition and multiplication are reduced about 96%. On the other hands, if we apply the proposed initial image to other decoding algorithms, the faster convergence speed is expected.

• IEIE Transactions on Smart Processing and Computing
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• 제5권4호
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• pp.231-234
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• 2016

The next-generation video coding standard known as High-Efficiency Video Coding (HEVC) was developed with the aim of doubling the bitrate reduction offered by H.264/Advanced Video Coding (AVC) at the expense of an increase in computational complexity. Mode decision with motion estimation is still one of the most time-consuming computations in HEVC, as it is with H.264/AVC. Several schemes for a fast mode decision have been presented in reference software and in other studies. However, a possible speed-up in conventional schemes is sometimes insignificant for videos that have inhomogeneous spatial and temporal characteristics. This paper proposes a bypass algorithm to skip large-block-size predictions for videos where small block sizes are preferred over large ones. The proposed algorithm does not overlap with those in previous works, and thus, is easily used with other fast algorithms. Consequently, an independent speed-up is possible.