• Physical Therapy Rehabilitation Science
• /
• 제6권4호
• /
• pp.189-195
• /
• 2017

Objective: The purpose of this study was to examine the effects of real-time visual feedback weight shift training during golf swinging on golf performance. Design: Repeated-measures crossover design. Methods: Twenty-sixth amateur golfers were enrolled and randomly divided into two groups: The golf swing training with real-time feedback on weight shift (experimental group) swing training on the Wii balance board (WBB) by viewing the center of pressure (COP) trajectory on the WBB. All participants were assigned to the experimental group and the control group. The general golf swing training group (control group) performed on the ground. The golf performance was measured using a high-speed 3-dimensional camera sensor which analyses the shot distance, ball velocity, vertical launch angle, horizontal launch angle, back spin velocity and side spin velocity. The COP trajectory was assessed during 10 practice sessions and the mean was used. The golf performance measurement was repeated three times and its mean value was used. The assessment and training were performed at 24-hour intervals. Results: After training sessions, the change in shot distance, ball velocity, and horizontal launch angle pre- and post-training were significantly different when using the driver and iron clubs in the experimental group (p<0.05). The interaction time${\times}$group and time${\times}$club were not significant for all variables. Conclusions: In this study, real-time feedback training using real-time feedback on weight shifting improves golf shot distance and accuracy, which will be effective in increasing golf performance. In addition, it can be used as an index for golf player ability.

• Journal of Biosystems Engineering
• /
• 제27권6호
• /
• pp.479-490
• /
• 2002

A dynamic model of a power shuttle transmission was developed and its validity was verified using the experimental data obtained from a transmission test bench. A 40㎾, 4WD tractor was also modeled using an application software EASY5 to investigate parameters and their effects on the power shifting performance. For a tractor model, the manual reverse gear was replaced by a power shuttle transmission. The tractor model also included an engine, main-gears for transmission, wheels, differentials and planet gears. Using the tractor model, the effects of the parameters such as modulating pressure and time, engine speed, tractor speed. tractor weight. reverse to forward speed ratio and torsional damper on the transient characteristics at starting and shuttle shifting were investigated by the computer simulation. The transient characteristics were represented by variations in clutch pressure, torque transmitted to input shaft and driving wheels, and power transmission capacity of the clutch. It was found that the modulating pressure and time affected most significantly the torque transmission and shifting time. The input torque, axle torque, power transmission capacity of the clutch and transmission time all increased with increase in engine speed, tractor speed. tractor weight and ratio of reverse to forward speeds. However, the axle torque decreased with tractor speed. Both the axle torque and power transmission capacity of the clutch also decreased with the ratio of reverse to forward speeds.

• 한국공간구조학회논문집
• /
• 제14권3호
• /
• pp.93-100
• /
• 2014

Ethylene Tetrafluoroethylene (ETFE) has been widely used in long-span buildings because of its light weight and high transparency. This paper studies the short and long term creep behaviour of ETFE foil. A series of short-term creep and recovery tests were performed, in which the residual strain was observed. A long-term creep test of the ETFE foil was also performed over 110 days. A viscoelastic-plastic model was then established to describe the short-term creep and recovery behaviour. The model contains a traditional multi-Kelvin part and an added steady-flow component to represent the viscoelastic and viscoplastic behaviour, respectively. The model successfully fit the data for three stresses and six temperatures. Additionally, time-temperature equivalency was adopted to predict the long-term creep behaviour of ETFE foil. Horizontal shifting factors were determined from the process of shifting creep-curves at six temperatures. The long-term creep behaviours at three temperatures were predicted. Finally, the long-term creep test showed that the short-term creep test at identical temperatures insufficiently predicted additional creep behaviour, and the long-term test verified the horizontal shifting factors derived from the time-temperature equivalency.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제12권7호
• /
• pp.3455-3474
• /
• 2018

As a unique form of signed-digit representation, non-adjacent form (NAF) minimizes Hamming weight by removing a stream of non-zero bits from the binary representation of positive integer. Thanks to this strong point, NAF has been used in various applications such as cryptography, packet filtering and so on. In this paper, to improve the NAF conversion speed of the $NAF_w$ algorithm, we propose a new NAF conversion algorithm, called w-bit Shifting Non-Adjacent Form($SNAF_w$), where w is width of scanning window. By skipping some unnecessary bit comparisons, the proposed algorithm improves the NAF conversion speed of the $NAF_w$ algorithm. To verify the excellence of the $SNAF_w$ algorithm, the $NAF_w$ algorithm and the $SNAF_w$ algorithm are implemented in the 8-bit microprocessor ATmega128. By measuring CPU cycle counter for the NAF conversion under various input patterns, we show that the $SNAF_2$ algorithm not only increases the NAF conversion speed by 24% on average but also reduces deviation in the NAF conversion time for each input pattern by 36%, compared to the $NAF_2$ algorithm. In addition, we show that $SNAF_w$ algorithm is always faster than $NAF_w$ algorithm, regardless of the size of w.

• Journal of Advanced Marine Engineering and Technology
• /
• 제24권6호
• /
• pp.155-163
• /
• 2000

A technology of full time four wheel drive(4WD) vehicle has been improved greatly, and the market share of full time 4WD has been extended steadily in recent days. The transfer case is an essential element in the 4WD automobile. In this paper, the details of electronically controlled transfer case is described. In order to achieve easy shifting, the shifting, the developed system automate the conversion of "$4\times2\longleftrightarrow4\times4(H)\longleftrightarrow4\times4(L)$". Furthmore, this system employs an chain drive type instead of gear drive type for drive type and synchromesh type instead of constant-mesh type for gear mesh type. Therefore, the developed transfer case is accomplished light-weight, low noise, and compact.d compact.

• The Journal of Korean Physical Therapy
• /
• 제32권1호
• /
• pp.29-33
• /
• 2020

Purpose: This study examined the effects of the weight-bearing pattern and calcaneal taping on the heel width and plantar pressure in standing. Methods: Fifteen healthy subjects with normal feet participated in this study. The heel width was measured using a digital caliper, and a pedoscan was used to measure the plantar pressure of the rear foot while standing. The participants were instructed to stand in three weight-bearing patterns (anterior, middle, and posterior weight bearing) before and after calcaneal taping. The heel width and plantar pressure were measured three times before and three times after calcaneal taping, with the three weight-bearing patterns applied in random order. A 2 (non-taping vs. taping) × 3 (anterior, middle, posterior weight bearing) two-way repeated ANOVA with a Bonferroni post hoc correction was used to assess the differences in heel width and plantar pressure. Results: The results revealed a significant main effect of the weight-bearing pattern (p<.01), but not of calcaneal taping (p>.05). Greater weight bearing applied to the heel resulted in a significantly increased heel width and planter pressure of the rear foot (p<.01). Conclusion: In standing, a posterior weight-bearing pattern increases the heel width due to side-to-side shifting of the plantar heel pad, which increases the heel plantar pressure. Therefore, to prevent high stress on the heel pad and plantar heel pain, it is important to refrain from posterior weight bearing while standing during the activities of daily living.

• 한국엔터테인먼트산업학회논문지
• /
• 제14권3호
• /
• pp.455-462
• /
• 2020

본 연구의 목적은 과제 지향적 활동을 뇌졸중 환자에게 중재 시 마비측 체중이동에 어떠한 영향이 있는지 알아보고자 진행하였다. 이를 위해 2019년 9월부터 12월까지 경기도 소재 S병원에서 재활치료를 받는 뇌졸중 환자 33명을 무작위 할당 후 실험그룹과 대조그룹으로 나누었다. 실험그룹 17명은 과제 지향적 활동을 제공하였으며, 대조그룹 16명은 일반적 작업치료를 주 3회, 회당 35분씩, 총 4주간 동안 진행하였다. 신체 좌·우측의 체중이동은 MTD balance system으로 평가하였으며, 중재 전 초기평가와 4주 중재 후 재평가를 실시하였다. 두 그룹의 중재 전·후 평가와 그룹 간 중재 전·후 평가를 실시하여 변화량을 비교 분석하였고 다음과 같은 결과를 얻었다. 그룹 내 중재 전·후 평가 시 마비측으로 체중이동은 실험그룹과 대조그룹 모두 마비측으로 체중이동의 향상을 보였다. 그룹 간 중재 전·후 평가에서 실험그룹이 대조그룹에 마비측으로 체중이동이 통계적으로 유의한 향상을 보였다. 추후 보완된 연구를 통해서 뇌졸중 환자 치료 시 과제 지향적 활동이 마비측으로 체중이동을 증진하는 데 유용하게 적용될 수 있을 것이라 생각된다.

• 전자공학회논문지
• /
• 제53권4호
• /
• pp.149-155
• /
• 2016

본 논문에서는 운전자의 체중 이동을 활용한 메카넘 휠 기반 전방향 전동 보드 제어 방법을 제안한다. 운전을 위한 별도의 운전 장치를 사용하지 않으며, 다수의 센서를 활용하여 측정한 체중 분포로부터 무게 중심의 위치를 구하여 전방향 전동 보드의 병진 운동과 회전 운동의 3 자유도 운전 명령을 생성한다. 체중 이동은 운전 명령으로 반영됨과 동시에 관성력을 극복하기 위한 운전자의 동작과 일치하여 직관적인 장점이 있다. 전체 제어 구조를 제시하며, 실험에 적용하여 제안된 방식의 타당성을 확인한다.

• 대한물리의학회지
• /
• 제12권1호
• /
• pp.9-14
• /
• 2017

PURPOSE: To evaluate the effect of weight shift training with Hula Hoop on weight shift change and gait in stroke patients. METHODS: Ten stroke patients were enrolled in this study, and randomly divided into 2 groups. The study group underwent weight shift training with Hula Hoop, while the control group received general physical therapy that included weight shift training. All the studies were performed over a period of 4 weeks. Before and after the intervention, plantar pressure and performance in the 10 m walk test (10MWT) were assessed. Wilcoxon signed ranks test was used to compare the change from before to after the intervention in each group. The differences between the study and control groups were analyzed by using the Mann-Whitney test. RESULTS: After 4 weeks of intervention, the change in weight shift and performance in the 10MWT from before to after the experiment showed no statistical significance (p>.05). In addition, the comparison between the groups showed no significance in terms of weight-shift change, and performance in the 10MWT (p>.05). CONCLUSION: Although the difference was not statistically significant, the degree of improvement was similar to that attained with the conventional exercise treatment related to weight- shift training. During the course of the treatment, the patients received feedback through repeated training by themselves. Weight-shift training with Hula Hoop would be effective in improving the walking ability and weight-shifting on the paralyzed side of stroke patients. In the future, the effectiveness of this training would need to be validated.

• 한국해양공학회:학술대회논문집
• /
• 한국해양공학회 2004년도 학술대회지
• /
• pp.62-67
• /
• 2004

Many ships in voyage experience weight and buoyancy distribution change by various reasons such as change of sea water density and waves, weather condition, and consumption of fuel, provisions, etc . The weight and buoyancy distribution change can bring the ships out of allowable trim, heeling angle. In these case, the ships should adjust trim and heeling angle by shifting of liquid cargo or ballasting, deballasting of ballast tanks for recovery of initial state or for a stable voyage. But, if the adjustment is performed incorrectly, ship's safety such as longitudinal strength, intact stability, propeller immersion, wide visibility, minimum forward draft cannot be secured correctly. So it is required that the adjustment of trim and heeling angle should be planned not by human operators but by optimization computer algorithm. To make an optimized plan to adjust trim and heeling angle guaranteeing the ship's safety and quickness of process, Uk! combined mechanical analysis and optimization algorithm. The candidate algorithms for the study were heuristic algorithm, meta-heuristic algorithm and uninformed searching algorithm. These are widely used in various kinds of optimization problems. Among them, heuristic algorithm $A^\ast$ was chosen for its optimality. The $A^\ast$ algorithm is then applied for the study. Three core elements of $A^\ast$ Algorithm consists of node, operator, evaluation function were modified and redefined. And we analyzed the $A^\ast$ algorithm by considering cooperation with loading instrument installed in most ships. Finally, the algorithm has been applied to tanker ship's various conditions such as Normal Ballast Condition, Homo Design Condition, Alternate Loading Condition, Also the test results are compared and discussed to confirm the efficiency and the usefulness of the methodology developed the system.