The nonlinear simple pendulum is investigated to find the exact closed-form analytical solution, satisfying initial conditions of angular position and angular velocity. While previous numerous studies have been conducted on the nonlinear simple pendulum, the exact closed-form analytical solution still remains not available in public domain for the most general initial condition including initial angular velocity as well as initial angular displacement. In this paper, the exact closed-form analytical solution for the general initial conditions is derived using Jacobi’s elliptic function and elliptic integral. The result was verified by comparing it with previous studies and the numerical solution of the equation of motion through the Runge-Kutta integration method.

MDPS control has been a difficult problem for the past two decades. Though there are many ways to control steering feeling, the MDPS control logic is still being upgraded or developed for steering feel improvement. A new point of view in MDPS is proposed by evolution logic, which is a new driver friendly improvement based on the analysis of driver’s driving pattern. As a result of the application of evolution logic, this paper shows that drivers behaviour effecting factors among MDPS parameters will efficiently lead to customers’ satisfaction.

본 연구는 진사회성(eusocial)곤충이며 우리나라 고유종인 참땅벌(Korean yellowjacket, Vespula koreensis)의 둥지(nest)입구 유리관 내로 진입 속도와 나오는 속도에 대한 측정치를 제시한다. 각 포식 재료(foraging material)인 nectar(에너지원), prey(유 충먹이), pulp(둥지 재료)에 속하는 3가지의 포식 재료를 가져 오는 forager의 유리 관 속 행동을 영상을 곤충 행동 관찰 장치(Noldus, EthoVision XT 8)를 사용하여 각 포식 재료를 들고 나는 속도를 측정 하였다. 측정은 각 포식 재료 별로 44개체씩 측 정하였으며, nectar forager의 속도 평균(4.655±0.556cm/s), prey forager (5.238± 0.601cm/s), pulp forager(5.200±0.631cm/s)이며, 전체 속도 평균(5.028±0.595cm/s) 로 측정 되었다. 속도는 prey forager가 가장 빠른 속도를 보이며, nectar forager가 가장 느린 속도를 보였다. 이 외에 개체의 나오는 속도와 개체의 무게와 길이 나이 등이 비교분석 되었다. 이 자료를 바탕으로 각 개체들의 속도의 차이와 개체의 나이 의 변수, 각 포식 재료의 비용들을 추정하고 비교 토의 하였다.

The purpose of this study was to examine the differentiation of proprioception, invertor and evertor muscle strength, and time to peak torque at a velocity of 300 °/sec of the ankle joint in people with or without functional ankle instability (FAI). Nineteen subjects with a history of ankle sprain participated. All subjects were divided into FAI group (n1=9, Cumberland ankle instability tool (CAIT)≤24) and a control group (n2=10) based on their CAIT scores. Isokinetic dynamometer was used to measure the sense of active joint position of the ankle at mid-range and end-range of an inversion motion and invertor as well as the evertor muscle strength and time to peak torque at 300 °/s. The FAI group showed a statistically reduction in invertor and evertor muscle strength and time to peak torque when compared to the control group (p<.05). Muscle strength and time to peak torque of the invertor and evertor, as well as the sense of active joint position at end-range were also lower in the FAI group than in the control (p<.05). Correlations between CAIT score and position sense at end-range (r=-.577) and invertor muscle strength (r=.554) were statistically significant (p<.05). Individuals with FAI showed reduction in invertor and evertor muscle strength and recruitment time as well as in proprioception of the ankle joint. Thus, proprioception and invertor and evertor muscle strength of the ankle joint at fast angular velocity may be investigated when examining and planning care for individuals with FAI.

Manual dexterity is often evaluated in rehabilitation because of its contribution to upper limb performance and to individual functional independence. Dexterity depends on age, sex, anthropometric measurements of the hand and sensitivity. The purpose of this study was to compare the finger dexterity with and without wearing different types of gloves (latex gloves and cotton gloves), and to investigate the correlation among the different measurement tools (VALPAR component work samples, O‘conner finger dexterity, and Minnesota grooved pegboard) for finger dexterity. Fifteen healthy young subjects (male: 6, female: 9) had a mean age of 26 years were evaluated. The results were as follows: There was no significant difference in finger dexterity between male and female group at all conditions except for wearing cotton glove condition. The finger dexterity was significant difference in Minnesota grooved pegboard test among conditions(bare hand, latex gloves and cotton gloves). However, finger dexterities were no significant differenece in other tests at different conditions. There was high correlation between measurement tool except for the Size discrimination item in VALPAR test. The results of this study suggest that Minnesota grooved pegboard test maybe a sensitive tool to measure the finger dexterity at sensory constrained conditions.

In general, research in isokinetic exercise has focussed on studies of peak torque. However, peak torque is not always sufficient to assess the real amount of motion or to determine endurance. In this study, the subjects were 54 healthy students who performed continuous maximal isokinetic knee flexion and extension until their total work per time reached 50% of their maximal total work. Isokinetic curves were then plotted. Total work sums, exercise durations in seconds, and the numbers of repetitions were compared with reference to subject gender, angular velocity and muscle group. The relationship between total work sum, duration and number of repetition and thigh circumference plus leg length was computed. In addition, the characteristics of total work per second and total work per time were calculated. Results showed the total work sums differed greatly from muscle group to muscle group and with different angular velocities. The duration in seconds and the numbers of repetition differed only at higher angular velocity. Males achieved higher levels in every category except for some duration in seconds and some numbers of repetitions. Thigh circumference and leg length were deciding fators in every case, but duration in seconds and number of repetitions were not. These results suggest that measures of endurance should be included along with measures of total work when isokinetic studies are done. Measures of endurance in seconds are more accurate when isokinetic exercise is performed at lower angular velocities and numbers of repetitions at higher angular velocities.

This study proposes a FE model updating strategy based on data fusion of acceleration and angular velocity. The use of acceleration and angular velocity gives richer information than the sole use of acceleration, allowing the enhanced performance particularly in determining the boundary conditions. A numerical simulation is presented to demonstrate the proposed FE model updating approach using the data fusion.

The finite element (FE) model updating is a commonly used approach in civil engineering, enabling damage detection, design verification, and load capacity identification. In the FE model updating, acceleration responses are generally employed to determine modal properties of a structure, which are subsequently used to update the initial FE model. While the acceleration-based model updating has been successful in finding better approximations of the physical systems including material and sectional properties, the boundary conditions have been considered yet to be difficult to accurately estimate as the acceleration responses only correspond to translational degree-of-freedoms (DOF). Recent advancement in the sensor technology has enabled low-cost, high-precision gyroscopes that can be adopted in the FE model updating to provide angular information of a structure. This study proposes a FE model updating strategy based on data fusion of acceleration and angular velocity. The usage of both acceleration and angular velocity gives richer information than the sole use of acceleration, allowing the enhanced performance particularly in determining the boundary conditions. A numerical simulation on a simply supported beam is presented to demonstrate the proposed FE model updating approach.

This study proposes a FE model updating strategy based on data fusion of acceleration and angular velocity. The use of acceleration and angular velocity gives richer information than the sole use of acceleration, allowing the enhanced performance particularly in determining the boundary conditions. A numerical simulation is presented to demonstrate the proposed FE model updating approach using the data fusion.