Earticle

The study aims at presenting directions of technical training for performance improvement to coaches and providing scientific basic data for training courses through quantitative data to athletes, by conducting a comparative analysis on glide and rotational techniques of world class eight athletes who competed in the finals of the IAAF World Championships Daegu 2011. The research was carried out on eight finalists, which showed that athletes played the glide technique was 0.06 second faster in the first part in terms of the average time per part and 0.22 second faster in the second part. The joint angles of athletes playing the glide technique showed smaller in the first event and second event in terms of knee joint, shoulder joint and elbow joint while athletes using the rotational technique showed smaller angels for the three joints in the third event. The release height was 0.13m higher, the release angle was 3.55 degree greater, the release velocity was 0.33 m/s faster and the angular velocity elbow was 405.33 degree/second faster for athletes using the glide technique. In terms of the angular velocity shoulder, athletes playing the rotational technique were 153.17 degree/second faster. The quantitative data of athletes with world class glide and rotational techniques based on the study are thought to be helpful in the way of coaching Korean shot put athletes and for athletes themselves.

Wireless Video Sensor Networks (WVSNs) have become a leading solution in many important applications, such as disaster recovery. By using WVSNs in disaster scenarios, the main goal is achieving a successful immediate response including search, location, and rescue operations. The achievement of such an objective in the presence of obstacles and the risk of sensor damage being caused by disasters is a challenging task. In this paper, we propose a fault tolerance model of WVSN for efficient post-disaster management in order to assist rescue and preparedness operations. To get an overview of the monitored area, we used video sensors with a rotation capability that enables them to switch to the best direction for getting better multimedia coverage of the disaster area, while minimizing the effect of occlusions. By constructing different cover sets based on the field of view redundancy, we can provide a robust fault tolerance to the network. We demonstrate by simulating the benefits of our proposal in terms of reliability and high coverage.

Objective To evaluate if shoulder and pelvic angular velocities differ at impact or peak magnitude between professional and amateur golfers. Golf swing rotational biomechanics are a key determinant of power generation, driving distance, and injury prevention. We hypothesize that shoulder and pelvic angular velocities would be highly consistent in professionals. Methods Rotational velocities of the upper-torso and pelvis throughout the golf swing and in relation to phases of the golf swing were examined in 11 professionals and compared to 5 amateurs using three-dimensional motion analysis.Results Peak rotational velocities of professionals were highly consistent, demonstrating low variability (coefficient of variation [COV]), particularly upper-torso rotational velocity (COV=0.086) and pelvic rotational velocity (COV=0.079) during down swing. Peak upper-torso rotational velocity and peak X-prime, the relative rotational velocity of upper-torso versus pelvis, occurred after impact in follow-through, were reduced in amateurs compared to professionals (p=0.005 and p=0.005, respectively) and differentiated professionals from most (4/5) amateurs. In contrast, peak pelvic rotational velocity occurred in down swing. Pelvic velocity at impact was reduced in amateurs compared to professionals (p=0.019) and differentiated professionals from most (4/5) amateurs. Conclusion Golf swing rotational velocity of professionals was consistent in pattern and magnitude, offering benchmarks for amateurs. Understanding golf swing rotational biomechanics can guide swing modifications to help optimize performance and prevent injury.

Background Subacromial pain syndrome (SAPS) is one of the causes of shoulder pain in workers performing repetitive upper extremity movements. However, there have been no studies on physical characteristics such as shoulder total rotational range of motion (ROM) and external to internal rotation muscle strength ratio of workers. Purpose The purpose of this study was to compare the total rotational ROM and external to internal rotation muscle strength ratio in workers with and without SAPS. Study design A cross-sectional study Methods This study included 35 workers with SAPS and 32 workers without SAPS. The total rotational ROM were measured using Smart KEMA motion sensor, and external to internal rotation muscle strength were measured using Smart KEMA pulling sensor. Results The results showed that there were significant differences in the total rotation ROM between the groups (p<0.05). However, no significant difference was found in the external to internal rotation muscle strength ratio (p>0.05). Conclusions Assembly line workers with SAPS had limited total rotational ROM. However, the ratio of external to internal rotation muscle strength ratio was not different for workers without SAPS. These characteristics can be considered factors that should be considered in evaluating workers with SAPS and establishing a treatment plan.

PURPOSE: This study compared the effects of proprioceptive sensation, subacromial space, and dynamic function according to proprioceptive neuromuscular facilitation (PNF), static stretching (SS), and complex rotational stretching (CRS). METHODS: Thirty students without any musculoskeletal disease who volunteered to participate were included in this study. The following metrics were measured to evaluate the function and stability under the normal conditions, with the PNF, SS, and CRS: special test and flexion, extension, abduction, adduction, internal rotation, external rotation (shoulder range of motion) and reaching distance on the medial (ME), superolateral (SL), inferolateral (IL), and subacromial space and proprioceptive sensation were evaluated. All measures were analyzed using one-way ANOVA and repeated measures of ANOVA. RESULTS: A clear difference in adduction in the range of motion was observed in all groups (p < .05). Significant differences could not be identified in all values in the error test, except for Ab (p < .05). Significant differences in reach were noted in all directions of the SS and PNF in the Me, SL, and IL (p < .05). After the intervention, significant differences in the average values could be identified in all groups except for the SS group after rest (p < .05). After the intervention, there was a significant difference between the CRS and SS and PNF groups (p < .05). CONCLUSION: The application of CRS is as helpful as the existing SS and PNF for improving the joint range of motion improvement, shoulder balance, and subacromial space.

In this paper, we have revisited the estimation of the rotational stiffness of sidewall of radial tire and have suggested a new method for evaluation of the rotational stiffness. Since thicknesses, and volume fractions of the constituents of sidewall are varied depending on radial position, the equivalent shear modulus of the sidewall also depends on radial position. For the estimation of rotational stiffness of sidewall's rubber, we have divided its cross-section into sufficient numbers of small parts and have calculated the equivalent shear modulus of each part of sidewall. Using the shear moduli of divided parts, we have obtained the rotational stiffness by employing in-plane shear deformation theory. This method is expected to be a useful tool in tire design since it relates such basic variables to the global stillness of tire. Applying the calculation method to a radial tire of P205/60R15, we have compared its rotational stiffness with experimental one.

The manufacture of rheology materials from wrought and casting aluminum alloys using controlling solid fraction and crystal grain is demonstrated in this paper. The equipment to form the rheology material was designed so that shear force and applied pressure could be carefully and simultaneously applied using a mechanical stirrer. The problems caused by using this method with the thixo forging process were studied by investigating the mechanical properties of a sample that had a controlled solid fraction of 45-50 %.

Background: This work aims to develop a new imaging system based on a pulse shape discrimination- capable Cs2LiYCl6:Ce (CLYC) scintillation detector combined with the rotational modulation collimator (RMC) technique for dual-particle imaging. Materials and Methods: In this study, a CLYC-based RMC system was designed based on Monte Carlo simulations, and a prototype was fabricated. Therein, a rotation control system was developed to rotate the RMC unit precisely, and a graphical user interface-based software was also developed to operate the data acquisition with RMC rotation. The RMC system was developed to allow combining various types of collimator masks and detectors interchangeably, making the imaging system more versatile for various applications and conditions. Results and Discussion: Operational performance of the fabricated system was studied by checking the accuracy and precision of the collimator rotation and obtaining modulation patterns from a gamma-ray source repeatedly. Conclusion: The prototype RMC system showed reliability in its mechanical properties and reproducibility in the acquisition of modulation patterns, and it will be further investigated for its dual-particle imaging capability with various complex radioactive source conditions.

3차원 회전 혈관 조영에서 헤드 오프 센터링을 통한 렌즈 저선량 프로토콜을 사용하면 렌즈에 대한 방사선 선량을 83% 감소시킬 수 있으며, 실제 3D-RA 검사 중 적용할 수 있다. 3차원 회전 혈관 조영(3D-RA)은 뇌동맥류를 평가하는 데 필수적인 진단 도구다. 그러나 3D-RA는 렌즈에 대한 방사 선 노출을 증가시킬 수 있으며, 이에 따라 백내장과 같은 방사선 위험이 증가할 수 있다. 본 연구는 3D-RA 동안 테이블 높이 조정에 의한 헤드 오프 센터링이 렌즈 선량에 미치는 영향을 연구하였다. 팬텀 연구에서, 다양한 테이블 높이 위치에서 헤드 오프 센터링이 렌즈 선량에 미치는 영향을 평가하기 위해 RANDO Head Phantom이 사용되었으며, 광발광 유리 선량계(PLD)를 사용하여 렌즈 선량을 측정하였다. 임상 연구는 뇌동맥류 로 인해 양측 3D-RA를 받기로 예정된 20명의 환자를 전향적으로 선정하였다. 각 환자에 대해 기존 프로토콜과 렌즈 저선량 감소 프로토콜을 양쪽 3D-RA에 모두 적용하였다. 렌즈 저선량 프로토콜은 테이블 높이를 올려 FOV의 전면 끝이 맥락막 음영 (Choroidal blush) 뒤쪽에 위치하도록 조정하였다. 두 프로토콜에서 PLD에 측정된 렌즈 선량과 방사선 선량을 비교하였다. 팬텀 연구는 테이블 높이가 1cm 증가할 때마다 렌즈 선량이 평균 38% 감소하였다. 임상 연구에서 테이블 높이를 평균 2.3cm 올리는 렌즈 저선량 감소 프로토콜은 기존 프로토콜(4653μGy, P <.001)에 비해 렌즈 방사선 선량(789μ Gy)이 83% 감소했다. 두 그룹 간 DAP, Air-Kerma는 유의한 차이가 없었다. 3D-RA 중 테이블 높이를 2.3cm 높이는 헤드 오프 센터링을 통해 렌즈에 대한 방사선 선량을 최대 83% 감소할 수 있다.

Background: Three-dimensional rotational angiography (3D-RA) has become an indispensable diagnostic tool for the evaluation of intracranial aneurysms. However, increased radiation exposure to the lens can increase the risk of radiation hazards such as cataracts. We investigated the effect of head off-centering by table height adjustment on the eye lens dose during 3D-RA and its feasibility in patient examinations. Material and Methods: In the phantom study, a RANDO head phantom was used to evaluate the effect of head off-centering at various table height positions on the lens dose, which was measured using photoluminescent glass dosimeters (PLDs). For the patient study, we prospectively enrolled 20 patients who were scheduled to undergo bilateral 3D-RA for unruptured intracranial aneurysms. For each patient, the conventional protocol and the lens dose reduction protocol were both applied to bilateral 3D-RA. In the lens dose reduction protocol, the table height was increased so that the front end of the 3D field-of-view was located just behind the choroidal blush. The lens dose measured by PLD and radiation dose metrics in both protocols were compared. Results: The phantom study showed that the lens dose was reduced by an average of 38% per 1-cm increase in the table height. In the patient study, the dose reduction protocol, which involved elevating the table height by 2.3 cm in average, led to 83% less lens radiation dose (789 μGy) compared with the conventional protocol (4653 μGy, P < .001). There was no significant difference in the dose area product and air kerma between the two groups. Conclusion: Head off-centering by elevating the table height by an average of 2.3 cm during 3D-RA reduced the radiation dose to the eye lens by 83%.

본 연구에서는 회전운동을 제어하기 위한 새로운 작동기로서 전기장에 대하여 매우 빠른 응답특성을 갖고 있는 두 쌍의 실린더형 ER(electro-rheological) 클러치/브레이크 작동기를 제안하였다. 자체조성 된 ER유체의 빙햄특성 모델을 실험적으로 도출하였으며, 이와 연계한 작동기 모델을 구성하여 전기장에 따른 전달 및 제동 토크를 해석한 후 알맞은 크기의 클러치/브레이크 작동기를 제작하였다. 제작된 작동기의 동적특성(시상수 등)을 작동기 모델에 고려하기 위하여 계단입력 전기장에 따른 과도응답 실험을 클러치와 브레이크 모드에서 각각 수행하였다. 제안된 작동기의 응용성을 보이기 위하여 두쌍의 작동기로 구동되는 실험실 차원의 소형 와권식 세탁기 시스템을 구성한 후 동적지배방정식을 유도하다. 각 작동기와 연계된 PID제어기를 설계하여 세탁과 탈수시의 회전운동을 제어하였으며, 부하질량의 변화에 대한 작동기 시스템의 제어 효율성과 장시간 운전을 통한 제어 내구성 실험을 수행하였다.

The principal operation rule of irrigation reservoir is to accelerate the water use and supply water actively when water is sufficient, and to restrict water use and supply water deficiently in order not to stop the irrigation activity when water is scarce. In drought seasons. water should be saved in order to keep the reservoir not to be dried up during the irrigation season. It is important to know how much water should be saved, depending on the rice-growing season and water storage volume. For the drought control of irrigation reservoirs. the rotational irrigation scheduling in paddy with the operation rule curve developed in this study could be utilized as a software program to install TM/TC system for irrigation water supply by automation facilities.

Parallel movement of a building is moving an existing building from a specific location to a new location, and refers to the displacement of a building along a straight line or curve in the horizontal direction. Unlike foreign countries where parallel movement of buildings is actively carried out, there is a lack of construction and research on parallel movement of buildings in Korea. Therefore, in this study, we classify domestic and foreign building parallel building movement construction methods by type, and investigate and present construction cases according to the construction methods. In addition, we propose a construction method for parallel movement of buildings using jack piles and steel bars, and present examples of on-site application of parallel movement.

In this technology development, we have developed an automation system after developing a material rotation mixing process so that the manual process of sound absorbing materials can be supplied in quantities. After setting up 5kgf supply of the fused acoustic material, the setting value of 5kg was automatically supplied to the molded frame to reach the quantification supply. In the process of producing noise goods between floors, the automatic compression system was developed, which was a manual operation of three persons, and the production of one person was allowed, and the production of 200 sound absorbers per day, It has improved to 450. Quantitative supply unit was developed to reach 50.7mm for target 50±3mm based on the sound absorption product thickness indication, reducing the defect rate to less.

The error motion of a machine tool spindle directly affects the surface errors of machined parts. Those are usually due to the imperfectness of bearings, stiffness of spindle, assembly errors, external force or unbalance of rotors. The error motions of the spindle have been needed to be decreased to desired goal of spindle's performance. The level of error motion is needed to be estimated during the design and assembly process of the spindle. In this paper, the estimation method for the five degree of freedom (5 D.O.F) error motions for rotary units such as a spindle and rotary table are suggested. To estimate the error motions of the rotary unit, waviness of bearings and external force model were used as input data. The estimation model considers geometric relationship and force equilibrium of the five degree of the freedom motions.

This paper describes the design, construction, and fundamental testing of a precision rotational device that utilizes piezoelectric elements as a source of driving force and impact drive mechanism as a driving principle. A novel device structure is designed and the numerical simulations about the static displacement, stress distribution, and mode shape of the designed structure are performed. A fabricated rotational device has been rotated successfully by applying saw-shaped voltages to the piezoelectric elements. The one-step rotational angle was $0.44{\times}10^{-3}$ rad at the applied voltages of 80V. The angular velocities of the device were revealed to be increased as the driving frequency and voltage were respectively increased and the preload was decreased. The device has a feature that it can be translated as well as rotated. An experimental result shows that the device was translated by ${\pm}4.56{\mu}m$ maximum when the 120V sinusoidal voltages with a phase difference of $180^{\circ}$ were respectively supplied to two piezoelectric elements.

영상을 기반으로 하는 기술들의 지속적인 발전으로 다양한 분야에서 활용되고 있고, 카메라를 통하여 획득한 영상의 객체를 분석하고 판별하는 비전 시스템의 기술 수요가 급속하게 증가하고 있다. 비전 시스템의 핵심 기술인 영상 처리는 반도체 생산 분야의 불량 검사, 타이어 표면의 숫자 및 심볼과 같은 객체 인식 검사 등에 사용되고 있고, 자동차 번호판 인식 등의 연구가 계속하여 이루어지고 있는 실정으로, 객체를 신속, 정확하게 인식할 필요가 있다. 본 논문에서 는 곡면과 같은 곳에 마킹되어 있는 숫자나 심볼과 같이 기울어진 객체를 인식하기 위하여 입력된 영상 이미지의 객체 기울기에 대한 각도 값을 확인하여 객체의 회전 정렬을 통한 인식 모델을 제안한다. 제안 모델은 컨투어 알고리즘을 기반으로 객체 영역을 추출하고, 객체의 각도를 산출한 후, 회전 정렬된 이미지에 대한 객체 인식을 진행할 수 있는 모델이다. 향후 연구에서는 기계학습을 통한 탬플릿 매칭 연구가 필요하다.

Video image based technology is being used in various fields with continuous development. The demand for vision system technology that analyzes and discriminates image objects acquired through cameras is rapidly increasing. Image processing is one of the core technologies of vision systems, and is used for defect inspection in the semiconductor manufacturing field, object recognition inspection such as the number of tire surfaces and symbols. In addition, research into license plate recognition is ongoing, and it is necessary to recognize objects quickly and accurately. In this paper, propose a recognition model through the rotational alignment of objects after checking the angle value of the tilt of the object in the input video image for the recognition of inclined objects such as numbers or symbols marked on the surface. The proposed model can perform object recognition of the rotationally sorted image after extracting the object region and calculating the angle of the object based on the contour algorithm. The proposed model extracts the object region based on the contour algorithm, calculates the angle of the object, and then performs object recognition on the rotationally aligned image. In future research, it is necessary to study template matching through machine learning.

It is an important thing for a designer to simulate and predict the performance of a spindle and a rotary table. In addition to the general performance such as static stiffness, the error motion performance information is beneficial to the designer in many cases. However for an aerostatic bearing the fluid film physical status should be calculated in order to simulate those performances and the calculation time is another obstacle for a simple performance simulation. In this paper the investigation on experiment and simulation is performed in order to find a more effective simulation method for the rotational error motion.