• The Journal of Korean Academy of Sensory Integration
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• v.6 no.1
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• pp.35-46
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• 2008

Objective : This study verifies the effects of sensory integrative (SI) therapy on vestibular- and proprioceptive sensory (BPS) processing ability of a child with Asperger Syndrome (AS). Method : A boy who is 11 years and 2 months old took the Functional Independence Measure for Children (Wee-FIM), Canadian Occupational Performance Measure (COPM), Short Sensory Profile, Bruininks-Oserestky Test of Motor Proficiency-2 (BOT-2), and Test of Playfulness (ToP) for the baseline. The child participated in 3 evaluation sessions and 8 therapy sessions based on the AB research design. Duration of each session is 50 min and the therapy session is divided into 40 minutes for treatment and 10 minutes for evaluation. Since the vestibular sense and proprioception build up one's ability of postural control, several tests were employed to evaluate the child' postural control as outcome measure; distance from front leg of chair to heel of the child with sitting (C-H distance), angle between trunk and thigh (hip joint angle) with sitting, and the 'prone-extension posture' which is a subtest of Clinical Observation of Motor and Postural Skill (COMPS) to examine postural control embodied with integration of reflex and BPS processing. Result : During the therapy, average data of the C-H distance is decreased from 27.33cm to 11.69cm, average data of the hip joint angle is also decreased from $43.3^{\circ}$ to $20^{\circ}$, and average time for the prone-extension posture is increased from 13.15seconds to 24.84seconds. Conclusion : This result indicates that the ability to postural control in sitting and to maintain the prone-extension posture can be improved by sensory integrative therapy, with enhanced BPS processing.

• Journal of the Ergonomics Society of Korea
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• v.31 no.5
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• pp.647-655
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• 2012

Objective: The purpose of this study was to confirm difference between angular foot movement time and existing foot Fitts' law predicting times, and to develop the angular foot Fitts' law in the foot tapping task. Background: Existing studies of foot Fitts' law focused on horizontal movement to predict the movement time. However, when driving a car, humans move their foot from the accelerator to the brake with a fixed heel. Therefore, we examined the experiment to measure angular foot movement time in reciprocal foot tapping task and compared to conventional foot Fitts' law predicting time. And, we developed the angular foot Fitts' law. Method: In this study, we compared the angular foot movement time in foot tapping task and the predicted time of four conventional linear foot Fitts' law models - Drury's foot Fitts' law, Drury's ballistic, Hoffmann's ballistic, Hoffmann's visually-controlled. 11 subjects participated in this experiment to get a movement time and three target degrees of 20, 40, and 60 were used. And, conventional models were calculated for the prediction time. To analyze the movement time, linear and arc distance between targets were used for variables of model. Finally, the angular foot Fitts' law was developed from experimental data. Results: The average movement times for each experiment were 412.2ms, 474.9ms, and 526.6ms for the 89mm, 172mm, and 253mm linear distance conditions. The results also showed significant differences in performance time between different angle level. However, all of conventional linear foot Fitts' laws ranged 135.6ms to 401.2ms. On the other hand, the angular foot Fitts' law predicted the angular movement time well. Conclusion: Conventional linear foot Fitts' laws were underestimated and have a limitation to predict the foot movement time in the real task related angular foot movement. Application: This study is useful when considering the human behavior of angular foot movement such as driving or foot input device.

• Korean Journal of Applied Biomechanics
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• v.18 no.1
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• pp.203-212
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• 2008

The purpose of this study is to propose appropriate model for 3 staged Didimsae movement to Jajinmori rhythm and to provide information for ideal foot step movements. For the locational change of body center, the height of body center is lowered at the moment of forward step and during forward intersection of the feet, forward direction linear motion is converted to vertical motion to maintain stability. Speed change of body center reduces flow of body on step forward moment and controls rapid forward movement for stabled movement and position when preventing fast forward horizontal direction movement of centroid speed while knee joint and foot joint are vertically risen for heel bone contacts the ground. For angle changes of joints, in order to prevent hyperextension of lower leg, hip joint is extended and knee joint is curved to secure stability of movement for smooth curves and extension. When centroid of foot joint is moved from top of the feet to whole foot sole and when left foot makes dorsal curve, stabled movement is accomplished.

• Journal of Biomedical Engineering Research
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• v.31 no.5
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• pp.344-350
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• 2010

The aim of this study was to investigate the characteristics of the flexion withdrawal reflex modulated during Lokomat treadmill walking in people with spinal cord injury. The influence of the limb position and movement were tested in 5 subjects with chronic spinal cord injury. EMG activities from tibialis anterior and moments of the hip joint elicited by the foot stimulation were examined during Lokomat treadmill walking. To trigger the flexion withdrawal reflex during Lokomat treadmill walking, a train of 10 stimulus pulses was applied at the skin of the medial arch. The TA EMG activity was modulated during gait phase and the largest TA reflex was obtained after heel-off and initial swing phase. During swing phase, TA EMG was 40.9% greater for the extended hip position (phase 6), compared with flexed hip position (phase 8). The measured reflex moment of the hip joint was also modulated during gait phase. In order to characterize the neural contribution of flexion reflex at the hip joint, we compared estimated moments consisted of the static and dynamic components with measured moment of the hip joint. The mean static gains of reflex hip moments for swing and stance phase are -0.1, -0.8, respectively. The mean dynamic gains of reflex hip moments are 0.25 for swing, 0.75 for stance phase. From this study, we postulate that the joint moment and muscle response of flexion withdrawal reflex have the phase-dependent modulation and linear relationship with hip angle and angular velocity for swing phase during Lokomat treadmill walking.

• Journal of the Korean Society of Clothing and Textiles
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• v.21 no.7
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• pp.1173-1183
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• 1997

In order to flatter the figures of average middle aged women by determining harmonious proportions for their costume forms, this study evaluates effects of varying design details of jackets(coats) with blouses and slacks using a ranking test and paired comparisons test. The result from clothing design C-2 which has the best design effect were as follows; 1. In order to look taller, the jacket(coats) is divided vertical long line and it has the emphasis point close to the face. 2. In order to make shoulder width look wider, armhole seam line attached 1-2 cm from the shoulder point. 3. In order to make chest width look slimmer, division was made up of a tailored collar with a deep V-neckline. 4. In order to make waist circumference look slimmer, the jacket has more fitted waist line than loosed it and tailored collar with a deep V-neckline. 5. In the case of the division of upper and lower garments, when the division was closer to the golden section, i.e., when the jacket hemline is hipline and slacks length is the heel excluded length of shoe heels, the overall appearance was better. 6. The V-neckline looked better, when it was cut along a long acute angle to the waist line. Because of dividing along above factors 1-6 i.e., clothing design C-2 was overall harmonious. Appropriate division of costume forms made for an aesthetic composition, which flattered the body types of middle aged women and presented harmonious, beautiful costume design effects. It made the women look taller, slim and balanced, and highlighted middle aged women's sense of beauty.

• Korean Journal of Applied Biomechanics
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• v.16 no.2
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• pp.193-205
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• 2006

This study was to analysis the kinematic and kinetic differences between new walking shoe(NWS : RYN) and general walking shoe(GWS). The subjects for this study were 10 male adults who had the walking pattern of rearfoot shrike with normal foot. The movement of one lower leg was measured using plantar pressure and Vicon Motion Analysis Program(6 MX13 and 2 MX40 cameras : 100 f / s) while the subjects walked at the velocity(1.5m/s. on 2m).. The results of this study was as follows : 1. The NWS was better than the GWS that caused injuries such as adduction, abduction and pronation are reduced While walking on a perpendicular surface, the landing angle and the knees angles were extensive which makes walking more safe which reduces anxiety and uneasiness. 2. The bottom of the NWS were now made into a more circular arch which supports the weight of the body and reduces the irregular angles when wearing GWS. This arch made the supporting area more wide which made the upholding the trunk of the body more effective. The whole bottom of the foot that supports the weight is more flexible in addition, increases the safeness of walking patterns and the momentum of the body. 3. The moment the heel of the foot of the NWS touch the ground, the range of the pressure were partially notable and the range of the pressure on the upper part of the thigh were dispersed The injuries that occurred while walking. primary factors when a shock related injuries are reduced Judgements of the impacts of the knees and the spinal column dispersing could be made.

• Journal of the Society of Naval Architects of Korea
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• v.56 no.6
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• pp.550-558
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• 2019

The roll motion of a general vessel, which is more influenced by resonance as compared to other motions, adversely affects the passenger and hull. Therefore, reducing the roll motion through an anti-rolling system is critical, and most ships use various devices such as anti-rolling tanks, bilge keels, and fin stabilizers to accomplish this. In this study, a simplified model is developed for the application of an anti-rolling device for unmanned semi-submersible vessels. The applied anti-rolling device is installed on the stern and stem of a ship using a pair of servo motors with added weight, and the motor is controlled through the Arduino. The moment of the motor is designed and implemented based on a mathematical model such that it is calculated through the restoring force according to the heel angle of the ship. The performance of the proposed system was verified by utilizing the roll damping coefficient calculated by the free-roll decay test and logarithmic decrement method and was validated by a towing tank test. The system is expected to be used for unmanned vessels to perform sustainable missions.

• Journal of the Society of Naval Architects of Korea
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• v.59 no.3
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• pp.173-182
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• 2022

The present study suggests a procedure of establishing a ship dynamics modeling by regression of free-running model test results. The hydrodynamic force and moment of the whole model ship is derived from the low-pass filtered acceleration in the turning circle and zigzag maneuver tests. Force and moment of the propeller and rudder are separated from that of the whole ship to acquire the hull force and moment terms, based on the principles of the component model. The low-pass filter frequency is verified in prior to dynamics modeling, to find the threshold frequency of 2.5 Hz. The dynamics modeling of the hull is compared with the component modeling by captive model tests. Because of strong correlation between sway velocity, yaw angular velocity, and heel angle, each maneuvering coefficient is not able to be validated, but the whole modeling shows good agreement with the captive model tests.

• Journal of the Korean Society of Radiology
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• v.6 no.5
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• pp.343-349
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• 2012

Intensity Modulated Radiotherapy (IMRT) is increasing its use recently due to its benefits of minimizing the dose on surrounding normal organs and being able to target a high dose specifically to the tumor. The study aims to measure and evaluate the dose distribution according to its dynamic changes in Mapcheck. In order to verify the dose distribution by EDW angle($10^{\circ}$,$15^{\circ}$,$20^{\circ}$,$25^{\circ}$,$30^{\circ}$,$45^{\circ}$,$60^{\circ}$), field size (asymmetric field) and depth changes (1.5 cm, 5.0 cm) using IMRT in Clinac ix, a solid phantom was placed on the Mapcheck and 100MU was exposed by 6 MV, 10MV X-ray. Using a 6MV, 10MV energy, the percentage depth dose according to a dynamic changes at a maximum dose depth (1.5 cm) and at 5.0 cm depth showed the value difference of maximum 0.6%, less than 1%, which was calculated by a treatment program device considering the maximum dose depth at the center as 100%, the percentage depth dose was in the range between 2.4% and 7.2%. Also, the maximum value difference of a percentage depth dose was 4.1% in Y2-OUT direction, and 1.7% in Y1-IN direction. When treating a patient using a wedge, it is considered that using an enhanced dynamic wedge is effective to reduce the scattered dose which induces unnecessary dose to the surroundings. In particular, when treating a patient at clinic, a treatment must be performed considering that the wedge dose in a toe direction is higher than the dose in a heel direction.

• Journal of radiological science and technology
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• v.21 no.2
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• pp.36-42
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• 1998

Treatment of a large diseased area with electron often requires the use of two or more adjoining fields. In such cases, not only electron beam divergence and lateral scattering but also fields overlapping and separation may lead to significant dose inhomogeneities(${\pm}20%$) at the region of junction of fields. In this study, we made Acrylic Electron Wedges to improve dose inhomogeneities(${\pm}5%$) in these junction areas and to apply it to clinical practices. All measurements were made using 6, 9, 12, 16, 20 MeV Electron beams from a linear accelerator for a $10{\times}10\;cm$ field at 100cm of SSD. Adding a 1 mm sheet of acryl gradually from 1 mm to 15 mm acquires central axis depth dose beam profile and isodose curves in water phantom. As a result, for all energies, the practical range was reduced by approximately the same distance according to the acryl insert, e.g. a 1 mm thick acryl insert reduces the practical range by approximately 1 mm. For every mm thickness of acryl inserted, the beam energy was reduced to approximately 0.2 MeV. These effects were almost Independent of beam energy and field size. The use of Acrylic Electron Wedges produced a small increase(less than 3%) in the surface dose and a small increase(less than 1%) in X-ray contamination. For acryl inserts, thickness of 3 mm or greater, the penumbra width increased nearly linear for all energies and isodose curves near the beam edge were nearly parallel with the incident beam direction at the point of penumbra width($35\;mm{\sim}40\;mm$). We decide heel thickness and angle of the wedge at this point. These data provide the information necessary to design Acrylic Electron Wedge which can be used to improve dose uniformity at electron field junctions and it will be effectively applied to clinical practices.