• Journal of Institute of Control, Robotics and Systems
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• v.5 no.5
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• pp.577-584
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• 1999

In this paper, the double inverted pendulum having a single actuator is built and the controller for the system is proposed. The lower link of the target pendulum system is hinged on the plate to free for rotation in the specified range($10^{\cire}$) on the x-z plane. The upper link is connected to the lower link through a DC motor. The double inverted pendulum built can be kept upright posture by controlling the position of the upper link even though it has no actuator in lower hinge. The algorithm to control the inverted pendulum consists of a state feedback controller within a linearizable range and a fuzzy logic controller coupled with a nonlinear feedback compensator for the rest of the range. Conventional state feedback control is employed, and the fuzzy controller is responsible for generating the reference joint angle of the upper link for the nonlinear feedback compensator which drives a DC motor to generate an indirect torque to the lower joint. As a result, we can get the upright posture of the proposed pendulum system. Simulations and experiments are conducted to show the validity of the proposed controller.

• Physical Therapy Korea
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• v.4 no.3
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• pp.61-69
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• 1997

The ability to maintain an upright position during quiet standing is a useful motor skill. The Sensory Organization Test (SOT) is a timed balance test that evaluates somatosensory, visual, and vestibular function for maintenance of upright posture. The Fugl-Meyer Sensorimotor Assessment (FMSA) balance subscale is the functional status assessment that indicates amount of assistance needed during various balance tasks. Functional Independence Measure (FIM) is the functional status assessment tool and FIM can be used clinically as an outcome measure. The purpose of this study was to see if the SOT can be used as a evaluation tool to measure hemiplegic patients' balance ability. Thirty-six patients with hemiplegia participated in this study. SOT scores were significantly correlated with FMSA balance scores and FIM scores(p<0.05). However correlation coefficients were not so high (r=0.60, and r=0.51, respectively). Therefore, further study is needed to verify the SOT's usefulness when physical therapists are evaluating for hemiplegic patients' balance ability.

• Archives of Plastic Surgery
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• v.33 no.5
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• pp.676-679
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• 2006

Purpose: Breast volume is one of the crucial measurements in preoperative planning and postoperative evaluation of the results in mammoplasty. There are several methods suggested by different authors, but there is still no commonly accepted standard methods for measuring breast volume. To help the surgeons to base their estimation on an objective evaluation, we developed a simple method using Polyethylene bag and plaster molding. Methods: After Polyethylene bags were put in suitable size on both breasts of the patient in upright position, silk plaster was molded on the surface evenly. Then molds can be obtained after marking boundaries of breasts with a pen. Breast volume measurement can be done by filling water in the molds and measuring it. Moreover, postoperative design for natural skin brassier was possible using the molds. Results: This method was applied to 2 patients for reduction mammoplasty and the breast volume measurement was simple, hygienic and accurate, done within 10 minutes. Conclusion: This method using Polyethylene bag and plaster molding has several advantages. 1. It is comparatively accurate regardless of the size and shape of patient's breasts in upright position. 2. Measurement time is short and inconvenience and shame of patients can be reduced by making molds after putting on Polyethylene bags. 3. It is relatively economical and uses easily available hygienic materials. 4. The postoperative shape and volume of breasts can be predicted by using molds preoperatively.

• The Korean Journal of Nuclear Medicine
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• v.9 no.1
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• pp.21-29
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• 1975

Radioimmunoassay for the measurement of plasma renin activity (PRA) was performed in 43 normal Koreans and 45 patients with essential hypertension. Plasma samples were drawn in supine position in the morning and after upright posture for 4 hours. Urinary sodium excretion rates were measured in the concurrent 24 hour urine samples, as an index of their sodium balance. The results were as follows: 1. There was an inverse correlation between 24hr sodium excretion and PRA. The normal values of PRA in supine position ranged from 1.0 to 7.0 ng/ml/hr. when 24 hour sodium excretion were between 50 to 150 mEq. PRA in elderly tended to be low. 2. When stimulated by 4 hour upright posture, PRA increased by 2.6 times from the baseline value. 3. Of the 45 patients with essential hypertension, PRA was low in 10 cases (22.2%), normal in 28 cases (62.2%), and high in 7 cases (15.6%). 4. In the normal and high renin groups, who tended to be younger in ages, mean diastolic blood pressure and BUN were higher than in low renin group. Though hypertensive retinopathy and left ventricular hypertrophy in ECG were more prevalent in the former, no significant differences were noted as in the case of serum cholesterol. 5. There were 8 cases of cardiovascular complications (7 with cerebral vascular accident, 1 with myocardial infarction); 3 in low renin group (30%), 2 in normal renin (7.1%) and 3 in high renin group (42.9%). This figure indicated higher rate of cardiovascular complications in high renin groups, and lower rate in normal renin group. But the incidence of the complication was not significantly low in low renin group.

• Korean Journal of Applied Biomechanics
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• v.17 no.3
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• pp.173-180
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• 2007

The purpose of study was to compare plantar pressure during walking wearing the curved rear balance and normal shoes. Twelve university students(height: $177.2{\pm}4.6cm$, weight: $68.4{\pm}5.8kg$, age: $26.2{\pm}1.6yrs.$) who have no known musculoskeletal disorders were recruited as the subjects. Plantar foot pressures were evaluated using the Tekscan's pressure measurement systems while subjects walked upright position wearing the curved rear balance and normal shoes in random order at a speed of 1.3 m/s. The contacting dimension, the mean plantar pressure, and the peak plantar pressure were determined for each trial. For each dependent variable, paired t-test was performed to test if significant difference existed between shoe conditions (p<.05). As a result, the curved rear balanced shoes showed as large as 38 up to 50 % of area at the rear side of feet than the normal shoes when measuring the contact area with upright position. In the distribution of average pressure, the curved rear balanced shoes displayed fairly low pressure compared to other normal shoes in general except for one area, which is M2, and especially, the measured pressures at the both rear (M1) and middle (M5) side of feet were low and statically significant. The contact area of the curved rear balanced shoes when walking was significantly larger at the rear (M1) and fore (M6, M7) side of feet. When considering pressure distribution at walking, low pressure was detected at the rear side of feet with the curved rear balanced shoes and at the fore side of feet for other normal shoes. The results showed that the contacting dimension of the curved rear balance shoes that acts between shoes and feet was higher than the corresponding value for the normal shoes in general; therefore it would reduce the pressure to the feet by allowing the each sole of the foot on the ground evenly.

• The Journal of Korea Robotics Society
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• v.5 no.2
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• pp.110-119
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• 2010

This paper aims to add the autonomous driving capability to the inverted pendulum system which maintains the inverted pendulum upright stably. For the autonomous driving from the starting position to the goal position, the motion control algorithm is proposed based on the dynamics of the inverted pendulum robot. To derive the dynamic model of the inverted pendulum robot, a three dimensional robot coordinate is defined and the velocity jacobian is newly derived. With the analysis of the wheel rolling motion, the dynamics of inverted pendulum robot are derived and used for the motion control algorithm. To maintain the balance of the inverted pendulum, the autonomous driving strategy is derived step by step considering the acceleration, constant velocity and deceleration states simultaneously. The driving experiments of inverted pendulum robot are performed while maintaining the balance of the inverted pendulum. For reading the positions of the inverted pendulum and wheels, only the encoders are utilized to make the system cheap and reliable. Even though the derived dynamics works for the slanted surface, the experiments are carried out in the standardized flat ground using the inverted pendulum robot in this paper. The experimental data for the wheel rolling and inverted pendulum motions are demonstrated for the straight line motion from a start position to the goal position.

• The Korean Journal of Pain
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• v.23 no.1
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• pp.46-50
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• 2010

Spontaneous intracranial hypotension (SIH) is considered to be a very rare disorder. It is characterized by an orthostatic headache that is aggravated with the patient in the upright position and it is relieved by the patient assuming the supine position. SIH is caused by a spontaneous spinal cerebrospinal fluid leakage without the patient having undergone trauma, surgery or dural puncture or having any other significant medical history. An autologous epidural blood patch (EBP) is effective in relieving SIH. We report here on a case of SIH with cerebrospinal fluid leakage at the upper cervical vertebral level and the middle thoracic vertebral level. The points of leakage were identified by radionuclide cisternography, and this patient was successfully managed by injecting an EBP at each level of leakage.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.131.5-131
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• 2001

A new measurement method to measure vibrational motions of objects is presented. The original principle is similar to the previous work that utilized a 3-facet mirror to obtain three dimensional positions and orientations of rigid bodies. While the previous work was presented for only stationary objects, in this paper, we newly investigate the feasibility of this method for dynamic applications. The 3-facet mirror that looks like a triangular pyramid having an equilateral cross-sectional shape. The mirror has three lateral reflective surfaces inclined 45 degrees to its bottom surface, and its mounted on the object whose motion is to be measured, As optical components, a He-Ne laser source and three position-sensitive detectors(PSD) are used. The laser beam is emitted from the He-Ne laser source located at the upright position and vertically incident to the top of the 3-facet ...

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.97.5-97
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• 2002

A sensor modeling via artificial neural network is presented in this paper. The optical sensor has been designed to treasure absolute 3-dimensional positions and orientations of objects in 6-DOF. The method utilizes a triangular pyramidal mirror having an equilateral cross-sectional shape referred as 3-facet mirror. The mirror has three lateral reflective surfaces inclined 45 degrees to its bottom surface. The 3-facet mirror is mounted on the object whose 6-DOF motion is to be measured. As optical components, a He-Ne laser source and three position-sensitive detectors(PSD) are used. The laser beam is emitted from the He-Ne laser source located at the upright position and vertically incident o...

• Korean Journal of Human Ecology
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• v.15 no.3
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• pp.449-455
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• 2006

We researched the comfort degree of 8 bodily parts while high school students carry out 9 different motions common to them. We observed high school students to study active effection when they are wearing Saenghwal Hanboks as a school uniform. As a result of this study, the highest degrees of comfort were recorded at standing position, walking, and upright sitting position with one's waist keeping 90 degree. On the other hand, the lowest degrees of comfort were experienced when they bend forward 45 degree and 90 degree each, and also when arms were folded across the chest. Furthermore, students reported that their buttocks, waist, and knees were comfortable during observation period, but that their backs, shoulders, and arm hole were uncomfortable throughout. In general, girls felt more comfortable than boys did, while they were wearing Saenghwal Hanbok as a school uniform.