• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.566-569
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• 2008

Recently, the biolistic process is emerging as an effective needle-free drug delivery technique to transfer adequate concentrations of pharmacologic agents to soft living tissues with minimum side effects. We have started developing an effective method for delivering drug coated particles using laser ablation. A thin metal foil with deposited micro-particles on one side is irradiated with laser beam on the opposite side so that a shock wave is generated. This shock wave travels through the foil and is reflected, which causes and instantaneous deformation of the foil. Due to such a sudden deformation, the micro-particles are ejected at a very high speed. Here we present the experimental results of direct and confined laser ablation, which correspond to the initial stage of the whole experiment.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.13 no.2
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• pp.200-210
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• 2000

objective to ascertain whether the concept of the therapeutic side is associated with changes in the blind sport mapping that represents the brain function. design Physiological blind spot maps were used as an integer of brain activity before and after acupuncture needling on the meridian point Hapkok(合谷) and Techung(太衝) in the unilateral side decided by double-blind controlled study(20 subjects). setting outpatient clinic participants: adult volunteers intervention twenty subjects were divided into two comparative groups and underwent specific acupuncture therapy on the unilateral side. Blinded examiners obtained reproducible pre and post-acupuncture cortical maps, which were subjected to statistical analysis. main outcome measures Brain activity was demonstrated by reproducible circumferential measurements of cortical hemispheric blind spot maps before and after acupuncture on the unilateral side. in case of acupuncture needling on the ipsilateral side of an enlarged side of bilnd spot, there were reduction of blind spot in 7 cases of 10 subjects, and enlargement in 3 cases. in case of acupuncture needling on the contralateral side of the enlarged side of blind spot, there were enlargement of blind spot in 6 cases of 10 subjects, and reduction in 4 cases. results the significant changes in the blind spots before and after acupuncture were observed Acupuncture needlings on the ipsilateral or contralateral side of an enlarged cortical map were associated with the concept of the therapeutic side traditionally accepted in the oriental medical society. Acupuncture needling on the ipsilateral side of an enlarged blind spot map is associated with the reduction of map, and increaed contralateral cortical activity. Acupuncture needling on the side opposite an enlarged blind spot map is associated with the enlargement of map, and decreased cortical activity. conclusion Reproducible maps of cortical responses can be used to measure the neurological consequences of acupuncture needling. Acupuncture can affect the somatic sensory informations that reach to the contralateral thalamus, and so affect thalamic integration. we found that acupuncture therapy may be associated with an increase or a decrease in brain function depending on the side of acupuncture needling. thus, the traditional concept of the contralateral therapeutic theory in acupuncture approach has the clinical significance in the view of brain function.

• Magazine of the Korean Society of Agricultural Engineers
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• v.28 no.4
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• pp.49-56
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• 1986

This study was carried out to investigate mechanical characteristics of the uniformly loaded skew-plate at 4 kinds of boundary condition : i) all edges are clamped (BC-1) , ii) all edges are simply supported (BC- 2), iii) two opposite edges are clamped and the other two edges are free (BC-3), and iv )two opposite edges are simply supported and the other two edges are free (BC-4). Various skew angles, 0$^{\circ}$, 10$^{\circ}$, 15$^{\circ}$, 30$^{\circ}$, 40: 45: and 60, of the plate were tested for the above boundary conditions. Resutts obtained from the study are summarized as follows ; 1.The lateral displacement at the center of a skew- plate was decreased as the skewangle increased at all of the boundary conditions. The decrements of the conditions of BC-3 and BC-4 were considerable. And, difference of the displacement between the boundary conditions was decreased as the skew-angle was increased. 2. X-moments (to the Y-axis) at the center of a skew- plate and the minimum principal moments were shown as a similar pattern of change with respect to the skew-angle variation between BC-i and BC-2 and between BC-3 and BC-4, and the pattern of change at the conditions of BC-3 and BC-4 were shown higher rates than those for the conditions of BC-i and BC-2 3.Y-moments (to the X- axis) at the center of a skew-plate and the maximum principal moment were decreased as the skew-angle increased in a similar pattern at all of the boundary conditions. 4.X-moments at the obtuse angle side of a skew-plate were shown as a parabolic pattern of change (frist increased after then decreased) as the skew-angle increased, and a skew-angle resulting the maximum absolute moment was depended on the boundary conditions. 5.Y-moments at the obtuse angle side of a skew-plate were affected by the skewangle much more at the boundary condtions of BC-2 and BC-4 than at the conditions of BC-i and BC-3. 6.Maximum principal moments at the obtuse angle side of a skew-plate at the skew angle of 40$^{\circ}$- 45$^{\circ}$ were resulted almost the same value at all of the boundary conditions .

• The Korean Journal of Physiology
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• v.24 no.1
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• pp.103-113
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• 1990

The role of cervical proprioceptors in the control of body posture was studied in bilaterally labyrinth-ectomized, decerebrate cats. The animals were suspended on hip pins with the neck extended horizontally. With this placement the EMG activities of extensor and flexor muscles of the upper extremities were observed by means of sinusoidal head rotator. The rotator can induce two kinds of neck movement: The one is 'pitch' which describes a rotatory neck motion to transverse axis of the body and mainly occurs at skull-C1 (atlantooccipital) joint and the other is 'roll', side-to-side relation of the neck to longitudinal axis, whose center is C1-C2 (atlanto-axial) joint. The following results were obtained. 1) Responses of EMG activity were closely dependent on the rotatory range of the neck. And the EMG activity was not changed during sustained neck torsion, eliciting a typical tonic neck reflex. 2) On pitching movement, the head-up rotation produced the excitation of bilateral triceps muscles, whereas the head-down rotation produced the inhibition. And the response of bilateral biceps muscles was the opposite to that of triceps. 3) On rolling movement, the side-up rotation of the head produced the excitation of ipsilateral triceps muscles and the inhibition of contralateral ones. And the response of biceps muscles was the opposite to that of triceps. 4) The minimum requirement of motion to evoke EMG activities in the upper extremities was $3.2^{\circ}{\sim}12.5^{\circ}$. These results have shown that the cervical proprioceptors produce tonic discharge on the upper brachial muscles, regulate the EMG activities of those muscles, and are very sensitive to neck rotation. And it can be stated that the cervical proprioceptors may play an important role in the control of body posture and movement.

• PNF and Movement
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• v.17 no.1
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• pp.119-127
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• 2019

Purpose: The purpose of this study is to show the effect of elastic band on balance and functional ability in chronic stroke patients living in community. Methods: The subjects who participated in the study were 9 patients with chronic stroke. One of them gave up during the study, finally 8 patients performed. The intervention was conducted once a week for 10 weeks. In this study functional reach test (FRT), timed up and go test (TUG), Tinetti performance oriented mobility assessment (Tinetti-POMA) were measured for balance. The coordination training of arms and legs using the elastic band was performed in three positions as supine, side lying, sitting. One arm performed flexion-adduction- external rotation with elbow flexion pattern and the opposite side(diagonal) leg was performed flexion-adduction-external rotation with knee flexion pattern, the other arm's pattern was extension-abduction-internal rotation with elbow extension and the opposite side (diagonal) leg was in extension-abduction-internal rotation with knee extension pattern. The training was performed in each position for 15 minutes in per position. The participants had a five minute break after each training. Results: The results are as follows. FRT and Tinetti-POMA showed significant increase statistically in each position. The TUG showed significant decrease statistically in each position. Conclusion: Even though the coordination training with elastic band had performed once a week, it showed positive effects on balance in chronic stroke patients. Therefore, if we can suggest the appropriate frequencies of coordination training of arms and legs using the elastic band, it can be a method to improve daily life and life quality to patients with chronic stroke.

• Membrane Journal
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• v.32 no.3
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• pp.191-197
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• 2022

Ammonia nitrogen can be effectively recovered from livestock manure waste, etc. by using the gas permeable membrane technology. In this case, ammonia gas in the waste passes through the pores in one-side of membrane, impregnated in waste, and then reach the opposite side of the membrane. The permeated ammonia gas molecules are captured and recovered by acid (such as sulfuric acid) in the solution existing on the opposite side of the membrane. In order to improve ammonia nitrogen removals in the inlet part, high pH should be maintained in the feed waste including ammonia nitrogen to recover, which requires the cost of the chemical. To resolve this issue, previous studies tested various methods, for example, utilization of cheap calcium hydroxide or aeration together with inhibition of unwanted nitrification. The gas permeable membranes used for the recovery of ammonia nitrogen may be characterized, not only by proper heat and chemical resistance, but also by hydrophobicity, allowing selective ammonia gas permeation through the hydrophobic membrane pores. Future research should consider the relevant pilot or upscale processes using on-site wastes with various properties, and identify the optimal design/operation conditions as well as economic feasibility improvement plans.

• Journal of the Korean Society of Radiology
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• v.14 no.3
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• pp.295-301
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• 2020

Radiation exposure exposed during mammography, which is performed for early examination of breast cancer, has also been suggested as a cause of carcinogenesis in the past, and scattered rays generated during examination may cause unnecessary radiation exposure to surrounding organs. In this study, the Monte Carlo simulation was used to evaluate the human organ doses exposed during conventional mammography, and to estimate the dose reduction effect for each organ when using 3D printing materials for radiation protection by scattered rays. As a result of organ dose evaluation, the breast on the opposite side of the examination was about 22.0% of the breast on the test side and about 58.6% on the eye, which was highly influenced by the scattering-ray. When using the 3D printing shield to protect it, the breast on the opposite side of the test showed an effective dose reduction effect at a thickness of 1 mm.

• Wind and Structures
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• v.17 no.4
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• pp.379-397
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• 2013

Large Eddy Simulations (LES) were carried out to investigate the aerodynamic characteristics of a rectangular cylinder with side ratio B/D=5 at Reynolds number Re=22,000 (based on cylinder thickness). Particular attention was devoted to the effects of velocity shear in the oncoming flow. Time-averaged and unsteady flow patterns around the cylinder were studied to enhance understanding of the effects of velocity shear. The simulation results showed that the Strouhal number has no significant variation with oncoming velocity shear, while the peak fluctuation frequency of the drag coefficient becomes identical to that of the lift coefficient with increase in velocity shear. The intermittently-reattached flow that features the aerodynamics of the 5:1 rectangular cylinder in non-shear flow becomes more stably reattached on the high-velocity side, and more stably separated on the low-velocity side. Both the mean and fluctuating drag coefficients increase slightly with increase in velocity shear. The mean and fluctuating lift and moment coefficients increase almost linearly with velocity shear. Lift force acts from the high-velocity side to the low-velocity side, which is similar to that of a circular cylinder but opposite to that of a square cylinder under the same oncoming shear flow.

• Journal of Oral Medicine and Pain
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• v.8 no.1
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• pp.43-60
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• 1983

In order to obtain the basic data for diagnosis of occlusion the author investigated the occlusal sounds produced by mandibular closing movement from rest position to centric occlusion by using the Korotkoff sounds microphone electrodes and physiograph for Korean 20S without TMJ problems. And the author analyzed the correlation of the occlusal sounds with height, body weight, mandibular closing movement distance, maxillary sinus size and masseter muscle activities relating to the production of occlusal sounds. The obtained results were as follows : 1. The occlusal sounds prouduced by mandibular closing movements from rest position to centric occlusion were ranged from 3.08mV to 52.00mV, their maen value 19.07mV in right side, and ranged from 2.41mV to 18.33mV, their mean value 9.19mV in left side in group of Angel's class I occlusion subjects having right habitual side of mastication. 2. In general the occlusal sounds in the habitual side of mastication were greater than those in the opposite side. 3. The correlations of the occlusal sounds with height and maxillary sinus size were not significant. 4. The correaltions of the occlusal sounds with body weight, mandibular closing movement distance and masster muscle activities were significant.

• The korean journal of orthodontics
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• v.38 no.4
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• pp.240-251
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• 2008

Objective: The purpose of this study was to evaluate the effect of head position changes on the root parallelism between adjacent teeth on panoramic radiographs. Methods: A model with normal occlusion was constructed in the SolidWorks program, then RP (rapid protyping) model was fabricated. The model was repeatedly imaged and repositioned five times at each of the following nine positions: ideal head position, $5^{\circ}$ up, $10^{\circ}$ up, $5^{\circ}$ down, $10^{\circ}$ down, $5^{\circ}$, right, $10^{\circ}$, up, and $5^{\circ}$ right rotation, $10^{\circ}$ right rotation. Panoramic radiographs were taken by Planmeca ProMax and the angle between the long axes of adjacent teeth was directly measured in the monitor. Results: Axes of adjacent teeth tended to converge toward the occlusal plane when the head tilted up and converged in the opposite direction to the occlusal plane when the head tilted down. Anterior teeth showed the most notable differences. When one side of the head tilted up $5^{\circ}$ and $10^{\circ}$ along the anteroposterior axis (Y axis), tooth axes of the same side tended to converge toward the occlusal plane and tooth axes of the opposite side tended to converge in the opposite direction to the occlusal plane. When the head rotated to one side along the vertical axis (Z axis), the canine and lateral incisor of the same side converged in the opposite direction to the occlusal plane and the canine and lateral incisor of the other side converged toward the occlusal plane. Conclusions: When assessing the root parallelism on panoramic radiographs, the occlusal plane cant (anteroposterior or lateral) or asymmetry of the dental arch should be considered because these can cause distortion of tooth axes on panoramic radiographs.