• Journal of Korean Foot and Ankle Society
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• v.8 no.2
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• pp.191-194
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• 2004

Purpose: Anatomic configuration of the ankle joint is useful information during various ankle procedures. This study was prospectively designed to investigate the sagittal inclination pattern of the ankle joint. Materials and Methods: Lateral standing ankle radiographs from one-hundred people (age: $17{\sim}68$, M:F=45:55) and magnetic resonance (MR) sagittal ankle images from twenty-four people (age: $16{\sim}65$, M:F=14:10) were studied. Post-traumatic, arthritic, or grossly deformed ankles at any reason were excluded. The posterior inclination angle (PIA) of the distal tibia was measured and compared between the lateral and the medial segment. Results: On plain radiographic data, the average PIA of the distal tibia was $6.14^{\circ}{\pm}3.56^{\circ}$ (range $0^{\circ}$ to $14^{\circ}$) in the lateral segment and $13.16^{\circ}{\pm}3.05^{\circ}$ (range $6^{\circ}$ to $22^{\circ}$) in the medial segment. On MR imaging data, the average PIA of the distal tibia was $5.08^{\circ}{\pm}4.26^{\circ}$ (range $1^{\circ}$ to $10^{\circ})$ in the lateral segment and $10.16^{\circ}{\pm}4.87^{\circ}$(range $5^{\circ}$ to $17^{\circ}$) in the medial segment. The PIA between two segments was significantly different. Conclusion: The sagittal configuration of the medial area ankle joint and the lateral area ankle joint has difference in the degree of posterior inclination and shape of curvature.

• Investigative Magnetic Resonance Imaging
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• v.1 no.1
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• pp.66-74
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• 1997

fMRI, functional MRI introduced receently appears based on the gradient echo technique which is sensitive to the field inhomogeneity developed due to the local susceptibility changes of blood oxygenation and deoxygenation. There has been many variants of the basic gradient echo sequence which is sensitive to the local inhomogeniety, among others such as GRASS or SSFP to EPISTAR are the most commonly used gradient echo techniques. Common to all these gradient echo techniques is that the signal due to the susceptibility effects is generally decreased with increasing inhomogeneity due to the $T2^{*}$ effect or conventionally konwn as blood oxygenation level dependent(BOLD) effect. It is, also found that the BOLD sensitivity is also dependent on the imaging modes, namely whether the imaging is in axial, or coronal or sagittal mode as well as the directions of the vessels against the main magnetic field. We have, therefore, launched a systematic study of imaging mode dependent signal change or BOLD sensitivity as well as the signal changes due tothe tilting angle of the imaging planes. Study has been made for both TRFGE sequence and CGE sequence to compare the distinctions of the each mode since each technique has different sensitivity againsst susceptibility effect. Method of computation and both the computer simulations and their corresponding experimental results are presented.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.1
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• pp.57-62
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• 2014

Most analytical models of the human body have focused on conscious responses. A patellar tendon reflex, a representative example of spinal reflexes, occurs without a neural command. Muscle forces and activation of the quadriceps femoris muscles in healthy adults during patellar tendon reflex are identified in this study. The model is assumed to move in the sagittal plane, and the thigh and the trunk are assumed to be fixed in a sitting position so that the shank can move similar to a pendulum. The knee joint is modeled as a revolute joint, and the ankle joint is modeled as a fixed joint so that the shank and the foot can be regarded as one rigid body. Muscle forces are calculated following the inverse dynamic approach. Kinematic data obtained from an experiment (Mamizuka, 2007) are used as input data. Muscle activations are identified using a Hill-type muscle model. The obtained simulation results are compared with experimental results for validating the model and the underlying assumptions.

• The Korean Journal of Nuclear Medicine
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• v.26 no.1
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• pp.33-39
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• 1992

Spontaneous pain and painful overreaction to external stimuli resulting from lesion confined central nervous system (CNS) were named as thalamic syndrome. Thalamic lesion and decreased regional cortical perfusion thought to the pathogenesis of thalamic syndrome due to decreased function of thalamocortical tract. We performed $^{99m}Tc-HMPAO$ regional cerebral perfusion in 10 patients with clinical diagnosis of thalamic syndrome due to thalamic lesion or near the thalamic lesion at Yonsei University Hospital, from January 1989 to August 1991. In contrast to five patients with lesions near the thalamus who did not show secondarily decreased perfusion at cerebral cortex, four among the five patients with thalamic lesions revealed decreased cortical perfusion in the ipsilateral cerebral cortex on brain SPECT. These phenomena may suggest the loss of afferent activating stimuli from the thalamus led to decreased neuronal activity and the followitng hypoperfusion of cerebral cortex, and might be one of the indirect signs for suggesting presence of the thalamocortical tract. A causal relationship between cortical hypoperfusion and neuropsychological deficit is strongly suggested.

• Journal of the Korean Society of Radiology
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• v.12 no.3
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• pp.397-402
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• 2018

The study best image for diagnosis of fracture, dislocation and unilateral degenerative arthritis of the Sacroiliac joint, this study was performed to obtain the best image of the joint space of the hip joint by giving angle change to the pelvis phantom and the x-ray tube. I received evaluation. The results of the Receiver Operating Characteristic that in the case of simple photographs for the detection of joint arthritis and degenerative arthritis in the prone position, the photograph taken in the prone position raises the buttocks of the opposite side of the test by $25^{\circ}{\sim}30^{\circ}$ and the x-ray tube is perpendicular to the sagittal plane passing 2.5 cm inward from the thorny vertebra In the lying position, lift the Sacroiliac joint of the test side by $25^{\circ}{\sim}30^{\circ}$, and take a $5^{\circ}$ angle of the x-ray tube angle toward the foot toward the center of the upper bruch spine from it will be helpful to diagnose arthritis. the center of the upper bruch spine to the side of the ankle joints in the transverse direction And posterior direction, it will be helpful to diagnose arthritis.

• Journal of the Korean Vacuum Society
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• v.6 no.4
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• pp.343-347
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• 1997

The dependence of compensation mechanism in $P^+$-InGaAs layer implanted with oxygen on the annealing temperatures was investigated. The oxygen implantation was performed for electrical isolation. The conductivity was controlled by damage related traps below $500^{\circ}C$. For the temperature of 500 to $600^{\circ}C$, oxygen began to show the chemical effect of compensating the acceptors due to activation and type conversion (plongrightarrown-type) occurred at $600^{\circ}C$. This indicates that the defects generated by the chemical activity of oxygen increased with increasing annealing temperature, where activation energy of 24.2 meV was obtained. It is attributed to the formation of native defects, such as In interstitials, acting as shallow donor in InGaAs. Above $600^{\circ}C$, the interstitial Be atoms become reactivated and the n-type conductivity decreases.

• The Korean Journal of Physiology
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• v.9 no.2
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• pp.23-31
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• 1975

The effects of ethanol intravenously administered on the mean arterial blood pressure and heart rate responses to electrical stimulation of vagus nerve and the hypothalamus were studied in the cats. Also investigated were the effects of ethanol on the cardiovascular responses to bilateral carotid occlusion and to intravenously injected epinephrine and acetylcholine separately. The results obtained from the present study were as follows; 1. In 1.0 ml/kg and 2.0 ml/kg of ethanol infused groups the mean arterial blood pressure increased gradually and reached plateaus in 10 minutes after ethanol infusion while no marked changes in blood pressure were observed in 0.5 ml/kg of ethanol infused group. 2. The pressor responses elicited by the electrical stimulation of the hypothalamus were depressed directly proportionally to amount of ethanol infused. In 0.5 ml/kg of ethanol infused group the pressor response was reduced to 84.5% of control value and it declined to 17.0% of control in 2.0 ml/kg of ethanol infused group. 3. After ethanol administration the heart rate decreased slightly and also was decreased positive chronotropic effect elicited by hypothalamic stimulation. In several cases even negative chronotropic responses were observed during electrical stimulation in the hypothalamus. 4. Since the pressor responses to bilateral carotid occlusion was reduced by ethanol administration it is suggested that activity of baroreceptor is inhibited by ethanol. 5. No changes were observed in the negative chronotropic effect Produced by electrical stimulation of the vegus nerve of ethanol infused animal. And cardiovascular responses to intravenously injected epinephrine and acetylcholine were not influenced by ethanol either.

• Korean Journal of Psychosomatic Medicine
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• v.7 no.2
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• pp.149-157
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• 1999

Food intake and body weight are determined by a complex interaction of regulatory pathways. Leptin, the product of the ob gene, is a recently discovered hormone secreted by adipocytes, that signals the amount of adipose tissue energy stores to the brain and exerts major effects on energy homeostasis and neuroendocrine function. In addition, leptin has recently been shown to affect reproductive function in rodents and humans. The study of leptin and its effectors in the hypothalamus may provide important insights with respect to the interplay of several hypothalamic neuropeptides in regulating feeding as well as the interaction of genetics and environment in the regulation of energy homeostasis. In this review we summarise the action of leptin in the regulation of food intake and highlight a working model of the effects of environmental factors on the leptin system.

• Journal of Biomedical Engineering Research
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• v.31 no.1
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• pp.67-73
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• 2010

The foot performs an important function in supporting the body and keeping body balance. An abnormal walking habit breaks the balance of the human body as well as the normal function of the foot. The influence of a flatfoot(pes planus) occupies a considerable portion of the various causes resulting in the wrong walking habit. But, little studies has been done by the functional foot orthotics for the flat foot. The object of this study, therefore, is to propose a new approach method to reveal the effects of the improvement of the foot function by using orthotics. The essential point of this study is to measure and analyze the change of ankle angle in the sagittal plane for flat foot subjects wearing the orthotics. Before and after wearing the functional orthotics, the gait analysis of flat foot subjects was conducted in three experimental aspects : the change of ankle angle, the change of the total Ankle ROM and the difference of left & right ankle angle in the sagittal plane. 1. The average ankle angle differences of before-and-after wearing the orthotics have declined like this; left : $2.71^{\circ}$, right: $1.91^{\circ}$ (p<0.05). 2. Total ankle ROM also showed decrease in both sides while the left side's is rather slight; left : $0.57^{\circ}$, right : $2.07^{\circ}$ (p<0.05). 3. The difference of left and right ankle angle in the sagittal plane decreased by $0.71^{\circ}$ (p<0.05). In result, it is confirmed that the functional foot orthotics have a significant effect on mechanical movement of ankle joint for flat foot. it is expected that this paper will be further studied and improved as a practical estimation method in the research on the effect of foot-orthotics.

• Journal of Korea Multimedia Society
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• v.14 no.10
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• pp.1262-1274
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• 2011

A fast and stable deformation model is essential for realistic simulation of image morphing. In order to stabilize deformation, we used two internal thin plate mass-spring systems that compute the displacements of the x- and y-components of all nodes on the mesh. The deformation results are globally smoother and more stable due to the direction limitation of thin plate mass-spring systems. One-to-one deformation is one of the important issues in image morphing. We focus on fast removing overlaps in the process of deformation. To rapidly remove overlaps, the external forces are set automatically on four or eight neighboring nodes. The speed of removing overlaps is faster when external forces are set on four or eight neighbouring nodes than when on two neighbouring nodes.