• Journal of the Ergonomics Society of Korea
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• v.33 no.1
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• pp.15-25
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• 2014

Objective: This study aims to analyze the factors that affect the ability to maintain dynamic sitting balance (DSB), biomechanical characteristics, and physical characteristics in spinal cord injuries (SCI) patients. Background: Virtual ski training systems, ski equipment, and training protocols for disabled skiers are being studied to spread awareness. However, few studies have been reported on the sitting balance ability associated with chair mono skiing. Method: A dynamic sitting balance border system was built to investigate the ability to maintain dynamic sitting balance in SCI patients. Trunk muscle activity was evaluated by electromyogram while conducting dynamic sitting balance tests. The trunk muscle strength was tested with a portable handheld dynamometer. Physical activity scores were measured with the physical activity recall assessment. Results: There were high levels of correlation between the ability to maintain DSB and trunk flexor strength, extensor strength, rotator strength, and physical activity score. However, height, weight, and injury level in SCI patients were not correlated with the ability to maintain DSB. Additionally, strong negative correlations were found between muscle activities of the external oblique and lumbar erector spinae muscles and the ability to perform the backward tilt test. Trunk extensor muscle activity during the ball lifting test was significantly higher than in other tests. Conclusion: The results indicate that improving trunk muscle strength and physical activity can increase the ability to maintain DSB. Application: The findings of a close relationship between trunk strength, physical activity, and the ability to maintain DSB need to be reflected in the chair mono ski training program.

• Korean Journal of Radiology
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• v.22 no.5
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• pp.759-769
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• 2021

Objective: To evaluate the application of laplacian-regularized mean apparent propagator (MAPL)-MRI to brain glioma-induced corticospinal tract (CST) injury. Materials and Methods: This study included 20 patients with glioma adjacent to the CST pathway who had undergone structural and diffusion MRI. The entire CSTs of the affected and healthy sides were reconstructed, and the peritumoral CSTs were manually segmented. The morphological characteristics of the CST (track number, average length, volume, displacement of the affected CST) were examined and the diffusion parameter values, including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), radial diffusivity (RD), mean squared displacement (MSD), q-space inverse variance (QIV), return-to-origin probability (RTOP), return-to-axis probabilities (RTAP), and return-to-plane probabilities (RTPP) along the entire and peritumoral CSTs, were calculated. The entire and peritumoral CST characteristics of the affected and healthy sides as well as those relative CST characteristics of the patients with motor weakness and normal motor function were compared. Results: The track number, volume, MD, RD, MSD, QIV, RTAP, RTOP, and RTPP of the entire and peritumoral CSTs changed significantly for the affected side, whereas the AD and FA changed significantly only in the peritumoral CST (p < 0.05). In patients with motor weakness, the relative MSD of the entire CST, QIV of the entire and peritumoral CSTs, and the AD, MD, RD of the peritumoral CST were significantly higher, whereas the RTPP of the entire and peritumoral CSTs and the RTOP of the peritumoral CST were significantly lower than those in patients with normal motor function (p < 0.05 for all). In contrast, no significant changes were found in the CST morphological characteristics, FA, or RTAP (p > 0.05 for all). Conclusion: MAPL-MRI is an effective approach for evaluating microstructural changes after CST injury. Its sensitivity may improve when using the peritumoral CST features.

• International Journal of Automotive Technology
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• v.7 no.7
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• pp.769-776
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• 2006

A mathematical model is developed in this paper to define the interaction between the occupant and vehicle passenger compartment and to predict the occupant dynamic response during a sudden impulse load. Two different types of occupants are considered in this study, child and adult occupants. The occupants are considered as lumped masses connected to the child seat and vehicle's body masses by means of restraint systems. In addition, the occupant restraint characteristics of seat belt and airbag are represented by stiffness and damping elements. To obtain the dynamic response of the occupant, the equations of motion of the occupants during vehicle collisions are developed and analytically solved. The occupant's acceleration and relative displacement are used as injury criteria to interpret the results. It is demonstrated from the numerical simulations that the dynamic response and injury criteria are easily captured and analyzed. It is also shown that the mathematical models are flexible, useful in optimization studies and it can be used at initial design stage.

• Journal of Mechanical Science and Technology
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• v.20 no.8
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• pp.1183-1194
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• 2006

The aim of this study was to identify the characteristics of the flexion withdrawal reflex modulated by the hip angle and hip movement in spinal cord injury (SCI). The influence of the hip position and passive movement were tested in 6 subjects with chronic SCI. Each subject placed in a supine position and lower leg was fixed with the knee at 5 -45 degree flexion and the ankle at 25-40 degree plantar flexion. A train of 10 stimulus pulses were applied at 200 Hz to the skin of the medial arch to trigger flexion reflexes. From results of the regression analysis, static properties of normalized muscle activation of flexor muscles have the linear relationship with respect to hip angle (P< 0.05). In order to verify the neural contribution of flexion reflex, we compared the static and dynamic gains of estimated muscle activations with measured EMG of ankle flexor muscle. Form this study, we postulate that the torque and muscle response of flexion withdrawal reflex have linear relationship with hip angle and angular velocity.

• Journal of Korean Neurosurgical Society
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• v.65 no.3
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• pp.334-341
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• 2022

Traumatic brain injury (TBI) is one of the leading causes of death in the pediatric population in Korea. In addition, it can cause disability in children and adolescents, with physical and mental consequences. This causes a substantial burden on the health care system and occurs globally and not just in Korea. We searched and reviewed current data on the epidemiologic characteristics of pediatric TBI in Korea. Our review provides the recent epidemiological trend mainly focusing on incidence and mortality along with worldwide reported data. This review will be helpful to understand the global epidemiology of pediatric TBI and its differences between countries.

• Journal of the Korea Safety Management & Science
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• v.2 no.4
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• pp.9-17
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• 2000

For the accident prevention, it is necessary to identify common factors and characteristics contributing to the industrial accidents. This study concerned with the accident characteristics by age of injured person in the manufacturing industries. To make the statistical comparisons for the accident characteristics by age group, we derived the distributions of occupational injuries in terms of accident time, accident type, activity at time of accident, injury type, injured part of body, agency of accident, and workday losses. The results show that the characteristics of the occupational injuries by age group are not significantly different in a31 characteristics investigated in this study.

• Archives of Reconstructive Microsurgery
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• v.21 no.1
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• pp.41-49
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• 2012

Purpose: To report clinical appearances and the outcomes of patients treated for wrist laceration with suicidal intent. Materials and Methods: Between March 2005 and February 2008, patients with wrist laceration were treated at our center. Among them, 14 patients with suicidal intent were reviewed retrospectively. They were 8 females and 6 males with a mean age of 33 years at the time of treatment. The side of injured wrist, injured structures, suicidal instrument, the time of injury, a suicidal motive, drug or alcohol abuse or not, indication of combined psychiatric disease, the duration of postoperative treatment, and the results of treatment were analyzed. Results: The injured wrist was the left one in 13 cases (93%), and knife wounds in 11 cases (79%) was the most frequent mechanism of injury. An average of 4.6 structures were injured including 3.5 tendons, 0.57 nerves and 0.5 arteries. The most frequently injured structures were the palmaris longus (71%), FCU (50%), FCR (43%), FDS 3 (36%), FDS 2, median nerve, and ulnar artery (each 29%). Simultaneous injury of both median and ulnar nerves occurred in 3 cases (21%), and simultaneous injury of both radial and ulnar artery occurred in 1 case (7%). The injury time was the night in 12 cases (86%), and the most frequent suicidal motive was human relations such as lover or spouse in 12 cases (86%). In 9 cases (64%), the injured were in a drunken state, 3 cases (21%) had been treated for a psychiatric disease at the time of the injury. The durations of postoperative treatment were an average of 5 days of admission and 1 day follow up. Only 1 case results could be evaluated. Conclusions: Patient's poor compliance in wrist laceration with suicidal intent should be expected and these characteristics may affect the management plan.

• Journal of Trauma and Injury
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• v.29 no.3
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• pp.68-75
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• 2016

Purpose: The purpose of this study was to analyze the effectiveness of regional trauma center's management. Methods: Data collected between January 2013 and December 2015 from a regional trauma center registry was retrospectively reviewed. The patients who had injury severity score (ISS) greater than 15 and over the age of 18 were included. We compared annual general characteristics, the injury mechanism, the pathway of transportation, the injury severity score, the length of stay in emergency department (ED) and hospital, the in-hospital mortality. Results: The annual numbers of enrolled patients were 337, 334 and 278, respectively. No significant differences were found in the annual patient's median ages, injury mechanism, ISS and in-hospital mortality. The annual proportions of coming from other hospital and the median length of stay in hospital were increased after establishment of regional trauma center. The annual median lengths of stay in ED were decreased remarkably. Conclusion: Through the establishment of regional trauma center, the length of stay in ED can be reduced but not in-hospital mortality. More multidisciplinary cooperation and well-organized study is needed to reduce mortality of major trauma patients and maximize effect of regional trauma center.

• Advances in pediatric surgery
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• v.19 no.2
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• pp.98-107
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• 2013

Debates exist about the appropriate treatment for pancreatic trauma in children. We intended to examine the safety of the operation of pancreatic trauma in children. This is a retrospective study of 13 patients, younger than 15, who underwent surgery for pancreatic trauma, between 1993 and 2011 in Seoul National University Children's Hospital. Medical records were reviewed for mechanism of trauma, clinical characteristics, radiological findings, operation and outcomes. Organ injury scaling from the AAST (American Association for Surgery of Trauma) was used. All injuries were caused by blunt trauma. Patients with grade III, IV, and those who were difficult to distinguish grade II from IV, underwent surgery due to severe peritonitis. Three patients with grade II were operated for reasons of mesenteric bleeding, tumor rupture of the pancreas, and progression of peritonitis. Distal pancreatectomy was performed in 10 patients and subtotal pancreatectomy and pylorus preserving pancreaticoduodenectomy in 1 patient each. The remaining one underwent surgical debridement because of severe adhesions. The location of injury, before and after operation, coincided in 83.3%. The degree of injury, before and after the operation, was identical in all the patients except for those who were difficult to tell apart grade II from grade IV, and those cannot be graded due to severe adhesion. Postoperative complications occurred in 23.1%, which improved with conservative treatment. Patients were discharged at mean postoperative 12(range 8~42) days. Even though patients with complications took longer in time from diagnosis to operation, time of trauma to operation and hospital stay, this difference was not significant. In conclusion, When pancreatic duct injury is present, or patient shows deterioration of clinical manifestation without evidence of definite duct injury, or trauma is accompanied by other organ injury or tumor rupture, operative management is advisable, and we believe it is a safe and feasible method of treatment.

• Journal of Sericultural and Entomological Science
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• v.44 no.1
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• pp.22-27
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• 2002

The Yongcheonppong was cultured in the form of a dense mulberry field coverd with polyethylene film and was tested in Suwon and Chunchon. The agronomic characteristic and some consideration on the result of the silkworm rearing were as follows. The Yongcheonppong was the medium budding variety and was longer in length of young shoots than the Kaeryangppong. The Yongcheonppong was higher in leaf yield in spring than the Kaeryangppong and was lower in leaf yield in autumn than the Kaeryangppong to the contrary. The Yongcheonppong was a little higher in the number of branches and was longer in the length of the branch than the Kaeryangppong and so was appropriate for rearing with mulberry shoots. Yongcheonppong was more resistant to twig blight and die-back and was a little susceptible to dwarf disease. As the Yongcheonppong was most resistant to the freezing injury, it was appropriate for the cold region and enabled the farmers to rear some amount of silkworms every year. In Chunchon, The Yongcheonppong increased by 11% in cocoon yield than the Kaeryangppong when the freezing injury occurred 1 year out of 2 years and produced about the same as the Kaeryangppong in cocoon yield when the freezing injury occurred 1 year out of 3 years.