• Proceedings of the Korean Geotechical Society Conference
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• 1998.10a
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• pp.397-404
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• 1998

• Journal of Cadastre & Land InformatiX
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• v.45 no.2
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• pp.131-147
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• 2015

In modern society, as to the underground urban infrastructure facilities(communication electricity water and sewage gas etc.) were contained many risks because of excavating. The exact position of underground facilities and the attribute information should be built in order to prevent accidents. As the result of analyzing the public surveying results from 2004 to 2009, it shows that low detecting rate of water pipeline which is only 52.4%, because the exploration of electromagnetic induction only detect metal pipeline and positioning survey only detect new pipeline before burying. Therefore development and verification of the correct and efficient exploration techniques are needed to improve the detecting rate. In this study, determined based on the location measurement results for the non-metal pipes and metal pipes before burial. It was compared with values that obtained through the ground penetrating radar and electromagnetic induction detecting. As a result, detecting rate of the concrete section showed a 100%, unpaved section showed a 94.7%, asphalt section showed 60%. So it confirmed the applicability of the ground penetrating radar at underground facilities detecting.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.1
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• pp.1-6
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• 2017

Ballistic impact on a soldier wearing a helmet can induce fatal injury, even if the helmet is not penetrated. Although studies on this type of injury have been performed, most of them have used an analytical model focused on head injury only. The injury of the neck muscles and cervical vertebrae by non-penetrating ballistic impact affects the survivability of soldiers, despite not inflicting fatal injury to the human body. Therefore, an analytical model of the head and neck muscles are necessary. In this study, an analysis of human body injury using the previously developed head model, as well as a cervical model with muscles, was performed. For the quantitative prediction of injury, the stress, strain, and HIC were compared. The results from the model including the cervical system indicated a lower extent of injury than the results from the model excluding them. The results of head injury were compared with other references for reliability.

• Journal of Chest Surgery
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• v.10 no.2
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• pp.327-336
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• 1977

A chinical analysis was performed on 383 ases of hest injurjes eperienced at Department of thoraci Surgery, Seoul National University Hospital during 21 year period From 1957 to 1977. Of 383 patients o hest injuries, 209 cases were result from nonpenetrating injuries whereas 175 were from penetrating injuries, and there were 258 cases of hemothorax or/and pneumothorax, 162 of rib fracture, 33 of foreign body, 26 of clavicle frcture, 26 of lung contusion, 17 of diaphragmati laceration, 14 of hemoperiardium, 14 of flail chest and others. Stab wound was the most common in penetrating injuries and followed by gunshot and shell fragments. The majority of nonpenetrating chest injury paiens were traffi accident vitims and falls accounted for the next largest group of accidents. Chest injuries were frequently encountered in the age group between 16 and 50 years, and 321 patients were male comparing to 62 of female. In blunt hest injuries the patients with five or more rib fractures had a 85 per ent incidence of intrathoracic injury and 19 per cent had an intraabdominal organ damage, whereas those with four or less rib fractures had a 69 per cent and a 6 per cent incidence respectively. The principal associated injuries were cerebral contusion on 19 cases, renal contusion on 10, liver laceration on 7, peripheral vessel laceration on 5, spleen laceration on 3 and extremity fracture on 18 patients. The principles of therapy for early complications of chest trauma were rapid reexpansion of the lungs by thoracentesis (46 cases) and closed thoracotomy (125 cases) but open thoracotomy had to be done on 90 cases (23.5%) because of massive bleeding or intrapleural hematoma, foreign body, cardiac injury, diaphragmatic laceration and bronhial rupture. The over all mortality was 2.87 per cent (11 among 383 cases), 8 cases were from penetrating injuries and 3 from nonpenetrating injuries.

• Journal of Chest Surgery
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• v.10 no.2
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• pp.337-342
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• 1977

A clinical analysis was performed on 383 cases of chest injurjes experienced at Department of Thoracic Surgery, Seoul National University Hospital during 21 year period from 1957 to 1977. Of 383 patients of chest injuries, 209 cases were result from nonpenetrating injuries whereas 175 were from penetrating injuries, and there were 258 cases of hemothorax or/and pneumothorax, 162 of rib fracture, 33 of foreign body, 26 of clavicle fracture, 26 of lung contusion, 17 of diaphragmatic laceration, 14 of hemopericardium, 14 of flail chest and others. Stab wound was the most common in penetrating injuries and followed by gunshot and shell fragments. The majority of nonpenetrating chest injury patients were traffic accident victims. and fails accounted for the next largest group of accidents. Chest injuries were frequently encountered in the age group between 16 and 50 years, and 321 patients were male comparing to 62 of female. In blunt chest injuries the patients with five or more rib fractures had a 85 per cent incidence-of intrathoracic injury and 19 per cent had an intraabdominal organ damage, whereas those with four or less rib fractures had a 69 per cent and a 6 per cent incidence respectively. The principal associated injuries were cerebral contusion on 19 cases, renal contusion on 10, liver laceration on 7, peripheral vessel laceration on 5, spleen laceration on 3 and extremity fracture on 18 patients. The principles of therapy for early complications of chest trauma were rapid reexpansion of the lungs by thoracentesis [46 cases] and closed thoracotomy [125 cases] but open thoracotomy .had to be done on 90 cases [23-5%] because of massive bleeding or intrapleural hematoma, foreign body, cardiac injury, diaphragmatic laceration and bronchial rupture. The over all mortality was 2.87 per cent [11 among 383 cases], 8 cases were from penetrating injuries and 3 from nonpenetrating injuries.

• Geophysics and Geophysical Exploration
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• v.2 no.1
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• pp.1-7
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• 1999

We investigated the weathering characteristics of On-Yang gneiss by means of geological survey and Ground Penetrating Radar(GPR). The results of geological survey and boring show the two sets of vertical joint and horizontal joint developed by foliation which is composed of salic and melanic layers. GPR section evidently shows foliation direction and differential weathering due to discontinuity and mineral composition of metamorphic rock. The GPR section for instantaneous phase attribute based on complex trace analysis evidently shows continuity and foliation direction of metamorphic rock. The strong reflection amplitude which is derived from the banded structure of weathered rock can be incorrectly interpreted as a reflection of bedrock. The depth of rock basement should be estimated from the overall exploration result such as boring, seismic method, and electrical resistivity method.

• International Journal of Highway Engineering
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• v.18 no.4
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• pp.55-61
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• 2016

PURPOSES : The objective of this study was to determine the relationship between the dielectric characteristics of asphalt mixtures and the air voids present in them using ground penetrating radar (GPR) testing. METHODS : To measure the dielectric properties of the asphalt mixtures, the reflection coefficient method and the approach based on the actual thickness of the asphalt layer were used. An air-couple-type GPR antenna with a center frequency of 1 GHz was used to measure the time for reflection from the asphalt/base layer interface. A piece of aluminum foil was placed at the interface to be able to determine the reflection time of the GPR signal with accuracy. An asphalt pavement testbed was constructed, and asphalt mixtures with different compaction numbers were tested. After the GPR tests, the asphalt samples were cored and their thicknesses and number of air voids were measured in the laboratory. RESULTS : It was found the dielectric constant of asphalt mixtures tends to decrease with an increase in the number of air voids. The dielectric constant values estimated from the reflection coefficient method exhibited a slight correlation to the number of air voids. However, the dielectric constant values measured using the approach based on the actual asphalt layer thickness were closely related to the asphalt mixture density. Based on these results, a regression equation to determine the number of air voids in asphalt mixtures using the GPR test method was proposed. CONCLUSIONS : It was concluded that the number of air voids in an asphalt mixture can be calculated based on the dielectric constant of the mixture as determined by GPR testing. It was also found that the number of air voids was exponentially related to the dielectric constant, with the coefficient of determination, $R^2$, being 0.74. These results suggest that the dielectric constant as determined by GPR testing can be used to improve the construction quality and maintenance of asphalt pavements.

• Journal of Microbiology and Biotechnology
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• v.28 no.3
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• pp.367-374
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• 2018

RNA interference provides an effective tool for developing antitumor therapies. Cell-penetrating peptides (CPPs) are delivery vectors widely used to efficiently transport small-interfering RNA (siRNA) to intracellular targets. In this study, we investigated the efficacy of the cancer-specific CPP carrier BR2 to specifically transport siRNA to cancer-target cells. Our results showed that BR2 formed a complex with anti-vascular endothelial growth factor siRNA (siVEGF) that exhibited the appropriate size and surface charge for in vivo treatment. Additionally, the BR2-VEGF siRNA complex exhibited significant serum stability and high levels of gene-silencing effects in vitro. Moreover, the transfection efficiency of the complex into a cancer cell line was higher than that observed in non-cancer cell lines, resulting in downregulated intracellular VEGF levels in HeLa cells and comprehensively improved antitumor efficacy in the absence of significant toxicity. These results indicated that BR2 has significant potential for the safe, efficient, and specific delivery of siRNA for diverse applications.

• Journal of Korean Neurosurgical Society
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• v.41 no.1
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• pp.16-21
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• 2007

Objective : Civilian gunshot injuries to the brain are relatively rare and study of these injuries has been neglected in South Korea. We present our experience with penetrating gunshot injuries to the brain and review the outcome of surgical management, as well as other clinical predictors influencing the prognosis. Methods : We present a retrospective analysis of 13 patients with penetrating gunshot injuries to the brain who were treated at our hospital over a period of 22 years. Results : The Glasgow Coma Scale[GCS] score on admission was recorded to be : 3-5 in 1 patient, 6-8 in 3 patients, 9-12 in 2 patients and 13-15 in 7 patients. There were 11 patients who underwent surgical treatment, and the surgical mortality rate was 0%. The admission GCS score was the most valuable prognostic factor. The best results were found to be in patients admitted with an initial GCS higher than 13. There were no favorable outcomes in patients admitted with a GCS of 8 or lower. There was a correlation between the presence of a transventricular or bihemispheric trajectory and poor outcome. The patients admitted with unilobar wounds resulted in better outcome than those with bilobar or multilobar wounds. Retained deep intracranial bone or metal fragments were the most common postoperative complication. However, retained fragments did not increase the risk of infection or seizure. Conclusion : Our results suggest that a less aggressive approach, consisting of minimal local debridement and removal of the bone and metal fragments that are easily accessible, can be successfully used in civilian gunshot wounds to the brain.

• International Journal of Highway Engineering
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• v.17 no.6
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• pp.1-9
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• 2015

PURPOSES : The objective of this study is to propose a quality control and quality assurance method for use during asphalt pavement construction using non-destructive methods, such as ground penetrating radar (GPR) and an infrared (IR) camera. METHODS : A 1.0 GHz air-coupled GPR system was used to measure the thickness and in situ density of asphalt concrete overlay during the placement and compaction of the asphalt layer in two test construction sections. The in situ density of the asphalt layer was estimated based on the dielectric constant of the asphalt concrete, which was measured as the ratio of the amplitude of the surface reflection of the asphalt mat to that of a metal plate. In addition, an IR camera was used to monitor the surface temperature of the asphalt mat to ensure its uniformity, for both conventional asphalt concrete and fiber-reinforced asphalt (FRA) concrete. RESULTS : From the GPR test, the measured in situ air void of the asphalt concrete overlay gradually decreased from 12.6% at placement to 8.1% after five roller passes for conventional asphalt concrete, and from 10.7% to 5.9% for the FRA concrete. The thickness of the asphalt concrete overlay was reduced from 7.0 cm to 6.0 cm for the conventional material, and from 9.2 cm to 6.4 cm for the FRA concrete. From the IR camera measurements, the temperature differences in the asphalt mat ranged from $10^{\circ}C$ to $30^{\circ}C$ in the two test sections. CONCLUSIONS : During asphalt concrete construction, GPR and IR tests can be applicable for monitoring the changes in in situ density, thickness, and temperature differences of the overlay, which are the most important factors for quality control. For easier and more reliable quality control of asphalt overlay construction, it is better to use the thickness measurement from the GPR.