• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.4
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• pp.17-24
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• 2006

Hydrodynamic ram of aircraft fuel tanks is one of main ballistic battle damages of an aircraft and has great importance to airframe survivability design. Basic concept, physics and research history of hydrodynamic ram are investigated. The penetration and internal detonation of a simple fuel tank and ICW(Intermediate Complexity Wing) are analyzed by computational method. Structural rupture and fluid burst are analytically realized using general coupling and coupling surface interaction. The results such as fluid pressure, tank stress and displacement are shown and future research chances are suggested based on the study.

• Journal of Chest Surgery
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• v.41 no.1
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• pp.124-127
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• 2008

Injury to the inferior vena cava (IVC) is associated with a high mortality rate, and little progress has been made for improving the treatment for this since the 1970s. Injury to the retrohepatic IVC, in particular, has been associated with up to a 75% mortality rate due to the difficulty in gaining adequate exposure and controlling the bleeding. Both the severity of injury and anatomic accessibility has been directly correlated with survival in IVC injury. We have experienced a patient with retrohepatic IVC that was ruptured by a penetrating gunshot injury and we managed to save this patient's life.

• Journal of the Korea Concrete Institute
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• v.22 no.4
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• pp.441-450
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• 2010

This is a preliminary study on the development of precast beam-column joints for dry construction methodology. Precast beam column joints with thru-connectors (BCJ_TC) using high strength bars or PS strands were developed and their seismic performance including strength degradation, stiffness degradation and energy dissipation capacity was experimentally evaluated. Test results showed that compressive failures at the end blocks of PC beam members occurred dominantly while PC columns including panel zones were free from any damage. However, the connections confined with CFRP at the end block showed much improved seismic performance than that of the unconfined connections. Connections with neoprene pad fillers between beam and column interfaces were better than the other connections in all the seismic performances except initial stiffness. To improve the seismic performances of BCJ_TC, compressive strength of the concrete at the end block need to be increased to compensate for the additional compressive stresses due to unbonded connectors and deformation of connectors should be controlled respectively.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.12
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• pp.1577-1583
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• 2012

Penetrator with enhanced lateral effect (PELE) is a novel projectile that does not require dynamite and a fuse. It comprises a high-density jacket that is closed at its rear end and filled with a low-density filling material. To study the explosion characteristics of PELE using AUTODYN-3D code, the calculation models of the projectile body and the bullet target were developed and the process of penetrating an aluminum-2024 alloy target using PELE was simulated. The scattering characteristics after PELE penetrated the aluminum-2024 alloy target were studied for different filling materials. The explicit finite element analysis of PELE fragmentation was implemented with the stochastic failure criterion in AUTODYN-3D code. As the filling expanded, the fragments gained velocity and dispersed laterally, increasing the damage area considerably. The number and shape of PELE fragments differed depending on the impact pressure of the filling that fragmented during the penetration and lateral dispersion processes.

• Journal of Chest Surgery
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• v.42 no.1
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• pp.46-52
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• 2009

Background: Vascular injuries to the extremities are potentially devastating and they can lead to limb loss and mortality if they are not appropriately managed. The vascular trauma caused by traffic and industrial accidents has recently increased according to the developing industry and transport system in Korea. Early recognition and treatment of these injuries are mandatory to achieve satisfactory outcomes. Material and Method: We retrospective reviewed 43 patients with vascular injuries that were due to blunt and penetrating trauma and they underwent emergency operations from January of 1998 to December of 2006. Result: There were 38 men and 5 women patients with a mean age of $42.0{\pm}16.8$ years (range: 17~77). The cause of vascular injuries were 28 traffic accidents (65%), 6 industrial accidents (14%), 6 glass injuries (14%) and 3 knife injuries (7%). The average time from admission to the operating room was $319.0{\pm}482.2$ minutes (range: 27~2,400 minutes). The average time from admission to discharge was $53.1{\pm}56.0$ days (range: 2~265 days). The anatomic injuries included the femoral artery in 16 cases (37%), the popliteal artery in 8 cases (19%), the brachial artery in 8 cases (19%), and the subclavian and axillary arteries in 7 cases (16%). The associated injuries were 23 bone fractures (53%), 18 muscle injuries (42%) 5 nerve injuries (12%) and 11 vein injuries (26%). The operation methods were 20 end to end anastomoses (46%), 16 interposition grafts (36%), 2 repairs with using patches (5%) and 5 others (12%). The number of amputations and cases of mortality were 3 cases (7%) and 4 cases (9%), respectively. Conclusion: Minimizing ischemia is an important factor for maximizing salvage of extremities. Prompt diagnosis and treatment can reduce the amputation and mortality rates.

• Journal of Korean Society of Steel Construction
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• v.20 no.2
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• pp.313-321
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• 2008

Recently in Japan, fracturing was observed on the diagonal member of a through truss bridge at the boundary region with the concrete slab. Local corrosion damage where the diagonal member was enclosed in the concrete slab is an important factor in the fracture. In this study, accelerated exposure tests were carried out on concrete-steel model specimens simulating steel members at the boundary with concrete. Fatigue tests were then performed on the corroded model specimens. Accelerated exposure tests of the S6-cycle, which is carried out on the model specimens for 150, 300, 450 and 600 da ys. Their surface geometry was then measured. From the accelerated exposure test results, change in maximum and mean corrosion depths was determined according to the testing periods. The effect of local corrosion on fatigue strength was also presented based on the fatigue test results.

• Journal of Chest Surgery
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• v.30 no.4
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• pp.402-407
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• 1997

The records of 28 patients with traumatic diaphragmatic injuries seen at Masan Samsung Hospital from march 1986 o March 1995 were reviewed. We treated 21 male and 7 female patients ranging in ages from 5 to 68 years. Thc diaphragimatic injuries were due to blunt trauma in'20 cases(Trawc accident 18, compression injury 1, Human trauma 1) and penetrating injuries 8 cases (all stab wound). Most common symptoms were dyspnea 27 (96%), chest pain 26 (93%), abdomianl pain 8 (29%), comatose mentality 36 (11 %). Chest X-ray were elevated diaphragm in 20 cases(71%) find hemothorax in 18 cases (64%) and 25 cascs (89%) were diagnosed or suspected as diaphragmatic inju,rims prcopcrativcly. The repair of 28 cases were performed with thoracic approach in 20 cases, abdominal approach 7, thoracoabdominal approach in 1 cases. There were 5 death (18%) and all death related to the severity of associated injury. (hypovolcmic shock 3, combined head injury 1, renal failure 1).

• Journal of Chest Surgery
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• v.40 no.12
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• pp.831-836
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• 2007

Background: Cardiac injuries are the most commonly overlooked injuries in patients who die from trauma. Patients who survive blunt cardiac rupture or penetrating injuries are rare and the incidence is not well defined. Many patients require urgent or emergency operations and operative mortality is very high. Material and Method: A retrospective review of 26 patients with cardiac injuries due to thoracic trauma undergoing emergency thoracotomy from January 1997 to December 2005. Result: There were 17 male and 9 female patients, with a mean age of $45.3{\pm}16.2\;(range:\;17{\sim}80)$. Thirteen patients (50%) were injured in motor vehicle accidents, and five patients (19%) in motorcycle accidents. Six patients (23%) were injured by knives, and two patients (8%) were injured by falling. Anatomic injuries included right atrium (12 [46%]), left atrium (1 [4%]), right ventricle (5 [19%]), left ventricle (5 [19%]), and cardiac chambers (2 [7%]). Diagnosis was made by computer tomography in 12 patients and sonography in 14 patients. The average times from admission to operating room was $89.2{\pm}86.7\;min\;(range:\;10{\sim}335)$. The average time for diagnosis was $51.3{\pm}13.6\;min\;(range:\;5{\sim}280)$. The mean Revised Trauma Score (RTS) was $6.7{\pm}0.8$, and the Glasgow Coma Scale (GCS), was $12.8{\pm}2.8$. The overall mortality rate was 12% (3 out of 26 patients). Conclusion: The mortality rate from cardiac injury is very high. The survival rate can be increased only by a high index of suspicion, aggressive expeditious diagnostic evaluation, and prompt appropriate surgical management.

• Composites Research
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• v.35 no.6
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• pp.469-476
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• 2022

In this paper, the microwave absorbing characteristics after the impact of the radar-absorbing structure (RAS) consisting of periodic pattern sheet (PPS) and glass fiber-reinforced plastic (GFRP) were experimentally investigated. The fabricated RAS effectively absorbed the microwave in the X-band (8.2-12.4 GHz). In order to induce the damage to the RAS, a low-velocity impact test with various impact energy of 15, 40, and 60 J was conducted. Afterward, the impact damage was observed by using visual inspection, non-destructive test, and image processing method. Moreover, the absorbing performance of intact and damaged RAS was measured by the free-space measurement system. The experiment results revealed that the delamination damage from the impact energy of 15 J did not considerably affect the microwave absorbing performance of the RAS. However, fiber breakage and penetration damage with a relatively large damaged area were occuured when the impact energy was increased up to 40 J and 60 J, and these failures significantly degraded the microwave absorbing characteristics of the RAS.

• Journal of Chest Surgery
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• v.37 no.12
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• pp.999-1002
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• 2004

Thirteen year old boy who had been stabbed in his left chest by the knife was transferred to our department from a general hospital, because of the massive bleeding from the intercostal tube drainage. Chest X-ray showed homogeneous density in the left lung field. He was confused and his vital signs were unstable. He was moved into a operating room as soon as possible. After resuscitation, his lacerated left ventricle wound was sutured through median sternotomy. The interventricular shunt was detected with intraoperative transesophageal echocardiography. The traumatic ventricular septal defect was closed via left ventricle using Dacron patch. His postoperative course was uneventful, and he was discharged with small residual shunt.