• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.4
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• pp.26-37
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• 2020

This study intends to present a fragility analysis method suitable for concrete cable-stayed bridges by performing an analysis reflecting design criteria and material characteristics from the results of inelastic time-history analysis. In order to obtain the fragility curve of the cable-stayed bridge, the limit state of the main component of the cable-stayed bridge is determined, and the damage state is classified by comparing it with the response value based on inelastic time history analysis. The seismic fragility curve of the cable-stayed bridge was made by obtaining the probability of damage to PGA that the dynamic response of the vulnerable parts to input ground motion would exceed the limit state of each structural member. According to the pylon's fragility curve, the probability of moderate damage at 0.5g is 32% for the longitudinal direction, while 7% for the transversal direction, indicating that the probability of damage in the longitudinal direction is higher in the same PGA than in the transversal direction. The seismic fragility curve of the connections showed a very high probability of damage, meaning that damage to the connections caused by earthquakes is very sensitive compared to damage to the pylon and cables. The cable's seismic fragility curve also showed that the probability of complete damage state after moderate damage state gradually decreased, resulting in less than 30% probability of complete damage at 2.0g.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.5
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• pp.179-186
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• 2010

When a structure is damaged, its dynamic responses (natural frequency, acceleration, strain) are found to be changed. The ANN(Artificial Neural Network) damage-assesment method is that some measured dynamic signals from the structural changing dynamic responses are applied to ANN to assess the structural damage. Although there have been some studies on a certain typical cases so far, it is rare to find studies about the characteristics of the ANN damage-assesment method or about its applicability, its strength and weakness. So this study researches on the characteristics of ANN damage assesment method and on a problem in application of the various dynamic responses to ANN. What the ANN damage assessment method usually does in past researches is to teach an ANN by using some response signals obtained from damaged structures under one kind of excitations and to identify the locations and the extents of damage of same structures under the same excitations. However, the excitations inflicted on the structures are not always the same. Thus this study experiments whether a ANN which is trained using the same excitations is able to identify the damage when different excitations inflict. All response signals are obtained from experimental models.

• Journal of Life Science
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• v.19 no.7
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• pp.878-885
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• 2009

Serum ferritin levels are elevated in subjects with acute lung injury (ALI), and abnormalities in plasma and lung iron chemistry have also been demonstrated in ALI and acute respiratory distress syndrome (ARDS). Stress-inducible heme oxygenase-1 (HO-1), as well as ferritin, had shown anti-inflammatory actions. Biomarkers for early detection in patients who are likely to develop ARDS would give several therapeutic chances to the patients. In order to verify the predictability in severe hemorrhage-induced ALI in rats, we measured serum ferritin and HO-1 concentrations before and after hemorrhage. Severe hemorrhages significantly increased the number of leukocytes in bronchoalveolar lavage (BAL) fluid and lung tissue myeloperoxidase activity. Both serum ferritin and HO-1 levels increased following hemorrhage, but ferritin levels were elevated earlier than HO-1. In BAL cell immunohistochemical studies, ferritin and HO-1 expressions increased after hemorrhage and localized in the cytoplasm of leukocytes. These findings suggest that inflammatory leukocytes in BAL fluid can secrete ferritin and HO-1, and serum ferritin levels might be more valid factor in predicting ARDS than HO-1 levels in hemorrhage-induced ALI.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.6
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• pp.148-156
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• 2022

Although most domestic concrete structures are simultaneously exposed to freeze-thaw and chloride environments, concrete durability in the field is evaluated by each single action, and the evaluation of chloride-caused damage of concrete requires additional indoor experimental analysis of chloride contents by coring samples from structures in the field. However, in Korea, policies to strengthen facility maintenance, such as 「Special Act on the Safety Control and Maintenance of Establishments」 and 「Framework Act on Sustainable Infrastructure Management」, have been established and implemented since 2018 and facilities subject to safety inspection management by the government and local governments increases, the effective simplification technology for the inspection and diagnosis of concrete structure is needed. Therefore, this study attempted to evaluate the possibility of determining the acceleration chloride penetration of freeze-thaw damaged concrete by using the surface rebound value. For this purpose, concrete specimens already having freeze-thaw damage by exposure to the freeze-thaw acceleration environment were immersed in chloride water. After that, the acceleration relationship of chloride penetration according to freeze-thaw damage was analyzed using the amount of chloride contents in concrete.

• Journal of the Korean Society of Radiology
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• v.84 no.4
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• pp.809-823
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• 2023

Trauma is an injury to the body that involves multiple anatomical and pathophysiological changes caused by forces acting from outside the body. The number of patients with trauma is increasing as our society becomes more sophisticated. The importance and demand of traumatology are growing due to the development and spread of treatment and diagnostic technologies. In particular, damage to the large blood vessels of the chest can be life-threatening, and the sequelae are often severe; therefore, diagnostic and therapeutic methods are becoming increasingly important. Trauma to nonaortic vessels of the thorax and aorta results in varying degrees of physical damage depending on the mechanism of the accident and anatomical damage involved. The main damage is hemorrhage from non-aortic vessels of the thorax and aorta, accompanied by hemodynamic instability and coagulation disorders, which can be life-threatening. Immediate diagnosis and rapid therapeutic access can often improve the prognosis. The treatment of trauma can be surgical or interventional, depending on the patient's condition. Among them, interventional procedures are increasingly gaining popularity owing to their convenience, rapidity, and high therapeutic effectiveness, with increasing use in more trauma centers worldwide. Typical interventional procedures for patients with thoracic trauma include embolization for non-aortic injuries and thoracic endovascular aortic repair for aortic injuries. These procedures have many advantages over surgical treatments, such as fewer internal or surgical side effects, and can be performed more quickly than surgical procedures, contributing to improved outcomes for patients with trauma.

• Journal of Korean Orthopaedic Sports Medicine
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• v.4 no.1
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• pp.49-54
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• 2005

Purpose: Complete rupture of metacarpophalangeal ulnar collateral ligament of thumb needs surgical exploration and repair, owing to the interposition of the adductor aponeurosis (Stener lesion) which interferes in healing process. We performed arthroscopic diagnosis and treatment on ulnar collateral ligament injury of thumb and evaluated it's efficiency. Materials and Methods: Arthroscopy was perfomed on 13 patients of whom injured on complete ruture of metacarpophalangeal ulnar collateral ligament. Follow-up period was over 1 year and mean age was 35.6 years old. Ulnar collateral ligament tears and Stener lesion were diagnosed and treated by arthroscopy procedure. Results were interpreted by joint instability, pinch power, grip power and range of motion on metacarpophalangeal joint of thumb. Results: We found 5 Stener lesions in 13 cases. There was no appreciable postoperative instability. Pinch and grip power were recovered to 92%, 94% of uninjured thumb respectively. Range of motion on metacarpophalangeal joint was mean $52^{\circ}$, almost equal to uninjured thumb. Conclusions: Arthroscopic treatment in metacapophalangeal ulnar collateral ligament injury of thumb is useful method that Stener lesion can be clearly comfirmed and treated. Also soft tissue injuries can be minimized, thereby early functional recovery can be expected.

• Journal of Korean Orthopaedic Sports Medicine
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• v.1 no.1
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• pp.15-20
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• 2002

Purpose: The purpose of this study is to evaluate diagnosis and treatment of acetabular labral tears in sports injuries. Materials and Methods: From March 1995 to January 2000, We treated 15 patients with acetabular labral tear by sports injuries. There were 6 men and 9 women. Mean age was 41 years old. Running injuries are 5 cases, fighting 3, aerobic exercise 3, swimming 2, climbing 1, bicycle 1. For conservative treatment, we performed medication and observation at least for 1 year. For the patients with arthroscopic surgery, we performed Harris Hip Score (pain and function) preoperatively and postoperatively at 6, 12 months, and evaluated patient’s pain by JOA pain scoring system and postoperative subjective satisfaction. Results: The mean score of HHS improved 15 points with conservative treatments and 32 points with hip arthroscopy. In 4 cases of conservative treatment, there was 1 scale improvement of JOA pain scoring system. In arthroscopic partial labrectomy, all cases were improved to more than 2 scale. Conclusion: We considered that acetabular labral tears occurred associated with sports injuries. So it is important to be interested in enthusiastic diagnosis and appropriate treatment for hip pain caused by sports injuries, especially about acetabular labral tears.

• Korean Journal of Heritage: History & Science
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• v.44 no.3
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• pp.92-111
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• 2011

This study focus on the restoration stone selection of break-out part based on material characteristics analysis and the conservational safety diagnosis using various nondestructive techniques for Jungdong and Banjukdong Stone Auariums. As a result, the original rocks of the stone aquariums body are porphyritic granodiorite with magnetite-series having igneous lineation, microcline phenocryst, veinlet and basic xenolith. As a result of the provenance presumption of the host rock, a rock around Gamgokri area in Nonsan City was identified the genetically same rock. Therefore, the rock is appropriate for restoration materials of the break-out part. The deterioration assessment showed that the stone aquariums were highly serious scaling, scale off and blackening. Particularly, the front face of Banjukdong stone aquarium needs reinforcement of structural crack (760mm) caused from igneous lineation of biotite. Blackening contaminants on the stone aquariums surface occurred by combining iron oxide, manganese oxide and clay mineral. Also, major factors of efflorescence contaminants were identified as calcite (Jungdong stone aquariums) and gypsum (Banjukdong stone aquariums). The physical characteristics of stone aquariums appeared that the original and new stone is third (moderately weathered) and second grade (slightly weathered), respectively. This study sets up an integrated conservation system from material analysis to restoration stone selection and conservational safety diagnosis of Jungdong and Banjukdong stone aquariums.

• 전기의세계
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• v.46 no.8
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• pp.34-40
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• 1997

케이블 시스템의 사고는 예방 진단에 근거한 정확한 진단으로 피할 수 있으며, 잔여수명 예측 기술은 진단 방법의 체계적인 적용에 의해 향상될 수 있다. 따라서 본 고에서는 케이블 시스템 진단 방법의 체계적인 개발을 위해서 60 kV급 이상의 종이 절연 혹은 고분자 절연 전력 케이블과 그 접속 자재에 대해서만 진단 방법을 개략적으로 소개만하고 있으며 수트리에 관련된 열화, 절연체의 열화를 제외한 모든 열화현상과 DC 케이블에 대해서는 언급을 하지 않았다. 회전기 고체절연체의 열화에 의해 야기되는 변화는 회전기 진동을 발생 시키고, 진동은 기계에 심각한 손상을 발생시킨다. 회전기의 절연열화 진단은 유전손실, 유전율, 음향 등의 측정/분석으로 가능하고 적용 방법은 on-line/off-line으로 가능하다. 절연 시스템의 열화정도 판정은 회전기의 적절한 보수시기의 판단을 가능하게 하여 유지 보수비의 절감 및 회전기의 수명연장을 가능하게 할 것이다.

• Journal of Korean Society of Spine Surgery
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• v.25 no.4
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• pp.180-184
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• 2018

Study Design: Case report Objectives: To document fistula formation between the disc and dura by an unrecognized dural tear after percutaneous endoscopic lumbar discectomy (PELD). Summary of Literature Review: The risk of durotomy is relatively low with PELD, but cases of unrecognized durotomies have been reported. An effective diagnostic tool for such situations has not yet been identified. Materials and Methods: A patient twice underwent transforaminal PELD under the diagnosis of a herniated lumbar disc at L4-5. She still complained of intractable pain and motor weakness around the left lower extremity at 6 months postoperatively. Magnetic resonance imaging showed no specific findings suggestive of violation of the nerve root. However, L5 and S1 nerve root injury was noted on electromyography. An exploratory operation was planned to characterize damage to the neural structures. Results: In the exploration, a dural tear was found at the previous operative site, along with a fistula between the disc and dura was also found at the dural tear site. The durotomy site was located on the ventrolateral side of the dura and measured approximately 5 mm. The durotomy site was repaired with Nylon 5-0 and adhesive sealants. The patient's preoperative symptoms diminished considerably. Conclusions: Fistula formation between the disc and dura can be caused by an unrecognized dural tear after PELD. Discography is a reliable diagnostic tool for fistulas formed by an unrecognized durotomy.