• Journal of Navigation and Port Research
• /
• v.35 no.9
• /
• pp.755-763
• /
• 2011

Recently, extreme tsunami waves generated by submarine earthquake have caused tremendous damages to the coastal cities and ports. Strong seiche oscillations and runups are observed in specific sea areas around the world. Although no frequent impacts to the coast of Korean peninsula, there exist some important events in the east of Korea in the past. This study focuses on two historical events and recalculate with different fault and rupture mechanism for prediction considering the recent trend of submarine earthquake. The present study of the 1983 Akita tsunamis demonstrates the multi-scale resonance along continental coasts. Together with the Nankai tsunami for inland sea, we have confirmed the inland sea resonance surrounded by islands in defining the impact along the coast. Coherence and wavelet analyses for deducing a predominant period and time frequency are useful in reasoning the inundation. The resonance modes, which are largely independent of the tsunami source, allow identification of at-risk communities and infrastructure for mitigation of tsunami hazards. Furthermore, understanding of the resonance and the predicted runups for the site of power plant and industrial complex in the east coast of Korea would allow better preparation for the future disasters.

• Earthquakes and Structures
• /
• v.12 no.3
• /
• pp.297-307
• /
• 2017

Evaluation on the sidesway seismic collapse capacity of the widely used low- and medium-height structures is meaningful. These structures with such type of collapse are recognized that behave as inelastic deteriorating single-degree-of-freedom (SDOF) systems. To incorporate the deteriorating effects, the hysteretic loop of the nonlinear SDOF structural model is represented by a tri-linear force-displacement relationship. The concept of collapse capacity spectra are adopted, where the incremental dynamic analysis is performed to check the collapse point and a normalized ground motion intensity measure corresponding to the collapse point is used to define the collapse capacity. With a large amount of earthquake ground motions, a systematic parameter study, i.e., the influences of various ground motion parameters (site condition, magnitude, distance to rupture, and near-fault effect) as well as various structural parameters (damping, ductility, degrading stiffness, pinching behavior, accumulated damage, unloading stiffness, and P-delta effect) on the structural collapse capacity has been performed. The analytical formulas for the collapse capacity spectra considering above influences have been presented so as to quickly predict the structural collapse capacities.

• Korean Journal of Head & Neck Oncology
• /
• v.23 no.1
• /
• pp.46-49
• /
• 2007

Soft tissue implantation of thyroid tissue is a very rare event. Needle tract implantation of thyroid carcinoma after fine-needle aspiration (FNA) biopsy has been occasionally reported, but implantation of benign thyroid tumor tissue is extremely rare. Rupture of thyroid tissues during surgery or trauma may cause the thyroid tissue to be implanted and result in multiple palpable nodules in soft tissue of the neck. Several reports have shown the possibility of implantation of normal or hyperplastic thyroid tissues in soft tissue. We herein report a case of implantation of adenomatous hyperplastic tissue in the neck along the trochar and previous operation site after endoscopic thyroid surgery, which was successfully treated by complete excision.

• Journal of Chest Surgery
• /
• v.17 no.1
• /
• pp.32-40
• /
• 1984

During the past six years from July 1977 to June 1983, fifteen adult patients of patent ductus arteriosus were surgically treated. The results were as follows: 1. Of the 15 patients, their age range was 17 to 34 years with a mean of 24 years, and sexual predominance was women [9. cf. 6 men]. 2. The most common symptom showed exertional dyspnea, and 10 patients were classed in NYHA class II, the rest were all class III. 3. On physical examination, all patients were auscultated continuous murmur, but concomitantly diastolic murmur was noted apical region in 2 patients. 4. On roentgenogram of chest, normal finding was 3 patients, and the other patients were revealed the evidence of pulmonary congestion. 5. The electrocardiogram was normal in 6 patients, but LVH was seen in 5, and 2 patients were LVH+ LAH. 6. Cardiac catheterization was performed in 12, and mean value of SO2[LPA-RV] was 6.3%, Q/Q 2.09, peak systolic pulmonary arterial pressure 45.3 mmHg, and Rp/Rs 0.365. 7. All operations were carried out by posterolateral thoracotomy. In 6 patients, division and suture of ductus were possible, the other patients were treated by division and ligation with heavy silk or Dacron patch. 8. Postoperative complications were hoarseness, persistent murmur, reoperation for bleeding, and atelectasis. Early and late mortality was 20% [3 patients], and cause of death was mainly aneurysmal rupture of previous operative site.

• Journal of the Korean Institute of Gas
• /
• v.11 no.1 s.34
• /
• pp.13-17
• /
• 2007

It is very insecure to treat a butane can for cooking out of door. The human injury from the accidents of butane cans has been getting increased 1.5 times yearly since 2003. In this context, the Institute of Gas Technology Training in Korea Gas Safety Corporation carries out explosion experiment to make trainees to take all possible measures to ensure safe management of gas in the field by fully recognizing the hazards of gas explosion accidents. This study intends to examine the influence of such explosion experiments on the trainees witnessing nearby. The GEN exposed to the active students participating in the experiment away from 25 meters from the explosion site was 57.94 dB and the GEN to the passive students not participating away from 50 meters was 51.92 dB. According to Weber-Fechner's law for the lower value than 65 dB which is the environmental standard, it is safe from the place 15 meter far from the explosion place. The environmental standard of offices is 50 dB, and it is lower than the environmental standard if the office is 65 meter far from the explosion place.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.6 no.3
• /
• pp.129-138
• /
• 2002

The purpose of this study is to propose the nonlinear analysis method which combines the nonlinear incremental method with the layered method to solve the problems due to the geometric and the material nonlinearities. As numerical analysis models, the reinforced concrete simple beam and the steel arch frame are used to verify the algorithm of the proposed nonlinear method. The results are gotten from the computation procedures. According to the results of this study, the fracture pattern of the beam according to the ratio of tensile steel and the strength of the concrete and the steel can be estimated by the proposed method. Therefore, the load-deflection curve of structure can be, exactly, depicted by the proposed method. Also, the rupture load, the site and the depth of crack of the beam can analytically be checked by the proposed method. In this respect, the proposed method contributes for the solving the stability problem of the actual structure.

• Journal of Korean Neurosurgical Society
• /
• v.48 no.6
• /
• pp.528-531
• /
• 2010

Ehlers-Danlos syndrome (EDS) type IV is characterized by its clinical manifestations, which are easy bruising, thin skin with visible veins, and rupture of arteries, uterus, or intestines. Arterial complications are the leading cause of death in vascular EDS because they are unpredictable and surgical repair is difficult due to tissue fragility. The authors report a case presented with cervical radiculopathy due to a segmental fusiform aneurysm of the cervical vertebral artery. Transfemoral cerebral angiography (TFCA) was done to verify the aneurysmal dilatation. However, during TFCA, bleeding at the puncture site was not controlled, skin and underlying muscle was disrupted and profound bleeding occurred during manual compression after femoral catheter removal. Accordingly, surgical repair of the injured femoral artery was performed. At this time it was possible to diagnose it as an EDS with fusiform aneurysm on cervical vertebral artery. Particularly, cervical fusiform aneurysm is rare condition, and therefore, connective tissue disorder must be considered in such cases. If connective tissue disorder is suspected, the authors suggest that a noninvasive imaging modality, such as, high quality computed tomography angiography, be used to evaluate the vascular lesion to avoid potential arterial complications.

• Journal of Chest Surgery
• /
• v.29 no.11
• /
• pp.1207-1211
• /
• 1996

During the recent 10 years, ten patients with ruptured sinus of Valsalva were operated on our institute. Eight patients were congenital but two patients were proved acquired lesions due to bacterial endocarditis. Coexistent cardiac lesions were 4 aortic regurgitations, 2 atrial septal defects, 1 ventricular septal defect, 1 tricuspid regurgitation and 1 mitral regurgitation. In all cases, aneurysms of sinus of Valsalva arose from the right coronary sinus, and they ruptured to right ventricle in 8 patients and to right atrium in 2 patients. We preferred double approach, through both the aorta and the involver. cardiac chamber, The repair of ruptured site was performed Dacron patch graft in 8 patients and simple closure in 2 patients. Operative results were very good in all cases with no surgical mortality.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2006.03a
• /
• pp.70-77
• /
• 2006

Stress drops of Brune's single-corner ${\omega}^2$ source model were estimated for the earthquakes (2.0$M3.5{\sim}4.0$ and increase up to $M4.5{\sim}5.0$ above which the level of the stress drop could be assumed to be flat or decrease according to whether the rupture process accompanies buried fault or surface rupturing. The converted data of corner frequency and seismic moment were nicely fitted to the relation of $M_0{\propto}f^3$ but show systematically higher corner frequencies for $M_0>10^15$ Nm. This relationship enables systematic evaluation of a scaling relation between magnitude and stress drop. The inverted level of the stress drop is comparable to the recent studies conducted domestic and abroad. A result of lower stress drop estimated by Jun(1991) is supposed to be due to the use of low frequency spectra and existence of two-comer source model around the Korean Peninsula.

• Earthquakes and Structures
• /
• v.20 no.1
• /
• pp.87-96
• /
• 2021

Ground motions recorded in near-fault sites, where the rupture propagates toward the site, are significantly different from those observed in far-fault regions. In this research, finite element modeling is used to investigate the effect of pile cap stiffness on the seismic response of soil-pile-structure systems under near-fault ground motions. The Von Wolffersdorff hypoplastic model with the intergranular strain concept is applied for modeling of granular soil (sand) and the behavior of structure is considered to be non-linear. Eight fault-normal near-field ground motion records, recorded on rock, are applied to the model. The numerical method developed is verified by comparing the results with an experimental test (shaking table test) for a soil-pile-structure system. The results, obtained from finite element modeling under near-fault ground motions, show that when the value of cap stiffness increases, the drift ratio of the structure decreases, whereas the pile relative displacement increases. Also, the residual deformations in the piles are due to the non-linear behavior of soil around the piles.