• Journal of Korean Neurosurgical Society
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• 제51권2호
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• pp.75-80
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• 2012

Objective : To optimize the recanalization of acute cerebral stroke that were not effectively resolved by conventional intraarterial thrombolysis (IAT), we designed a double device technique to allow for rapid and effective reopening. In this article, we describe the feasibility and efficacy of this technique. Methods : From January 2008 to September 2009, twenty patients with acute cerebral arterial occlusion (middle cerebral artery : n=12; internal carotid artery terminus : n=5; basilar artery : n=3) were treated by the double device technique. This technique was applied when conventional thrombolytic methods using drug, microwires, microcatheters and balloons did not result in recanalization. In the double device technique, two devices are simultaneously placed at the lesion (for example, one microcatheter and one balloon or two microcatheters). Chemicomechanical or mechanicomechanical thrombolysis was performed simultaneously using various combinations of two devices. Recanalization rates, procedural time, complications, and clinical outcomes were analyzed. Results : The initial median National Institute of Health Stroke Scale (NIHSS) was 16 (range 5-26). The double device technique was applied after conventional IAT methods failed. Recanalization was achieved in 18 patients (90%). Among them, 55% (11 cases) were complete (thrombolysis in cerebral infarction 2B, 3). The median thrombolytic procedural time including the conventional technique was $135{\pm}83.7$ minutes (range 75-427). Major symptomatic hemorrhages (neurological deterioration ${\geq}4$ points in NIHSS) developed in two patients (10%). Good long term outcomes (modified Rankin Scale ${\leq}2$ at 90 days) occurred in 25% (n=5) of the cases. Mortality within 90 days developed in two cases (10%). Conclusion : The double device technique is a feasible and effective technical option for large vessel occlusion refractory to conventional thrombolysis.

• Journal of the Korean Society for Marine Environment & Energy
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• 제15권3호
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• pp.186-197
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• 2012

In order to understand hydrodynamic and water quality changes on the Saemangeum reservoir in accordance to inner development plan, intensive numerical simulations using EFDC have been done. Due to inner dike construction and proposed dredging plans, stratification might occur and yield flow field change. It should be noticed that very conditional gate operation schedule adjusting target water elevation of -1.5 meter causes severe stratification and hence plays an important role in poor water qualities. By using random walk particle tracking residence simulations, it is found that hydrodynamic characteristics depends greatly on riverine inflow conditions. It is also inferred that the northern part of the Mangyeong reservoir behaves as a dead zone and acts as major reasoning of water quality deterioration owing to benthic flux from long-term residing settled sediment.

• Journal of Korean Foot and Ankle Society
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• 제9권1호
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• pp.31-37
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• 2005

Purpose: To report our opinions of management about avascular necrosis following operative treatment of talar fracture and dislocation. Materials and Methods: We followed up 5 patients who were diagnosed as talar avascular necrosis after operation of talar fracture and dislocation. Clinical and radiological analysis were performed. The mean age of patients was 36 years. There were 4 males and 1 females. The average follow up was 51 months. Hawkins scoring system was used as clinical evaluation. Results: Regardless of radiological sclerotic finding, all patients showed satisfactory clinical result. Despite arthritic change in one patient, there were no further radiological and clinical deterioration to require salvage procedure. Conclusion: Most avascular necrosis after operative treatment of talar fracture and dislocation showed satisfactory result with conservative treatment. Thus, salvage operation such as talectomy or ankle fusion should be reserved in cases of intractable ankle pain and claudication.

• Journal of the Korean Recycled Construction Resources Institute
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• 제5권4호
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• pp.488-495
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• 2017

In this study, we conducted the kinetic hydration modeling of OPC and the final product according to the substitution ratio of GGBS by using the geochemical code, GEMS, in order to calculate the thermodynamic equilibrium. The thermodynamic data was used by GEMS's 3rd party database, Cemdata18, and the cement hydration model, the Parrot & Killoh model was applied to simulate the hydration process. In OPC modeling, ion concentration of pore solution and hydration products by mass and volume were observed according to time. In the GGBS modeling, as the substitution rate increases, the amount of C-S-H, which contributes the long-term strength, increases, but the amount of Portlandite decreases, which leads to carbonation and steel corrosion. Therefore, it is necessary to establish prevention of some deterioration.

• Childhood Kidney Diseases
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• 제15권2호
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• pp.179-183
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• 2011

Abrupt progression of renal scarring associated with vesicoureteral reflux (VUR) is rare in males over 2 years old of age. We report a 5 year old boy with sustained unilateral high grade VUR who experienced abrupt progression of renal scarring; he had a relative renal radionuclide uptake of 38% at 2 years of age that dropped to 8% after three years. Per his parent's wishes, he took prophylactic antibiotics for 25 months after his first febrile urinary tract infection (UTI) at 4 months old without surgical management. One episode of recurrent breakthrough infection occurred at the age of 2 years. This observation reminds us that a recommending surgical management for sustained high grade VUR associated with renal scarring might be needed. Close follow up of DMSA for renal scanning, and long term follow up of patients after the first febrile UTI are important.

• Asia-Pacific Journal of Business
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• 제9권2호
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• pp.105-121
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• 2018

In 1995, the WTO started to ease the trade barriers. Globalization has accelerated. The opening of the agricultural products market is rapidly gaining momentum with the conclusion of an FTA. The acceleration of this FTA is expected to be a threat to Korea's agriculture, and a new strategy is needed. At the beginning of the nuclear accident, mainly radioactive materials are found in the surface layer of the soil. Over time, the concentration of the plant gradually increases. After 5 years, it becomes noticeable. In March 2016, it will be five years after the nuclear accident. Radioactive contamination is very likely to occur in agricultural products produced in the Fukushima area at this time. In this period, agricultural products produced in the Fukushima region are expected to generate supply disruptions in Japan, and imports to replace them will increase. Therefore, it is necessary to establish a mid- and long-term strategy for exporting to Japan by analyzing the competitiveness of Korean agricultural products. In this study, standardization index was derived by using agricultural price ratio, TSI, export CAC. Based on this, we analyzed the competitiveness of each item in the Japanese market. The analysis shows that garlic is the most competitive product in the Japanese market. Also, strawberry, tomato, and cucumber were found to be competitive. On the other hand, Kiwi, pineapple, soybean, onion, potato, etc. As a result of the analysis, the following strategies were proposed for the export of agricultural products with high competitiveness. First, it is necessary to develop technology to suppress deterioration of export transportation quality. Second, continuous supply of local consumption pattern information is required. Third, it is necessary to expand exports by processing fresh food. Fourth, it suggested the establishment of export base and strengthening of support system.

• Proceedings of the Korean Institute of Building Construction Conference
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• 한국건축시공학회 2017년도 춘계 학술논문 발표대회
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• pp.238-239
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• 2017

Waterproofing is a very important process in terms of durability of buildings. The materials used for waterproofing work to protect the concrete structure from external deterioration factors. In particular, the waterproofing materials applied to the exterior of the concrete structure have various problems due to changes in the external environment and variables in the construction process. The waterproof layer is repeatedly dried and shrunk according to changes in the external moisture environment, and the surface may be deteriorated due to exposure to long-term sunlight. In the case of the roof waterproofing in the structure, the waterproof layer which does not have a sufficient curing period shows much swelling and floating phenomenon. These defects, such as swelling and lifting, account for most of the defects that occur in the waterproof layer of the concrete slabs. Generally, it is difficult to expect the same level of performance as the initial state even if the waterproofing work is repaired when a defect occurs. Therefore, it is possible to reduce the defects of the waterproof layer such as swelling and lifting by forming a waterproof layer which can be integrated with the concrete surface by using a polyurethane type waterproofing material having a relatively low defective ratio compared to other waterproofing materials. So in this study, the basic properties of polyurethane waterproof sheet reinforced with non-woven fabric are investigated in order to understand field applicability.

• International Journal of Highway Engineering
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• 제5권3호
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• pp.21-29
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• 2003

The management of existing airfield pavement information has currently become difficult and the maintenance cost has increased over time due to the long-term performance. It is needed to develop the method for effective budget allocation and systematic airfield pavement management services. The objectives of this paper are to introduce Micro PAVER, one of the popular pavement management systems, into our management system and customize Micro PAVER based on our environment and pavement management level. This study focused on the analysis on logics and structures of Micro PAVER and customization of important parts in the program using the existing pavement evaluation data and survey method. Customized items selected in this study included the pavement deterioration prediction models, critical PCI, maintenance cost by PCI, maintenance or rehabilitation method and unit cost, and PCI rank.

• Journal of Korean Society on Water Environment
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• 제26권1호
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• pp.61-70
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• 2010

The increase of impervious cover (IC) in a watershed is known as an important factor causing alteration of water cycle, deterioration of water quality and biological communities of urban streams. The study objective was to assess the impact of IC changes on the surface runoff characteristics of Kap Stream basin located in Geum river basin (Korea) using the Storm Water Management Model (SWMM). SWMM was calibrated and verified using the flow data observed at outlet of the watershed with 8 days interval in 2007 and 2008. According to the analysis of Landsat satellite imagery data every 5 years from 1975 to 2000, the IC of the watershed has linearly increased from 4.9% to 10.5% during last 25 years. The validated model was applied to simulate the runoff flow rates from the watershed with different IC rates every five years using the climate forcing data of 2007 and 2008. The simulation results indicated that the increase of IC area in the watershed has resulted in the increase of peak runoff and reduction of travel time during flood events. The flood flow ($Q_{95}$) and normal flow ($Q_{180}$) rates of Kap Stream increased with the IC rate. However, the low flow ($Q_{275}$) and drought flow ($Q_{355}$) rates showed no significant difference. Thus the subsurface flow simulation algorithm of the model needs to be revisited for better assessment of the impact of impervious cover on the long-term runoff process.

• Journal of the Korea institute for structural maintenance and inspection
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• 제18권3호
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• pp.153-159
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• 2014

This research reviewed the joint and duration characteristics depending on the surface treatment condition and lap spliced length in the PET film jointing method using the high hardness liquid material. As a result, the corona discharge treatment was improved to the contact angle, joint tensile strength, and joint peel resistance compared to non-treatment. Particularly, a surface treatment E (Corona discharge + Primer + PU bond + Polyester fabric) turned out to the best, and especially when the lap spliced length is longer than 15mm, stable joint performance was secured under the long term deterioration treatment of 16 weeks. Thus, the joint is considered to be applicable as the water-proof material.