• Journal of Korea Water Resources Association
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• v.54 no.6
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• pp.443-452
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• 2021

The authors obtained the discrete hedging rule for a reservoir's water supply operation by applying mixed-integer programming to save more water by earlier rationing of water supply for a drought period. The 'water supply adjustment guide' is the current operational method applied to the multipurpose reservoirs, and it was derived by a simulation method. Applying the two rules to the Hapcheon multipurpose dam's reservoir simulations with the inflow record from 2003 to 2018, the water supply deficit occurred for the long drought from 2015 to 2018. Especially, the no water supply or intermittent water supply persisted for the second half of 2017. The water supply adjustment guide had the 'normal water supply recovery threshold on storage,' which resulted in the water supply being unavailable in July 2017; then, the water supply suspension occurred until January 2018, when the reservoir storage was greater than the normal water supply recovery threshold. Despite the storage increasing due to the inflow of water into the reservoir, the suspension occurrence needs to be improved in practice. The current water supply adjustment guide and the discrete hedging rule for a reservoir's water supply operation are useful and realistic as the reservoir operation guide, which shows the concept of reducing water supply during the drought phase as scientific figures. However, to improve the reservoir simulation results, which do not provide any or intermittent water for several months, it is necessary to increase the current water supply reduction for drought phases.

• Journal of Korean Neurosurgical Society
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• v.30 no.6
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• pp.705-710
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• 2001

Objective : Postoperative seizure is a well documented complication of aneurysm surgery. The purpose of the present study was to analyze risk factors for postoperative seizure. Methods : Between January 1990 and December 1996, we performed craniotomy for ruptured cerebral aneurysms in 321 patients. Among them 206 patients who could be followed up for more than 1 year(range, 1 to 4.6 years) were enrolled to present study. All patients were treated with anticonvulsants for 3 to 18 months postoperatively. We analyze the incidence of postoperative seizure in different sex and age groups, and risk factors associated with postoperative seizures following aneurysm rupture. For statistical processing chi-square test and Fisher's exact test were used. Results : In the follow-up period of 1 to 4.6 years(mean, 1.8 years) postoperative seizure appeared in 18 out of 206 patients(8.7%). Mean latency between the operation and the first seizure was 6 months(range, 3 weeks to 18 months). The age of the patients has significant influence on the risk of seizure, it occurred more often in younger patients(p =0.0014). Aneurysm location in the MCA was associated with a significantly a higher risk of seizure(p = 0.042). Eight patients(19%) out of 42 patients who suffered delayed ischemic neurologic deficit(DID) developed seizure. Delayed ischemic neurologic deficit was associated with significantly a higher risk of seizure(p =0.019). Infarct and hypertension were associated with significantly a higher risk of seizure(p <0.05). pre- or postoperative intracranial hematoma(intracerebral or epidural hematoma) was associated with significantly a higher risk of seizure(p <0.0001). H-H grade, Fisher grade, Glasgow Outcome Scale of patients and timing of operation after subarachnoid hemorrhage had no significant relation with the risk of seizure. Conclusion : Factors associated with the development of postoperative seizure were middle cerebral artery aneurysm, delayed ischemic neurologic deficit, infarct on late postoperative CT scan, hypertension, pre or postoperative intracranial hematoma(intracerebral or epidural hematoma). Identification of the risk factors may be help to focus the antiepileptic drug threapy in cases prone to develop seizures. Prospective evaluation is indicated.

• Journal of Korean Neurosurgical Society
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• v.30 no.4
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• pp.463-471
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• 2001

Objective : The authors reviewed 51 patients of spinal cord tumor located at the craniovertebral junction and high cervical area to determine which factors influenced resectability, complications, and postoperative outcomes. Methods : Radiological examinations, clinical data, and operation notes were evaluated, and additional follow-up information was obtained from outpatient examinations. The mean follow-up period was 3.5 years Results : The most common neurological findings were motor deficit(72.5%) and sensory change(47.1%). There was no clinical finding that is considered as pathognomic. Meningioma(18 cases, 35.3%) was the most common tumor in this region. Total removal was achieved in 45 patients. There was no surgical mortality. Immediate postoperative motor weakness were encounted in 11 cases(21.6%) which improved in long term followup except two patients. Conclusions : The location and relationship of the tumor to surrounding struncture determine its resectability. Postoperative results were related to the preoperative neurological status and pathological findings.

• Journal of Korean Neurosurgical Society
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• v.49 no.5
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• pp.287-289
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• 2011

Thalamoperforating artery aneurysms are rarely reported in the literature. We report an extremely rare case of ruptured distal anterior thalamoperforating artery aneurysm which was treated by endovascular obliteration in a patient with occlusion of both the internal carotid arteries (ICAs) : A 72-year-old woman presented with severe headache and loss of consciousness. Initial level of consciousness at the time of admission was drowsy and the Glasgow Coma Scale score was 14. Brain computed tomography (CT) scan was performed which revealed intracerebral hemorrhage in right basal ganglia, subarachnoid hemorrhage, and intraventricular hemorrhage. The location of the aneurysm was identified as within the globus pallidus on CT angiogram. Conventional cerebral angiogram demonstrated occlusion of both the ICAs just distal to the fetal type of posterior communicating artery and the aneurysm was arising from right anterior thalamoperforating artery (ATPA). A microcatheter was navigated into ATPA and the ATPA proximal to aneurysm was embolized with 20% glue. Post-procedural ICA angiogram demonstrated no contrast filling of the aneurysm sac. The patient was discharged without any neurologic deficit. Endovascular treatment of ATPA aneurysm is probably a more feasible and safe treatment modality than surgical clipping because of the deep seated location of aneurysm and the possibility of brain retraction injury during surgical operation.

• Journal of Korean Neurosurgical Society
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• v.46 no.4
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• pp.413-416
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• 2009

Since the start of the antibiotic era, syphilis has become rare. However, in recent times, it has tended to be prevalent concomitantly with human immunodeficiency virus (HIV) infection and coinfection in North America and Europe. Now, such cases are expected to increase in elsewhere including Korea. A 40-year-old male patient visited hospital complaining of a headache for about one month. Brain computed tomography and magnetic resonance imaging, showed leptomeninged enhancing mass with edema an right porisylvian region, which was suspected to be glioma. Patient underwent a blood test and was diagnosed with syphilis and acquired immune deficiency syndrome. Partial cortical and subcortical resection were performed after small craniotomy. The dura was thick, adhered to the brain cortex, and was accompanied by hyperemic change of the cortex. The pathologic diagnosis was meningovascular syphilis (MS) in HIV infection. After the operation, the patient was treated with aqueous penicillin G. Thereafter, he had no neurological deficit except intermittent headache. At first, this case was suspected to be glioma, but it was eventually diagnosed as MS in HIV coinfection. At this point the case was judged to be worth reporting.

• Journal of Korean Foot and Ankle Society
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• v.7 no.1
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• pp.78-82
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• 2003

Purpose: The purpose of the study is to evaluate the clinical outcomes of acute achilles tendon rupture patients treated by early mobilization after operative repair. Materials and Methods: In this retrospective study, 12 patients of acute Achilles tendon rupture were surgically treated from May 2001 to November 2002, with follow-up period of at least 6 months. There were 10 men and 2 women, and mean age was 35.9 year. The repair method was single Krackow suture technique. Two to three weeks after the operation, early ROM with removable ankle-foot orthosis(AFO) was started. We used Amer-Lindholm scale for the clinical evaluation and analyzed patient's satisfaction and subjective strength deficit. Results: We had 11 excellent results(92%), and 1 good results(8%). One-leg heel raising was possible in all patients. All the patients returned to the preinjury occupations and 7 patients(58%) reached the preoperative level of sports activities. There was no significant difference in ankle ROM and ankle plantar flexion isokinetic strength compared to contralateral side. There was, no reruptures. Conclusion: Early mobilization proved to be a well tolerated, safe, and effective means for the compliant patient.

• Journal of Environmental Science International
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• v.14 no.6
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• pp.533-542
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• 2005

In this study, an optimization technique was developed from the application of Allocation Rule. Average Allocation coefficients of the Andong and Imha dam compare constant water supply condition with vary water supply condition that are above the contribute ratio $67\%\~50\%$ the Andong dam in Rule(A)-Rule(C). In the Refill Season, Andong dam water supply contribution is higher than Imha dam at the Control point water supply. In the Allocation analysis results, Rule(A) is calculated storage ratio because Andong dam contribute to Control point larger than Imha dam which Andong dam storage is larger than Imha dam storage. Rule(B) calculated sum of the storage and inflow ratio for Andong dam and Imha dam, as Andong dam contribution is higher than Imha dam. Rule(C) calculated that sum of storage, inflow and water supply is divided average storage ratio, as the best results of the Allocation coefficients and water supply capacity. The results of storage analysis is larger vary water supply condition than constant water supply condition and the results of water supply analysis is larger vary water supply condition than constant water supply condition. Water supply deficit is decrease $30\%$ for vary water supply condition.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.2
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• pp.251-255
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• 2009

Foreign and domestic seawater desalination plant market investigation was performed to analyze the worldwide trend of seawater desalination plant market and to establish the activation plan for seawater desalination plant application. Water demand and seawater desalination related laws and regulations were investigated and analyzed for the activation plan. RO type and large scale plants are popular nowadays however there are only small plants in island region in Korea. There will be about $1 million\;m^3/day$ deficit in 2015 according to the water demand forecasting from Ministry of Environment and Ministry of Land, Transportation, and Maritime Affairs in Korea. Therefore, it is necessary to activate the domestic application of seawater desalination plant to secure stable water resources. To activate the domestic application of seawater desalination plant, first, we need to establish regulations, support system in the water service law for seawater desalination plant. Second, related Ministry should increase the support for the operation and management of seawater desalination plant and suggest the construction of seawater desalination plant for water resources security near seaside region.

• Journal of Chest Surgery
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• v.52 no.1
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• pp.58-60
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• 2019

Herein, we report a case of lung transplantation in a patient with profound preoperative hypercapnia, focusing on the cardiopulmonary bypass strategy used for brain perfusion during the operation. We applied the pH-stat method for acid-base regulation, and thereby achieved the desired outcome without any neurologic deficit.

• Laboraroty Animal Research
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• v.33 no.3
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• pp.244-250
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• 2017

${\alpha}$-Synuclein is abundantly expressed in neuronal tissue, plays an essential role in the pathogenesis of neurodegenerative disorders, and exerts a neuroprotective effect against oxidative stress. Cerebral ischemia causes severe neurological disorders and neuronal dysfunction. In this study, we examined ${\alpha}$-synuclein expression in middle cerebral artery occlusion (MCAO)-induced cerebral ischemic injury and neuronal cells damaged by glutamate treatment. MCAO surgical operation was performed on male Sprague-Dawley rats, and brain samples were isolated 24 hours after MCAO. We confirmed neurological behavior deficit, infarction area, and histopathological changes following MCAO injury. A proteomic approach and Western blot analysis demonstrated a decrease in ${\alpha}$-synuclein in the cerebral cortices after MCAO injury. Moreover, glutamate treatment induced neuronal cell death and decreased ${\alpha}$-synuclein expression in a hippocampal-derived cell line in a dose-dependent manner. It is known that ${\alpha}$-synuclein regulates neuronal survival, and low levels of ${\alpha}$-synuclein expression result in cytotoxicity. Thus, these results suggest that cerebral ischemic injury leads to a reduction in ${\alpha}$-synuclein and consequently causes serious brain damage.