• Journal of the Korean Institute of Gas
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• v.3 no.3 s.8
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• pp.45-50
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• 1999

The LPG refueling station's explosion at Bucheon city was a major accident which with rare frequency of occurrence and large damage effect. Therefore, to prevent similar accident in the future from LPG charging stations which located in urban area. It needs to identify the damage effects of such facilities by comparing theoretically quantities risk and actual damage. The BLEVE effects from the accident showed similar damage effect in case of heat flux, however, the overpressure level reflected at the reduced distance by $15\%$. The structure damage to the near by area showed comparatively large heat radiation damage to the concrete structure strength and shape changes through heat flux while the overpressure effect was small.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.251-251
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• 2018

도로설계기준(2012)에 따르면 노면 배수시설은 측구, 집수정, 배수관, 배수구(빗물받이, 맨홀) 등으로 구성되며 중앙분리대 배수에서 구조가 방호벽일 경우 원칙적으로 집수정과 종배수관, 횡배수관을 설치하여 노면수를 배수한다. 최근 기후변화에 따른 국지성 집중호우로 교량 배수시설의 배수능력 부족으로 교량의 노후화, 노면의 체수와 수막현상을 야기한다. 교량 설계 시, 교량의 외관은 점배수에 의한 배수불량으로 막힘부에서의 식물생육, 부식, 배수구의 오염 등으로 심미성에 악영향을 미치고 있다. 따라서 국토교통부 도로 배수시설 설계 및 관리지침에서는 기존의 집수정으로 유도하여 배수하는 점배수 형태에서 우수의 지체시간을 저감하기 위해 배수구로 즉시 배수되어 배수 효율을 증가시켜주는 선배수시설을 권장하고 있다. 그러나 선배수 구조의 일반적인 내용만을 기술하고 있으므로 보다 상세한 설계기준이 필요하다. 또한 국내에서는 교면 배수를 위한 횡배수구의 배수능력에 관한 설계 개념은 미국의 빗물받이 설계 개념을 그대로 적용하고 있어서 교량 배수시설의 배수능력 증대를 위한 수치 및 수리실험에 관한 기술적인 자료가 부족한 실정이다. 따라서 도로의 흐름해석 및 선배수를 위한 측구 횡배수관의 흐름개선에 관한 구체적인 연구가 필요한 실정이다. 본 연구에서는 배수로 전반의 유향 분석 및 횡유입관 유입부에서의 상세한 흐름해석과 통수능력을 분석하기 위해서는 수리실험을 통한 연구가 필요한 실정이다. 그러나 최적 횡배수관의 형상 및 간격 설정에 대한 수리실험의 물리적 및 시간적 한계를 극복하기 위해 Fluent 모형(Ansys Workbench 13.0)을 활용한 수치모의를 수행하여 모형의 적용성을 검토하였다. 다상유동 해석을 위해 VOF(Volume of Fluid)방법을 적용하였고, 수치해석 방법으로는 비정상류, 난류 모형으로는 standard ${\kappa}-{\varepsilon}$모형을 적용했다. 도로 형상에 따른 우수유출량을 비교 분석하기 위하여 횡경사는 2%로 고정하고 종경사를 2%로 선정하여 수치모의를 통한 배수능력을 분석하고 설계에 직접적인 적용성을 검토하였다. 횡배수관의 간격변화 및 배수공의 위치 변화 등에 따른 차집량을 분석하였으며, 개략적인 수리실험 결과와 수치모의의 차집율을 비교 및 분석하여 Fluent 모형의 적용성을 확인하였다. 또한, 횡배수관의 유입부에서의 유속 변화 및 유출부에서의 유속이 모의가 가능하므로 배수시설에서 보다 정확한 흐름 해석이 가능하여 보다 적정한 배수능력 분석이 가능할 것으로 판단된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.360-360
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• 2016

도시 배수 시스템에서 유입유량이 관거의 만관 상태를 초과하거나 하류 흐름 때문에 발생하는 역류의 영향을 받는다면, 관거 시설은 과부하(surcharge) 상태인 압력흐름이 된다. 중력흐름 상태에서 맨홀의 수두 손실은 일반적으로 무시되지만, 과부하 맨홀에서의 수두 손실은 중요하며, 우수 관거 시스템의 전체 손실에 상당한 부분을 차지하게 된다. 이러한 현상은 여러 개의 맨홀을 가지는 도시 배수 시스템에서 특히 중요한 사항이 된다. 따라서 관거 시설 내 맨홀에서의 수리적 에너지 손실에 대한 연구와 보다 구체적인 설치 기준의 제시가 요구되고 있는 실정이다. 특히 배수관거 시스템의 하류부에 설치되는 4방향 합류맨홀은 맨홀으로 유입되는 주 유입관과 측면 유입관의 유입흐름의 영향으로 맨홀 내의 유수교란에 의한 흐름특성이 복잡하므로 이에 따른 흐름특성의 변화를 분석하고 에너지 손실을 연구할 필요가 있다. 그러므로 우수 관거 시스템의 우수 배제 능력을 증가시켜 도심지의 침수를 방지하기 위한 관거시설의 적정 설계 기준이 필요하며, 합리적인 설계 기준을 제시하기 위하여 과부하 4방향 합류 맨홀 내에서의 수두 손실을 분석할 필요가 있다. 본 연구에서는 수리모형 실험의 물질적, 시간적 한계를 극복하고 과부하 4방향 합류맨홀에서의 복잡한 흐름특성을 분석하기 위하여 일반적으로 3차원 유체거동의 특성분석에 많이 사용되는 FLUENT 6.3 모형을 선택하였다. 합류맨홀 및 접합 관거의 기하 모형의 격자망은 수치해석의 안정성 확보를 위하여 맨홀과 연결관의 합류부분에서는 사면체 격자로 구성하고 합류부분을 제외한 구간에서는 6면체 격자로 구성하였으며, 각 격자의 면은 가능한 사각형 또는 삼각형의 형태를 취하도록 하였다. 합류맨홀 모형의 벽면에는 No-Slip 경계조건을 부여하였으며, 유입부에는 속도 조건, 유출부와 맨홀의 자유수면 부분의 경계에서는 대기압 조건을 부여하였다. 수리모형 실험 결과와 비교하기 위하여 유입 관거의 유속 조건을 수리 모형실험의 조건과 동일하게 채택하여 수치모의를 수행하였다. 수치모형의 적용 결과 맨홀 내에서의 유속변화, 수심변화 및 압력변화에 대해서는 수리모형 실험 결과와 유사한 경향을 나타내고 있으며, 수치모형에 의하여 산정된 4방향 합류맨홀에서의 손실계수 값과 수리모형 실험에 의하여 산정된 손실계수 값이 유사하므로 우수 관거 시스템의 4방향 합류맨홀에서의 흐름 변화 및 손실계수 예측하는 데에 있어서 FLUENT 6.3 모형은 사용 가능하리라 판단된다.

• Journal of Korean Foot and Ankle Society
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• v.25 no.4
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• pp.171-176
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• 2021

Purpose: This study sought to compare needle fenestration with a corticosteroid injection for the treatment of chronic plantar fasciitis. We hypothesized that needle fenestration would be as effective as a corticosteroid injection while avoiding the potential adverse effects of the corticosteroid. Materials and Methods: Forty female patients with unilateral chronic plantar fasciitis who did not respond to a minimum of 6 months of various conservative treatments were prospectively randomized to receive either a corticosteroid injection or needle fenestration. Visual analogue scale and American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score were used for all patients before treatment and at 3-, 6-, and 12-month following treatment. Results: The corticosteroid injection group had a before-treatment average AOFAS Ankle-Hindfoot score of 56.4, which increased to 87.3 at 3 months and 78.2 at 6 months after treatment but decreased to 62.4 at 12 months. The needle fenestration group had a before treatment average AOFAS ankle-hindfoot score of 49.5, which increased to 77.8 at 3 months and 92.1 at 6 months after treatment and remained at a high score of 89.4 at 12 months. There were no complications in either group. Conclusion: In the treatment of chronic plantar fasciitis, needle fenestration is as effective at 3- and 6-month post-treatment as a corticosteroid injection. Also, unlike a corticosteroid, its effect remains until 12 months post-treatment.

• Journal of the Korea Convergence Society
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• v.10 no.2
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• pp.325-330
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• 2019

The purpose of this study was to verify the physical activity planning behavior theory model of rehabilitation center users. For this purpose, a questionnaire survey was conducted for sports athletes who visited the sports rehabilitation hospital and rehabilitation center in the metropolitan area. A total of 203 questionnaires were used for the actual analysis. The collected data were analyzed using SPSS 18.0 and AMOS 18.0. In this way, we confirmed that intention has a significant direct effect on the behavior in the application of the physical activity planning theoretical model based on the social cognitive theory of rehabilitation center participants.

• Journal of Korean Foot and Ankle Society
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• v.22 no.4
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• pp.151-155
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• 2018

Purpose: Toe ulcers have been implicated as a causative factor in diabetic foot amputation. The aim of this study was to evaluate the outcomes of percutaneous needle flexor tenotomies of diabetic claw toes with ulcers or pending ulcers. Materials and Methods: The authors undertook a retrospective chart review between January 2014 and June 2016 to identify those patients who underwent a percutaneous needle flexor tenotomy for diabetic claw toe deformities. We evaluated 54 toes in 42 patients. Twenty-four patients were female and the mean age at the time of operation was 57 years. The mean follow-up time was 11 months. Thirty-four patients (46 toes) had tip toe ulcers or pending ulcers and 8 patients (8 toes) had dorsal pending ulcers. All patients had palpable pulses and good capillary refill. Results: Forty-three of 46 tip toe ulcers (93.5%) healed without significant complications and 8 dorsal ulcers showed no specific changes within 5 weeks. There were no recurrent ulcers at final follow-up. Four patients developed transfer lesion of the adjacent toe and needed subsequent tenotomy. Conclusion: Percutaneous needle tenotomy in an outpatient clinic was an effective and safe method for treating toe ulcers in neuropathic patients to offload the tip of the toe so that ulcer healing could occur.

• Journal of The Korean Society of Emergency Medicine
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• v.29 no.5
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• pp.391-398
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• 2018

Objective: This study was conducted to analyze and compare the classifications of a prehospital triage system and an in-hospital triage system. Methods: The records of patients transferred from the '119' emergency service for 5 months (from January 1 to May 31, 2016) were collected and records of first aid activities were assessed. We examined cases classified as four (urgent, semi-urgent, potentially urgent, and non-urgent) of five stages, excluding death. In the hospital, data were collected from medical records and classifications made using the five Korean Triage and Acuity Scale (KTAS) stages (1, resuscitation; 2, emergency; 3, urgent; 4, less urgent; and 5, non-urgent) were analyzed. Results: The number of patients enrolled in the study was 3,457. Of them, 2,301 were discharged after treatment and 1,156 were hospitalized. According to the prehospital triage classification, 726 of the 3,457 cases were urgent, 593 were semi-urgent, 1,944 were potentially urgent, and 194 were non-urgent. The results of the in-hospital triage were as follows: 114 KTAS 1 (3.3%), 491 KTAS 2 (14.2%), 1,345 KTAS 3 (38.9%), 1,227 KTAS 4 (35.5%), and 280 KTAS 5 (8.1%). The odds ratio trend for hospitalization showed a larger decrease according to in-hospital staging (95% CI, 0.32-0.39) than according to prehospital staging (95% CI, 0.50-0.60). The odds ratio trend for intensive care unit (ICU) admission also showed a larger decrease according to in-hospital staging (95% CI, 0.16-0.22) than according to prehospital staging (95% CI, 0.37-0.48). Conclusion: We found little correspondence in classifications made according to the KTAS and prehospital triage systems. However, the tendencies toward decreases in the hospitalization and ICU admission rates were similar.

• Journal of the Korean Society of Radiology
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• v.14 no.7
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• pp.957-964
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• 2020

T2 FLAIR sequence of MRI in Acute Ischemic Stroke patients is meaningful to those who have the diagnosis of cerebral hemorrhage and neurological deficiency, including the detection of cerebral infarction around Cerebrospinal fluid. However, because of the long acquisition time and mutative motion artifacts caused by movement, It is difficult to take the MRI image acquisition for non-cooperative patients who need to apply a rapid image acquisition. In this study, we applied the EPI-FLAIR sequence, which is one of the fastest pulse sequences in use, which is a combination of EPI sequence and T2 FLAIR sequence, to patients with acute ischemic cerebral infarction. Based on the qualitative and quantitative evaluation results of the EPI-FLAIR and T2 FLAIR image, we will evaluate the diagnostic usefulness of the EPI-FLAIR sequence.

• Journal of Industrial Convergence
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• v.19 no.1
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• pp.129-135
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• 2021

The purpose of this study was to examine the relationship between college students' health perception, health beliefs, and health promotion behaviors. For data analysis, item analysis, factor analysis, and reliability analysis were conducted. In addition, correlation analysis and path analysis were conducted to understand the relationship between variables. As a result of the analysis, the following conclusions were obtained. As a result of conducting path analysis to verify the causal effect between college students' health perception, health beliefs, and health promotion behaviors, the model was relatively high in various fitness indices, and all path coefficients included in the model were statistically significant. Specifically, there were significant positive relationships in all pathway coefficients, but health perception and perceived disability, perceived disability and health promotion behavior were negatively related. In subsequent studies, it is considered necessary to analyze various variables related to health promotion behavior.

• Journal of radiological science and technology
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• v.44 no.6
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• pp.663-669
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• 2021

The purpose of this study was to evaluate the usefulness of the rice bolus for upper-lower extremity radiation therapy by Tomotherapy. The computed tomography images were obtained for air, water, and rice bolus. The average and standard deviation of the Hounsfield unit (HU) were measured for image evaluation. The conformity index (CI) and homogeneity index (HI) were calculated for dose distribution of the planning target volume (PTV) which was treated by direct mode with gantry angle (90 and 270 angle). The point dose of a total of ten axial planes was measured to confirm the different regions. The mean of HU was -999.72 ± 0.72 at the air. The water and rice bolus were -0.13 ± 1.65 and -170 ± 27.2, respectively. The CI (HI) of PTV was 0.96 (1.36) at the air. 0.95 (1.04) at the water bolus, and 0.95 (1.04) at the rice bolus. The maximum dose for air was 136 cGy which is about 32% higher than 103 cGy for water and 104 cGy for rice bolus. There was a statistical difference for point dose between air and water including rice bolus (p=0.04), however, no statistical difference between water and rice bolus (p=0.579).The rice bolus phantom for extremities radiation therapy could be not only the optimized dose distribution but also the convenience and equipment safety at Tomotherapy. However, additional research will be necessary to more accurately verify the clinical usefulness of rice bolus phantom due to not enough examination.