• 대한토목학회논문집
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• 제37권5호
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• pp.815-825
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• 2017

야간 혹은 우천시에 노면표시의 시인성이 저하되어 교통안전에 위협을 초래하고 있는 가운데, 본 연구에서는 최근 소개된 차선도색 장비 성능개량에 따른 노면표시 수명 연장(1.5배), 생산성 향상(56.3%), 축광차선도료를 배합한 야광 노면표시의 시인성 개선(97.0%) 등 다양한 기대 편익과 종합적인 소요비용을 고려한 경제적 타당성을 제시하고자 하였다. 노면표시 시인성 개선에 따라 45.4%의 사고가 감소, 연간 2,463억원의 교통사고 절감편익이 발생하며, 재도색주기 증가에 따른 공사중 교통혼잡비용 절감 연간 123억원, 자율주행자동차 차선인식 성능 개선에 따른 장비 가격 절감으로 연간 453억원의 편익이 발생하여, 축광노면표시 도입에 따른 연간 총 편익은 3,039억원으로 산정되었다. 전국 도로 91,195km의 차로구분선, 중앙선 및 가장자리차선에 야광차선 도입시 총비용 증가분은 연간 1조 9,222억원으로 경제성(비용-편익비 0.16) 확보가 어려운 것으로 나타났다. 교통사고 잦은 곳의 지방부 분석 구간길이(400m)에 대한 도로유형별 차로수별 차선도색비용과 교통사고비용 원단위를 적용하여 축광 노면표시의 경제적 타당성이 확보되는 사고 규모를 산정한 결과, 노면표시가 직 간접적 원인인 사고로 유발된 사망자가 연간 1명 이상이거나, 부상자가 연간 2명 이상(단, 왕복 4차로 미만인 경우는 연간 1명 이상)인 경우 경제적 타당성이 확보되는 것으로 나타났다. 구체적으로, 관련 사고구간(5,697개)에 대한 야광 노면표시 설치비용을 사고감소편익과 비교한 결과, 충분한 경제성(비용-편익비 3.91)이 확보되었다. 연구의 한계와 향후 연구주제가 논문의 말미에 토의되었다.

• 국제물리치료학회지
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• 제9권4호
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• pp.1683-1686
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• 2018

Low back pain (LBP) is the most common reason for seeking physical therapy (PT) care. Recent studies suggest that axial loading can have a positive impact on the intervertebral disc by improving its tensile strength. Further, whole body vibration (WBV) appears to improve spinal muscle relaxation. Therefore, this case study describes the use of axial loading using a mini-trampoline in a female with chronic LBP. This case report is a single subject design. This patient is a 29-year-old female with a six-month history of low back pain following a motor vehicle accident. MRI found herniated discs at L4 and L5, clinical tests were positive for pain in the L4 and L5 dermatome and myotome the slump test was positive for neural tension, and LBP was constant at 4-6/10 over the past four months. She received axial loading exercises using a mini-trampoline and performed six sessions that were, scheduled twice a week for three weeks. Her Oswestry Disability Index (ODI) score improved from 40% at the time of her first visit to 22% at her final visit. Pain measure on the Numeric Pain Rating Scale (NPRS) after the first treatment was 7/10, and her pain after the final treatment was 0/10. These changes in the pain scores are clinically significant and exceed the minimal clinically important difference (MCID). This patient had a significant improvement in her pain using the NPRS and the ODI. This case study suggests that axial loading may be an effective treatment for some individuals with discogenic chronic low back pain.

• 한국정보통신학회논문지
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• 제23권10호
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• pp.1248-1253
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• 2019

재난 상황 시 대피 경로를 유도하기 위해 대부분의 건물 등의 구조물에서는 중앙통제센터나 안전요원의 안내 및 대피 경로 유도등을 통해 대피 경로를 안내하고 있다. 하지만 규모가 커지고 갈수록 내부 구조가 복잡해짐에 따라 비상 상황 시 안전을 보장할 수 있는 지능적 안내 시스템의 필요성이 증가하고 있다. 따라서 경로 탐색 알고리즘에 기반한 지능적 대피경로 탐색 및 안내 시스템이 제안되었고, 구조물 내 설치된 센서 노드로부터 수집된 상황 정보를 기반으로 중앙 서버에서 각 위치별 최적의 경로를 제시하는 방식으로 대피 유도가 이루어졌다. 그러나 대피자의 효과적인 대피와 함께 중요한 부분이 구조자의 효율적인 구조활동이다. 현재까지 대피자의 대피 경로 유도에 대한 연구는 다양하게 이루어져왔으나, 구조자의 효율적 진입 경로 탐색에 대한 연구는 전무하였다. 따라서 본 논문에서는 센서 네트워크 환경에서 유전 알고리즘을 적용한 구조자 진입 경로 탐색 방안에 대해 제안하였다. 제안된 방식의 실효성을 검증하기 위해 컴퓨터 시뮬레이션을 통해 제안된 방식의 성능을 검증하였고, 그 결과 작업량 기준의 적응도 평가 시 적응도가 일정 시간 내에 수렴되었으며, 각 출구별 이동하는 노드의 비율로 환산한 출구집중도 역시 최대값과 최소값 차이가 현저하게 감소하였다.

• 전력전자학회논문지
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• 제21권5호
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• pp.453-456
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• 2016

The major causes of electrical fire in low-voltage distribution lines are classified into short-circuit fault, overload fault, electric leakage, and electric contact failure. The special principal factor of the fire is electric arc or spark accompanied with such electric faults. This paper studies the development of an electric fire prevention system with detection and alarm of that in case of parallel arc fault occurrence in low-voltage distribution lines. The proposed system is designed on algorithm sensing the instantaneous voltage drop of line voltage at arc fault occurrence. The proposed detector has characteristics of high-speed operation responsibility and superior system reliability from composition using a large number of semiconductor devices. A new sensing control method that shows the detection of parallel arc fault is sensed to ripple voltage drop through a diode bridge full-wave rectifier at electrical accident occurrence. Some experimental tests of the proposed system also confirm the practicality and validity of the analytical results.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 춘계학술발표회논문집(2)
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• pp.637-642
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• 1996

This paper presents the analysis results for the core degradation processes and the fission product release of the PHEBUS FPT0 experiment using MELCOR1.8.3. The objective of this study is to assess models associated with the core damage and fission product behavior in MELCOR. The calculation results were much improved through sensitivity studies. Thermal/hydraulic behavior in the core and the circuit was well predicted under the intact core geometry. In non-eutectic model case. the UO$_2$ dissolution model in the MELCOR always showed such a tendency that the resulting dissolved UO$_2$ mass was small at the highly oxidized condition due to the model logic. Total H$_2$ generation mass was underpredicted because the stiffner was not modeled and the liner in the shroud was not allowed to be oxidized in MELCOR. Some difficulties were found in modeling the activation product were solved by manipulating the RN input associated with the initial fission product inventory. These problem were occurred because there are no control rod model in MELCOR. Generally the fission product release ratio showed a similar trend compared with the measured data except the activation product. which have no model to simulate in MELCOR.

• 한방재활의학과학회지
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• 제26권3호
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• pp.143-151
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• 2016

A 57-year-old male patient was diagnosed as Incomplete cervical spinal cord injury and Neurogenic bladder after falling accident and suffered from tetraplegia and urinary retention. The patient was hospitalized and treated with Complex Korean Medical treatment such as acupuncture, electro-acupuncture, bee venom pharmacopuncture and herbal medication for 13 weeks. International Standard for Neurological Classification of Spinal Cord Injury (ISNCSCI) was adopted to evaluate the functional recovery and Korean version of Modified Barthel Index (K-MBI) was adopted to evaluate the recovery of activities of daily living (ADL). After treatment, Total scores of ISNCSCI and K-MBI were improved. Also patient's micturition reflex was recovered and symptoms of neurogenic bladder were improved. This result shows that Korean Medical treatment may be an effective treatment option for spinal cord injury and neurogenic bladder patients. Further clinical studies are needed to clarify the effect of Korean Medical treatment on spinal cord injury.

• 융합보안논문지
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• 제15권5호
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• pp.77-86
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• 2015

조직은 고객 정보 유출과 관련된 비즈니스 위험을 최소화하고, 자발적인 사전 검사를 통해 정보 보안 활동을 강화하고 부주의 방치 사고에 의한 개인 정보의 누출을 검출하는 방법을 발견해야 한다. 최근 많은 기업들이 정보유출방지솔루션을 도입하였으나, 업무산 필요에 의한 허용된 권한을 가진 내부 사용자에 의한 유출가능성이 존재한다. 이에 정보취급행위 및 활동에 대한 정보를 수집하여 분석할 수 있는 환경이 필요하다. 본 연구에서는 내부자의 활동 수준을 평가하기 위해서 RFM 모델을 응용한 SFI 분석기법을 활용, 실제 기업에 적용하여 사례 연구를 수행하였다.

• 한국안전학회지
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• 제29권4호
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• pp.191-198
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• 2014

In the event of continued train operation being impossible as the result of a breakdown, it will be essential to dispatch a relief train to recover the broken down train. Operation of relief train carries with the risk of collision in the process of connection with broken down train. The present study looks at the suitability of risk management procedures and associated problems in the light of case studies of relief train operation, and of national legal standards and railroad company regulations. It looks at appropriate methods of risk management and the problems that can arise. Based on the study a method is proposed of operating the relief train which is consistent with appropriate risk management. The proposed method will improve the safety of relief train operation, It is hoped that the results of the study will be reflected in relevant laws and operating company regulations, and so contribute to enhancing the overall level of railroad safety.

• 센서학회지
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• 제31권1호
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• pp.64-68
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• 2022

Herein, we propose a LoRaWAN-based small draft system that can measure the ocean current flow (speed, direction, and distance) in real time at the request of the Coast Guard to develop a device that can promptly find survivors at sea. This system has been implemented and verified in the early stages of rescue after maritime vessel accidents, which are frequent. GPS signals often transmit considerable errors, so correction algorithms using the improved triangulation method algorithm are required to accurately indicate the direction of currents in real time. This paper is structured in the following manner. The introduction section elucidates rescue activities in the case of a maritime accident. Chapter 2 explains the characteristics and main parameters of the GPS surveying technique and LoRaWAN communication, which are related studies. It explains and expands on the critical distance error correction algorithm for GPS signals and its improvement. Chapter 3 discusses the design and analysis of small draft buoys. Chapter 4 presents the testing and validation of the implemented system in both onshore and offshore environments. Finally, Section 5 concludes the study with the expected impact and effects in the future.

• Nuclear Engineering and Technology
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• 제54권11호
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• pp.4159-4169
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• 2022

Hydrogen mitigation using Passive Autocatalytic Recombiners (PARs) has been widely accepted methodology inside reactor containment of accident struck Nuclear Power Plants. They reduce hydrogen concentration inside reactor containment by recombining it with oxygen from containment air on catalyst surfaces at ambient temperatures. Exothermic heat of reaction drives the product steam upwards, establishing natural convection around PAR, thus invoking homogenisation inside containment. CFD models resolving individual catalyst plate channels of PAR provide good insight about temperature and hydrogen recombination. But very thin catalyst plates compared to large dimensions of the enclosures involved result in intensive calculations. Hence, empirical correlations specific to PARs being modelled are often used in integral containment studies. In this work, an experimentally validated CFD model of PAR has been employed for developing an empirical correlation for Indian PAR. For this purpose, detailed parametric study involving different gas mixture variables at PAR inlet has been performed. For each case, respective values of gas mixture variables at recombiner outlet have been tabulated. The obtained data matrix has then been processed using regression analysis to obtain a set of correlations between inlet and outlet variables. The empirical correlation thus developed, can be easily plugged into commercially available CFD software.