• 한국콘텐츠학회논문지
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• 제17권1호
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• pp.50-57
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• 2017

본 논문은 대전도시철도 개통 이후 내부자료 통계분석을 통해 열차지연 원인과 문제점을 살펴보고 고위험군의 위험도를 평가하여 위험도 지수 심각도와 위험도를 측정하였다. 측정방법으로는 위험도 관리방법인 risk matrix($5{\times}5$)를 적용하여 위험도 등급을 산정하였으며, 결과에 따른 안전수준과 허용수준 범위를 분석하였다. 그 결과 차량분야가 가장 위험도가 심각하고, 다음으로 기계설비분야가 위험도를 내재하고 있는 것으로 나타났다. 특히 차량의 출입문장치결함으로 인한 출입문고장과 열차신호 및 제어장치는 심각도도 높지만, 빈도수가 매우 잦아 추가적인 사고 잠재성을 보이고 있다. 기계설비 분야의 PSD결함도 PSD의 안전문 개폐불량이 가장 위험한 것으로 나타났으며, PSD의 오취급 및 PSD의 유리파손 등도 위험도를 내포하고 있는 것으로 나타났다. 본 연구는 이러한 위험도를 내재하고 있는 사고의 빈도수를 경감하고, 심각도를 낮춰서 위험도를 예방할 수 있는 방안을 예측하여 미리 선제적으로 대비할 수 있는 분석결과를 제시함으로써 안전한 도시철도운영으로 이용자의 교통편익에 기여할 것으로 기대된다.

• 한국철도학회논문집
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• 제16권6호
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• pp.447-453
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• 2013

기 현재 많은 역사 내에 PSD(Platform Screen Door)가 설치되어 있고, 이러한 PSD의 안전성이 중요시 되고 있다. 특히 운행중인 도시철도차량과의 간섭은 가장 중요한 부분으로 PSD와 차량의 충돌은 차량 및 승강장에 위치한 승객의 안전을 위협하기 때문이다. 곡선구간에 위치한 승강장을 차량이 진입할 때에 차량의 병진운동과 회전운동을 하기 때문에 PSD와 충분한 간격을 가지고 있어야 한다. 차량의 병진운동과 회전운동은 레일상태, 차량한계, 차량속도 등에 의해 영향을 받는다. 본 연구에서는 도시철도차량, 레일, 기타 매개변수들과 같이 차량의 움직임에 영향을 미치는 요소들을 고려한 도시철도차량의 동적 해석방법을 제시하고자 한다.

• 한국항해항만학회지
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• 제26권1호
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• pp.127-136
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• 2002

항공 대잠수함전에 사용되는 방향주파수분석저장 소노부위 (DIFAR Sonobuoy)에 방위정보를 제공하는 플럭스-게이트 콤파스의 위상감응검출 (PSD) 회로 설계와 구현에 관해서 기술하였다. PSD 회로는 쌍동-T RC 회로망을 갖는 능동형 대역필터로 구성하였다. PSD 회로에 대한 성능실험 결과, 대역통과 필터가 지구자장 방향에 비례하는 2Fe의 2차 고조파 신호를 효과적으로 걸러냄을 확인하였다. 그 결과 방위 신호 정보를 획득할 수 있었다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1996년도 추계학술대회
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• pp.217-220
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• 1996

In this paper, we compare three mehods to obtain PSD of HRV - FFT, AR modeling, and residual integration. Using these methods we speculate the balances of the LP and HF powers of HRV at $0^{\circ}$, $45^{\circ}$, $90^{\circ}$ tilt levels of head-up tilt table for young and healthy 24 men. R peaks are located at the highest point of QRS complex detected from modified spacial velocity algorithm. In general FFT is the most fast way to obtain PSD but PSD from FFT has too many peaks and valleies. AR PSD can show frequency of ANS activity effectively but LF component of PSD is often invisible due to interference of VLF power. The residual integration method that decomposes the AR PSD is very efficient way to extract LF component. Applying the above three methods to HRV we can visualize the trend of PSD variations along tilt levels.

• 노인간호학회지
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• 제20권3호
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• pp.167-176
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• 2018

Purpose: Post Stroke Depression (PSD) is one of the most common complications for stroke survivors and is associated with negative health outcomes such as disability, death. The purpose of this study was to investigate the prevalence and predictors of PSD among older Korean adults living in the community. Methods: Data collection was done using the 2014 Survey of Living Conditions and Welfare Needs of Korean Older Adults. Participants were 706 older adults who had a stroke. Logistic regression analysis was used to determine the predictors of PSD. Results: The prevalence of PSD which was assessed by the short form of the geriatric depression scale was 49.4%. In a logistic regression model, the predictors of PSD were self-rated health (OR=5.90, CI=3.70~9.40), economic state (OR=2.97, CI=2.07~4.24), independent activities of daily living (IADL) (OR=2.17, CI=1.30~3.63), Activities of Daily Living (ADL) (OR=2.02, CI=1.07~3.80), and education (OR=1.53, CI=1.05~2.24). Conclusion: PSD was common among older Korean adults living in the community. Poor self-rated health status, lower economic state, lower levels of Instrumental Activities of Daily Living (IADL) and ADL, lower levels of education should be considered when conducting activities related to prevention and management of PSD in older adults.

• Earthquakes and Structures
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• 제13권2호
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• pp.193-200
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• 2017

To overcome the difficulty of performing multi-point response spectrum analysis for engineering structures under spatially varying ground motions (SVGM) using the general finite element code such as ANSYS, an approach has been developed by improving the modelling of the input ground motions in the spectral analysis. Based on the stochastic vibration analyses, the cross-power spectral density (c-PSD) matrix is adopted to model the stationary SVGM. The design response spectra are converted into the corresponding PSD model with appropriate coherency functions and apparent wave velocities. Then elements of c-PSD matrix are summarized in the row and the PSD matrix is transformed into the response spectra for a general spectral analysis. A long-span high-pier bridge under multiple support excitations is analyzed using the proposed approach considering the incoherence, wave-passage and site-response effects. The proposed approach is deemed to be an efficient numerical method that can be used for seismic analysis of large engineering structures under SVGM.

• 대한원격탐사학회지
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• 제22권5호
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• pp.397-402
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• 2006

China Coastal Water (CCW) usually appears in the seas surrounding Jeju Island annually (June-October) and is very pronounced in August. The power spectrum density (PSD), sea level anomalies (SLAs), and sea surface temperatures (SSTs) were found to peak annually and semiannually. The peaks at intervals of 80-, 60-, and 43-days are considered to be influenced by CCW and the Kuroshio Current. Generally, low-salinity water appears to the west of Jeju Island from June through October and gradually propagates to the east, where CCW meets the Tsushima Current. Empirical orthogonal function (EOF) analysis of SLAs and SSTs indicated that the variance in SLAs and SSTs was 55.70 and 98.09% in the first mode, respectively. The PSD for the first mode of EOF analysis of SLAs was stronger in the western than in the eastern waters because of the influence of CCW. The PSD for the EOF analysis of SSTs was similar in all areas (the Yangtze Estuary and the waters to the west and east of Jeju Island), with a period of approximately 260 days.

• 한국철도학회논문집
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• 제9권5호
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• pp.594-600
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• 2006

In this study, transient and quasi-static analysis were done for the evaluation of structural integrity of the platform screen door due to train wind pressure. Fluent 6.0 was used to calculate the train wind pressure, and Ansys 10.0 was used to evaluate the structural stability of platform screen door due to train wind pressure. Transient analysis was used to check the design requirements of platform screen door, and quasi-static analysis was introduced to save the calculating time and check quickly structural performances when compared to those of transient analysis. The results show that structural stability of the platform screen door under train wind pressure is proven and quasi-static analysis can quickly check the structural integrity of platform screen door.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.1190-1197
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• 2006

We have evaluated the structural stability of a platform screen door due to train wind pressure. The platform screen door was installed at the ground and underground station and had 65 meters in length. Also, the platform screen door was a safety device because it was placed between the train and the platform. The finite element analysis was used to calculate the stresses and deflections of platform screen door caused by wind pressure using ANSYS 10.0. Quasi-static analysis was introduced to save calculating time and check quickly structural performances when compared to those of transient analysis. The results show that structural stability of the platform screen door under train wind pressure is proven and quasi-static analysis can quickly check the structural integrity of platform screen door.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.1054-1061
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• 2009

본 연구에서는 현재 국내외적으로 설치가 이루어지고 있는 PSD에 대하여 설치 유무에 따른 화재유동 변화와 배연효율변화에 중점을 두어 연구를 진행하였다. 시뮬레이션 모델은 대구지하철 중양로 역사이며, 승강장과, 대합실 2개층을 포함하여 화재해석을 수행하였고, 화재해석 프로그램은 FDS를 사용하였다. 역사 전체를 모델링함에 따른 격자수 증가로 많은 계산시간이 소요되므로 병렬처리 기법을 통한 화재해석을 수행하였다. PSD 유무에 따른 화재유동 및 배연효율 변화의 비교를 위하여 화재사나리오를 작성하여 Case 별로 화재해석을 수행하였다. 화재규모는 NFPA-130 을 참조하여 10Mw 상황에서의 화재유동 을 연구하였다. 해석 결과는 NFPA-130을 참고하여 승객안전에 중점을 두어 분석하였다.