• 한국경영과학회지
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• 제14권1호
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• pp.72-79
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• 1989

In this paper we consider the problem of finding an optimal straight line path of moving facility which interacts with a set of existing facilities fixed within a given rectangular area. We present a simple algorithm for rectilinear metric which greatly improves the pervious method and also propose algorithms for Euclidean and squared Euclidean distances.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2009년도 IWAIT
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• pp.566-571
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• 2009

A calibration method for multiple sets of stereo vision cameras is proposed. To measure the three-dimensional shape of a very long object, measuring the object at different viewpoints and registration of the data are necessary. In this study, two lasers beams generate two strings of calibration targets, which form straight lines in the world coordinate system. An evaluation function is defined to calculate the sum of the squares of the distances between each transformed target and the fitted line representing the laser beam to each target, and the distances between points appearing in the data sets of two adjacent viewpoints. The calculation process for the approximation method based on data linearity is presented. The experimental results show the effectiveness of the method.

• 대한조선학회논문집
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• 제52권6호
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• pp.494-500
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• 2015

It has been reported that a ship sailing in shallow water possesses better straight-line stability due to the change of fluid flow around the ship. This tendency affects manoeuvring characteristics of the ship. To investigate this phenomenon, indoor free running model test(FRMT) on KVLCC2 was carried out in three water depth conditions(H/T = 1.2, 1.5 & 2.0). Turning circle tests(± 35° ) and zigzag tests(± 20° /5° and ± 20° /10° ) were conducted with newly developed indoor FRMT system, and the manoeuvring results were compared with test results from other institutes. As the water depth decreased, the yaw rate of the ship decreased, and the distances of circular trajectories at the same heading angle increased in the turning circle tests. The first overshoot angles of the zigzag tests decreased. From both tests, the time for course change increased as the water depth decreased. These manoeuvring characteristics show that KVLCC2 in shallow water becomes more stable in terms of straight-line stability.

• 한국ITS학회 논문지
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• 제12권2호
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• pp.12-21
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• 2013

본 연구에서는 최단경로 탐색 소요시간을 줄이기 위한 목적으로 탐색영역을 축소하는 알고리즘을 개발하였다. 개발된 알고리즘은 출발노드와 목적노드를 최소의 노드 수로 연결하면서 직선거리의 합이 최소인 임시경로를 구축하고, 구축된 임시경로의 부하량 보다 적은 부하량의 경로를 연결할 가능성이 있는 노드들을 찾는 것이다. 하나의 노드에서 출발노드까지의 직선거리와 목적노드까지의 직선거리 합이 임시경로의 부하량을 최소 가로 부하량 원단위로 나눈 값보다 적을 경우, 그 노드는 임시경로 보다 더 적은 부하량을 가질 수 있는 경로를 구성할 가능성이 있는 노드가 된다. 이와 같은 노드들만을 탐색영역으로 하면 탐색영역이 축소됨에 따라 최단경로 탐색 소요시간을 줄일 수 있게 된다. 개발된 알고리즘은 큰 탐색영역에서 출발노드와 목적노드가 가까울 경우 더욱 효과적이다.

• 한국재난정보학회 논문집
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• 제19권2호
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• pp.439-450
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• 2023

연구목적: 국내에서 소방점검을 시행시 바닥면적 400m2 미만일 경우 공기유입구와 배출구간의 직선거리 5m이상 하라는 소방법규에 위반되는 대상물들이 있으며 이러한 이유를 분석하고 관련 소방법규의 필요성을 뒷받침 하기 위해 모형실험연구를 시행한 논문이다. 연구방법: 국내소방 대상물을 조사확인 하였고, 국내 및 해외논문 및 정책, 법규를 문헌고찰 하였으며, 400m² 미만의 거실에서 공기 유입구와 배출구간의 직선거리 5m 이하와 5m이상인 공간을 선정하여 모형실험 을 통해 분석하였다. 연구결과: 국내 소방법규(NFPC-화재안전성능기준)를 고찰 하였을 때 바닥면적 400m² 미만일 경우 공기유입구와 배출구 간의 5m 이상으로 이격 거리가 규정되어있지 만 실제 조사해 본 결과 이격 거리를 지키지 못하는 소방대상물이 있는 것으로 확인되었다. 또한 5m 이상의 직선거리에 대한 해외 소 방법규에 대한 논문 고찰을 해봤을 때 공기유입구와 배출구간의 직선거리에 대한 규정이 없는 것으로 나타났지만, 모형실험 한 결과 공기유입 구와 배출구간의 직선거리가 5m이상 일 때가 5m미만 일 때보다 배출속도가 우수한 것으로 나타났다. 결론: 본 연구에서는 공기유입구와 배출구간의 직선거리에 대한 제연설비 성능비교로 해외 소방법규 를 조사하였을 때 직선거리에 대한 강제규정이 없지만 국내 소방법규(NFPC_화재안전성능 기준)에 서는 5m이상을 해야 한다는 법규를 뒷받침하는 근거를 마련하는 논문이다. 앞으로 설계 단계에서 이를 반영하여 소방 감리의 책임과 부담을 줄여줄 수 있는 토대가 마련되길 바란다.

• Journal of Korean Neurosurgical Society
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• 제53권4호
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• pp.218-222
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• 2013

Objective : To clarify the anatomical correlations of the sphenoid sinus with surrounding structures in the normal Korean population, and to identify surgical landmarks for safe sellar floor dissection in the anterior skull base by endoscopy and microscopy. Methods : We reviewed the 196 brain magnetic resonance imaging findings showing a normal appearance, and measured the distances between anatomical landmarks. Results : The mean distances from the base of the columella to the anterior wall of the sphenoid sinus and the sellar floor were $69.71{\pm}4.25$ mm and $86.26{\pm}4.57$ mm, respectively in the over 15 age group, and showed the smallest degree of variation among the measurements. The mean angles between the floor of the nasal cavity and the straight line connecting the base of the columella and the sellar floor were $29.45{\pm}3.25^{\circ}$ and $24.75{\pm}4.00^{\circ}$ in the over 15 and under 15 age groups, respectively. The mean values of both distances and angles increased with age until 15 years after which no further increases were evident. There were no significant differences in the measurements between males and females or among subjects with different degrees of pneumatization in the over 15 age group. Conclusion : The distances from the base of the columella to the sellar floor and the anterior wall of the sphenoid sinus, which were consistent among individuals, could be used as a surgical indicator to investigate the sellar floor in endoscopic or microscopic transsphenoidal approaches.

• Nuclear Engineering and Technology
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• 제55권2호
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• pp.696-706
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• 2023

Consequences of an anticipated Beyond Design Basis Accident (BDBA) Long-Term Station Blackout (LTSBO) event with complete loss of grid power in the VVER-1200 reactor of Rooppur Nuclear Power Plant (NPP) of Unit-1 are assessed using the RASCAL 4.3 code. This study estimated the released radionuclides, received public radiological dose, and ground surface concentration considering 3 accident scenarios of International Nuclear and Radiological Event Scale (INES) level 7 and two meteorological conditions. Atmospheric transport, dispersion, and deposition processes of released radionuclides are simulated using a straight-line trajectory Gaussian plume model for short distances and a Gaussian puff model for long distances. Total Effective Dose Equivalent (TEDE) to the public within 40 km and radionuclides contribution for three-dose pathways of inhalation, cloudshine, and groundshine owing to airborne releases are evaluated considering with and without passive safety Emergency Core Cooling System (ECCS) in dry (winter) and wet (monsoon) seasons. Source term and their release rates are varied with the functional duration of passive safety ECCS. In three accident scenarios, the TEDE of 10 mSv and above are confined to 8 km and 2 km for the wet and dry seasons, respectively in the downwind direction. The groundshine dose is the most dominating in the wet season while the inhalation dose is in the dry season. Total received doses and surface concentration in the wet season near the plant are higher than those in the dry season due to the deposition effect of rain on the radioactive substances.

• 전기학회논문지
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• 제65권11호
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• pp.1879-1886
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• 2016

In this paper, we propose a real-time recognition algorithm of lanes, stop lines and speed bumps on roads for autonomous vehicles. First, we generate a top-view using the image transmitted from a camera that is installed to see the front of a vehicle. To speed up the processing, we simplify the mapping algorithm in constructing a top-view wherein the region of interest (ROI) is concerned. The features of lanes, stop lines and speed bumps, which are composed of lines, are searched in the edge image of the top-view, then followed by labeling and clustering specialized to detect straight lines. The width of lines, distances from the center of a vehicle, and curvature of each cluster are considered to select final candidates. We verify the proposed algorithm on real roads using the commercial car (KIA K7) which is converted into an autonomous vehicle.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2002년도 춘계 국제 학술대회
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• pp.33-36
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• 2002

This study was performed to investigate vibration generated from machines that were used at factories and construction works. Vibrations were measured at three points in a straight line based on distance from the vibration sources, and analyzed to assess the vibration levels. The average vibration level of factory machines was 65.4 dBV at 2 m, and that of construction machines was 74.0 dBV at 5m. Vibration attenuations was 4.0∼8.2 dBV by double distance. All such data were applied to gain coefficients of attenuation equations for predicting vibration level by distances from the vibration sources. Data recorded on tapes were analyzed to understand the characteristics of frequency because these characteristics are important factors to design a plan for installing the vibration-proof devices. Finally, considering results from these analysis, assessment, and prediction, the methods for reducing vibration generated from machines were discussed.

• 한국항행학회논문지
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• 제26권6호
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• pp.434-440
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• 2022

ICAO (international civil aviation organization)에서는 전략적인 의사결정과 항공교통관리 평가를 위해 세계항행계획인 GANP (global air navigation plan) 수행을 체약국에게 권고하였다. 본 연구에서는 항공교통관리 평가를 위해 제시된 KPI (key performance indicator) 05 실제 항로 연장에서 항로거리를 구하는 새로운 방법을 제안하였다. 이를 위해 한 달간의 항적 데이터를 수집하고 ICAO에서 제시한 방법과 본 저자가 제시하는 방법으로 각각 항로거리를 산출하였다. ICAO 방법은 반경 40 NM 원형에 대한 원의 방정식과 항적 데이터 내 원에 근접한 내·외부 지점에 대한 직선의 방정식을 통하여 교점을 추정하여야 하고, 네 가지의 비행거리를 계산하여 항로거리를 산출한다. 본 연구에서 제시한 방법은 교점을 추정하지 않고 두 가지의 비행거리를 계산하여 항로거리를 산출한다. 두 방법의 오차를 확인하기 위해 회귀모형 성능평가지표인 RMSE (root mean square error)와 결정계수 R² 를 사용하였다.