• Proceedings of the Korea Water Resources Association Conference
• /
• 2010.05a
• /
• pp.1179-1183
• /
• 2010

본 연구에서는 하천유역에 대한 호우의 대표 이동방향을 결정하였다. 대상유역으로는 내성천 유역을 고려하였으며, 101개의 호우사상을 선정하여 각각의 호우사상별로 방향적 특성을 분석하였다. von Mises 분포의 주방향을 이용하여 모든 호우사상의 대표 이동방향을 결정하고, 이를 이용하여 내성천 유역에 대한 호우 대표 이동방향을 결정하였다. 아울러 호우 발생특성별(장마, 태풍, 대류성 강우)로 호우의 방향적 특성을 분류하여 각각의 특성이 구분될 수 있도록 하였다. 적용 결과, 태풍에 의한 호우의 이동방향은 기존 연구결과와 유사하게 주로 북동 방향으로 진행되었으며, 장마와 대류성 강우에 의한 호우가 대표방향 결정에 가장 큰 영향력을 갖는 것으로 나타났다. 아울러 대상유역에 대한 호우의 대표 이동방향은 mode의 특성이 뚜렷하게 한 방향으로 나타나며, 내성천 유역의 경우 대표 호우 이동방향은 59.45도로 결정되었다. 이러한 결과는 한반도에 발생하는 강우의 특성과도 잘 부합하는 것으로 판단된다.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2005.05b
• /
• pp.649-653
• /
• 2005

유역형상의 변화에 따라서 이동강우가 유출에 미치는 영향을 운동파이론을 적용하여 분석하였으며, 유역형상은 신장형유역과 정4각형유역 및 장방형유역에 대하여 분석하였고, 이동강우 분포형은 균등분포형, 전진형, 지연형, 중앙집중형을 사용하였다. 이와 같은 형상의 유역에 대하여 다양한 이동속도를 가진 강우가 유역내 하천의 상류방향, 하류방향, 횡방향으로 이동할 때 강우분포형에 따르는 유출수문곡선을 모의하여 그 특성을 비교분석하였다. 유출수문곡선의 모양과 첨두시간, 첨두유량은 시간적, 공간적으로 변화하는 강우와 유역형상에 의하여 크게 영향을 받는다. 횡방향의 이동강우에서는 상류방향과 하류방향의 경우보다 더 큰 첨두유량이 발생하며, 하류방향 이동강우의 첨두유량은 상류방향의 첨두유량보다 더 크게 나타났다. 신장형유역의 경우 하류방향 이동강우의 첨두시간은 상류방향과 횡방향의 경우보다 더 지체되며, 수문곡선의 총유출량과 기저시간은 강우속도가 증가함에 따라 감소하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2017.05a
• /
• pp.229-232
• /
• 2017

기존의 이동방향 인식 시스템은 개인의 스마트폰 내부에 있는 센서 중 자이로/가속도 센서를 이용하여 측정하였다. 자이로/가속도 센서는 외부의 영향을 거의 받지 않아 정확도가 높다고 볼 수 있지만, 스마트폰의 위치에 따라 정확도가 변한다. 따라서, 기존의 이동방향 인식 시스템은 개인의 이동방향을 감지하기에는 적합하나 다수의 보행자에 대한 이동방향을 시스템에서 인식하기에는 부적합하다. 본 논문에서는 다수의 보행자에 대한 이동방향을 인식하기 위해 압전센서 어레이를 이용하여 특정 구역의 바닥에 설치하고 보행자와 압전센서 사이의 접촉형태와 개수를 파악하고, 시간을 측정하여 보행자의 이동방향을 계산한다.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.9 no.2
• /
• pp.338-347
• /
• 2005

In this paper, a decimation-in-time search direction algorithm for displacement prediction of moving object is proposed. The initialization of the proposed algorithm for moving direction prediction is performed by detecting moving objects at sequential frames and by obtaining a moving angle and a moving distance. A moving direction of the moving object at current frame is obtained by applying the decimation-in-time search direction mask. The decimation-in-tine search direction mask is that the moving object is detected by thinning out frames among the sequential frames, and the moving direction of the moving object is predicted by the search mask which is decided by obtaining the moving angle of the moving object in the 8 directions. to examine the propriety of the proposed algorithm, velocities of a driving car are measured and tracked, and to evaluate the efficiency, the proposed algorithm is compared to the full search algorithm. The evaluated results show that the number of displacement search times is reduced up to 91.8$\%$ on the average in the proposed algorithm, and the processing time of the tracking is 32.1ms on the average.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.10 no.2
• /
• pp.91-102
• /
• 2010

This study analyzed methodologies for determining the representative direction of a storm event. The mean direction, median direction, and modal direction of von Mises distribution were considered as representative directions. In addition, the results with and without considering the storm moving distance were also compared. As results, the modal directions of von Mises distribution were found to explain the directional characteristics of a moving storm much better than other methods. Also, it was found that the storm moving distance has a significant effect on the determination of representative directions of a moving storm, whose uncertainty can also be decreased significantly by considering the moving distance.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.26 no.1B
• /
• pp.15-25
• /
• 2006

Using kinematic wave equation, the influence of moving storms to runoff was analysised with a focus on watersheds. Watershed shapes used are the oblong, square and elongated shape, and the distribution types of moving storms used are uniform, advanced and intermediate type. The runoff hydrographs according to the rainfall distribution types were simulated and the characteristics were explored for the storms moving down, up and cross the watershed with various velocity. The shape, peak time and peak runoff of a runoff hydrograph are significantly influenced by spatial and temporal variability in rainfall and watershed shapes. A rain storm moving in the cross direction of channel flow produces a higher peak runoff than in the downstream direction and upstream direction. A peak runoff from a storm moving downstream exceeds that from a storm moving upstream. For storms moving downstream peak time was more delayed than for other storm direction in the case of elongated watershed. The runoff volume and time base of the hydrograph decreased with the increasing storm speed.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.10 no.6
• /
• pp.109-117
• /
• 2010

This study quantified the storm direction for a river basin by applying the von Mises distribution, also determined the representative storm direction. Additionally, the whole procedure was repeated for several storm types such as frontal, typhoon and convective storms for their comparison. From the results derived by analyzing a total of 101 storm events for the Naesung river basin, the von Mises distribution was found to explain the directional characteristics of storms. The representative moving directions derived for three different storm types were significantly different each other, which is coincident with the climate of Korea. The results derived in this study could be helpful to estimate more quantitatively the difference in the runoff response with respect to the moving direction of a storm.

• The Mathematical Education
• /
• v.62 no.3
• /
• pp.417-433
• /
• 2023

In the 2022 revised mathematics curriculum, a new content on 'Movement of a point' was added. Therefore, this study analyzed the contents of the movement of a point presented in Finnish mathematics textbooks as elements of spatial orientation. Analysis was conducted by dividing it into direction, distance, and route. As a result of the study, in Finnish textbooks, directions were expressed in various ways, such as linguistic, visual, and coded expressions. In the case of distance, activities to move as much as the distance or compare the distance were presented using the number of cells, length, steps, coordinate points, ratio, etc. In the case of routes, activities such as moving according to instructions, making routes, finding the route, and modifying the route were presented using unconditional movement and conditional movement. In particular, the movement of a point could be linked not only to various mathematical content areas such as 'number and arithmetic' and 'change and relationship', but also to digital literacy and programming education. Knowing that the movement of a point can be presented in various ways according to the direction, distance, and route, it is expected that it can be used to organize the contents of the 2022 revised mathematics textbook.

• Journal of Korea Water Resources Association
• /
• v.37 no.10
• /
• pp.823-836
• /
• 2004

Using the simple geometry for the idealized catchment consisting of two plane surfaces and a stream between them, runoff was analysed for the moving storms based on the kinematic wave equation. The storm velocity applied in this study was 0.25∼2.0 m/s moving up, down and cross direction of catchment. Applied rainfall distribution types are uniform, advanced, delayed, intermediate type. The results indicate that the moving storms of cross direction generate the largest peak runoff, and the smallest runoff appears in the case of up stream direction. The sensitivity of runoff to rainfall distribution types decreases as storm velocity increases. It is clear that faster storm velocity generates faster peak time and becomes thin hydrographs rapidly.

• Journal of KIISE:Information Networking
• /
• v.30 no.1
• /
• pp.48-64
• /
• 2003

Recently, as the number of mobile users keeps increasing explosively, the location management to track the mobile users in mobile communication systems is being more important. However, the previous location management schemes have been used static location information without the consideration of a user's moving direction. This results in unnecessary pagings, consequently it increases location management costs. In this paper, we propose a mew location management costs. In this paper, we propose a new location the cell occurred a location update. It also determines whether the location update will be executed or not, by the offset operation of direction vector. Thus, a user's paging areas are generated dynamically along the user's moving direction. The wide of paging areas is also determined dynamically. Besides, we present analytic model for our scheme. To compare with our scheme, the distance-based scheme is analyzed. The numerical result shows that our scheme is more efficient than the distance-based scheme in the most cases except a low CMR. Particularly if a user move into a specific direction, our scheme has the lower location management cost than that of the distance-based scheme.