• 제목/요약/키워드: Change-point analysis

검색결과 1,296건 처리시간 0.033초

Landsat 영상을 이용한 서해안 지형 변화 추이 분석 (An Analysis on the change in Topography in the West Coast Using Landsat Image)

  • 강준묵;윤희천;강영미
    • 한국측량학회:학술대회논문집
    • /
    • 한국측량학회 2004년도 추계학술발표회 논문집
    • /
    • pp.275-279
    • /
    • 2004
  • This study was done to detect the topographic and terrain change of the vicinity of the west coast. To make the basic map of the change in topology and terrain, the mosaic images were made using the images from the satellite, which were given the geometric correction based on the GCP (Ground Control Point) and DEM (Digital Elenation Model) data. The accuracy of the images was examined by .empaling them with CCP through 1:25,000's digital map. After that, among the resultant images of the 1970s and 2000s, those of Sihwa, Hwaong and Ansan, the lands reclaimed by drainage were compared to observe the change in the area. From this study, the accuracy of the images of the west coast from satellite could be acquired and the change of the topology and terrain was detected effectively. From the results, it was known that, in case of the land the topological change was not so big due to the development in the reclaimed land or the bare land. In Sihwa, the size of the land was increased 180 $\textrm{km}^2$ and that of the seashore was decreased 110 km. in Hwaong the size was increased 50 $\textrm{km}^2$ and in Ansan the city space was increased 71 $\textrm{km}^2$ due to the formation of the industrial complex.

  • PDF

학생 개념체계의 연속적 세련화와 정교화를 통한 개념 변화 분석 - 이론적 논의를 중심으로 - (An analysis of the processes of conceptual change through the successive refinement and articulation of student's conceptual framework - Focused on the theoretical discussions -)

  • 박종원
    • 한국과학교육학회지
    • /
    • 제22권2호
    • /
    • pp.357-377
    • /
    • 2002
  • 본 연구에서는 학생의 개념변화 과정을 연속적인 세련화와 정교화의 과정으로 보았다. 이러한 관점은 학생의 개념변화에 대한 학습심리학적 연구의 재고찰과 물리학 지식의 발달과정에 대한 물리학사적 사례 연구의 분석에 기초하였으며, 구체적으로 세련화와 정교화를 통한 개념변화 과정 사례를 추출할 수 있었다. 본 연구 결과는 실제 학생의 반응을 분석하는데 지침 역할을 할 수 있을 것으로 기대된다.

준분포형 유역모델 STREAM을 이용한 기후변화가 농업유역의 하천유량에 미치는 영향 분석 (Analysis of Impact of Climate Change on River Flows in an Agricultural Watershed Using a Semi-distributed Watershed Model STREAM)

  • 정의상;조홍래
    • 한국물환경학회지
    • /
    • 제35권2호
    • /
    • pp.131-144
    • /
    • 2019
  • Climate Change affects the hydrological cycle in agricultural watersheds through rising air temperature and changing rainfall patterns. Agricultural watersheds in Korea are characterized by extensive paddy fields and intensive water use, a resource that is under stress from the changing climate. This study analyzed the effects of climate change on river flows for Geum Cheon and Eun-San Choen watershed using STREAM, a semi-distributed watershed model. In order to evaluate the performance and improve the reliability of the model, calibration and validation of the model was done for one flow observation point and three reservoir water storage ratio points. Climate change scenarios were based on RCP data provided by the Korea Meteorological Administration (KMA) and bias corrections were done using the Quantile Mapping method to minimize the uncertainties in the results produced by the climate model to the local scale. Because of water mass-balance, evapotranspiration tended to increase steadily with an increase in air temperature, while the increase in RCP 8.5 scenario resulted in higher RCP 4.5 scenario. The increase in evapotranspiration led to a decrease in the river flow, particularly the decrease in the surface runoff. In the paddy agricultural watershed, irrigation water demand is expected to increase despite an increase in rainfall owing to the high evapotranspiration rates occasioned by climate change.

사면 변형 측정을 위한 3차원 레이저 스캐너의 적용 (Application of 3-D Laser Scanner for the Measurement of Slope Displacement)

  • 오석훈;서백수
    • 한국지구과학회지
    • /
    • 제31권6호
    • /
    • pp.555-562
    • /
    • 2010
  • 응력을 받고 있는 사면의 변형 여부를 분석하기 위해 3차원 레이저 스캐너를 이용하여 일정 기간의 차이를 두고 정밀 측량을 수행하였다. 3차원 레이저 스캐너는 비접촉식으로 레이저 빔의 주행시간을 이용하여 대상점의 3차원 좌표를 결정할 수 있는 장비로써, 사면이나 대형 구조물의 변위를 분석하는데 매우 유용한 장비이다. 스캐닝은 약 7개월의 시간차이를 두고 이루어졌으며, 측정간의 비교를 위해 사면의 외부에 기준점을 유지하여 사용하였다. 변형 여부를 판단하기 위해, 평면각 변화, 곡면도 변화, 격자 틀의 각도 변화, 공통 병합점의 편차 등을 분석하였다. 분석 결과, 사면의 변형이 특히 많이 발생한 지점을 결정할 수 있었고 이를 보수·보강 방안의 마련에 활용할 수 있었다.

동작적합성을 위한 슬랙스 패턴의 허리선 및 허리뒤점 설계에 관한 연구 (Analysis of the Waistline and the Back Waist Point of Slacks Pattern for Optimizing the Range of Motion)

  • 권숙희;홍지운
    • 대한가정학회지
    • /
    • 제47권4호
    • /
    • pp.61-72
    • /
    • 2009
  • The purpose of this research is to suggest a new way to approach measuring the waist line of slacks. The pattern formulated enables a construction method that optimizes motion. The method is based on the measurement on the length change of the body surface line. The research reveals: 1. The analysis of expansion and contraction by area showed that G8 markedly shrunk, whilst G15 maximally stretched during M4 motion. 2. The areas that stretched during M2 motion were, in order of size: G10, G17, G16, and G8. Conversely, the areas that shrunk are, in order, G9, G11, and G18. The areas that stretched during M3 motion were G10, G17, G16, G12, and G15; the areas that shrunk were G9, G11, G18, and G8. 3. In constructing the slacks pattern to allow for appropriate movement, we calculated the length between the knee and back of the waist, point (y), using Pythagoras’theorem and trigonometry. The equation was y = 1.005x. 4. In the two pattern N method and L method, y is equal or less than x, but for our research pattern, y was larger than x

도심지 빌딩주변 자동차 배가스 분산에 관한 연구 (Numerical Simulation of Air Contaminant Dispersion around Urban City)

  • 유경석;유일광
    • 환경위생공학
    • /
    • 제21권2호
    • /
    • pp.11-19
    • /
    • 2006
  • Ran numerical analysis about simplicity warm current model (simple turbulence model) to examine closely distributed laying stress on NOx of contaminant that happen in downtown that building is massed and result is as following. Downtown building is massed and transfer of vehicles can know that frequent area receives greatly effect of building. Pollution displays class kind phenomenon striking in the building, class kind done pollution that show high density being mixed with pollution that happen in vehicles being flowed in again side know can. Divide velocity vector of pollution and density change to ancient city and did numerical analysis. Because NOx is flowed in diversion of water neighborhood by continuous this kind in Godo 20m point, density showed density of $0.0907mg/m^3s$, and can know that Banryuhyeon that Pollution strikes in the building at ancient city 30m point is decreased and approaches with freedom flowing without cooperation (cavity) phenomenon remarkably. Because pollution strikes in the building at distance shaft 383m point, class kind do phenomenon that know appeared notedly Nopeungeonmulgwanat between building pollution density $0.067mg/m^3$ head of a families high appear.

신장 이혈 상응점 자극에 따른 얼굴 색상 기반의 신장 기능 상태 분석 (Analysis of Kidney Function States Based on Face Color Observation by Kidney Ear Acupuncture Point Irritation)

  • 김봉현;조동욱
    • 한국통신학회논문지
    • /
    • 제35권12B호
    • /
    • pp.1192-1198
    • /
    • 2010
  • 삶의 질이 향상되면서 현대 사회에서는 건강에 대한 관심도가 높아져 질병이 발생되기 전에 조기에 진단하여 예방하는 대체의학이 건강 패턴의 중심으로 자리잡고 있다. 이러한 대체의학 중 귀에 침을 자입하여 치료를 하는 것이 이침(耳針)요법이다. 따라서 본 논문에서는 신장과 관련된 이(耳)혈 상응점을 자극하여 신장의 기능이 향상되는 것을 얼굴 영역 색상 분석 기반 기술의 적용으로 실험을 수행하였다. 이를 위해 동일한 조건에서 시행되는 신장 이혈 상응점을 자극하기 전과 후의 얼굴 영상을 수집하였다. 수집된 얼굴 영상에서 신장과 관련된 지각 부위에 대해 CMYK 색체계 중 K값과 Lab 색체계 중 L값의 변화율을 추출, 분석하여 신장 기능의 향상 정도를 실험하는 연구를 수행하였다.

3차원 얼굴 인식을 위한 PSO와 다중 포인트 특징 추출을 이용한 RBFNNs 패턴분류기 설계 (Design of RBFNNs Pattern Classifier Realized with the Aid of PSO and Multiple Point Signature for 3D Face Recognition)

  • 오성권;오승훈
    • 전기학회논문지
    • /
    • 제63권6호
    • /
    • pp.797-803
    • /
    • 2014
  • In this paper, 3D face recognition system is designed by using polynomial based on RBFNNs. In case of 2D face recognition, the recognition performance reduced by the external environmental factors such as illumination and facial pose. In order to compensate for these shortcomings of 2D face recognition, 3D face recognition. In the preprocessing part, according to the change of each position angle the obtained 3D face image shapes are changed into front image shapes through pose compensation. the depth data of face image shape by using Multiple Point Signature is extracted. Overall face depth information is obtained by using two or more reference points. The direct use of the extracted data an high-dimensional data leads to the deterioration of learning speed as well as recognition performance. We exploit principle component analysis(PCA) algorithm to conduct the dimension reduction of high-dimensional data. Parameter optimization is carried out with the aid of PSO for effective training and recognition. The proposed pattern classifier is experimented with and evaluated by using dataset obtained in IC & CI Lab.

CKGS: A Way Of Compressed Key Guessing Space to Reduce Ghost Peaks

  • Li, Di;Li, Lang;Ou, Yu
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • 제16권3호
    • /
    • pp.1047-1062
    • /
    • 2022
  • Differential power analysis (DPA) is disturbed by ghost peaks. There is a phenomenon that the mean absolute difference (MAD) value of the wrong key is higher than the correct key. We propose a compressed key guessing space (CKGS) scheme to solve this problem and analyze the AES algorithm. The DPA based on this scheme is named CKGS-DPA. Unlike traditional DPA, the CKGS-DPA uses two power leakage points for a combined attack. The first power leakage point is used to determine the key candidate interval, and the second is used for the final attack. First, we study the law of MAD values distribution when the attack point is AddRoundKey and explain why this point is not suitable for DPA. According to this law, we modify the selection function to change the distribution of MAD values. Then a key-related value screening algorithm is proposed to obtain key information. Finally, we construct two key candidate intervals of size 16 and reduce the key guessing space of the SubBytes attack from 256 to 32. Simulation experimental results show that CKGS-DPA reduces the power traces demand by 25% compared with DPA. Experiments performed on the ASCAD dataset show that CKGS-DPA reduces the power traces demand by at least 41% compared with DPA.

갈수기 경향성 분석을 활용한 상류 유역의 가뭄위험 변동성 분석 (Analysis of Drought Risk in the Upper River Basins based on Trend Analysis Results)

  • 정일원;김동영;박지연
    • 한국농공학회논문집
    • /
    • 제61권1호
    • /
    • pp.21-29
    • /
    • 2019
  • This study analyzed the variability of drought risk based on trend analysis of dry-seasonal dam inflow located in upper river basins. To this, we used areal averaged precipitation and dam inflow of three upper river dams such as Soyang dam, Chungju dam, and Andong dam. We employed Mann-Kendall trend analysis and change point detection method to identify the significant trends and changing point in time series. Our results showed that significant decreasing trends (95% confidence interval) in dry-seasonal runoff rates (= dam inflow/precipitation) in three-dam basins. We investigated potential causes of decreasing runoff rates trends using changes in potential evapotranspiration (PET) and precipitation indices. However, there were no clear relation among changes in runoff rates, PET, and precipitation indices. Runoff rate reduction in the three dams may increase the risk of dam operational management and long-term water resource planning. Therefore, it will be necessary to perform a multilateral analysis to better understand decreasing runoff rates.