• Title/Summary/Keyword: change point analysis

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

  • 강준묵;윤희천;강영미
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2004.11a
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    • pp.275-279
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    • 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.

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

  • Park, Jong-Won
    • Journal of The Korean Association For Science Education
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    • v.22 no.2
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    • pp.357-377
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    • 2002
  • This study is for better understanding about the process of students' conceptual change. As a starting point, it is assumed that the process of students' conceptual change can be viewed as the process of the successive refinement and articulation of students' conceptual framework. Based on the theoretical review of conceptual change literature, various processes, which can be involved in the above assumed process, can be found. And also, by analyzing the process of development of scientific knowledge about Planck's blackbody radiation law and Bohr's atom, six types of processes of refinement and articulation of scientific knowledge can be found. It is hoped that these theoretical discussions can guide the direction for obtaining and interpreting the students' real responses during the process of conceptual change.

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

  • Jeong, Euisang;Cho, Hong-Lae
    • Journal of Korean Society on Water Environment
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    • v.35 no.2
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    • pp.131-144
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    • 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.

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

  • Oh, Seok-Hoon;Suh, Baek-Soo
    • Journal of the Korean earth science society
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    • v.31 no.6
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    • pp.555-562
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    • 2010
  • Three-dimensional laser scanner was used to accurately measure any possible strain on a slope under pertaining stress with the time difference of 7 months. The laser scanner has the ability to measure the 3-D coordinate of a target point by calculating the travel time of laser beam between the laser device and the target point, and has been proved to be effective for analysis of the displacement of slopes or large construction. The scanning data measured with time difference were analyzed to find any strain by approaches of plane angle change, curvature variation, twist of frame, displacement of merging point, etc. From the analysis, some weak points showing heavily distorted shape were detected, which was used to design the reinforcement.

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

  • Kwon, Sook-Hee;Hong, Ji-Un
    • Journal of the Korean Home Economics Association
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    • v.47 no.4
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    • pp.61-72
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    • 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

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

  • Yu, Kyung-Seok;Ryu, Il-Kwang
    • Journal of environmental and Sanitary engineering
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    • v.21 no.2 s.60
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    • pp.11-19
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    • 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.

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

  • Kim, Bong-Hyun;Cho, Dong-Uk
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.12B
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    • pp.1192-1198
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    • 2010
  • As indicators of life quality have recently shown great improvement, alternative medicine is becoming a mainstream health care pattern, in which early stage medical examinations and treatments are usually preformed before diseases occur. In this context, the ear-acupuncture method is increasingly used these day as one of important alternative medicine treatments. In this paper, we performed an experiment of facial region color analysis with kidney ear acupuncture point irritation. For this, we collected facial image samples before and after kidney ear acupuncture point irritation under the same condition. From the samples, the change rates of K, L values of CMYK color system and Lab color system, respectively, on kidney related facial parts were extracted and analyzed to investigate kidney function improvement.

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

  • Oh, Sung-Kwun;Oh, Seung-Hun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.63 no.6
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    • pp.797-803
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    • 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)
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    • v.16 no.3
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    • pp.1047-1062
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    • 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.

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

  • Jung, Il Won;Kim, Dong Yeong;Park, Jiyeon
    • Journal of The Korean Society of Agricultural Engineers
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    • v.61 no.1
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    • pp.21-29
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    • 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.