• Title/Summary/Keyword: Difference Map

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A Study on the Mapping of Wind Resource using Vegetation Index Technique at North East Area in Jeju Island (영상자료의 식생지수를 이용한 제주 북동부 지역의 풍력자원지도 작성에 관한 연구)

  • Byun, Ji Seon;Lee, Byung Gul;Moon, Seo Jung
    • Journal of Korean Society for Geospatial Information Science
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    • v.23 no.1
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    • pp.15-22
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    • 2015
  • To create a wind resource map, we need a contour map, a roughness map and wind data. We need a land cover map for the roughness map of these data. A land cover map represents the area showing similar characteristics after color indexing based on the scientific method. The features of land cover is classified by Remote sensing technique. In this study, we verified the application of the NDVI technique is reasonable after we created the wind resource map using roughness maps by unsupervised classification and NDVI technique. As a result, the wind resource map using the NDVI technique showed a 60% accordance rate and difference in class less than one. From the results, The NDVI technique is found alternative to create roughness maps by the unsupervised classification.

A Study on High Performance Torque Control of 48V Wound Rotor Synchronous Motor Using Flux Mapping (48V 계자 권선형 동기전동기 고성능 자속기반 토크제어)

  • Kim, Seonhyeong;Chun, Kwangsu;Park, Hongjoo;Park, Kyusung;Jin, Wonjoon;Lee, Geunho
    • Journal of Institute of Control, Robotics and Systems
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    • v.21 no.12
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    • pp.1142-1151
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    • 2015
  • In this paper, High performance torque control based on the flux mapping of 48V Wound Rotor Synchronous Motor has been studied to improve torque control. Flux map considering MTPA (Maximum Torque Per Ampere), MFPT (Minimum Flux Per Torque), Maximum efficiency point at the same torque command and flux command for each field current was produced. Current map using flux mapping of Each field current was applied to the MTPA, MFPT. Generating a current vector locus was to determine the characteristics of the operation region. Through the Matlab/Simulink simulation, difference between speed-torque map and flux map was represented. The suggested flux map was tested actual experiments on a dynamometer.

Extraction of an Effective Saliency Map for Stereoscopic Images using Texture Information and Color Contrast (색상 대비와 텍스처 정보를 이용한 효과적인 스테레오 영상 중요도 맵 추출)

  • Kim, Seong-Hyun;Kang, Hang-Bong
    • Journal of Korea Multimedia Society
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    • v.18 no.9
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    • pp.1008-1018
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    • 2015
  • In this paper, we propose a method that constructs a saliency map in which important regions are accurately specified and the colors of the regions are less influenced by the similar surrounding colors. Our method utilizes LBP(Local Binary Pattern) histogram information to compare and analyze texture information of surrounding regions in order to reduce the effect of color information. We extract the saliency of stereoscopic images by integrating a 2D saliency map with depth information of stereoscopic images. We then measure the distance between two different sizes of the LBP histograms that are generated from pixels. The distance we measure is texture difference between the surrounding regions. We then assign a saliency value according to the distance in LBP histogram. To evaluate our experimental results, we measure the F-measure compared to ground-truth by thresholding a saliency map at 0.8. The average F-Measure is 0.65 and our experimental results show improved performance in comparison with existing other saliency map extraction methods.

Map Building Using ICP Algorithm based a Robot Position Prediction (로봇 위치 예측에 기반을 둔 ICP 알고리즘을 이용한 지도 작성)

  • Noh, Sung-Woo;Kim, Tae-Gyun;Ko, Nak-Yong
    • The Journal of the Korea institute of electronic communication sciences
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    • v.8 no.4
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    • pp.575-582
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    • 2013
  • This paper proposes a map building using the ICP algorithm based robot localization prediction. Proposed method predicts a robot location to dead reckoning, makes a map in the ICP algorithm. Existing method makes a map building and robot position using a sensor value of reference data and current data. In this case, a large interval of the difference of the reference data and the current data is difficult to compensate. The proposed method can map correction through practical experiments.

Real-Time 2D-to-3D Conversion for 3DTV using Time-Coherent Depth-Map Generation Method

  • Nam, Seung-Woo;Kim, Hye-Sun;Ban, Yun-Ji;Chien, Sung-Il
    • International Journal of Contents
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    • v.10 no.3
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    • pp.9-16
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    • 2014
  • Depth-image-based rendering is generally used in real-time 2D-to-3D conversion for 3DTV. However, inaccurate depth maps cause flickering issues between image frames in a video sequence, resulting in eye fatigue while viewing 3DTV. To resolve this flickering issue, we propose a new 2D-to-3D conversion scheme based on fast and robust depth-map generation from a 2D video sequence. The proposed depth-map generation algorithm divides an input video sequence into several cuts using a color histogram. The initial depth of each cut is assigned based on a hypothesized depth-gradient model. The initial depth map of the current frame is refined using color and motion information. Thereafter, the depth map of the next frame is updated using the difference image to reduce depth flickering. The experimental results confirm that the proposed scheme performs real-time 2D-to-3D conversions effectively and reduces human eye fatigue.

A Comparison of Estimation Method for Population Exposed to Noise Using Noise Map (소음지도를 이용한 소음노출인구 산정방법별 비교)

  • Choi, Sung Kyu;Lee, Byung Chan
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.24 no.10
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    • pp.802-808
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    • 2014
  • The purpose of this study is to suggest efficient methods for estimating population exposed to noises by analyzing differences of population exposed to noises estimated by each method through comparing exposed population estimated by utilizing existing methods and those estimated by using census output areas reflecting the actual population information of each address. For population exposed to noises, the error of exposed population estimated by using the per capita living space turned out to be the biggest, and other estimation methods had no significant difference. For population exposed to excess noises, as a result of analyzing population estimated by each method based on census output areas, the error of the method using a grid noise map turned out to be the biggest. For the method to estimate population exposed to noises by using a noise map, the estimation methods using census output areas and total ground area are considered to be more rational than the grid noise map estimation method or the method to estimate the living space per capita.

Performance Comparison of Depth Map Based Landing Methods for a Quadrotor in Unknown Environment (미지 환경에서의 깊이지도를 이용한 쿼드로터 착륙방식 성능 비교)

  • Choi, Jong-Hyuck;Park, Jongho;Lim, Jaesung
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.50 no.9
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    • pp.639-646
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    • 2022
  • Landing site searching algorithms are developed for a quadrotor using a depth map in unknown environment. Guidance and control system of Unmanned Aerial Vehicle (UAV) consists of a trajectory planner, a position and an attitude controller. Landing site is selected based on the information of the depth map which is acquired by a stereo vision sensor attached on the gimbal system pointing downwards. Flatness information is obtained by the maximum depth difference of a predefined depth map region, and the distance from the UAV is also considered. This study proposes three landing methods and compares their performance using various indices such as UAV travel distance, map accuracy, obstacle response time etc.

Function Approximation for Reinforcement Learning using Fuzzy Clustering (퍼지 클러스터링을 이용한 강화학습의 함수근사)

  • Lee, Young-Ah;Jung, Kyoung-Sook;Chung, Tae-Choong
    • The KIPS Transactions:PartB
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    • v.10B no.6
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    • pp.587-592
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    • 2003
  • Many real world control problems have continuous states and actions. When the state space is continuous, the reinforcement learning problems involve very large state space and suffer from memory and time for learning all individual state-action values. These problems need function approximators that reason action about new state from previously experienced states. We introduce Fuzzy Q-Map that is a function approximators for 1 - step Q-learning and is based on fuzzy clustering. Fuzzy Q-Map groups similar states and chooses an action and refers Q value according to membership degree. The centroid and Q value of winner cluster is updated using membership degree and TD(Temporal Difference) error. We applied Fuzzy Q-Map to the mountain car problem and acquired accelerated learning speed.

A Base Study of Intergrated Map for Integrated Coastal Zone Management (연안통합관리를 위한 통합수치도 개발에 관한 연구)

  • Yi, Gi-Chul;Suh, Sang-Hyun;Jeong, Hui-Gyun;Park, Chang-Ho;Yeo, Ki-Tae
    • Journal of the Korean association of regional geographers
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    • v.9 no.4
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    • pp.425-436
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    • 2003
  • Integrated approach is presented by developing the technology and the ways of the practical use of the integrated digital map of and Electronical Navigational Chart (ENC) and Digital Terrain Map (DTM) for the effective and scientific based conservation, development and management of coastal area in this study. At first as preliminary studies to make eventual integrated maps, the necessity of the integrated map is described with the concept of coastal areas. Then, the characteristics of digital maps developed by Korean Geography Institute and National Marine Investigation Institute are carefully analyzed and integrated to a digital map as a test for edge matching in coastal line. Developed test coastal map was overlayed with a high-resolution satellite image (KVR-1000). The ground survey using Global Positioning System was conducted for the analysis of edge matching along the coastal line. Results from the edge matching analysis of coastal lines showed about 14 meters mean difference in artificial terrain and 4 meters mean difference in natural terrain. The problems, causes and solutions for the edge-matched differences are described. Furthermore, the value of utilization, the future use and various fields of application produced by the integrated digital map database are suggested as a basis for ICZM implementation in South Korea.

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Comparative Analysis of NDWI and Soil Moisture Map Using Sentinel-1 SAR and KOMPSAT-3 Images (KOMPSAT-3와 Sentinel-1 SAR 영상을 적용한 토양 수분도와 NDWI 결과 비교 분석)

  • Lee, Jihyun;Kim, Kwangseob;Lee, Kiwon
    • Korean Journal of Remote Sensing
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    • v.38 no.6_4
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    • pp.1935-1943
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    • 2022
  • The development and application of a high-resolution soil moisture mapping method using satellite imagery has been considered one of the major research themes in remote sensing. In this study, soil moisture mapping in the test area of Jeju Island was performed. The soil moisture was calculated with optical images using linearly adjusted Synthetic Aperture Radar (SAR) polarization images and incident angle. SAR Backscatter data, Analysis Ready Data (ARD) provided by Google Earth Engine (GEE), was used. In the soil moisture processing process, the optical image was applied to normalized difference vegetation index (NDVI) by surface reflectance of KOMPSAT-3 satellite images and the land cover map of Environmental Systems Research Institute (ESRI). When the SAR image and the optical images are fused, the reliability of the soil moisture product can be improved. To validate the soil moisture mapping product, a comparative analysis was conducted with normalized difference water index (NDWI) products by the KOMPSAT-3 image and those of the Landsat-8 satellite. As a result, it was shown that the soil moisture map and NDWI of the study area were slightly negative correlated, whereas NDWI using the KOMPSAT-3 images and the Landsat-8 satellite showed a highly correlated trend. Finally, it will be possible to produce precise soil moisture using KOMPSAT optical images and KOMPSAT SAR images without other external remotely sensed images, if the soil moisture calculation algorithm used in this study is further developed for the KOMPSAT-5 image.