• Title/Summary/Keyword: The Resolution

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Study on the Reconstruction of Pressure Field in Sloshing Simulation Using Super-Resolution Convolutional Neural Network (심층학습 기반 초해상화 기법을 이용한 슬로싱 압력장 복원에 관한 연구)

  • Kim, Hyo Ju;Yang, Donghun;Park, Jung Yoon;Hwang, Myunggwon;Lee, Sang Bong
    • Journal of the Society of Naval Architects of Korea
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    • v.59 no.2
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    • pp.72-79
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    • 2022
  • Deep-learning-based Super-Resolution (SR) methods were evaluated to reconstruct pressure fields with a high resolution from low-resolution images taken from a coarse grid simulation. In addition to a canonical SRCNN(super-resolution convolutional neural network) model, two modified models from SRCNN, adding an activation function (ReLU or Sigmoid function) to the output layer, were considered in the present study. High resolution images obtained by three models were more vivid and reliable qualitatively, compared with a conventional super-resolution method of bicubic interpolation. A quantitative comparison of statistical similarity showed that SRCNN model with Sigmoid function achieved best performance with less dependency on original resolution of input images.

Effects of Resolution, Cumulus Parameterization Scheme, and Probability Forecasting on Precipitation Forecasts in a High-Resolution Limited-Area Ensemble Prediction System

  • On, Nuri;Kim, Hyun Mee;Kim, SeHyun
    • Asia-Pacific Journal of Atmospheric Sciences
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    • v.54 no.4
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    • pp.623-637
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    • 2018
  • This study investigates the effects of horizontal resolution, cumulus parameterization scheme (CPS), and probability forecasting on precipitation forecasts over the Korean Peninsula from 00 UTC 15 August to 12 UTC 14 September 2013, using the limited-area ensemble prediction system (LEPS) of the Korea Meteorological Administration. To investigate the effect of resolution, the control members of the LEPS with 1.5- and 3-km resolution were compared. Two 3-km experiments with and without the CPS were conducted for the control member, because a 3-km resolution lies within the gray zone. For probability forecasting, 12 ensemble members with 3-km resolution were run using the LEPS. The forecast performance was evaluated for both the whole study period and precipitation cases categorized by synoptic forcing. The performance of precipitation forecasts using the 1.5-km resolution was better than that using the 3-km resolution for both the total period and individual cases. The result of the 3-km resolution experiment with the CPS did not differ significantly from that without it. The 3-km ensemble mean and probability matching (PM) performed better than the 3-km control member, regardless of the use of the CPS. The PM complemented the defect of the ensemble mean, which better predicts precipitation regions but underestimates precipitation amount by averaging ensembles, compared to the control member. Further, both the 3-km ensemble mean and PM outperformed the 1.5-km control member, which implies that the lower performance of the 3-km control member compared to the 1.5-km control member was complemented by probability forecasting.

A Study on Super Resolution Algorithm to Improve Spatial Resolution of Optical Signals (광신호의 공간 해상도 향상을 위한 초 분해능 알고리즘 연구)

  • Lee, Byung-Jin;Yu, Bong-Guk;Kim, Kyung-Seok
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.18 no.1
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    • pp.71-77
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    • 2018
  • The optical time domain reflectometer (OTDR) is the most widely used method to monitor problems with currently installed optical fibers. The OTDR is an instrument designed to test the FTTx network and evaluates the physical properties of the fiber, such as transmission loss and connection loss. It is important to improve the spatial resolution in order to accurately grasp the optical path problems by using the OTDR. When the pulse width is less than twice the distance between the two reflectors, the signals reflected from the two reflectors are reflected without overlap, so that the reflected signal can be distinguished. However, when the pulse width is larger than twice the distance between the two reflectors, so that the reflected signal can not be distinguished. In order to overcome these limitations, this paper proposed a method of improving spatial resolution by applying a super resolution algorithm. As a result of the simulation, the resolution is improved when the super resolution algorithm is applied, and the event interval can be analyzed more precisely.

A Study on the Establishment of an Arbitration System for the Resolution of Domestic Sports Disputes (국내 스포츠분쟁해결기구의 설치에 관한 소고)

  • Kim, Dae-Hee
    • Journal of Arbitration Studies
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    • v.24 no.1
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    • pp.159-179
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    • 2014
  • Currently disputes related to sports arise in various ways. Moreover, as the awareness of the rights of the people in the field of sports grows the chances of disputes occurring increases. Therefore, the number of sports disputes which will be dealt with by courts will increase. On the other hand, there are demands for fast and efficient legal resolutions for diverse sports disputes. However, as a dispute resolution system, the current domestic arbitration for sports disputes exposed several problems: the lack of professional arbitrators for sports disputes, procedural elements of delay, and the lack of promotion of the arbitration system. This study will first analyze the system for the resolution of domestic sports disputes. Then this study will review of the system for the resolution of international sports disputes and propose the establishment of an arbitration system for the resolution of domestic sports disputes.

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Image Fusion Framework for Enhancing Spatial Resolution of Satellite Image using Structure-Texture Decomposition (구조-텍스처 분할을 이용한 위성영상 융합 프레임워크)

  • Yoo, Daehoon
    • Journal of the Korea Computer Graphics Society
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    • v.25 no.3
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    • pp.21-29
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    • 2019
  • This paper proposes a novel framework for image fusion of satellite imagery to enhance spatial resolution of the image via structure-texture decomposition. The resolution of the satellite imagery depends on the sensors, for example, panchromatic images have high spatial resolution but only a single gray band whereas multi-spectral images have low spatial resolution but multiple bands. To enhance the spatial resolution of low-resolution images, such as multi-spectral or infrared images, the proposed framework combines the structures from the low-resolution image and the textures from the high-resolution image. To improve the spatial quality of structural edges, the structure image from the low-resolution image is guided filtered with the structure image from the high-resolution image as the guidance image. The combination step is performed by pixel-wise addition of the filtered structure image and the texture image. Quantitative and qualitative evaluation demonstrate the proposed method preserves spectral and spatial fidelity of input images.

Generation and Verification on the Synthetic Precipitation/Temperature Data

  • Oh, Jai-Ho;Kang, Hyung-Jeon
    • Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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    • 2016.09a
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    • pp.25-28
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    • 2016
  • Recently, because of the weather forecasts through the low-resolution data has been limited, the demand of the high-resolution data is sharply increasing. Therefore, in this study, we restore the ultra-high resolution synthetic precipitation and temperature data for 2000-2014 due to small-scale topographic effect using the QPM (Quantitative Precipitation Model)/QTM (Quantitative Temperature Model). First, we reproduce the detailed precipitation and temperature data with 1km resolution using the distribution of Automatic Weather System (AWS) data and Automatic Synoptic Observation System (ASOS) data, which is about 10km resolution with irregular grid over South Korea. Also, we recover the precipitation and temperature data with 1km resolution using the MERRA reanalysis data over North Korea, because there are insufficient observation data. The precipitation and temperature from restored current climate reflect more detailed topographic effect than irregular AWS/ASOS data and MERRA reanalysis data over the Korean peninsula. Based on this analysis, more detailed prospect of regional climate is investigated.

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Changes in the Emotion by the Expressive Definition of Visual Contents (영상콘텐츠의 표현밀도에 따른 감정의 변화)

  • Kim, Se-Hwa
    • The Journal of the Korea Contents Association
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    • v.10 no.1
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    • pp.192-201
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    • 2010
  • This research deals with expressive definition of visual contents by using the distance between a subject and a screen resolution, and what changes affect the emotion of those looking at the expressive definition. A visual image captured from a HDTV screen was shown to the 61 students attending a university in the Busan area and SAM evaluation method was used to measure 3 different emotions such as pleasant, arousal, and dominance. While comparing different resolution, looking at high resolution contents rather than low resolution resulted in a direction of pleasant, arousal, and dominance. Also showing a different resolution than consistently showing the same resolution had a more volatile emotional effect. Aftermath multiple comparison resulted in a tendency for emotions to become unpleasant and un-arousal when high resolution contents were shown and then switched to a low resolution contents. There was no result of any significance in the control variables. Also on the aftermath multiple comparison on short, medium and long distance between the subject and the screen resolution, short distance had a bigger pleasant, arousal, and dominance emotional numbers than the rest. In a multiple variable verification result, a resolution and the distance of happiness and excitement showed a positive correlation.

LOW RESOLUTION RAINFALL ESTIMATIONS FROM PASSIVE MICROWAVE RADIOMETERS

  • Shin, Dong-Bin
    • Proceedings of the KSRS Conference
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    • 2007.10a
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    • pp.378-381
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    • 2007
  • Analyses of Tropical Rainfall Measuring Mission (TRMM) microwave radiometer (TMI) and precipitation radar (PR) data show that the rainfall inhomogeneity, represented by the coefficient of variation, decreases as rain rate increases at the low resolution (the footprint size of TMI 10 GHz channel). The rainfall inhomogeneity, however, is relatively constant for all rain rates at the high resolution (the footprint size of TMI 37 GHz channel). Consequently, radiometric signatures at lower spatial resolutions are characterized by larger dynamic range and smaller variability than those at higher spatial resolution. Based on the observed characteristics, this study develops a low-resolution (${\sim}40{\times}40$ km) rainfall retrieval algorithm utilizing realistic rainfall distributions in the a-priori databases. The purpose of the low-resolution rainfall algorithm is to make more reliable climatological rainfalls from various microwave sensors, including low-resolution radiometers.

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GCP(GROUND CONTROL POINT) FOR AUTOMATION OF THE HIGH RESOLUTION SATELLITE IMAGE REVISION

  • Jo, Myung-Hee;Jung, Yun-Jae
    • Proceedings of the KSRS Conference
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    • 2007.10a
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    • pp.219-222
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    • 2007
  • Today, use of high resolution satellite image with at least 1m resolution is expanding into many more areas including forest, river way, city, seashore and so forth for disaster prevention. Interest in this medium is increasing among the general public due to the roll-out to the private sector as Google earth, Virtual Earth and so forth. However, pre-processing process that revises the geometrical distortion that result at the time of photographing is required in order to use high resolution satellite image. The purpose of this research is to search the most accurate GCP(Ground Control Point) information acquisition method that is used for the revision of high resolution satellite image's geometrical distortion through automated processing. Through this, it is possible to contribute to increasing the level of accuracy at the time of high resolution satellite image revision and to secure promptness.

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VARIOGRAM-BASED URBAN CHARACTERIZATION USING HIGH RESOLUTION SATELLITE IMAGERY

  • Yoo, Hee-Young;Lee, Ki-Won;Kwon, Byung-Doo
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.413-416
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    • 2006
  • As even small features can be classified as high resolution imagery, urban remote sensing is regarded as one of the important application fields in time of wide use of the commercialized high resolution satellite imageries. In this study, we have analyzed the variogram properties of high resolution imagery, which was obtained in urban area through the simple modeling and applied to the real image. Based on the grasped variogram characteristics, we have tried to decomposed two high-resolution imagery such as IKONOS and QuickBird reducing window size until the unique variogram that urban feature has come out and then been indexed. Modeling results will be used as the fundamental data for variographic analysis in urban area using high resolution imagery later on. Index map also can be used for determining urban complexity or land-use classification, because the index is influenced by the feature size.

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