• Title/Summary/Keyword: data depth

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Simplicial Regression Depth with Censored and Truncated Data

  • Park, Jinho
    • Communications for Statistical Applications and Methods
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    • v.10 no.1
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    • pp.167-175
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    • 2003
  • In this paper we develop a robust procedure to estimate regression coefficients for a linear model with censored and truncated data based on simplicial regression depth. Simplicial depth of a point is defined as the proportion of data simplices containing it. This simplicial depth can be extended to regression problem with censored and truncated data. Any line can be given a depth and the deepest regression line is the line with the maximum simplicial regression depth. We show how the proposed regression performs through analyzing AIDS incubation data.

Coding Technique using Depth Map in 3D Scalable Video Codec (확장된 스케일러블 비디오 코덱에서 깊이 영상 정보를 활용한 부호화 기법)

  • Lee, Jae-Yung;Lee, Min-Ho;Chae, Jin-Kee;Kim, Jae-Gon;Han, Jong-Ki
    • Journal of Broadcast Engineering
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    • v.21 no.2
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    • pp.237-251
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    • 2016
  • The conventional 3D-HEVC uses the depth data of the other view instead of that of the current view because the texture data has to be encoded before the corresponding depth data of the current view has been encoded, where the depth data of the other view is used as the predicted depth for the current view. Whereas the conventional 3D-HEVC has no other candidate for the predicted depth information except for that of the other view, the scalable 3D-HEVC utilizes the depth data of the lower spatial layer whose view ID is equal to that of the current picture. The depth data of the lower spatial layer is up-scaled to the resolution of the current picture, and then the enlarged depth data is used as the predicted depth information. Because the quality of the enlarged depth is much higher than that of the depth of the other view, the proposed scheme increases the coding efficiency of the scalable 3D-HEVC codec. Computer simulation results show that the scalable 3D-HEVC is useful and the proposed scheme to use the enlarged depth data for the current picture provides the significant coding gain.

Nonparametric two sample tests for scale parameters of multivariate distributions

  • Chavan, Atul R;Shirke, Digambar T
    • Communications for Statistical Applications and Methods
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    • v.27 no.4
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    • pp.397-412
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    • 2020
  • In this paper, a notion of data depth is used to propose nonparametric multivariate two sample tests for difference between scale parameters. Data depth can be used to measure the centrality or outlying-ness of the multivariate data point relative to data cloud. A difference in the scale parameters indicates the difference in the depth values of a multivariate data point. By observing this fact on a depth vs depth plot (DD-plot), we propose nonparametric multivariate two sample tests for scale parameters of multivariate distributions. The p-values of these proposed tests are obtained by using Fisher's permutation approach. The power performance of these proposed tests has been reported for few symmetric and skewed multivariate distributions with the existing tests. Illustration with real-life data is also provided.

Extraction of Snow Cover Area and Depth Using MODIS Image for 5 River Basins South Korea (MODIS 위성영상을 이용한 국내 5대강 유역 적설분포 및 적설심 추출)

  • Hong, U-Yong;Sin, Hyeong-Jin;Kim, Seong-Jun
    • KCID journal
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    • v.14 no.2
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    • pp.225-235
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    • 2007
  • The shape of streamflow hydrograph during the early period of spring is very much controlled by the area and depth of snow cover especially in mountainous area. When we simulate the streamfolw of a watershed snowmelt, we need some information for snow cover extent and depth distribution as parameters and input data in the hydrological models. The purpose of this study is to suggest an extraction method of snow cover area and snow depth distribution using Terra MODIS image. Snow cover extent for South Korea was extracted for the period of December 2000 and April 2006. For the snow cover area, the snow depth was interpolated using the snow depth data from 69 meteorological observation stations. With these data, it is necessary to run a hydrological model considering the snow-related data and compare the simulated streamflow with the observed data and check the applicability for the snowmelt simulation.

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Development of a Stochastic Snow Depth Prediction Model Using a Bayesian Deep Learning Method (베이지안 딥러닝 기법을 이용한 확률적 적설심 예측 모델 개발)

  • Jeong, Youngjoon;Lee, Sang-ik;Lee, Jonghyuk;Seo, Byunghun;Kim, Dongsu;Seo, Yejin;Choi, Won
    • Journal of The Korean Society of Agricultural Engineers
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    • v.64 no.6
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    • pp.35-41
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    • 2022
  • Heavy snow damage can be prevented in advance with an appropriate security system. To develop the security system, we developed a model that predicts snow depth after a few hours when the snow depth is observed, and utilized it to calculate a failure probability with various types of greenhouses and observed snow depth data. We compared the Markov chain model and Bayesian long short-term memory models with varying input data. Markov chain model showed the worst performance, and the models that used only past snow depth data outperformed the models that used other weather data with snow depth (temperature, humidity, wind speed). Also, the models that utilized 1-hour past data outperformed the models that utilized 3-hour data and 6-hour data. Finally, the Bayesian LSTM model that uses 1-hour snow depth data was selected to predict snow depth. We compared the selected model and the shifting method, which uses present data as future data without prediction, and the model outperformed the shifting method when predicting data after 11-24 hours.

A New Copyright Protection Scheme for Depth Map in 3D Video

  • Li, Zhaotian;Zhu, Yuesheng;Luo, Guibo;Guo, Biao
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.7
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    • pp.3558-3577
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    • 2017
  • In 2D-to-3D video conversion process, the virtual left and right view can be generated from 2D video and its corresponding depth map by depth image based rendering (DIBR). The depth map plays an important role in conversion system, so the copyright protection for depth map is necessary. However, the provided virtual views may be distributed illegally and the depth map does not directly expose to viewers. In previous works, the copyright information embedded into the depth map cannot be extracted from virtual views after the DIBR process. In this paper, a new copyright protection scheme for the depth map is proposed, in which the copyright information can be detected from the virtual views even without the depth map. The experimental results have shown that the proposed method has a good robustness against JPEG attacks, filtering and noise.

Depth-Based rank test for multivariate two-sample scale problem

  • Digambar Tukaram Shirke;Swapnil Dattatray Khorate
    • Communications for Statistical Applications and Methods
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    • v.30 no.3
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    • pp.227-244
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    • 2023
  • In this paper, a depth-based nonparametric test for a multivariate two-sample scale problem is proposed. The proposed test statistic is based on the depth-induced ranks and is thus distribution-free. In this article, the depth values of data points of one sample are calculated with respect to the other sample or distribution and vice versa. A comprehensive simulation study is used to examine the performance of the proposed test for symmetric as well as skewed distributions. Comparison of the proposed test with the existing depth-based nonparametric tests is accomplished through empirical powers over different depth functions. The simulation study admits that the proposed test outperforms existing nonparametric depth-based tests for symmetric and skewed distributions. Finally, an actual life data set is used to demonstrate the applicability of the proposed test.

View Synthesis and Coding of Multi-view Data in Arbitrary Camera Arrangements Using Multiple Layered Depth Images

  • Yoon, Seung-Uk;Ho, Yo-Sung
    • Journal of Multimedia Information System
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    • v.1 no.1
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    • pp.1-10
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    • 2014
  • In this paper, we propose a new view synthesis technique for coding of multi-view color and depth data in arbitrary camera arrangements. We treat each camera position as a 3-D point in world coordinates and build clusters of those vertices. Color and depth data within a cluster are gathered into one camera position using a hierarchical representation based on the concept of layered depth image (LDI). Since one camera can cover only a limited viewing range, we set multiple reference cameras so that multiple LDIs are generated to cover the whole viewing range. Therefore, we can enhance the visual quality of the reconstructed views from multiple LDIs comparing with that from a single LDI. From experimental results, the proposed scheme shows better coding performance under arbitrary camera configurations in terms of PSNR and subjective visual quality.

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A study on the Effective Utilization of Temperature Logging Data for Calculating Geothermal Gradient (지온경사 산출을 위한 효율적인 온도검층자료 이용방법 연구)

  • 김형찬
    • Economic and Environmental Geology
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    • v.32 no.5
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    • pp.503-517
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    • 1999
  • The purpose of this study is to verfify a more effecive techique for calculating geothermal gradient. this study examines 370 data of temperature-logging having been collected since 1985. The daya are divided into three different grades grades according to the type of temperature-depth plots: 204 data show typical linear gradient (Grade A); 126 data do not explicitily show the gradient becase of various external effects such as water flow (Grade B); and the rest 40 data do not show the gradient at all (Grade D). The new technique for calculating geothermal gradient is to be required to use Greade-B data more effctiviely. This new technique includes (1) calculating the independer depth of atmospheric temperature in the earth; (2) drawing a distribution map of subsurface tempurature by using the distribution map of subsurface temperature by using Grade-A data at the independent depth; and (3) recalculating geothermal gradient of Grade-B data by using the distrbution map of subsurface temperature, borehole depth, and bottom temperature of Grade-B data by using the distribution map of subsurface temperature, borehole depth, and bottom temperature of Grade-B data. As a result, 330 data-both Grade-A and Grade-B data--can be used to draw a distribution map of hot spradient. The map clearly distinguishes anomaly areas, and helps interpret their relations to the distribution of hot springs, geology, geological structures, and geophysical anomaly areas. These new results reveal that the average of geothermal in south Korea is 25.6$^{\circ}C$/km, when calculated to the Kriging method.

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