• Title/Summary/Keyword: 통계적 특성

Search Result 2,393, Processing Time 0.028 seconds

Nonlinear Destriping Algorithm of Satellite Images (비선형 보정을 이용한 위성영상의 줄무늬잡음 제거 알고리즘)

  • 박종현;최은철;강문기;김용승
    • Proceedings of the Korean Society of Broadcast Engineers Conference
    • /
    • 2001.11b
    • /
    • pp.135-138
    • /
    • 2001
  • 위성에 탑재된 전자광학 카메라(Electro-Optical Camera)로부터 획득된 영상에서는 카메라의 스캔 방향과 통일한 방향으로 "줄무늬잡음"이 발생하게 된다. 이는 센서의 특성이 통일하지 않고, 우주라는 열악한 환경에서 영상의 획득이 일어나기 때문이다. 똔 논문에서는 줄무늬잡음을 제거하기 위해 비선형 보정방법을 제안한다. 영상의 준균일성(quasi-homogeneous)과 센서특성의 시불변성(time-invariancy) 가정을 바탕으로, 보정하려는 열의 이웃 열을 참조하여 줄무늬잡음에 의한 오차를 추정하고 이를 최소화한다. 줄무늬 잡음 정도를 추정하기 위해 줄무늬잡음을 바이어스에 의한 것과 특성곡선의 경향 차이에 의한 것으로 나눈다. 바이어스에 의한 오차는 센서가 스캔하는 방향과 통일한 방향으로 통계적 특성을 이용하여 추정한다. 특성곡선의 경향차에 의한 오차는 보정하려는 열에서 동일한 박기 레벨을 갖는 화소들을 조사하고, 이들과 이웃하는 열의 동일 위치에 있는 화소의 밝기 레벨의 통계적 특성을 파악하여 추정한다. 이렇게 추정된 오차를 최소화함으로써, 줄무늬잡음을 효과적으로 제거하였다.적으로 제거하였다.

  • PDF

A study on the characterization and traffic modeling of MPEG video sources (MPEG 비디오 소스의 특성화 및 트래픽 모델링에 관한 연구)

  • Jeon, Yong-Hee;Park, Jung-Sook
    • The Transactions of the Korea Information Processing Society
    • /
    • v.5 no.11
    • /
    • pp.2954-2972
    • /
    • 1998
  • It is expected that the transport of compressed video will become a significant part of total network traffic because of the widespread introduction of multimedial services such as VOD(video on demand). Accordingly, VBR(variable bit-rate) encoded video will be widely used, due to its advantages in statistical multiplexing gain and consistent vido quality. Since the transport of video traffic requires larger bandwidth than that of voice and data, the characterization of video source and traffic modeling is very important for the design of proper resource allocation scheme in ATM networks. Suitable statistical source models are also required to analyze performance metrics such as packet loss, delay and jitter. In this paper, we analyzed and described on the characterization and traffic modeling of MPEG video sources. The models are broadly classified into two categories; i.e., statistical models and deterministic models. In statistical models, the models are categorized into five groups: AR(autoregressive), Markov, composite Marko and AR, TES, and selfsimilar models. In deterministic models, the models are categorized into $({\sigma},\;{\rho}$, parameterized model, D-BIND, and Empirical Envelopes models. Each model was analyzed for its characteristics along with corresponding advantages and shortcomings, and we made comparisons on the complexity of each model.

  • PDF

Recognition for Self-efficacy by Demographic Characteristics of Hotel Staffs; Deluxe Hotels in Seoul (호텔직원의 인구통계적특성에 따른 자기효능감에 대한 인식; 서울지역 특급호텔을 중심으로)

  • Kim, Jae-Gon;Kim, Yeon-Sun
    • The Journal of the Korea Contents Association
    • /
    • v.10 no.6
    • /
    • pp.450-459
    • /
    • 2010
  • The purpose of this study is to difference of the recognition for self-efficacy which staffs of deluxe hotel. This study aimed at: The first, I measure recognizing for self-efficacy which staffs at the first grade Hotel and the second grade hotel. The second, self-efficacy is factor analyzes for the study. The third, I study a difference of self-efficacy the first grade Hotel and between the second grade Hotel staffs. The fourth, I study whether there is a difference in recognition of self-efficacy by each demographic characteristic in Hotel staffs. To research and analyze, survey was conducted to 400 employees working at deluxe hotels in Seoul and 352 survey data were analyzed. The results come up with: The first, As for the recognition of self-efficacy the first grade Hotel and the second grade Hotel staffs, there was the difference that a level of significance. The second, marriage, major, educational background, work period and income level were the difference that a level of significance.

Attenuation Estimation of Soft Tissue by the Entropy Method and Statistical Averaging of Speckle Patterns (스펙클 패턴의 통계적 평균과 엔트로피 방식에 의한 초음파 감쇄계수 추정방법)

  • Song, T.K;Park, J.C;Park, S.B
    • Journal of Biomedical Engineering Research
    • /
    • v.10 no.3
    • /
    • pp.253-260
    • /
    • 1989
  • The time domain methods of estimating the attenuation coefficient are generally based on the analysis of statisical properties of the reflected echoes form an attenuating medium. Hence, it is often required to have a large number of data samples in order to obtain a statistically stable estimation result. In the attenuation estimation problem, this means that many different speckle patterns are required in the spatial resolution volume of an attenLlation image. In this paper, by using the fact that the speckle pattern Is sensitive to the point spread function of the ultrasound beam, we suggest a method to generate the statiscally uncorrelated or slightly correlated data samples in a given region by rotating a linear transducer and carrying out lateral scans for all rotating angles. This technique is applied to the entropy method for attenuation estimation proposed recently by the authors where the performance is verified by experiments using a tissue equivalent phantom.

  • PDF

Statistical Characteristics and Complexity Analysis of HEVC Encoder Software (HEVC 부호화기 소프트웨어의 통계적 특성 및 복잡도 분석)

  • Ahn, Yongjo;Hwang, Taejin;Yoo, Sungeun;Han, Woo-Jin;Sim, Donggyu
    • Journal of Broadcast Engineering
    • /
    • v.17 no.6
    • /
    • pp.1091-1105
    • /
    • 2012
  • In this paper, we analyzed statistical characteristics and complexity of HEVC encoder as a leading research of acceleration, optimization and parallelization. Computational complexity of the HEVC encoder is approximately twice the compression performance compared to H.264/AVC. But, the increase of encoder complexity remains a problem to be solved in the future. Before performing the research on acceleration, optimization and parallelization to reduce high complexity of HEVC encoder, we measure the complexity each module for HEVC encoder using it's reference software HM 7.1. We also measured the predicted complexity of fast HEVC encoder software, used in real applications, using HM 7.1 applying fast encoding method. The complexity is measured in terms of the operating cycle of the encoder software under the common test sequences and conditions in the Windows PC environment. In addition, we analyze statistical characteristics of HEVC encoder software according to encoding structures and limitation using coded bitstreams.

Spectral Signatures of Tombs and their Classification (묘지의 분광적 특성과 통계적 분류)

  • Eunmi Change;Kyeong Park;Minho Kim
    • Journal of the Korean Geographical Society
    • /
    • v.39 no.2
    • /
    • pp.283-296
    • /
    • 2004
  • More than 0.5 percent of land in Korea is used for cemetery and the rate is growing in spite of the increase in cremation these days. The systematic management of tombs may be possible through the ‘Feature Extraction’ method which is applied to the high-resolution satellite imagery. For this reason, this research focused on finding out the radiometric characteristics of tombs and the classification of them. An IKONOS image of northwest areas of Seoul with 8km x 10km dimension was analyzed. After sampling 24 tombs in the study area, the statistical radiometric characteristics of tombs are analyzed. And tombs were classified based on the criteria such as landscape, NDVI, and cluster analysis. In addition, it was investigated if the aspect or slope of the terrain influenced to the classification of tombs. As a result of this research, authors find that there is similarity between the classification tv NDVI and the classification through cluster analysis. And aspect or slope didn't have much influence on the classification of tombs.