• 제목/요약/키워드: Spatial Correlations

검색결과 259건 처리시간 0.022초

A Spatial Band Wavelet Video Coding

  • Kim, Eung-Tae;Park, Sang-Ju
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2002년도 ITC-CSCC -1
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    • pp.603-606
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    • 2002
  • EZW, a wavelet transformation based compression algorithm, utilizes the correlations of the wavelet coefficients between subbands. Due to the reason that, it is based on Zero Tree's parent-descendant dependency of the subbands, subband coding is possible, but it is not efficient for applications, which require multi-resolution restorations. In this paper we compare and analyze the performance between spatial band coding, which apply the correlation between adjusting pixels, and EZW So as to prove that spatial band coding is superior to EZW in the sense that it exhibit higher PSNR values and that it is apt to molti-resolution restoration.

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Comparison of Small Area Estimations by Sample Sizes

  • Kim, Jung-O;Shin, Key-Il
    • Communications for Statistical Applications and Methods
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    • 제13권3호
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    • pp.669-683
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    • 2006
  • Model-based methods are generally used for small area estimation. Recently Shin and Lee (2003) suggested a method which used spatial correlations between areas for data set including some auxiliary variables. However in case of absence of auxiliary variables, Direct estimator is used. Even though direct estimator is unbiased, the large variance of the estimator restricts the use for small area estimation. In this paper, we suggest new estimators which take into account spatial correlation when auxiliary variables are not available. We compared Direct estimator and the newly suggested estimators using MSE, MAE and MB.

스케일러블 비디오 부호화와 AT-DMB (Scalable Video Coding and its Application to AT-DMB)

  • 김재곤;김진수;최해철;강정원
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2008년도 하계종합학술대회
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    • pp.45-48
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    • 2008
  • This paper presents a brief overview of scalable video coding (SVC) with a focus on spatial scalability and its application to Advanced Terrestrial-DMB (AT-DMB). By adopting SVC with two spatial-layers and hierarchical modulation, AT-DMB provides standard definition (SD)-level video while maintaining compatability with the existing CIF-level video. In this paper, we suggest a layer-configuration and coding parameters of SVC which are well suit for an AT-DMB system. In order to reduce extremely large encoding time resulted by an exhaustive search of a macroblock coding mode in spatial scalability, we propose a fast mode decision method which excludes redundant modes in each layer. It utilizes the mode distribution of each layer and their correlations. Experimental results show that a simplified encoding model with the method reduces the computational complexity significantly with negligible coding loss.

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SPATIAL EXPLANATIONS OF SPEECH PERCEPTION: A STUDY OF FRICATIVES

  • Choo, Won;Mark Huckvale
    • 대한음성학회:학술대회논문집
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    • 대한음성학회 1996년도 10월 학술대회지
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    • pp.399-403
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    • 1996
  • This paper addresses issues of perceptual constancy in speech perception through the use of a spatial metaphor for speech sound identity as opposed to a more conventional characterisation with multiple interacting acoustic cues. This spatial representation leads to a correlation between phonetic, acoustic and auditory analyses of speech sounds which can serve as the basis for a model of speech perception based on the general auditory characteristics of sounds. The correlations between the phonetic, perceptual and auditory spaces of the set of English voiceless fricatives /f $\theta$ s $\int$ h / are investigated. The results show that the perception of fricative segments may be explained in terms of 2-dimensional auditory space in which each segment occupies a region. The dimensions of the space were found to be the frequency of the main spectral peak and the 'peakiness' of spectra. These results support the view that perception of a segment is based on its occupancy of a multi-dimensional parameter space. In this way, final perceptual decisions on segments can be postponed until higher level constraints can also be met.

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Abnormal Behavior Recognition Based on Spatio-temporal Context

  • Yang, Yuanfeng;Li, Lin;Liu, Zhaobin;Liu, Gang
    • Journal of Information Processing Systems
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    • 제16권3호
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    • pp.612-628
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    • 2020
  • This paper presents a new approach for detecting abnormal behaviors in complex surveillance scenes where anomalies are subtle and difficult to distinguish due to the intricate correlations among multiple objects' behaviors. Specifically, a cascaded probabilistic topic model was put forward for learning the spatial context of local behavior and the temporal context of global behavior in two different stages. In the first stage of topic modeling, unlike the existing approaches using either optical flows or complete trajectories, spatio-temporal correlations between the trajectory fragments in video clips were modeled by the latent Dirichlet allocation (LDA) topic model based on Markov random fields to obtain the spatial context of local behavior in each video clip. The local behavior topic categories were then obtained by exploiting the spectral clustering algorithm. Based on the construction of a dictionary through the process of local behavior topic clustering, the second phase of the LDA topic model learns the correlations of global behaviors and temporal context. In particular, an abnormal behavior recognition method was developed based on the learned spatio-temporal context of behaviors. The specific identification method adopts a top-down strategy and consists of two stages: anomaly recognition of video clip and anomalous behavior recognition within each video clip. Evaluation was performed using the validity of spatio-temporal context learning for local behavior topics and abnormal behavior recognition. Furthermore, the performance of the proposed approach in abnormal behavior recognition improved effectively and significantly in complex surveillance scenes.

Cure rate proportional odds models with spatial frailties for interval-censored data

  • Yiqi, Bao;Cancho, Vicente Garibay;Louzada, Francisco;Suzuki, Adriano Kamimura
    • Communications for Statistical Applications and Methods
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    • 제24권6호
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    • pp.605-625
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    • 2017
  • This paper presents proportional odds cure models to allow spatial correlations by including spatial frailty in the interval censored data setting. Parametric cure rate models with independent and dependent spatial frailties are proposed and compared. Our approach enables different underlying activation mechanisms that lead to the event of interest; in addition, the number of competing causes which may be responsible for the occurrence of the event of interest follows a Geometric distribution. Markov chain Monte Carlo method is used in a Bayesian framework for inferential purposes. For model comparison some Bayesian criteria were used. An influence diagnostic analysis was conducted to detect possible influential or extreme observations that may cause distortions on the results of the analysis. Finally, the proposed models are applied for the analysis of a real data set on smoking cessation. The results of the application show that the parametric cure model with frailties under the first activation scheme has better findings.

가변형 공동주택의 평면 선택에 대한 연구 (A Study on the Choice of Flexible Housing Unit Plan)

  • 이보라;김영욱;이현수;김수암
    • 한국주거학회:학술대회논문집
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    • 한국주거학회 2005년도 추계학술대회 논문집
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    • pp.163-166
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    • 2005
  • The purpose of this study was to analyze the Characteristics of Flexible housing Unit Plan Choice. It is believed that Flexible Housing relates to Family life cycle and the number of family. But this study revealed another factor, Space Syntax. It is reviewed that the Space Syntax effectively reveals the relative spatial depth of the spatial elements composing flexible housing unit plan. Thus, the Space Syntax is adopted as an analytic method of this study to objectify the concrete spatial changes. Through this study, the spatial organization of each case before changing is compared wi th that after changing, to find out the spatial changes over variation, Based on this theory, this study provide basic data to be used for architectural planning for flexible design. To design common facilities that support residents' leisure activities is one of the contemporary issues in Korea. People became interested in the leisure facilities in near-home environments. This trend encouraged this research study. The objectives of this study are to analyze the current status and characteristics of leisure facilities in apartment communities, to examine the correlations among leisure facilities, and to suggest design considerations for korean multi-family housing communities.

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확률강우량의 공간분포 추정을 위한 KED 기법의 적용 (Application of KED Method for Estimation of Spatial Distribution of Probability Rainfall)

  • 서영민;여운기;이승윤;지홍기
    • 한국수자원학회논문집
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    • 제43권8호
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    • pp.757-767
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    • 2010
  • 본 연구는 확률강우량에 대한 공간분포 추정시 신뢰도를 향상시키는데 있어서 외부변수 사용의 유효성을 평가하기 위하여 확률강우량과 단일 보조변수로서 지형특성인자들과의 상관관계를 고려한 KED 기법을 적용하였으며, 그 결과 강우공간분포 및 유역평균강우량의 추정에 있어서 확정론적 공간보간기법 및 크리징 기법과 대체로 비슷한 결과를 나타내는 것으로 분석되었으며, KED 및 크리징 기법에 대한 교차검증 결과 보조변수로서 표고를 사용한 KED 기법이 가장 좋은 결과를 나타내고는 있으나 다른 기법들과 비교했을 때 큰 차이를 보이지 않는 것으로 분석되었다.

Spatial Variability of Soil Properties using Nested Variograms at Multiple Scales

  • Chung, Sun-Ok;Sudduth, Kenneth A.;Drummond, Scott T.;Kitchen, Newell R.
    • Journal of Biosystems Engineering
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    • 제39권4호
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    • pp.377-388
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    • 2014
  • Purpose: Determining the spatial structure of data is important in understanding within-field variability for site-specific crop management. An understanding of the spatial structures present in the data may help illuminate interrelationships that are important in subsequent explanatory analyses, especially when site variables are correlated or are a combined response to multiple causative factors. Methods: In this study, correlation, principal component analysis, and single and nested variogram models were applied to soil electrical conductivity and chemical property data of two fields in central Missouri, USA. Results: Some variables that were highly correlated, or were strongly expressed in the same principal component, exhibited similar spatial ranges when fitted with a single variogram model. However, single variogram results were dependent on the active lag distance used, with short distances (30 m) required to fit short-range variability. Longer active lag distances only revealed long-range spatial components. Nested models generally yielded a better fit than single models for sensor-based conductivity data, where multiple scales of spatial structure were apparent. Gaussian-spherical nested models fit well to the data at both short (30 m) and long (300 m) active lag distances, generally capturing both short-range and long-range spatial components. As soil conductivity relates strongly to profile texture, we hypothesize that the short-range components may relate to the scale of erosion processes, while the long-range components are indicative of the scale of landscape morphology. Conclusion: In this study, we investigated the effect of changing active lag distance on the calculation of the range parameter. Future work investigating scale effects on other variogram parameters, including nugget and sill variances, may lead to better model selection and interpretation. Once this is achieved, separation of nested spatial components by factorial kriging may help to better define the correlations existing between spatial datasets.

범죄연구에 있어 가변적 공간단위 문제(MAUP)의 스케일효과 검증 : 전국 읍면동과 시군구를 대상으로 한 성범죄 분석 (Test of the Scale Effect of MAUP in Crime Study: Analyses of Sex Crime Using Nation-Wide Data of Eup-Myon-Dong and Si-Gun-Gu)

  • 정진성;박종하
    • 한국콘텐츠학회논문지
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    • 제15권10호
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    • pp.150-159
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    • 2015
  • 본 연구는 지역사회 차원의 범죄연구에 있어 분석단위의 규모에 따라 결과가 달라지는 MAUP의 스케일 효과를 검증하고자 했다. 특히, 국내 최초로 전국의 모든 읍면동과 시군구를 대상으로 최근 이슈의 중심에 서있는 성범죄에 대한 공간적 자기상관, 변수들 간의 상관관계, 인과관계 분석을 시도했다. 분석 결과, 성범죄율의 자기상관은 가설과 달리 시군구의 Moran's I가 읍면동보다 큰 반면, 상관계수와 회귀분석의 결정계수는 가설에 맞게 대부분 시군구에서 더 큰 것으로 드러났다. 이는 합역수준이 높아질수록 자료의 통합으로 인해 발생하는 평균효과 때문으로 사료되었다. 성범죄의 원인에 대해서는 두 가지 특이한 점이 발견되었는바, 첫째, 비아파트거주비율이 읍면동과 시군구 단위에서 모두 성범죄를 감소시켰고, 둘째, 숙박음식업 비율은 읍면동 단위에서만 성범죄를 증가시키는 것으로 드러났다. 이는 향후 지역특성(예, 도시 vs. 시골, 풍요지역 vs. 빈곤지역)에 따른 세부적인 분석과 독립변수가 분석 단위별로 갖는 차별적 의미에 대한 추가적인 연구가 필요함을 시사한 결과였다. 본 연구가 지역사회 범죄연구를 촉진하고 성범죄에 대한 효과적인 대안 마련에 기여할 수 있기를 바란다.