Positive autocorrelation implies that proximate observations take on similar values. “Proximate” can be defined in many different dimensions. In a cross-section of nations, it can be defined using physical distance, cultural similarity, ecological similarity, or using frequency and intensity of interaction, such as trade relationships or enemy and ally relationships. Autocorrelation of regressi...

spatial environmental autocorrelation is a known phenomenon in the environmental studies explaining spatial relationship of environmental characteristics of different geographical units. different mechanisms have been proposed to clarify how the environments of especially neighboring countries response to changes of each other. this paper attempts to propose a new mechanism, namely spatial inst...

This paper examines the role of spatial effects in ecological inference. Both formally and through simulation experiments, we consider the problems associated with ecological inference and cross-level inference methods in the presence of increasing degrees of spatial autocorrelation. Past assessments of spatial autocorrelation in aggregate data analysis focused on unidimensional, one-directiona...

The autocorrelation and the linear complexity of a key stream sequence in a stream cipher are important cryptographic properties. Many sequences with these good properties have interleaved structure, three classes of binary sequences of period 4N with optimal autocorrelation values have been constructed by Tang and Gong based on interleaving certain kinds of sequences of period N . In this pape...

This paper proposes a new musical instrument estimation of polyphony using autocorrelation functions. We notice that each musical instrument has each autocorrelation function. Polyphony can be separated into each monophony using comb filters ( ). We can obtain the autocorrelation functions for the outputs of comb filters from the autocorrelation functions of the monophony. By the pattern patchi...

A general construction of binary sequences with low autocorrelation are considered in the paper. Based on recent progresses about this topic and this construction, several classes of binary sequences with optimal autocorrelation and other low autocorrelation are presented.

A method of calculating an autocorrelation function with extremely narrow peaks is described. This is done by including terms in the autocorrelation expression corresponding to delays at 2 tau, 3 tau, etc., in addition to the usual term with delay tau. Implications in the frequency domain are explored. Graphs of this autocorrelation function for a number of violin sound samples, including a two...

Hand, foot, and mouth disease (HFMD) causes characteristic blisters and sores mainly in infants and children, and has been monitored in South Korea through sentinel surveillance since 2009. We described the patterns of HFMD occurrence and analyzed the effect of climatic factors on national HFMD incidence. Weekly clinically diagnosed HFMD case rates (per 1,000 outpatients) in sentinel sites and ...

In this paper, we propose an improved autocorrelation function (ACF) based watermarking. The autocorrelation function based watermarking has been known to be one of the effective watermarking schemes that are resilient to geometric transform attacks. In this watermarking scheme, both the peaks in the autocorrelation function of a marked image and the embedded watermark should survive after vari...

Our algorithm is based on autocorrelation. What distinguishes it from other autocorrelation approaches is that we computes the distribution of lag autocorrelation energy as a function of phase. This results in a lag-by-phase matrix that compactly represents the repetitive structure of a musical example. The model is designed to allow meter analysis of audio files. However it can also be used to...