Ambivalence and Control: State Action Against the Civil Rights-Era Ku Klux Klan

Models that purport to explain the interplay between dissidents and the state generally assert, either explicitly or implicitly, that the path from state interests to action to outcomes is a linear one. Using the case of the United Klans of America (UKA) in North Carolina, I argue that state efforts to exert social control upon a perceived threat are shaped by a range of internal and external contingencies. In particular, I undertake a comparative analysis of two state agencies to demonstrate how a particular mechanism—ambivalence, here conceptualized as the relational consequence of a mismatch between organizational culture and organizational goals—leads to distinct, and sometimes heterogeneous, actions and outcomes not directly traceable to organizational mandates. Findings lend insight into how endogenous organizational processes shape contentious political outcomes in potentially divergent ways.     

DCT域分形图像压缩编码方法

首先研究了一般分形图像压缩方法存在的缺陷，然后对它进行改进。最后在ＤＣＩ域做进一步的改进。实验结果表明，和原来方法相比较，ＤＣＴ域分形图像压缩编码方法具有明显的优越性。     

Neighborhood context and racial differences in early adolescent sexual activity

Evidence suggests that African American youths initiate sexual activity at earlier ages than do European American or Latino youths. Using data from a multilevel study in Chicago, we developed and tested a neighborhood-based model of the timing of first adolescent intercourse that emphasizes the impact of neighborhood structural disadvantage and collective efficacy on early sexual activity (at ages 11 to 16). In turn, we explored the extent to which neighborhood factors account for racial differences in the timing of first intercourse. The findings indicate that demographic background, family processes, peer influences, and developmental risk factors account for about 30% of the baseline increased likelihood of early sexual onset for African American youths compared with European American youths. However, a significant residual racial difference remained even after we considered a host of micro-level factors. Neighborhood-level concentrated poverty largely explained this residual racial difference. Collective efficacy also independently contributed to the delay of sexual onset. No significant baseline difference in age of sexual initiation was found between Latino and European American youths.     

Effect of family structure on life satisfaction: australian evidence

How do family arrangements affect subjective well-being? We investigate this issue using data pooled from the IsssA and HILDA, both large, representative national samples of Australia (pooled n=38 447). Our regression analysis of cross-sectional and panel data examines how large are the differences in life satisfaction according to marital status and cohabitation. We find that women and men in formal marriages experience higher levels of life satisfaction than do people in other family arrangements. Moreover, both multiple tests in the cross-section, and tests controlling for prior happiness in the panel analysis, suggest that this is a causal relationship. Aggregating up the levels of life satisfaction generated by different marriage and cohabitation arrangements across a lifetime, suggests that a life-long marriage is the most satisfying. Early divorce followed by an enduring second marriage is little worse (because little time is spent outside the married state). But divorce without remarriage, or long lasting cohabitation without formal marriage, reduce the lifetime sum of subjective well-being by 4–12% for both women and men.     

Inequality and welfare evaluation of heterogeneous income distributions

This paper establishes the principles that should govern the welfare and inequality analysis of heterogeneous income distributions. Two basic criteria – the equity preference condition and the compensation principle – are shown to be fundamentally incompatible. The paper favours the latter, thereby vindicating the traditional method of dealing with heterogeneous samples. However, inequality and welfare comparisons will usually be well defined only if equivalent incomes are obtained using constant scale factors; and researchers will need to distinguish clearly between inequality of nominal incomes and inequality of living standards. Furthermore, household observations must always be weighted according to family size.     

A weighted polynomial regression method for local fitting of spatial data

Typically, parametric approaches to spatial problems require restrictive assumptions. On the other hand, in a wide variety of practical situations nonparametric bivariate smoothing techniques has been shown to be successfully employable for estimating small or large scale regularity factors, or even the signal content of spatial data taken as a whole.We propose a weighted local polynomial regression smoother suitable for fitting of spatial data. To account for spatial variability, we both insert a spatial contiguity index in the standard formulation, and construct a spatial-adaptive bandwidth selection rule. Our bandwidth selector depends on the Gearys local indicator of spatial association. As illustrative example, we provide a brief Monte Carlo study case on equally spaced data, the performances of our smoother and the standard polynomial regression procedure are compared.This note, though it is the result of a close collaboration, was specifically elaborated as follows: paragraphs 1 and 2 by T. Sclocco and the remainder by M. Di Marzio. The authors are grateful to the referees for constructive comments and suggestions.     

Missing at random (MAR) in nonparametric regression - A simulation experiment

The additive model is considered when some observations on x are missing at random but corresponding observations on y are available. Especially for this model, missing at random is an interesting case because the complete case analysis is expected to be no more suitable. A simulation experiment is reported and the different methods are compared based on their superiority with respect to the sample mean squared error. Some focus is also given on the sample variance and the estimated bias. In detail, the complete case analysis, a kind of stochastic mean imputation, a single imputation and the nearest neighbor imputation are discussed.     

An efficient polynomial space and polynomial delay algorithm for enumeration of maximal motifs in a sequence

In this paper, we consider the problem of enumerating all maximal motifs in an input string for the class of repeated motifs with wild cards. A maximal motif is such a representative motif that is not properly contained in any larger motifs with the same location lists. Although the enumeration problem for maximal motifs with wild cards has been studied in Parida et al. (2001), Pisanti et al. (2003) and Pelfrêne et al. (2003), its output-polynomial time computability has been still open. The main result of this paper is a polynomial space polynomial delay algorithm for the maximal motif enumeration problem for the repeated motifs with wild cards. This algorithm enumerates all maximal motifs in an input string of length n in O(n ³) time per motif with O(n) space, in particular O(n ³) delay. The key of the algorithm is depth-first search on a tree-shaped search route over all maximal motifs based on a technique called prefix-preserving closure extension. We also show an exponential lower bound and a succinctness result on the number of maximal motifs, which indicate the limit of a straightforward approach. The results of the computational experiments show that our algorithm can be applicable to huge string data such as genome data in practice, and does not take large additional computational cost compared to usual frequent motif mining algorithms. This work is done during the Hiroki Arimura’s visit in LIRIS, University Claude-Bernard Lyon 1, France.