University of Haifa

About: University of Haifa is a education organization based out in Haifa, Israel. It is known for research contribution in the topics: Population & Poison control. The organization has 7558 authors who have published 27141 publications receiving 711629 citations. The organization is also known as: Haifa University & Universiṭat Ḥefah.

Analysis of the Linux random number generator

Abstract: Linux is the most popular open source project. The Linux random number generator is part of the kernel of all Linux distributions and is based on generating randomness from entropy of operating system events. The output of this generator is used for almost every security protocol, including TLS/SSL key generation, choosing TCP sequence numbers, and file system and email encryption. Although the generator is part of an open source project, its source code (about 2500 lines of code) is poorly documented, and patched with hundreds of code patches. We used dynamic and static reverse engineering to learn the operation of this generator. This paper presents a description of the underlying algorithms and exposes several security vulnerabilities. In particular, we show an attack on the forward security of the generator which enables an adversary who exposes the state of the generator to compute previous states and outputs. In addition we present a few cryptographic flaws in the design of the generator, as well as measurements of the actual entropy collected by it, and a critical analysis of the use of the generator in Linux distributions on diskless devices.

Divison of Labor, Perceived Fairness, and Marital Quality: The Effect of Gender Ideology

Abstract: This study assesses the relations between division of household labor, perceived fairness, and marital quality by comparing three ethnic-religious groups in Israel that reflect traditional, transitional, and egalitarian ideologies. The findings, based on structural equation modeling (SEM) methodology, show that sense of fairness mediates the relation between division of labor and marital quality and gender ideology moderates these relations for women but not for men. Perceived fairness is related to the division of labor for women in egalitarian and transitional families but not in traditional ones. For egalitarian women, a more segregated division of labor is linked directly with lower marital quality whereas for women in transitional families it is mediated by sense of fairness. The findings are discussed on two overlapping levels-conceptual-theoretical and sociocultural-with implications for understanding families in cultural transition. Key Words: division of labor, equity, gender ideology, Isreal, marital quality. In the past decade, there has been growing interest in the causes and consequences of the way in which household tasks are allocated. A large volume of research has focused on predictors of the allocation of household tasks, demonstrating its association with a host of factors including employment and relative earnings of husbands and wives, as well as cultural norms and beliefs. In his review of research on the division of household labor during the 1990s, Coltrane (2000) concluded that although men's relative contributions have increased, women still do at least twice as much routine housework as men. Inequality in the division of household labor, in turn, is associated with women's sense of unfairness, depression, and marital dissatisfaction, whereas men's participation in routine repetitive chores is the primary predictor of marital satisfaction (Coltrane, 2000). In regard to the link between division of household labor and outcome measures such as marital satisfaction, two hypotheses have been posited: (a) The mediating hypothesis of perceived fairness states that inequality in the division of household labor affects marital satisfaction mainly through perceptions of unfairness; and (b) the moderating hypothesis of gender role ideology states that gender ideology shapes the perception of fairness of the division of labor and the extent to which perceived fairness is linked to marital satisfaction, thereby moderating the associations between division of household labor, perceived fairness, and marital quality. Although both hypotheses have received some empirical attention, findings regarding the mediating effect of perceived fairness are mixed and inconclusive. Additionally, research on the moderating effect of gender ideology has typically been discussed in terms of traditional and egalitarian gender ideologies with only scant attention given to families in transition, who are located somewhere in the middle. In concluding his review, Coltrane (2000) recommended that future research should specify in more detail "how the performance of housework in different families is implicated in various cultural, economic, and gender-reproductive processes" (p. 1227) and how gender ideology influences fairness evaluations and individual well-being. Along this line, the present study extends previous research by examining both the mediating and moderating hypotheses through a comparison of three ethnic-religious groups in Israel that reflect traditional, transitional, and egalitarian family patterns. DIVISION OF LABOR AND MARITAL QUALITY: THE MEDIATING EFFECT OF PERCEIVED FAIRNESS Despite the tendency of both women and men to report that the division of labor is fair, research shows significant associations between various characteristics of the division of household labor and perceived justice. In particular, the greater the men's contribution to household tasks, especially those typically relegated to women (Blair & Johnson, 1992; Demo & Acock, 1993; Sanchez, 1994), and the more balanced the relative contribution of husbands and wives to such tasks (DeMaris & Longmore, 1996; Hawkins, Marshall, & Meiners, 1995; Lennon & Rosenfield, 1994), the higher the sense of fairness in regard to division of labor. …

Origin and evolution of circadian clock genes in prokaryotes

Abstract: Regulation of physiological functions with approximate daily periodicity, or circadian rhythms, is a characteristic feature of eukaryotes. Until recently, cyanobacteria were the only prokaryotes reported to possess circadian rhythmicity. It is controlled by a cluster of three genes: kaiA, kaiB, and kaiC. Using sequence data of ≈70 complete prokaryotic genomes from the various public depositories, we show here that the kai genes and their homologs have quite a different evolutionary history and occur in Archaea and Proteobacteria as well. Among the three genes, kaiC is evolutionarily the oldest, and kaiA is the youngest and likely evolved only in cyanobacteria. Our data suggest that the prokaryotic circadian pacemakers have evolved in parallel with the geological history of the earth, and that natural selection, multiple lateral transfers, and gene duplications and losses have been the major factors shaping their evolution.

Redrawing the boundaries of OCB? An empirical examination of compulsory extra-role behavior in the workplace

Abstract: Contemporary literature on Organizational Citizenship Behavior (OCB) has primarily focused on the positive connotations of the “good soldier syndrome.” Most of the studies published in recent decades about OCB have pointed to the benefits and advantages of voluntary helping behaviors, pro-social behavior, and extra-role behavior. In contrast with this view we suggest a different look at OCB by focusing on the exploitative and abusive tendency of supervisors and managements to impose so-called “voluntary” or “extra-role” activities via compulsory mechanisms in the workplace. Mostly, we are interested in empirically testing the relationship between such behaviors and employees’ performance. We follow the approach suggested by Vigoda-Gadot (Journal for the Theory of Social Behavior, 2006) to argue that such behaviors are a substantial deviation from the original meaning of OCB and thus should be recognized and analyzed separately. Our arguments are based on an exploratory study conducted in 13 Israeli schools. Of the 206 teachers who participated in the study, a substantial majority of 75% reported feeling strong pressure to engage in what we usually define as OCB, but should actually be defined as Compulsory Citizenship Behavior (CCB). The findings are discussed in light of present knowledge about OCB, and the implications question the normally positive image of this behavior.

Underwater Single Image Color Restoration Using Haze-Lines and a New Quantitative Dataset

Abstract: Underwater images suffer from color distortion and low contrast, because light is attenuated while it propagates through water. Attenuation under water varies with wavelength, unlike terrestrial images where attenuation is assumed to be spectrally uniform. The attenuation depends both on the water body and the 3D structure of the scene, making color restoration difficult. Unlike existing single underwater image enhancement techniques, our method takes into account multiple spectral profiles of different water types. By estimating just two additional global parameters: the attenuation ratios of the blue-red and blue-green color channels, the problem is reduced to single image dehazing, where all color channels have the same attenuation coefficients. Since the water type is unknown, we evaluate different parameters out of an existing library of water types. Each type leads to a different restored image and the best result is automatically chosen based on color distribution. We also contribute a dataset of 57 images taken in different locations. To obtain ground truth, we placed multiple color charts in the scenes and calculated its 3D structure using stereo imaging. This dataset enables a rigorous quantitative evaluation of restoration algorithms on natural images for the first time.