Software-Architecture Recovery from Machine Code

In this paper, we present a tool, called Lego, which recovers object-oriented software architecture from stripped binaries. Lego takes a stripped binary as input, and uses information obtained from dynamic analysis to (i) group the functions in the binary into classes, and (ii) identify inheritance and composition relationships between the inferred classes. The information obtained by Lego can be used for reengineering legacy software, and for understanding the architecture of software systems that lack documentation and source code. Our experiments show that the class hierarchies recovered by Lego have a high degree of agreement---measured in terms of precision and recall---with the hierarchy defined in the source code

Social Hierarchies and the Formation of Customary Property Law in Pre-Industrial China and England

Comparative lawyers and economists have often assumed that traditional Chinese laws and customs reinforced the economic and political dominance of elites and, therefore, were unusually “despotic” towards the poor. Such assumptions are highly questionable: Quite the opposite, one of the most striking characteristics of Qing and Republican property institutions is that they often gave significantly greater economic protection to the poorer segments of society than comparable institutions in early modern England. In particular, Chinese property customs afforded much stronger powers of redemption to landowners who had pawned their land. In both societies, land-pawning occurred far more frequently among poorer households than richer ones, but Chinese customary law allowed debtors to indefinitely retain redemption rights over collateralized property, whereas English debtors would generally lose the property permanently if they failed to redeem within one year. This article argues that the comparatively “egalitarian” tendencies of Qing and Republican property institutions stemmed from the different ways Chinese and English rural communities allocated social status and rank. Hierarchical “Confucian” kinship networks dominated social and economic life in most Chinese villages. Within these networks, an individual’s status and rank depended, in large part, on his age and generational seniority, rather than personal wealth. This allowed many low-income households to enjoy status and rank quite disproportionate to their wealth. In comparison, substantial landed wealth was generally a prerequisite for high status in early modern England, effectively excluding lower-income households from positions of sociopolitical authority. Chinese smallholders possessed, therefore, significantly more social bargaining power, and were more capable of negotiating desirable property institutions. Paradoxically, the predominance of kinship hierarchies actually enhanced macro-level political and economic equality

Object orientation without extending Z

The good news of this paper is that without extending Z, we can elegantly specify object-oriented systems, including encapsulation, inheritance and subtype polymorphism (dynamic dispatch). The bad news is that this specification style is rather different to normal Z specifications, more abstract and axiomatic, which means that it is not so well supported by current Z tools such as animators. It also enforces behavioural subtyping, unlike most object-oriented programming languages. This paper explains the proposed style, with examples, and discusses its advantages and disadvantages

Evaluating Knowledge Representation and Reasoning Capabilites of Ontology Specification Languages

The interchange of ontologies across the World Wide Web (WWW) and the cooperation among heterogeneous agents placed on it is the main reason for the development of a new set of ontology specification languages, based on new web standards such as XML or RDF. These languages (SHOE, XOL, RDF, OIL, etc) aim to represent the knowledge contained in an ontology in a simple and human-readable way, as well as allow for the interchange of ontologies across the web. In this paper, we establish a common framework to compare the expressiveness of "traditional" ontology languages (Ontolingua, OKBC, OCML, FLogic, LOOM) and "web-based" ontology languages. As a result of this study, we conclude that different needs in KR and reasoning may exist in the building of an ontology-based application, and these needs must be evaluated in order to choose the most suitable ontology language(s)