Transformations of CCP programs

We introduce a transformation system for concurrent constraint programming (CCP). We define suitable applicability conditions for the transformations which guarantee that the input/output CCP semantics is preserved also when distinguishing deadlocked computations from successful ones and when considering intermediate results of (possibly) non-terminating computations. The system allows us to optimize CCP programs while preserving their intended meaning: In addition to the usual benefits that one has for sequential declarative languages, the transformation of concurrent programs can also lead to the elimination of communication channels and of synchronization points, to the transformation of non-deterministic computations into deterministic ones, and to the crucial saving of computational space. Furthermore, since the transformation system preserves the deadlock behavior of programs, it can be used for proving deadlock freeness of a given program wrt a class of queries. To this aim it is sometimes sufficient to apply our transformations and to specialize the resulting program wrt the given queries in such a way that the obtained program is trivially deadlock free.Comment: To appear in ACM TOPLA

From iron rice bowl to the world's biggest sweatshop: globalization, institutional constraints, and the rights of Chinese workers

This article discusses how China's institutional constraints combine with its integration into the global economy to suppress its workers' rights. The rapid expansion of China's market economy is the consequence of the government's active embrace of global capitalism and global capitalists' ongoing search for new markets and lower production costs. China's traditional socialist labor relationships collapsed as a result of state-owned enterprise (SOE) reform and the emergence of private enterprises. In the wake of these events, China's leaders promulgated new labor legislation and social insurance schemes, but these initiatives fail to safeguard workers' rights effectively. This is because the SOEs fail to compensate their workers properly, local authorities do not actively monitor labor abuses, the judicial system cannot effectively defend workers' rights, and the Chinese government suppresses efforts to organize independent labor unions. In short, global capitalism together with China's authoritarian polity have limited workers' rights and undermined their well-being

A Categorical View on Algebraic Lattices in Formal Concept Analysis

Formal concept analysis has grown from a new branch of the mathematical field of lattice theory to a widely recognized tool in Computer Science and elsewhere. In order to fully benefit from this theory, we believe that it can be enriched with notions such as approximation by computation or representability. The latter are commonly studied in denotational semantics and domain theory and captured most prominently by the notion of algebraicity, e.g. of lattices. In this paper, we explore the notion of algebraicity in formal concept analysis from a category-theoretical perspective. To this end, we build on the the notion of approximable concept with a suitable category and show that the latter is equivalent to the category of algebraic lattices. At the same time, the paper provides a relatively comprehensive account of the representation theory of algebraic lattices in the framework of Stone duality, relating well-known structures such as Scott information systems with further formalisms from logic, topology, domains and lattice theory.Comment: 36 page

Parameterized Construction of Program Representations for Sparse Dataflow Analyses

Data-flow analyses usually associate information with control flow regions. Informally, if these regions are too small, like a point between two consecutive statements, we call the analysis dense. On the other hand, if these regions include many such points, then we call it sparse. This paper presents a systematic method to build program representations that support sparse analyses. To pave the way to this framework we clarify the bibliography about well-known intermediate program representations. We show that our approach, up to parameter choice, subsumes many of these representations, such as the SSA, SSI and e-SSA forms. In particular, our algorithms are faster, simpler and more frugal than the previous techniques used to construct SSI - Static Single Information - form programs. We produce intermediate representations isomorphic to Choi et al.'s Sparse Evaluation Graphs (SEG) for the family of data-flow problems that can be partitioned per variables. However, contrary to SEGs, we can handle - sparsely - problems that are not in this family

Co-Creation: The Public Sector Perspective

This article continues to explore the partnership between the State of Connecticut, the Connecticut Early Childhood Funder Collaborative, and the Connecticut Council for Philanthropy. These three entities have been working to coordinate their efforts toward a shared goal of establishing a statewide early childhood system, reducing the fragmented array of Connecticut's existing early childhood services and supports, and improving outcomes for young children and their families across the State.Independently and collectively, each partner continues to adopt new processes and working structures that enable the voluntary contribution of their diverse skills, expertise, and resources to create a new approach to early childhood in Connecticut. While clearly not the only constituencies working to improve outcomes for children and families throughout the state, this partnership between the public sector and the philanthropic community has resulted in important transformations within all entities involved. This paper highlights the role of the public sector within this public-private partnership, and, more specifically, the experience and perspectives of those working within state government

The Vulnerable State and Technical Fixes: An Analysis of Official Climate Change Discourses in Nepal

I conduct discourse analysis of seven selected official climate change policies and documents of Nepal. In the first part of my analysis, I draw from international climate justice discourses to analyze how policy makers construct Nepal’s position in the global arena, in relation to the issue of climate change. In the second part, I draw from political ecology and anthropological understandings of ‘vulnerability’ and ‘adaptation’ to analyze how policy makers construct those terms in the context of Nepal. The result shows that Nepal has adhered to the ‘vulnerability’ and ‘transition’ discourses, which serve as important tools to advocate for financial support from the international climate change regime. Driven primarily by international processes and guidelines, the climate change policies and documents in Nepal project a heavily technocratic approach with little socio-cultural considerations. Vulnerability is understood as a static property and assessed based on sectors and geographic areas, while adaptation is understood as series of actions to be implemented. Overall, the policies are at risk of perpetuating the existing systemic ills, as well as impeding imaginaries to pursue more radical socio-political and cultural change as effective adaptation measures

Transformations of Logic Programs on Infinite Lists

We consider an extension of logic programs, called \omega-programs, that can be used to define predicates over infinite lists. \omega-programs allow us to specify properties of the infinite behavior of reactive systems and, in general, properties of infinite sequences of events. The semantics of \omega-programs is an extension of the perfect model semantics. We present variants of the familiar unfold/fold rules which can be used for transforming \omega-programs. We show that these new rules are correct, that is, their application preserves the perfect model semantics. Then we outline a general methodology based on program transformation for verifying properties of \omega-programs. We demonstrate the power of our transformation-based verification methodology by proving some properties of Buechi automata and \omega-regular languages.Comment: 37 pages, including the appendix with proofs. This is an extended version of a paper published in Theory and Practice of Logic Programming, see belo