Model Checking Dynamic UML Consistency

Abstract. Being the de facto industry standard of software modeling, UML is well accepted and extensively used. However, using different diagrams to model different aspects of a system brings the risk of inconsistency among diagrams. In this paper, we investigate an approach to check the consistency between the sequence diagrams and statechart diagrams using the SPIN model checker. To deal with the hierarchy structure of statechart diagrams, we propose a formalism called Split Automata, a variant of automata, which is helpful to bridge the statechart diagrams to SPIN efficiently. Compared with the existing work on model checking UML which do not have formal verification for their translation from UML to the model checker, we formally define the semantics and prove that the automatically translated model (i.e. Split Automata) does simulate the UML model. Via this way, we can guarantee that the translated models does represent the original models with respect to the checking motivation

A Type System for the Relational Calculus of Object Systems

Abstract. Being a successful technique in software practice, Object Orientation (OO) is a hot topic in academic research fields. Within many formalisms, rCOS, a refinement calculus of object-oriented systems based on Unifying Theories of Programming (UTP), has been proven a promising one in the sense of its applications on incremental software constructions, the formal use and checking for UML based develop processes, etc. However, equipped with a semantics including both static and dynamic properties, rCOS is not designed for static checking. We believe introducing static checking will numerously extend the power of rCOS. In this paper, as a first step, we develop a type system for rCOS with type safety theorems. To make the theoretical results of this paper convincible and easy to be understood, we follow the traditional approaches of type systems construction. That is, we use an operational semantics as the basic explanation of rCOS language in spite of the fact that rCOS is originally developed in a denotational framework. Keywords: Type system, rCOS, Object-orientation, Operational semantics

Software Technology POST: A Case Study for rCOS Incremental Development

Training Centre of the United Nations University (UNU). It is based in Macau, and was founded i

Software Technology A Type System for the Relational Calculus of Object Systems

in July 1992. UNU-IIST is jointly funded by the Governor of Macau and the governments of the People’s Republic of China and Portugal through a contribution to the UNU Endownment Fund. As well as providing twothirds of the endownment fund, the Macau authorities also supply UNU-IIST with its office premises and furniture and subsidise fellow accommodation. The mission of UNU-IIST is to assist developing countries in the application and development of software technology. UNU-IIST contributes through its programmatic activities: 1. Advanced development projects, in which software techniques supported by tools are applied, 2. Research projects, in which new techniques for software development are investigated, 3. Curriculum development projects, in which courses of software technology for universities in developing countries are developed, 4. University development projects, which complement the curriculum development projects by aiming to strengthen all aspects of computer science teaching in universities in developing countries, 5. Schools and Courses, which typically teach advanced software development techniques, 6. Events, in which conferences and workshops are organised or supported by UNU-IIST, and 7. Dissemination, in which UNU-IIST regularly distributes to developing countries information on internationa

Circ_0020256 induces fibroblast activation to drive cholangiocarcinoma development via recruitment of EIF4A3 protein to stabilize KLF4 mRNA

Abstract Cancer-associated fibroblasts (CAFs) are a kind of stromal cells in the cholangiocarcinoma (CCA) microenvironment, playing crucial roles in cancer development. However, the potential mechanisms of the interaction between CCA cells and CAFs remain obscure. This work investigated the role of circ_0020256 in CAFs activation. We proved circ_0020256 was up-regulated in CCA. High circ_0020256 expression facilitated TGF-β1 secretion from CCA cells, which activated CAFs via the phosphorylation of Smad2/3. Mechanistically, circ_0020256 recruited EIF4A3 protein to stabilize KLF4 mRNA and upregulate its expression, then KLF4 bound to TGF-β1 promoter and induced its transcription in CCA cells. KLF4 overexpression abrogated the inhibition of circ_0020256 silencing in TGF-β1/Smad2/3-induced CAFs activation. Furthermore, CCA cell growth, migration, and epithelial-mesenchymal transition were favored by CAFs-secreted IL-6 via autophagy inhibition. We also found circ_0020256 accelerated CCA tumor growth in vivo. In conclusion, circ_0020256 promoted fibroblast activation to facilitate CCA progression via EIF4A3/KLF4 pathway, providing a potential intervention for CCA progression