On Kleene Algebra vs. Process Algebra

We try to clarify the relationship between Kleene algebra and process algebra, based on the very recent work on Kleene algebra and process algebra. Both for concurrent Kleene algebra (CKA) with communications and truly concurrent process algebra APTC with Kleene star and parallel star, the extended Milner's expansion law $a\parallel b=a\cdot b+b\cdot a+a\parallel b +a\mid b$ holds, with $a,b$ being primitives (atomic actions), $\parallel$ being the parallel composition, $+$ being the alternative composition, $\cdot$ being the sequential composition and the communication merge $\mid$ with the background of computation. CKA and APTC are all the truly concurrent computation models, can have the same syntax (primitives and operators), maybe have the same or different semantics

Development and evaluation of Formula Editor (a tool-based approach to enhance reusability in software product line model checking) on SAFER case study

Although model checking is extensively used for verification of single software systems, currently there is insufficient support for model checking in product lines. The presence of commonalities within the different products in the product line requires that the properties and the corresponding specifications for these properties be verified for every product in the product line. Specification and management of properties for every product in a product line can incur high overhead and make the task of model checking very difficult. It is hence essential to exploit the presence of commonalities to our advantage by providing reusability in model checking of product lines. Since different products in the product line need to be checked for same or similar properties, reuse of properties specified for one product for other products within a product line will significantly reduce the overall property specification and verification time. FormulaEditor is a property specification and management tool for enhancing the reusability of model checking of software product lines. The core of the technique is a product line-oriented user interface to guide users in generating, selecting, managing, and reusing useful product line properties, and patterns of properties for model checking. The previous version of the FormulaEditor tool supports Cadence SMV models, but not the typical CMU-SMV models. This work extends the FormulaEditor tool to allow verification of models written in CMU-SMV. The advantage of providing support to another model checker is twofold: first, it enhances the tool\u27s capability to check design specifications written in different models; and second, it allows users to specify the same design in different modeling languages to detect problems

Enhancing Computation Pushdown for Cloud OLAP Databases

Network is a major bottleneck in modern cloud databases that adopt a storage-disaggregation architecture. Computation pushdown is a promising solution to tackle this issue, which offloads some computation tasks to the storage layer to reduce network traffic. Existing cloud OLAP systems statically decide whether to push down computation during the query optimization phase and do not consider the storage layer's computational capacity and load. Besides, there is a lack of a general principle that determines which operators are amenable for pushdown. Existing systems design and implement pushdown features empirically, which ends up picking a limited set of pushdown operators respectively. In this paper, we first design Adaptive pushdown as a new mechanism to avoid throttling the storage-layer computation during pushdown, which pushes the request back to the computation layer at runtime if the storage-layer computational resource is insufficient. Moreover, we derive a general principle to identify pushdown-amenable computational tasks, by summarizing common patterns of pushdown capabilities in existing systems. We propose two new pushdown operators, namely, selection bitmap and distributed data shuffle. Evaluation results on TPC-H show that Adaptive pushdown can achieve up to 1.9x speedup over both No pushdown and Eager pushdown baselines, and the new pushdown operators can further accelerate query execution by up to 3.0x.Comment: 13 pages, 15 figure

Behavioural Theory of Reflective Algorithms I: Reflective Sequential Algorithms

We develop a behavioural theory of reflective sequential algorithms (RSAs), i.e. sequential algorithms that can modify their own behaviour. The theory comprises a set of language-independent postulates defining the class of RSAs, an abstract machine model, and the proof that all RSAs are captured by this machine model. As in Gurevich's behavioural theory for sequential algorithms RSAs are sequential-time, bounded parallel algorithms, where the bound depends on the algorithm only and not on the input. Different from the class of sequential algorithms every state of an RSA includes a representation of the algorithm in that state, thus enabling linguistic reflection. Bounded exploration is preserved using terms as values. The model of reflective sequential abstract state machines (rsASMs) extends sequential ASMs using extended states that include an updatable representation of the main ASM rule to be executed by the machine in that state. Updates to the representation of ASM signatures and rules are realised by means of a sophisticated tree algebra.Comment: 32 page

Graduate Catalogue 2007-2009

https://digitalscholarship.tnstate.edu/graduatecatalogues/1000/thumbnail.jp

Graduate Catalogue 2009-2011

https://digitalscholarship.tnstate.edu/graduatecatalogues/1001/thumbnail.jp

Graduate Catalogue 2015-2017

https://digitalscholarship.tnstate.edu/graduatecatalogues/1004/thumbnail.jp