A Partial Order Approach to Branching Time Logic Model Checking

Partial order techniques enable reducing the size of the state space used for model checking, thus alleviating the “state space explosion” problem. These reductions are based on selecting a subset of the enabled operations from each program state. So far, these methods have been studied, implemented, and demonstrated for assertional languages that model the executions of a program as computation sequences, in particular the linear temporal logic. The present paper shows, for the first time, how this approach can be applied to languages that model the behavior of a program as a tree. We study here partial order reductions for branching temporal logics, e.g., the logics CTL and CTL* (with the next time operator removed) and process algebra logics such as Hennesy–Milner logic (withτactions). Conditions on the selection of subset of successors from each state during the state-space construction, which guarantee reduction that preserves CTL* properties, are given. The experimental results provided show that the reduction is substantial.     

Kolmogorov complexity and combinatorial methods in communication complexity

We introduce a method based on Kolmogorov complexity to prove lower bounds on communication complexity. The intuition behind our technique is close to information theoretic methods.We use Kolmogorov complexity for three different things: first, to give a general lower bound in terms of Kolmogorov mutual information; second, to prove an alternative to Yao’s minmax principle based on Kolmogorov complexity; and finally, to identify hard inputs.We show that our method implies the rectangle and corruption bounds, known to be closely related to the subdistribution bound. We apply our method to the hidden matching problem, a relation introduced to prove an exponential gap between quantum and classical communication. We then show that our method generalizes the VC dimension and shatter coefficient lower bounds. Finally, we compare one-way communication and simultaneous communication in the case of distributional communication complexity and improve the previous known result.     

An extension of first-order LTL with rules with application to runtime verification

International Journal on Software Tools for Technology Transfer - Linear temporal logic (LTL) is extensively used in formal methods, in particular in runtime verification (RV) and in model...     

On an Approach to the Estimation of the Complexity of Curves (Using as an Example an Electroencephalogram of a Human Being)

A new approach to the estimation of the complexity of a continuous curve on a section is suggested. The basic idea of the approach consists in that the complexity of the curve must be estimated by a relative share of information, which is necessary for its recovery with a specified accuracy from a set of values in the finite number of points by means of a prescribed aggregate of methods. The suggested approach is illustrated by an estimate of the complexity of various fragments of an electroencephalogram (EEG) of a human being and can be used, in particular, for the macrostructural and microstructural analysis of the EEG.     

Specification and Verification using Message Sequence Charts

Message sequence charts is a notation used in practice by protocol designers and system engineers. In this survey, some of the recent results related to this notation, in the context of specification and automatic verification of communication protocols, are presented.     

AFM characterization of the structure of Au-colloid monolayers and their chemical etching

Modification of a glass support with triethoxy propylaminosilane yields an active interface for the assembly of Au colloids. The colloids are imaged by AFM using a low applied load (0.5–0.7 nN). The lateral Au-colloid dimensions, 33±3 nm, deviate from the particle dimensions determined by TEM (19±2 nm) and absorption spectroscopy (15 nm). This deviation is attributed to the intrinsic curvature of the AFM tip. Application of higher loads on the tip (3 nN) results in the sweeping of Au colloids from the monolayer. The Au colloid monolayer is etched in the presence of CN⁻. The etching proceeds by the initial coincidental etching of Au particles followed by the kinetically favored etching of particles at the edges of the etched domains. This provides means for the micro machining and the chemical manipulation of Au colloids of controlled spatial arrangement.     

Nearest Common Ancestors: A Survey and a New Algorithm for a Distributed Environment

Several papers describe linear time algorithms to preprocess a tree, in order to answer subsequent nearest common ancestor queries in constant time. Here, we survey these algorithms and related results. Whereas previous algorithms produce a linear space data structure, in this paper we address the problem of distributing the data structure into short labels associated with the nodes. Localized data structures received much attention recently as they play an important role for distributed applications such as routing. We conclude our survey with a new simple algorithm that labels in O(n) time all the nodes of an n-node rooted tree such that from the labels of any two nodes alone one can compute in constant time the label of their nearest common ancestor. The labels assigned by our algorithm are of size O(log n) bits.     

Exact and heuristic algorithms for the aerial refueling parallel machine scheduling problem with due date-to-deadline window and ready times

The Aerial Refueling Scheduling Problem (ARSP) can be defined as determining the refueling completion times for fighter aircrafts (jobs) on multiple tankers (machines) to minimize the total weighted tardiness. ARSP can be modeled as a parallel machine scheduling with ready times and due date-to-deadline window to minimize total weighted tardiness. ARSP assumes that the jobs have different ready times and a due date-to-deadline window between refueling due date and a deadline to return without refueling. In this paper, we first formulate the ARSP as a mixed integer programming model. The objective function is a piece-wise tardiness cost that takes into account due date-to-deadline windows and job priorities. Since ARSP is NP-hard, two heuristics are proposed to obtain solutions in reasonable computation times, namely (1) modified ATC rule (MATC), (2) a simulated annealing method (SA). The proposed heuristic algorithms are tested in terms of solution quality and CPU time through computational experiments with data randomly generated to represent aerial refueling operations of an in-theater air operation. Solutions provided by both algorithms were compared to optimal solutions for problems with up to 12 jobs and to each other for larger problems with up to 60 jobs. The results show that, MATC is more likely to outperform SA especially when the problem size increases, although it has significantly worse performance than SA in terms of deviation from optimal solution for small size problems. Moreover CPU time performance of MATC is significantly better than SA in both cases.     

The Equilibrium and Pre-equilibrium Triton Emission Spectra of Some Target Nuclei for (<Emphasis Type="Italic">n</Emphasis>,<Emphasis Type="Italic">xt</Emphasis>) Reactions up to 45 MeV Energy

Although there have been significant research and development studies on the inertial and magnetic fusion reactor technology, there is still a long way to go to penetrate commercial fusion reactors to the energy market. Tritium self-sufficiency must be maintained for a commercial power plant. For self-sustaining (D-T) fusion driver tritium breeding ratio should be greater than 1.05. So, working out the systematics of (n,t) reaction cross sections and triton emission differential data are important for the given reaction taking place on various nuclei at different energies. In this study, (n,xt) reactions for some target nuclei as ¹⁶O, ²⁷Al, ⁵⁹Co and ²⁰⁹Bi have been investigated up to 45 MeV incident neutron energy. In the calculations of the triton emission spectra, the pre-equilibrium and equilibrium effects have been used. The calculated results have been compared with the experimental data taken from the literature.