In this study, a solid oxide fuel cell (SOFC) stack has been successfully fabricated and tested by using direct natural gas. The main objective of this research was to achieve optimal long-term performance of the SOFC stack without carbon deposition by using low-cost natural gas as a fuel. The stack configuration was improved by a new interconnect design and made of cost-effective raw materials...

A circular Nim game is a two player impartial combinatorial game consisting of n stacks of tokens placed in a circle. A move consists of choosing k consecutive stacks, and taking at least one token from one or more of the k stacks. The last player able to make a move wins. We prove results on the structure of the losing positions for small n and k and pose some open questions for further invest...

Walukiewicz gave in 1996 a solution for parity games on pushdown graphs: he proved the existence of pushdown strategies and determined the winner with an EXPTIME procedure. We give a new presentation and a new algorithmic proof of these results, obtain a uniform solution for parity games (independent of their initial configuration), and extend the results to prefix-recognizable graphs. The winn...

ion Refinement for Pushdown Systems

The presence of gas hydrate and associated gas in the Makran Accretionary Prism, offshore Iran, has been confirmed by various seismic indicators, including the bottom-simulating reflector (BSR), amplitude blanking, and bright spot. The pre-stack analysis and the study of amplitude-variation-with-offset (AVO) attributes are the most reliable tools for semi-quantitative study of gas hydrate and f...

the conventional approach to seismic data analysis consists of two main steps: estimating seismic velocities, (the subsurface macro-model), and seismic imaging, (mapping of the reflected seismic energy to the reflector positions). the aim and the major challenge in the seismic data analysis is the construction of the best undistorted image. this challenge would be more problematic when geometri...

A stack-based processor where the instruction set acts on data resided on an evaluation stack, has its performance bottleneck due to the limit of access to the stack. Although the stack-based processor has low performance, it is very low cost to implement. This paper proposes a method to improve the performance of a stack-based processor. A number of fast registers are used to “cache” part of t...

With the growing focus on energy efficiency, it is important to find ways to reduce energy without sacrificing performance. The L1 data cache is a significant contributor to processor energy consumption. We advocate treating data from the program’s stack differently from non-stack data to reduce energy. We characterize stack accesses to determine how they differ from general memory accesses in ...

K-extended basic macro grammars are introduced, where K is any class of languages. The class B(K) of languages generated by such grammars is investigated, together with the class LB(K) of languages generated by the corresponding linear basic grammars. For any full semiAFL K, B(K) is a full AFL closed under iterated LB(K)-substitution, but not necessarily under substitution. For any machine type...