State (computer science)

About: State (computer science) is a research topic. Over the lifetime, 24436 publications have been published within this topic receiving 225733 citations.

Integer Programming Algorithms: A Framework and State-of-the-Art Survey

Abstract: A unifying framework is developed to facilitate the understanding of most known computational approaches to integer programming. A number of currently operational algorithms are related to this framework, and prospects for future progress are assessed.

State of the art and perspectives

Abstract: Being asked to comment on the state of the art in machine translation and to predict its future bears a strong resemblance to being asked to read the Tarot. In neither case is very much solid objective data available on which to base an interpretation: in the case of the Tarot for obvious reasons, and in the case of machine translation mainly, perhaps, because the field is still relatively new, with no established or commonly accepted theoretical base, and one in which, although private industry has been able to construct and market application systems, the technology used is often carefully concealed or systematically misrepresented whilst the economic viability of the vendors frequently seems more like the raw material for a soap opera than information on which to base market predictions. In both cases, too, the wheel of fortune seems to play a major role. Launched into the limelight by a privately circulated memorandum 111, almost killed by government decree [2], partially restored to life through shifts in the weather [3], who would have predicted ten years ago when talk of machine translation still provoked a range of reactions between amused disbelief and downright hostility in the artificial intelligence community that DARPA would, in 1990, issue a call for proposals in the area, thus uncovering a strong but previously concealed interest in the topic in a surprisingly large number of research workers. In order, then, to avoid any semblance of a claim to specious authority, this response will be structured around five basic elements of one of the classic Tarot spreads. First we shall look at the seeker, the person questioning the cards for a way to respond to a specific problem. Then we shall look at what is beneath the seeker’s question the elements of the past which determine perception of the problem and of possible solutions. Next comes what is behind, the influences which have dominated recent history, but which may now be fading. Then we turn to the crown, the possible future which results from nothing going wrong, and finally we look at what is before, the immediate, inescapeable future which is already almost present.

Optimal State Assignment for Finite State Machines

Abstract: Computer-Aided synthesis of sequential functions of VLSI systems, such as microprocessor control units, must include design optimization procedures to yield area-effective circuits. We model sequential functions as deterministic synchronous Finite State Machines (FSM's), and we consider a regular and structured implementation by means of Programmable Logic Arrays (PLA's) and feedback registers. State assignment, i.e., binary encoding of the internal states of the finite state machine, affects substantially the silicon area taken by such an implementation. Several state assignment techniques have been proposed in the past. However, to the best of our knowledge, no Computer-Aided Design tool is in use today for an efficient encoding of control logic. We propose an algorithm for optimal state assignment. Optimal state assignment is based on an innovative strategy: logic minimization of the combinational component of the finite state machine is applied before state encoding. Logic minimization is performed on a symbolic (code independent) description of the finite state machine. The minimal symbolic representation defines the constraints of a new encoding problem, whose solutions are the state assignments that allow the implementation of the PLA with at most as many product-terms as the cardinality of the minimal symbolic representation. In this class, an optimal encoding is one of minimal length satisfying these constraints. A heuristic algorithm constructs a solution to the constrained encoding problem. The algorithm has been coded in a computer program, KISS, and tested on several examples of finite state machines. Experimental results have shown that the method is an effective tool for designing finite state machines.

Boolean Function Complexity: Advances and Frontiers

Abstract: Boolean circuit complexity is the combinatorics of computer science and involves many intriguing problems that are easy to state and explain, even for the layman. This book is a comprehensive description of basic lower bound arguments, covering many of the gems of this complexity Waterloo that have been discovered over the past several decades, right up to results from the last year or two. Many open problems, marked as Research Problems, are mentioned along the way. The problems are mainly of combinatorial flavor but their solutions could have great consequences in circuit complexity and computer science. The book will be of interest to graduate students and researchers in the fields of computer science and discrete mathematics.

Mechanism for restoring, porting, replicating and checkpointing computer systems using state extraction

Abstract: A computer system is interrupted, and its entire state information is extracted as one or more checkpoints at one or more respective points during operation of the system. The checkpoint may be restored into the system at any later time, even multiple times, and it may also even be loaded into one or more other systems; all systems loaded with the same checkpoint will then execute from the same checkpointed state. The state extraction mechanism is preferably a virtual machine monitor, on which one or more virtual machines are installed, each virtual machine constituting an encapsulated, virtualized computer system whose states can be checkpointed under control of the virtual machine monitor. Checkpoints may be stored on a portable memory device or transmitted as a batch or dynamically over a network so that even virtual machines installed at different sites may execute from the same state.