A new technique for the logic synthesis of asynchronous circuits is presented. It is based on the structural theory of Petri nets and integer linear programming. The technique is capable of checking implementability c...
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ISBN:
(纸本)9781581137620
A new technique for the logic synthesis of asynchronous circuits is presented. It is based on the structural theory of Petri nets and integer linear programming. The technique is capable of checking implementability conditions, such as, complete state coding, and deriving a gate netlist to implement the specified behavior. This technique can synthesize specifications with few thousands of transitions in the Petri net, providing a speed-up of several orders of magnitude with regard to other existing techniques.
Production cycle time reduction in their discrete-event control systems (DECS) helps increase the productivity of automated manufacturing systems (AMS). Methods developed to evaluate the production cycle time are usua...
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ISBN:
(纸本)0780377362
Production cycle time reduction in their discrete-event control systems (DECS) helps increase the productivity of automated manufacturing systems (AMS). Methods developed to evaluate the production cycle time are usually based on either the Design for Manufacture (DFM) or Design for Production (DFP) scheduling techniques. To evaluate the real cycle time at the programming level of controllers such as the ladder logic design of programmable logic controller (PLC) in DECS, this paper discusses a method to analyze the production cycle time based on the sensor-based stage Petri nets technique. The production time can be estimated at each stage directly from all the I/O sensors that are represented by the extended Petri nets: the sensor-based stage Petri net (SBSPN). The production cycle time required to complete each product is marked on the individual stage transition through the real timers in the SBSPN model. For the production of multiple products, different production cycles times are estimated through the stage-by-stage real timers of controller program. These production cycle times are able to evaluate the bottleneck of integrated manufacturing systems. An example is used to illustrate the approach.
A key component of many logic programming analysis tasks is defining a safe (superset) approximation to the success set of the program. Our primary application is a declarative mode system which can express polymorphi...
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ISBN:
(纸本)9780909925949
A key component of many logic programming analysis tasks is defining a safe (superset) approximation to the success set of the program. Our primary application is a declarative mode system which can express polymorphic modes and linearity information. Others include analysis of type and groundness dependencies. Even analysis of procedural properties generally uses declarative information. For example, termination analyses use inter-argument relations, which can be seen as safe approximations to the success set. In this paper we show how the success set can be approximated by constrained regular types. This is a domain similar to regular types but can contain constraints to express relationships between multisets of subterms and between well-typedness of subterms. It allows very precise analysis. Even meta interpreters can be analysed with no loss of precision. We define constrained regular types and describe a system which checks if a constrained regular type is a superset of the success set.
We show that the first-order theory of structural subtyping of non-recursive types is decidable, as a consequence of a more general result on the decidability of term powers of decidable theories. Let /spl Sigma/ be a...
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We show that the first-order theory of structural subtyping of non-recursive types is decidable, as a consequence of a more general result on the decidability of term powers of decidable theories. Let /spl Sigma/ be a language consisting of function symbol and let /spl Cscr/; (with a finite or infinite domain C) be an L-structure where L is a language consisting of relation symbols. We introduce the notion of /spl Sigma/-term-power of the structure /spl Cscr/; denoted /spl Pscr/;/sub /spl Sigma//(/spl Cscr/;). The domain of /spl Pscr/;/sub /spl Sigma//(/spl Cscr/;) is the set of /spl Sigma/-terms over the set C. /spl Pscr/;/sub /spl Sigma//(/spl Cscr/;) has one term algebra operation for each f /spl isin/ /spl Sigma/, and one relation for each r /spl isin/ L defined by lifting operations of /spl Cscr/; to terms over C. We extend quantifier for term algebras and apply the Feferman-Vaught technique for quantifier elimination in products to obtain the following result. Let K be a family of L-structures and K/sub P/ the family of their /spl Sigma/-term-powers. Then the validity of any closed formula F on K/sub P/ can be effectively reduced to the validity of some closed formula q(F) on K. Our result implies the decidability of the first-order theory of structural subtyping of non-recursive types with covariant constructors, and the construction generalizes to contravariant constructors as well.
PID control is widely used as a basic control technology in industries today, but tuning of PID control systems is not always easy. Based on model-driven control concept, we developed a model-driven PID control system...
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PID control is widely used as a basic control technology in industries today, but tuning of PID control systems is not always easy. Based on model-driven control concept, we developed a model-driven PID control system, named MD PID controller, combining with PD local feedback, IMC and set point filter. This paper provides a brief introduction of new model driven two-degrees of freedom PID control system, named MD TDOF PID controller, and shows some case studies results. We have confirmed that MD TDOF PID can show better control results compared with conventional PID control.
The knowledge society brings its own challenges and demands upon its citizens. Key amongst these is the need to empower people to become lifelong learners, to reflect upon their own learning, to become problem solvers...
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The knowledge society brings its own challenges and demands upon its citizens. Key amongst these is the need to empower people to become lifelong learners, to reflect upon their own learning, to become problem solvers and to appreciate technology. We record the experiences of an innovative project using a constructionist mindtool approach in a module on logic, robotics, and programming for nontechnical third level students.
Building highly available enterprise applications using Web-oriented middleware is hard. Runtime implementations frequently do not address the problems of application state persistence and fault-tolerance, placing the...
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Building highly available enterprise applications using Web-oriented middleware is hard. Runtime implementations frequently do not address the problems of application state persistence and fault-tolerance, placing the burden of managing session state and, in particular, handling system failures on application programmers. This paper describes Phoenix/APP, a runtime service based on the notion of recovery guarantees. Phoenix/APP transparently masks failures and automatically recovers component-based applications. This both increases application availability and simplifies application development. We demonstrate the feasibility of this approach by describing the design and implementation of Phoenix/APP in Microsoft's .NET runtime and present results on the cost of persisting and recovering component-based applications.
Summary form only given. This tutorial surveys the state of the art in type systems for programming languages, focusing on the achievements and changes in emphasis during the past decade. The first part of the talk co...
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Summary form only given. This tutorial surveys the state of the art in type systems for programming languages, focusing on the achievements and changes in emphasis during the past decade. The first part of the talk considers the trajectory of work on object types, one of the major hot topics of the early and mid-'90s. Following some fundamental conceptual breakthroughs, the focus of attention in this area has shifted from foundational research to applications to the development and analysis of real-world language designs. The next part outlines recent progress on a number of "bread and butter" type systems topics and their applications in new programming languages: subtyping, polymorphism, type inference, effect systems, dependent types, and type systems for modular programming. The final section introduces some newer topics that have emerged (or gained unexpected prominence) in the past few years, including type systems for concurrent and distributed languages, high-level type systems for low-level languages such as assembly and C, substructural type systems based on linear logic and its relatives, modal type systems, the burgeoning area of language-based security, and native language support for statistically typed XML processing.
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