Rotating stall is a primary constraint for the performance of axial #ow compressors. This paper establishes a necessary and su$cient condition for a feedback controller to locally stabilize the critical equilibrium of the uniform #ow at the inception of rotating stall. The explicit condition obtained in this paper provides an e!ective synthesis tool for rotating stall control. 2001 Elsevier Sci...

The paper describes how to translate a Prolog program into a control ow graph (CFG). The program is annotated with control information and a system of simple set constraints is formed and solved. Using this information, a CFG can be constructed straightforwardly, which is described. In order to represent control information compactly, the paper proposes a method to structure the solution of the...

A recently developed analytical version of the discrete-ordinates method is used to establish a concise and particularly accurate solution to the problem of Couette #ow of a binary gas mixture in a plane channel. The model kinetic equations used to describe the #ow are based on the BGK theory of the linearized Boltzmann equation, and, in addition to the complete distribution functions for the t...

A work ow is a series of tasks that comprise a business process. In conventional information systems, the process structure is often implicitly encoded in the system. In contrast, work ow management systems (WFMSs) separate the process structure from the rest of the system. A WFMS is a software system which supports the enactment of business processes, based on a work ow model : a formalism whi...

This paper presents a survey of current research in the areas of work ow and work ow management systems. We motivate this work by introducing the underlying problems and how they can be addressed by work ow systems. We review and examine the terminology, concepts, methodologies, and problems in the relevant areas. The general requirements of work ow management systems are also introduced and di...

A classic problem in security is that of checking that a program has secure information ow. Informally, this problem is described as follows: Given a program with variables partitioned into two disjoint sets of “high-security” and “low-security” variables, check whether observations of the low-security variables reveal any information about the initial values of the high-security variables. Alt...

Pär Johannesson Department of Mathematical Statistics, Lund Institute of Technology, Lund University, Sweden ABSTRACT: How does the fatigue damage to a vehicle depend on the usage of the vehicle? When it is used in its natural environment by a customer, both the drivers and the environmental properties vary in a more or less random way. One can say that the vehicle is subjected to a series of d...

Real-time applications involve the sequencing of different modes of continuous interaction with the environment. This suggests a hybrid language with data ow and sequencing constructs. To this purpose, we introduce the notion of time interval into the real-time declarative data ow language Signal, which is instant-based. Associating an execution interval with a data ow process speciies a task. ...

Submodular ow problems, introduced by Edmonds and Giles 2], generalize network ow problems. Many algorithms for solving network ow problems have been generalized to submodular ow problems (cf. references in Fujishige 4]), e.g. the cycle canceling method of Klein 9]. For network ow problems, the choice of minimum-mean cycles in Goldberg and Tarjan 6], and the choice of minimum-ratio cycles in Wa...

Most optical ow estimation techniques have substantial diiculties dealing with ow discontinuities. Methods which simultaneously detect ow boundaries and use the detected boundaries to aid in ow estimation can produce signiicantly improved results. Current approaches to implementing these methods still have important limitations, however. We demonstrate three such problems: errors due to the mix...