We propose a classification of partial order temporal properties into a hierarchy, which is a generalization of the safety-progress hierarchy of Chang, Manna and Pnueli. The classes of the hierarchy are characterized ...
详细信息
This paper deals with the sampled-data H/sub 2/ optimal control problem. Given a linear time-invariant continuous-time system, the problem of minimizing the H/sub 2/ performance over all sampled-data controllers with ...
详细信息
This paper deals with the sampled-data H/sub 2/ optimal control problem. Given a linear time-invariant continuous-time system, the problem of minimizing the H/sub 2/ performance over all sampled-data controllers with a fixed sampling period can be reduced to a pure discrete-time H/sub 2/ optimal control problem. This discrete-time H/sub 2/ problem is always singular. Motivated by this, in this paper the authors give a treatment of the discrete-time H/sub 2/ optimal control problem in its full generality. The results obtained are then applied to the singular discrete-time H/sub 2/ problem arising from the sampled-data H/sub 2/ problem. In particular, the authors give conditions for the existence of optimal sampled data controllers. It is also shown that the H/sub 2/ performance of a continuous-time controller can always be recovered asymptotically by choosing the sampling period sufficiently small. Finally, it is shown that the optimal sampled-data H/sub 2/ performance converges to the continuous time optimal H/sub 2/ performance as the sampling period converges to zero.< >
A compositional proof system is presented to axiomatize the real-time behavior of asynchronously communicating processes. Programs are written in a real-time version of CSP where processes asynchronously send and rece...
详细信息
A compositional proof system is presented to axiomatize the real-time behavior of asynchronously communicating processes. Programs are written in a real-time version of CSP where processes asynchronously send and receive messages along channels that are capable of buffering an arbitrary number of messages. Timing properties are expressed in explicitly clock temporal logic, which extends linear temporal logic with a special time variable, referring to a global clock.< >
An infinite series of curves is constructed in order to show that all linear codes can be obtained from curves using Goppa's construction. If one imposes conditions on the degree of the divisor used, then we deriv...
详细信息
An infinite series of curves is constructed in order to show that all linear codes can be obtained from curves using Goppa's construction. If one imposes conditions on the degree of the divisor used, then we derive criteria for linear codes to be algebraic-geometric. In particular, the family of q-ary Hamming codes is investigated, and it is proven that only those with redundancy one or two and the binary [7,4,3] code are algebraic-geometric in this sense. For these codes we explicitly give a curve, rational points and a divisor. It is proven that this triple is in a certain sense unique in the case of the [7,4,3] code.
Motivated by the close relation between reai-time and fault-tolerance, we investigate the foundations of a formal framework to specify and verify real-time distributed systems that incorporate fault-tolerance techniqu...
详细信息
暂无评论