The authors study the fault diagnosis of multiprocessor systems when fault constraints in the local domain of each processor are specified. They use the comparison-based model. A multiprocessor system S is t-in-L diagnosable if, given a syndrome, all faulty processors can be uniquely identified provided there are at most t faulty processors in the local domain L(u/sub i/) union (u/sub i/) of every processor, u/sub i/ in S, where L (u/sub i/) denotes the set of processors adjacent to u/sub i/. Certain basic results that lead to efficient conditions for unique diagnosis of a system when certain fault constraints are satisfied in the local domain of each processor in the system are presented. The t-in-L diagnosability of certain regular interconnected systems is examined under the assumption that less than half of the processors in the system are faulty. Diagnosis algorithms for these systems are presented.>

The authors study the problem of sorting n distinct elements in ascending sequence according to a total order, using comparison queries which receive 'yes' or 'no' answers, but of which as many as e may be erroneous. In a half-lie version, all 'yes' answers are guaranteed to be correct and the errors are confined to 'no' answers. It is shown that the comparison query complexity of the sorting problem for this case is Omega (n log n+e), and an asymptotically optimal algorithm is demonstrated. In a full-lie version, both 'yes' and 'no' answers can be false. It is shown that the comparison query complexity of the sorting problem for this case is Omega (n log n+en).>

The authors attempt to formalize some properties which any reasonable control-flow complexity measure must satisfy. Since large programs are often built by sequencing and nesting of simpler constructs, the authors explore how control-flow complexity measures behave under such compositions. They analyze five existing control flow complexity measures-cyclomatic number, total adjusted complexity, scope ratio, MEBOW, and NPATH. The analysis reveals the strengths and weaknesses of these control flow complexity measures.>

The design is discussed of distributed algorithms for the single-source shortest-path problem to run on an asynchronous directed network in which some of the edges may be associated with negative weights, and thus in which a cycle of negative total weight may also exist. The only existing solution in the literature for this problem is due to K.M. Chandy and J. Misra (1982), and it has, in the worst case, an unbounded message complexity. A synchronous version of the Chandy-Misra algorithm is described and studied, and it is proved that for a network with m edges and n nodes, the worst case message and time complexities of this algorithm are O(mn) and O(n), respectively. This algorithm is then combined with an efficient synchronizer to yield an asynchronous protocol that retains the same message and time complexities.>

The set of all binary strings terminated by a specific pattern is countably infinite and regular and satisfies the prefix property. Some properties of such codeword sets in the context of source coding are studied. It is shown that some of them are universal and some of them are not, but none is asymptotically optimal.

The design of optimal, time-invariant, randomized, finite-state automata forK-hypothesis testing is an open problem forK > 2. A lower bound is constructed on the smallest probability of error achievable bym-state automata solving a three-hypothesis Bernoulli problem. A class of close-to-optimal automata is exhibited that requires at most one extra bit of memory to match the performnnce of an optimal automaton.

The least upper bound on the asymptotic proportion of the choice of the correct coin, achievable by {\em expedient} finite-memory algorithms in certain two-armed bandit problems, is derived and schemes which achieve these bounds in a limiting sense are displayed. A deterministic automaton whose performance is close to optimal is also presented.