This paper deals with finite automaton public key cryptosystem and digital signatures. A new system FAPKC3 is proposed which can be used for encryption and implementing digital signatures as well. Some performances of a software implementation of FAPKC3 are presented and its security is discussed.

A large class of NP optimization problems called MNP are studied. It is shown that Rmax(2) is in this class and some problems which are not likely in Rmax(2) are in this class. A new kind of reductions, SL-reductions, is defined to preserve approximability and nonapprokimability, so it is a more general version of L-reductions and A-reductions. Then some complete problems of this class under SL-reductions are shown and it is proved that the max-clique problem is one of them. So all complete problems in this class are as difficult to approximate as the max-clique problem.

A unified approach called partition-and-recur for developing efficient and correct algorithmic programs is presented. An algorithm (represented by recurrence and initiation) is separated from program, and special attention is paid to algorithm manipulation rather than program calculus. An algorithm is exactly a set of mathematical formulae. It is easier for formal derivation and proof. After getting efficient and correct algorithm, a trivial transformation is used to get a final program. The approach covers several known algorithm design techniques, e.g. dynamic programming, greedy, divide-and-conquer and enumeration, etc. The techniques of partition and recurrence are not new. Partition is a general approach for dealing with complicated objects and is typically used in divide-and-conquer approach. Recurrence is used in algorithm analysis, in developing loop invariants and dynamic programming approach. The main contribution is combining two techniques used in typical algorithm developm…

This paper presents a new approach to hyper-distributed hyper-parallel heuristic AI problem solving, which is based on asynchronous superimposition of synchronous homogeneous concurrent propagations of competitive waves. In comparison with synchronous homogeneous mechanism, the proposed approach shows better generalityl suitability and feasibility for real-time AI processing,especially for the search of implicit AND/OR graphs.

Based on the approach implementing a deductive object-oriented database system through the underlying relational database, this paper presents an object reasoning language O-Datalog, which is the extension of Datalog in form and can deal with object-oriented data. For any O-Datalog program, an equivalent Datalog program can be built to help evaluate the original program. This paper focuses on the syntax, semantics and evaluation of O-Datalog

This paper distinguishes among three kinds of linear recursions: canonical strongly linear recursion (CSLR), non-interdependent linear recursion (NILR) and interdependent linear recurstion (ILR) and presents an optimal algorithm for each. First, for the CSLRs, the magic-set method is refined in such a way that queries can be evaluated efficiently. Then, for the NILRS and ILRs, the concept of query dependency graphs is introduced to partition the rules of a program into a set of CSLRs and the computation is elaborated so that the oplimization for CSLRs can also be applied

A short-time scaling criterion of variable ordering of OBDDs is proposed. By this criterion it is easy and fast to determine which one is better when several. variable orders are given, especially when they differ 10% or more in resulted BDD size from each other. An adaptive variable order selection method, based on the short-time scaling criterion, is also presented. The experimental results show that this method is efficient and it makes the heuristic variable ordering methods more practical.

This paper examines the feasibility of providing multimedia mail, in particular video mail, on the existing World-Wide-Web platform. In this instance,the Web browser will act as the user agent of the mailing system. With this,users will be able to compose, send and read video mail directly on the Web.This paper examines a number of different system architectures which can be employed for the development of Video Mail. Based on the following key issues:portability of system, flexibility of system, Internet standard support, securityand authentication, and message compression and storage, a final architecturewas chosen to build Video Mail. The approach taken is that the system will beinterfaced to the Web using a standard HyperText Transfer Protocol (HTTP)server and a standard Web browser. This is achieved through the use of Common Gateway interface (CGI) programs and forms which reside in a standard HTTP server to provide the functionality of video mail, and a separate mail server for t…