Automated and semi-automated ships have developed rapidly in recent years, but various external communication links have introduced some external threats. To solve the unknown impact of multiple attacks on intelligent ships, a cellular automaton is proposed to model the risk propagation process. We identify risk assessment indicators from the perspective of attack-defense confrontation and analyze the risk propagation situation from six different angles. Based on the experimental results, we identify the system’s weak nodes and propose cyber security protection suggestions to reduce the loss caused by multisource attacks on the system.

This paper focuses on addressing encryption and security concerns in wireless communications, by considering the utilizing of overlapped time domain multiplexing (OvTDM) to enhance transmission security. In this paper, a method is suggested in order to simultaneously balance the requirements of high speed rate and secure encryption in the communication process. Specifically, we propose a method for generating two-dimensional secret key by leveraging OvTDM's shaping filter parameters. The proposed approach enables secure and encrypted transmissions at the physical layer, contributing to improved communication security.

A probabilistic diagnosis algorithm is presented for constant degree structures. The performance of the algorithm is analyzed under a negative binomial failure distribution to account for fault clustering. It is shown that the algorithm can correctly identify almost all units even when the yield is low (much lower than 50%) and when faults are clustered. A wafer test structure is proposed, which utilizes the test access port of each die to perform comparison tests on its neighbors and incorporates a localized version of the diagnosis algorithm to determine the status of each die. Both the test time and the diagnosis time are invariant with respect to the number of dies on the wafer. The saving of test costs could be significant as compared with probe testing, because with probe testing dies are probed one at a time while they are tested in parallel with this scheme. The scheme is unique in that it is shown to work well when faults are clustered and when the yield is low.

A simple diagnosis algorithm is presented for constant degree systems such as rectangular grids connected as tori. The algorithm determines the status of a unit according to the size of its faction, a cluster of units that call each other fault-free but outsiders faulty. Almost all units are correctly identified with this algorithm under a binomial failure distribution even when the probability of failure is rather high. The complexity of the algorithm is O(n), where n is the number of units in a constant degree system. The application of the algorithm to production testing of VLSI chips is also considered. With a test board that houses a large number of chips to be tested, all the chips can be tested in parallel in a way that they test each other and the test outcomes, not necessarily correct, are reported to a host system for analysis. The actual status of each chip is determined by using this new diagnosis algorithm. The above chip screening process can be repeated for higher accuracy. It is shown that no more than two steps are needed in most real situations. Compared with testing by test equipment that usually tests only one chip at a time, the saving of test time and the test equipment cost could be significant with our approach.>

We demonstrate a structure for mutual test among N processing elements. We indicate how this structure might be used to identify the good dice on a semiconductor wafer at a cost below that of current techniques. Under either a digraph or a comparison model, our proposed test structure has the following properties: 1) It is nearly regular. 2) It can be laid out in area O(/spl ominus/(n). 3) In time /spl ominus/(N) and with high probability, all but at most an arbitrarily small fraction of the good elements can be identified. 4) The number of tests or comparisons per element is bounded by a constant. We approximate this constant analytically. The result is a substantial savings over the /spl ominus/(log N) tests per element in regular structures whose purpose is to identify, with high probability, every good element. In contrast with the majority of previous work, our results apply even when less than half of the elements are good.>

This correspondence proposes a new fault model for system diagnosis, wherein the interaction among faulty subsystems and fault propagation is considered. Criteria for one-step diagnosability are given. Optimal design of diagnosable systems is also developed. As to sequential diagnosis, single-loop systems are studied in depth.