This paper uses a reduced model for simulating propagation of acoustic signals in fluid filled pipelines. The study allows a better understanding of the multipath environment found in a pipeline system with the goal o...This paper uses a reduced model for simulating propagation of acoustic signals in fluid filled pipelines. The study allows a better understanding of the multipath environment found in a pipeline system with the goal of finding optimum solutions for monitoring the pipeline integrity. Data provided both from the simplified model and from an equivalent experimental test rig are implemented using classical time delay estimation algorithms. It is observed an improved accuracy when closing gradually the pipeline end as a result of cancelling the multipath effect at the system＇s terminal.展开更多
The circuit testable realizations of multiple-valued functions are studied in this letter. First of all,it is shown that one vector detects all skew faults in multiplication modulo circuits or in addi-tion modulo circ...The circuit testable realizations of multiple-valued functions are studied in this letter. First of all,it is shown that one vector detects all skew faults in multiplication modulo circuits or in addi-tion modulo circuits,and n+1 vectors detect all skew faults in the circuit realization of multiple-valued functions with n inputs. Secondly,min(max) bridging fault test sets with n+2 vectors are pre-sented for the circuit realizations of multiple-valued logic functions. Finally,a tree structure is used instead of cascade structure to reduce the delay in the circuit realization,it is shown that three vec-tors are sufficient to detect all single stuck-at faults in the tree structure realization of multiple-valued logic functions.展开更多
文摘This paper uses a reduced model for simulating propagation of acoustic signals in fluid filled pipelines. The study allows a better understanding of the multipath environment found in a pipeline system with the goal of finding optimum solutions for monitoring the pipeline integrity. Data provided both from the simplified model and from an equivalent experimental test rig are implemented using classical time delay estimation algorithms. It is observed an improved accuracy when closing gradually the pipeline end as a result of cancelling the multipath effect at the system＇s terminal.
基金Supported by the National Natural Science Foundation of China (No.60006002)the Education Department of Guangdong Province of China (No.02019).
文摘The circuit testable realizations of multiple-valued functions are studied in this letter. First of all,it is shown that one vector detects all skew faults in multiplication modulo circuits or in addi-tion modulo circuits,and n+1 vectors detect all skew faults in the circuit realization of multiple-valued functions with n inputs. Secondly,min(max) bridging fault test sets with n+2 vectors are pre-sented for the circuit realizations of multiple-valued logic functions. Finally,a tree structure is used instead of cascade structure to reduce the delay in the circuit realization,it is shown that three vec-tors are sufficient to detect all single stuck-at faults in the tree structure realization of multiple-valued logic functions.
