Sensor location problem for large-scale complex systems in the framework of the dynamic Signed Directed Graph

2007 ◽  
Author(s):  
Fan Yang ◽  
Deyun Xiao
Keyword(s):  
Complex Systems ◽  
Directed Graph ◽  
Large Scale ◽  
Location Problem ◽  
Sensor Location ◽  
Signed Directed Graph

Research on Fault Diagnosis Approach Based on the Signed Directed Graph Model for Nuclear Power Plant

2013 ◽  
Author(s):  
Zhen Liu ◽  
Yong-kuo Liu ◽  
Xiao-tian Wu ◽  
Xian Zeng
Keyword(s):  
Fault Diagnosis ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Directed Graph ◽  
Nuclear Power ◽  
Large Scale ◽  
Stable Operation ◽  
Strong Completeness ◽  
Signed Directed Graph ◽  
Propagation Paths

Signed Directed Graph (SDG) is a kind of fault diagnosis method based on a qualitative model. SDG can not only efficiently express the interrelations among variables of complex systems and has strong completeness, flexible reasoning ways and effective reasoning algorithm, but also shows faults propagation paths and faults detailed explanations. In this paper, SDG is applied to fault diagnosis in nuclear power plant which is a large-scale and complex system, and diagnosis results are transformed into a series of expert rules. The case studies show this method can find faults propagation paths and fault source can be determined effectively and improve the efficiency of fault diagnosis. The application of SDG in nuclear power plant can provide operation support to operators, so as to guarantee the safe and stable operation of the system.

scholarly journals A Fault Identification Method in Distillation Process Based on Dynamic Mechanism Analysis and Signed Directed Graph

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 229
Author(s):  
Wende Tian ◽  
Shifa Zhang ◽  
Zhe Cui ◽  
Zijian Liu ◽  
Shaochen Wang ◽  
...  
Keyword(s):  
Directed Graph ◽  
Process Simulation ◽  
Expert Knowledge ◽  
Dynamic Mechanism ◽  
Fault Identification ◽  
Mechanism Analysis ◽  
Distillation Process ◽  
Complex Network Theory ◽  
Identification Method ◽  
Signed Directed Graph

Due to the complexity of materials and energy cycles, the distillation system has numerous working conditions difficult to troubleshoot in time. To address the problem, a novel DMA-SDG fault identification method that combines dynamic mechanism analysis based on process simulation and signed directed graph is proposed for the distillation process. Firstly, dynamic simulation is employed to build a mechanism model to provide the potential relationships between variables. Secondly, sensitivity analysis and dynamic mechanism analysis in process simulation are introduced to the SDG model to improve the completeness of this model based on expert knowledge. Finally, a quantitative analysis based on complex network theory is used to select the most important nodes in SDG model for identifying the severe malfunctions. The application of DMA-SDG method in a benzene-toluene-xylene (BTX) hydrogenation prefractionation system shows sound fault identification performance.

scholarly journals Sensor Location Problem for Network Traffic Flow Derivation Based on Turning Ratios at Intersection

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Minhua Shao ◽  
Lijun Sun ◽  
Xianzhi Shao
Keyword(s):  
Network Flow ◽  
Location Problem ◽  
Optimal Solution ◽  
Coefficient Matrix ◽  
Sensor Location ◽  
The Road ◽  
Minimum Number ◽  
Flow Conservation ◽  
The Greedy Algorithm ◽  
Counting Points

The sensor location problem (SLP) discussed in this paper is to find the minimum number and optimum locations of the flow counting points in the road network so that the traffic flows over the whole network can be inferred uniquely. Flow conservation system at intersections is formulated firstly using the turning ratios as the prior information. Then the coefficient matrix of the flow conservation system is proved to be nonsingular. Based on that, the minimal number of counting points is determined to be the total number of exclusive incoming roads and dummy roads, which are added to the network to represent the trips generated on real roads. So the task of SLP model based on turning ratios is just to determine the optimal sensor locations. The following analysis in this paper shows that placing sensors on all the exclusive incoming roads and dummy roads can always generate a unique network flow vector for any network topology. After that, a detection set composed of only real roads is proven to exist from the view of feasibility in reality. Finally, considering the roads importance and cost of the sensors, a weighted SLP model is formulated to find the optimal detection set. The greedy algorithm is proven to be able to provide the optimal solution for the proposed weighted SLP model.

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