6447863
Controllability of a Leader-Follower Dynamic Network with Interaction Time Delays
This paper studies the controllability of a leader-follower network of dynamic agents in the presence of communication delays. The network dynamics is governed by nearest neighbor rules over a fixed communication topology. The leader is a particular agent acting as an external input to steer the other member agents. We derive sufficient conditions of the controllability of the dynamic network and give an example to illustrate the main results.
11561145
Collective Behavior Analysis of a Class of Social Foraging Swarms
This paper considers an anisotropic swarm model that consists of a group of mobile autonomous agents with an attraction-repulsion function that can guarantee collision avoidance between agents and a Gaussian-type attractant/repellent nutrient profile. The swarm behavior is a result of a balance between inter-individual interplays as well as the interplays of the swarm individuals (agents) with their environment. It is proved that the members of a reciprocal swarm will aggregate and eventually form a cohesive cluster of finite size. It is shown that the swarm system is completely stable, that is, every solution converges to the equilibrium point set of the system. Moreover, it is also shown that all the swarm individuals will converge to more favorable areas of the Gaussian profile under certain conditions. The results of this paper provide further insight into the effect of the interaction pattern on self-organized motion for a Gaussian-type attractant/repellent nutrient profile in a swarm system.
17698779
Neural Network Identification Method Applied to the Nonlinear System
A kind of neural network solution method has been proposed in the paper aiming at a class of non-linear process control system with the characteristic of time delay. In this scheme, a new-type associative memory neural network is used to model the controlled system, and the fuzzy neural network with inverse identification structure is adopted to control the nonlinear process system. This fuzzy neural network control method adopts the structure of three layers combine neural network identifier with inverse structure. Computer simulation and lab application show that it is effective to adopt this scheme to control on-linear process system with time delay.
203663524
Multi-Agent Based Network Management Task Decomposition and Scheduling
The rapid development of Internet makes network management on large-scale network a critical issue. But with the management task of large-scale network becoming more complicated, neither centralized network management nor agent based network management can satisfy the increasing demands. This paper presents a network management framework to support dynamic scheduling decisions. In this framework, some algorithms are proposed to decompose the whole network management task into several groups of sub-tasks. During the course of decomposition, different priorities are assigned to sub-tasks. Then based on the priorities of these sub-tasks, the strategies of agent scheduling are established. Priority-ranked sub-tasks are grouped according to their inter-dependences. Sub-tasks with the same priority are put into the same group and they can be performed in parallel manner, while different groups of sub-tasks with different priorities must be implemented according to the order of their priorities. An experiment has been done with the algorithms, the results of which demonstrate the advantage of the algorithms.
17205706
Rule interestingness analysis using OLAP operations
The problem of interestingness of discovered rules has been investigated by many researchers. The issue is that data mining algorithms often generate too many rules, which make it very hard for the user to find the interesting ones. Over the years many techniques have been proposed. However, few have made it to real-life applications. Since August 2004, we have been working on a major application for Motorola. The objective is to find causes of cellular phone call failures from a large amount of usage log data. Class association rules have been shown to be suitable for this type of diagnostic data mining application. We were also able to put several existing interestingness methods to the test, which revealed some major shortcomings. One of the main problems is that most existing methods treat rules individually. However, we discovered that users seldom regard a single rule to be interesting by itself. A rule is only interesting in the context of some other rules. Furthermore, in many cases, each individual rule may not be interesting, but a group of them together can represent an important piece of knowledge. This led us to discover a deficiency of the current rule mining paradigm. Using non-zero minimum support and non-zero minimum confidence eliminates a large amount of context information, which makes rule analysis difficult. This paper proposes a novel approach to deal with all of these issues, which casts rule analysis as OLAP operations and general impression mining. This approach enables the user to explore the knowledge space to find useful knowledge easily and systematically. It also provides a natural framework for visualization. As an evidence of its effectiveness, our system, called Opportunity Map, based on these ideas has been deployed, and it is in daily use in Motorola for finding actionable knowledge from its engineering and other types of data sets.
12487339
Mining community structure of named entities from free text
Although community discovery has been studied extensively in the Web environment, limited research has been done in the case of free text. Co-occurrence of words and entities in sentences and documents usually implies connections among them. In this paper, we investigate the co-occurrences of named entities in text, and mine communities among these entities. We show that identifying communities from free text can be transformed into a graph clustering problem. A hierarchical clustering algorithm is then proposed. Our experiment shows that the algorithm is effective to discover named entity communities from text documents.
14246442
A Bottom-up Distance-based index Tree for Metric Space
Similarity search is of importance in many new database applications. These operations can generally be referred as similarity search in metric space. In this paper, a new index construction algorithm is proposed for similarity search in metric space. The new data structure, called bu-tree (bottom-up tree), is based on constructing the index tree from bottom-up, rather than the traditional top-down approaches. The construction algorithm of bu-tree and the range search algorithm based on it are given in this paper. And the update to bu-tree is also discussed. The experiments show that bu-tree is better than sa-tree in search efficiency, especially when the objects are not uniform distributed or the query has low selectivity