NECESSARY AND SUFFICIENT CONDITION FOR GLOBAL CONTROLLABILITY OF A CLASS OF AFFINE NONLINEAR SYSTEMS

In this paper, we investigate the global controllability of a class of n-dimensional affine nonlinear systems with n- 1 controls and constant control matrix. A necessary and sufficient condition for its global controllability has been obtained by using the methods recently developed. Furthermore, we generalize the above result to a class of affine nonlinear systems with a block-triangular-like structure. Finally, we will give three examples to show the applications of our results.     

Revitalizing the Public Sphere: The Current System of Discourse and the Need for the Participative Design of Social Action

Public discourse in Western democracies, particularly in the United States, is far from the Habermasian ideal of citizens engaging in a rational discussion of public affairs. Rather than providing an arena for informed deliberation, the growing expertise of the media, lobbyists, and politicians has sub-optimized the current system of discourse to focus on emotional manipulation and the creation of polarized interests, each competing with each other for dominance. Avoiding a potentially disastrous outcome from this unbalancing of public discourse requires a revitalization of the public sphere and a return of the citizen voice in public decision making. To that end, systems thinkers have a tremendous opportunity and can play an important role. This article will explore the current challenges facing public discourse and outline that potential role.     

The Knowledge Age or the Age of Ignorance and the Decline of Freedom?

Increasingly knowledge has become a determining factor in achieving life’s potential and is the currency of the age. Without access to Information an individuals’ knowledge base cannot be enriched and without knowledge the individual becomes increasingly powerless. Advances in technology have provided opportunities for some to add to their stock of knowledge but access to sources of information is uneven and can lead to social unrest. The availability of information is an important factor in managing change and empowering citizens. The question about information and power then becomes one of ownership or sovereignty of the information. If we are to create an open society then we need to ensure that there is open access to knowledge through flexible and intelligent information systems that are available for all. In this paper we consider if we are truly entering the knowledge age or the age of ignorance.     

From Researching Regions at a Distance to Participatory Network Building: Integrating Action Research and Economic Geography

This paper describes the change in a researcher's practices from one of studying regional industrial development at a distance to one of working closely with a network of agri-food managers. This is accompanied by a discussion of the methodological and theoretical possibilities for an action research inspired economic geography. Some of the core characteristics of a pragmatic conceptualization of action research are revised. It is argued that theoretical developments within economic geography make possible a dialogue between researchers and local actors and that economic geography is challenged to accept that knowledge is generated through such a dialogue. Attempts to create a dialogue between action research and economic geography in a specific Norwegian industrial and geographical context are described. These attempts indicate that the researcher's methodological approach has been transformed from a narrow one relying solely on conventional social science methods to a broader one including participatory action research.     

Using Action Research to Improve Communication and Facilitate Group Work in a Multicultural Classroom: A South African Case Study

This study started with problems that my colleagues (and I) were experiencing with interaction and intercultural communication among students in our diverse classrooms. Educators were also experiencing difficulties in motivating students to work effectively in groups. The purpose of this paper was to seek solutions to these problems by exploring variations of the group oral assessment structure in a multilingual and multicultural context. Four phases of assessments were conducted at two tertiary institutions in South Africa using a combination of action research and a participatory approach. Not only did this study succeed in addressing the problems but it also revealed the added benefits of using an action research methodology.     

CONSTRUCTIVE KISSING NUMBERS IN HIGH-DIMENSIONAL SPACES

In the present paper, we focus on constructive spherical codes. By employing algebraic geometry codes, we give an explicit construction of spherical code sequences. By making use of the idea involved in the proof of the Gilbert-Varshamov bound in coding theory, we construct a spherical code sequence in exponential time which meets the best-known asymptotic bound by Shamsiev and Wyner.     

On the Meromorphic Solutions of Linear Differential Equations

In this paper, we investigate the growth of meromorphic solutions of higher order linear differential equation f^（k） ＋Ak-1 （z）e^Pk-1^（z） f^（k-1） ＋…＋A1 （z）e^P1（z） f′ ＋Ao（z）e^Po（z） f = 0 （k ≤ 2）, where Pj（z） （j = 0, 1,..., k - 1） are nonconstant polynomials such that deg Pj = n （j = 0, 1,..., k - 1） and Aj（z）（≠ 0） （j = 0, 1,..., k - 1） are meromorphic functions with order p（Aj） 〈 n （j = 0, 1,..., k - 1）.     

EXPLORATION/EXPLOITATION TRADEOFF WITH CELL-SHIFT AND HEURISTIC CROSSOVER FOR EVOLUTIONARY ALGORITHMS

In order to tradeoff exploration/exploitation and inspired by cell genetic algorithm a cellshift crossover operator for evolutionary algorithm （EA） is proposed in this paper. The definition domain is divided into n-dimension cubic sub-domains （cell） and each individual locates at an ndimensional cube. Cell-shift crossover first exchanges the cell numbers of the crossover pair if they are in the different cells （exploration） and subsequently shift the first individual from its initial place to the other individual＇s cell place. If they are already in the same cell heuristic crossover （exploitation） is used. Cell-shift/heuristic crossover adaptively executes exploration/exploitation search with the vary of genetic diversity. The cell-shift EA has excellent performance in terms of efficiency and efficacy on ten usually used optimization benchmarks when comparing with the recent well-known FEP evolutionary algorithm.