A neural' network applied to tlie calculation of lyapunov exponents

Chaotic deterministics systems are characterised by the instability of orbits on an attractor. The largest Lyapunov exponent measures on average the exponential growth rate of small deviations along an orbit and gives as such an indication whether or not the dynamic generating process is unstable. The direct method for calculation of the Lyapunov exponent, based on finite differences as formulated by the so-called Wolf-algorithm,fails on medium sized data sets. Alternatively, one can use a neural network with backpropagation to estimate a data generating function. This so-calletl indirect method enables us to recover the theoretical value of the largest Lyapunov exponent in several examples.     

Visual extended enterprise engineering and operation-embedding knowledge management and work execution

This paper describes a new approach to extended enterprise engineering and operation-embedding knowledge management and work-tops for work execution. The approach is based on web technologies and a new technology we call active knowledge models (AKM). By developing and using AKMs of extended enterprises, most methodologies, work environments and business solutions will converge. Enterprises will be integrated by externalized shareable knowledge. During forming and managing of extended enterprises, knowledgesharing infrastructures and the process of generating operational solutions will be simplified and facilitated. Extended enterprises will be engineered and managed as reflective, selfadapting AKMs. By using process-oriented methods to externalize internal and tacit knowledge, the AKM technology provides an environment of work-tops and views to produce, share, cultivate and manage situated knowledge. This knowledge will be applied and managed as competences and skills, and as improved methods. AKMs let us benefit from the intrinsic properties of knowledge. They facilitate convergence of methodologies and integration of technologies.     

“如实述说”：逻辑中的信息流动

本文把逻辑表述为关于信息流动的一般理论，它涉及推理、观察和社会交往等人类能力。由此导致的多主体动力学可以用关于信息更新的动态认知逻辑系统来加以研究，后者也能够处理信念更新和学习问题；可以把这种语义动态学与作为信息阐明的推理的语法过程相结合：本文最后讨论了如何（将已有结果）扩展到主体之间的长期互动，并描述了（主体的）偏好和目标，以及由此导致的逻辑、博弈论和社会选择理论之间的相互作用。     

Worlds apart,worlds together: converging and diverging frames in climate and energy governance

This paper argues that past research has overlooked how the way problems and solutions are framed contribute to a prevailing gap in the global governance of climate and energy. Empirically, this paper investigates the frames of energy and climate change as expressed in key documents from the International Panel on Climate Change (IPCC) and International Energy Agency (IEA). Partly in contrast to past research, this paper finds (1) that there is a growing similarity in how the IPCC and IEA frame climate and energy; (2) that the IEA has gone from ignoring to acknowledging climate change and the transformation to a low-carbon energy system; and (3) that there is a prevailing difference in emphasis, whereas the IPCC only marginally discuss energy, while the IEA is still mainly talking about energy needs and fossil fuels even if climate change and renewables have entered their agenda.     

Volunteering and Civic Action: Boundaries Blurring,Boundaries Redrawn

VOLUNTAS: International Journal of Voluntary and Nonprofit Organizations - The aim of this introduction to the special issue is to call into question the presumed conceptual divide between...     

Associations Online: Barriers for Using Web-Based Communication in Voluntary Associations

Despite the high adoption level of Facebook and other social network sites (SNSs) in Norway, local level voluntary associations have not embraced SNSs to the same degree. Regular websites are the main web representation, and information provision is the main function of the associations’ web representations. Using quantitative data on website content and organizational characteristics we have analyzed which factors hinder SNS adoption. The results point to size and complexity of associations and to age-based digital divides among members as important factors for having a profile on a SNS. It seems that a certain numerical point must be reached in terms of organizational and community size, for SNSs to be useful. Also, older members, smaller economy and a low degree of formalization in associations might hamper the implementation of SNSs in associations. Using Norway as a critical case, this article contributes new knowledge about web communication in voluntary organizations, an increasingly important field of research internationally.     

State estimation for nonlinear state-space transmission models of tuberculosis

Given the high prevalence of tuberculosis (TB) and the mortality rate associated with the disease, numerous models, such as the Gammaitoni and Nucci (GN) model, were developed to model the risk of transmission. These models typically rely on a quanta generation rate as a measurement of infectivity. Since the quanta generation rate cannot be measured directly, the unique contribution of this work is to develop state estimators to estimate the quanta generation rate from available measurements. To estimate the quanta generation rate, the GN model is adapted into an augmented single-room GN model and a simplified two-room GN model. Both models are shown to be observable, i.e., it is theoretically possible to estimate the quanta generation rate given available measurements. Kalman filters are used to estimate the quanta generation rate. First, a continuous-time extended Kalman filter is used for both adapted models using a simulation and measurement sampling rate of 60 s. Accurate quanta generate rate estimates are achieved in both cases. A more realistic scenario is also considered with a measurement sampling rate of one day. For these estimates, a hybrid extended Kalman filter (HEKF) is used. Accurate quanta generation rate estimates are achieved for the more realistic scenario. Future work could potentially use the HEKFs, the adapted models, and real-time measurements in a control system feedback loop to reduce the transmission of TB in confined spaces such as hospitals.     

Organizing Professionalism – New Elites,Stratification and Division of Labor

Public Organization Review - The case in this study is the introduction of a new more prominent position for teachers. The aim is to contribute to the literature on stratification and organizing of...