Dirac cohomology for degenerate affine Hecke-Clifford algebras

In this paper, we study the Dirac cohomology theory on a class of algebraic structures. The main examples of this algebraic structure are the degenerate affine Hecke-Clifford algebra of type An-1 by Nazarov and of classical types by Khongsap-Wang. The algebraic structure contains a remarkable subalgebra, which usually refers to Sergeev algebra for type An-1. We define an analogue of the Dirac operator for those algebraic structures. A main result is to relate the central characters of modules of those algebras with the central characters of modules of the Sergeev algebra via the Dirac cohomology. The action of the Dirac operator on certain modules is also computed. Results in this paper could be viewed as a projective version of the Dirac cohomology of the degenerate affine Hecke algebra

Neurovascular Pharmacology of Prospective Antimigraine Drugs

Migraine is a paroxysmal neurovascular disorder, which affects a significant proportion of the population. Since dilatation of cranial blood vessels is likely to be responsible for the headache experienced in migraine, many experimental models for the study of migraine have focussed on this feature. The current review discusses a model that is based on the constriction of carotid arteriovenous anastomoses in anaesthetized pigs, which has during the last decades proven to be of great value in identifying potential antimigraine drugs acting via a vascular mechanism. Further, the use of human isolated blood vessels in migraine research is discussed. Thirdly, we describe an integrated neurovascular model, where dural vasodilatation in response to trigeminal perivascular nerve stimulation can be studied. Suc

Riesz basis generation, eigenvalues distribution, and exponential stability for a euler-bernoulli beam with joint feedback control

Using an abstract result on Riesz basis generation for discrete operators in general Hilbert spaces, we show, in this article, that the generalized eigenfunctions of an Euler-Bernoulli beam equation ith oint linear feedback control form a Riesz basis for the tate space. The spectrum-determined growth condition is hence obtained. Meanwhile, the exponential stability as well as the asymptotic expansion of eigenvalues are also readily obtained by a straightforward computation

The Effects of Agile Methodology Use on Knowledge Management Outcomes

In this research, we examine how the use of different agile practices contributes tosuccessful knowledge management. We review the literature on agile methodologies andidentify agile practices that are particularly relevant to knowledge management--i.e., pairprogramming, collective ownership, and coding standards

A relational view of knowledge transfer effectiveness in small new technology-based firms:An empirical analysis of a South African case

The open innovation model often neglects the frictions that external knowledge flows could encounter when crossing organisational boundaries. This study recognises such barriers and investigates the impact of these barriers on knowledge transfer effectiveness by using data on small new technologybased firms (NTBFs) located in the emerging South African economy. The empirical results show that the characteristics of inter-organisational knowledge exchange relationships (organisational and technological similarity and contact frequency) do have an impact on the effectiveness of knowledge transfer. The findings stress the relevance of a relational approach, as factors derived from it act as barriers to effective knowledge transfer for small firms

Authentication of traditional Chinese medicine using infrared spectroscopy: Distinguishing between ginseng and its morphological fakes

10.1007/s11373-006-9133-3Journal of Biomedical Science142265-273JBCI

Keep it simple:External resource utilisation and incremental product innovation in resource-challenged South African manufacturing firms

This paper examines how firms in an emerging economy cope with resource challenges by implementing compensation strategies for incremental product innovations. The model is empirically tested using firm-level survey data from 497 South African manufacturing firms. Results show that higher diversity among a specific set of external knowledge sources is associated with a higher likelihood of incremental product innovation. Stronger embeddedness in non-domestic inter-organisational networks increases this likelihood as well. The positive effect of external knowledge diversity is more positive for higher levels of localised ties. Recommendations to enhance incremental product innovation concern the development of external relationships with domestic and international partners while limiting knowledge source diversity to a specific actor set. This paper shows that in an emerging economy firms have agency with which they can use contact learning leading to product innovations tailored to local market needs and opportunities

A guided search genetic algorithm using mined rules for optimal affective product design

Affective design is an important aspect of new product development, especially for consumer products, to achieve a competitive edge in the marketplace. It can help companies to develop new products that can better satisfy the emotional needs of customers. However, product designers usually encounter difficulties in determining the optimal settings of the design attributes for affective design. In this article, a novel guided search genetic algorithm (GA) approach is proposed to determine the optimal design attribute settings for affective design. The optimization model formulated based on the proposed approach applied constraints and guided search operators, which were formulated based on mined rules, to guide the GA search and to achieve desirable solutions. A case study on the affective design of mobile phones was conducted to illustrate the proposed approach and validate its effectiveness. Validation tests were conducted, and the results show that the guided search GA approach outperforms the GA approach without the guided search strategy in terms of GA convergence and computational time. In addition, the guided search optimization model is capable of improving GA to generate good solutions for affective design