Range of validity of weakly non-linear theory in Rayleigh-Bénard problem

In this paper we examine the equilibrium states of finite amplitude flow in a horizontal fluid layer with differential heating between the two rigid boundaries. The solutions to the Navier-Stokes equations are obtained by means of a perturbation method for evaluating the Landau constants and through a Newton-Raphson iterative method that results from the Fourier expansion of the solutions that bifurcate above the linear stability threshold of infinitesimal disturbances. The results obtained from these two different methods of evaluating the convective flow are compared in the neighborhood of the critical Rayleigh number. We find that for small Prandtl numbers the discrepancy of the two methods is noticeable. © 2009 The Physical Society of Japan.

Range of validity of weakly non-linear theory in Rayleigh-Bénard convection

In this paper we examine the equilibrium states of periodic finite amplitude flow in a horizontal channel with differential heating between the two rigid boundaries. The solutions to the Navier-Stokes equations are obtained by means of a perturbation method for evaluating the Landau coefficients and through a Newton-Raphson iterative method that results from the Fourier expansion of the solutions that bifurcate above the linear stability threshold of infini- tesimal disturbances. The results obtained from these two different methods of evaluating the convective flow are compared in the neighbourhood of the critical Rayleigh number. We find that for small Prandtl numbers the discrepancy of the two methods is noticeable.

Enabling innovation:knowledge control, sharing and coordination boundaries in UK and German manufacturing

We investigate how boundaries in knowledge control, sharing and co-ordination influence UK and German manufacturing firms’ innovation intensity (an indicator of the volume of product change) and product life (an indicator of the pace of generational change). In general UK plants more commonly face knowledge control boundaries related to plant ownership or control, while German plants more commonly face boundaries related to knowledge sharing and knowledge co-ordination between functional groups. Our empirical results emphasise the importance of the strategic management of innovation. Knowledge control boundaries – related to external ownership, group membership and decision making autonomy – have a weak negative influence on plants’ innovation outcomes. Strategic decisions relating to multifunctional working and networking are found to be more important in overcoming knowledge sharing and co-ordination boundaries. Knowledge sharing boundaries, related to plant or company boundaries, prove most important where a plant has no in-house R&D capability. Knowledge co-ordination boundaries related to functional or multi-functional working have strong but differential effects on different innovation output measures: functional boundaries increase product life in both countries, and in Germany maintaining functional boundaries is also associated with increased innovation intensity.

The boundaries of reporting sustainable development in social housing

The Registered Social Landlord (an independent housing association in the UK) examined here was widely recognized as providing an example of good governance. The organization was using extensive internal reporting, both corporate and quasi-governmental in language, to try to accurately capture different aspects of performance. This article reveals that reporting sustainable development has boundaries to be overcome, particularly in measuring performance of environmental and community activities. © 2008 The Authors.

Non-rigid object tracking in complex scenes

A recently proposed colour based tracking algorithm has been established to track objects in real circumstances [Zivkovic, Z., Krose, B. 2004. An EM-like algorithm for color-histogram-based object tracking. In: Proc, IEEE Conf. on Computer Vision and Pattern Recognition, pp. 798-803]. To improve the performance of this technique in complex scenes, in this paper we propose a new algorithm for optimally adapting the ellipse outlining the objects of interest. This paper presents a Lagrangian based method to integrate a regularising component into the covariance matrix to be computed. Technically, we intend to reduce the residuals between the estimated probability distribution and the expected one. We argue that, by doing this, the shape of the ellipse can be properly adapted in the tracking stage. Experimental results show that the proposed method has favourable performance in shape adaption and object localisation.

International selling and sales management:sales force research beyond geographic boundaries

An introduction is presented for this issue which includes the articles "Internationalizing Sales Research: Current Status, Opportunities and Challenges" by Nikolaos G. Panagopoulos and colleagues, "Cultural Intelligence in Cross-Cultural Selling: Propositions and Directions for Future Research" by John D. Hansen and colleagues, and "A New Conceptual Framework of Sales Force Control Systems" by Ren Y. Darmon and Xavier C. Martin

Filling knowledge gaps:knowledge sharing across inter-firm boundaries and occupational communities

This paper explores the micro-level processes of interaction across organisational boundaries and occupational communities. Based on a retrospective processual analysis, this study shows that in filling knowledge gaps, organisations put in place a series of knowledge mechanisms, which lead them to socially interact with their alliance partners. Both the deployment of existing knowledge and the creation of new knowledge are based on processes of interaction, which derive from the interplay between alliance actors. It is suggested that through both social interaction and the use of boundary objects, individuals are able to communicate, engage in problem-solving activities and share their ideas to fill knowledge gaps.

Intergroup leadership in organizations:leading across group and organizational boundaries

Intergroup leadership-leadership of collaborative performance of different organizational groups or organizations-is associated with unique intergroup challenges that are not addressed by traditional leadership theories. To address this lacuna, we describe a theory of intergroup leadership. Firmly grounded in research on social identity and intergroup relations, the theory proposes that effective intergroup performance rests on the leader's ability to construct an intergroup relational identity. We describe key leadership actions to establish such an identity. © 2012 Academy of Management Review.

Are we on the same page? Knowledge boundaries and transactive memory system development in cross-functional teams

One of the key challenges that organizations face when trying to integrate knowledge across different functions is the need to overcome knowledge boundaries between team members. In cross-functional teams, these boundaries, associated with different knowledge backgrounds of people from various disciplines, create communication problems, necessitating team members to engage in complex cognitive processes when integrating knowledge toward a joint outcome. This research investigates the impact of syntactic, semantic, and pragmatic knowledge boundaries on a team’s ability to develop a transactive memory system (TMS)—a collective memory system for knowledge coordination in groups. Results from our survey show that syntactic and pragmatic knowledge boundaries negatively affect TMS development. These findings extend TMS theory beyond the information-processing view, which treats knowledge as an object that can be stored and retrieved, to the interpretive and practice-based views of knowledge, which recognize that knowledge (in particular specialized knowledge) is localized, situated, and embedded in practice.

Plasticity, plasticity, plasticity . . . and the rigid problem of sex

Why is popular understanding of female-male differences still based on rigid models of development, even though contemporary developmental sciences emphasize plasticity? Is it because the science of sex differences still works from the same rigid models?

Optimal time following fluorescein instillation to evaluate rigid gas permeable contact lens fit

PURPOSE: To examine the optimum time at which fluorescein patterns of gas permeable lenses (GPs) should be evaluated. METHODS: Aligned, 0.2mm steep and 0.2mm flat GPs were fitted to 17 patients (aged 20.6±1.1 years, 10 male). Fluorescein was applied to their upper temporal bulbar conjunctiva with a moistened fluorescein strip. Digital slit lamp images (CSO, Italy) at 10× magnification of the fluorescein pattern viewed with blue light through a yellow filter were captured every 15s. Fluorescein intensity in central, mid peripheral and edge regions of the superior, inferior, temporal and nasal quadrants of the lens were graded subjectively using a +2 to -2 scale and using ImageJ software on the simultaneously captured images. RESULTS: Subjectively graded and objectively image analysed fluorescein intensity changed with time (p<0.001), lens region (centre, mid-periphery and edge: p<0.05) and there was interaction between lens region with lens fit (p<0.001). For edge band width, there was a significant effect of time (F=118.503, p<0.001) and lens fit (F=5.1249, p=0.012). The expected alignment, flat and steep fitting patterns could be seen from approximately after 30 to 180s subjectively and 15 to 105s in captured images. CONCLUSION: Although the stability of fluorescein intensity can start to decline in as little as 45s post fluorescein instillation, the diagnostic pattern of alignment, steep or flat fit is seen in each meridian by subjective observation from about 30s to 3min indicating this is the most appropriate time window to evaluate GP lenses in clinical practice.

The blurring boundaries between synchronicity and asynchronicity:new communicative situations in work-related Instant Messaging

Instant messaging is one of the most popular communication technologies in virtual teams, enabling interactions to intertwine whole working days, thus creating the sense of copresence for team members who are geographically dispersed. Through close linguistic analyses of naturally occurring data from a virtual team, this article discusses the implications of two novel communicative situations enabled by instant messaging: presence information and the persistence of transcript. The preliminary findings of this study indicate that these new communicative situations require the flouting or rethinking of previously existing interactional norms and that communicative practices employed by the team members are not yet conventionalized/normalized, the expectations and interpretations of interactional rituals and timing vary highly, even within the same virtual team.

Re-making a frontier community or defending ethnic boundaries? The Caucasus in Cossack identity

The essay focuses on the notion of the Caucasus as a reference point in the construction of Cossack identity in southern Russia. Since the late Soviet period, the Cossack revivalist/nativist movement has emerged in the territories which constituted the frontier zones of Tsarist Russia. Arguably, the historical Cossack hosts were established as a kind of frontier community which played an important role in the expansion of the Russian Empire. This essay examines how post-Soviet Cossacks reinterpret the meanings of the Caucasus as a spatial and cultural realm where, or in relation to which, they produce their identity as a distinct ethnic and cultural community.

Coordinating expertise across knowledge boundaries in offshore-outsourcing projects:the role of codification

The coordination of effort within and among different expert groups is a central feature of contemporary organizations. Within the existing literature, however, a dichotomy has emerged in our understanding of the role played by codification in coordinating expert groups. One strand of literature emphasizes codification as a process that supports coordination by enabling the storage and ready transfer of knowledge. In contrast, another strand highlights the persistent differences between expert groups that create boundaries to the transfer of knowledge, seeing coordination as dependent on the quality of the reciprocal interactions between groups and individuals. Our research helps to resolve such contested understandings of the coordinative role played by codification. By focusing on the offshore-outsourcing of knowledge-intensive services, we examine the role played by codification when expertise was coordinated between client staff and onsite and offshore vendor personnel in a large-scale outsourcing contract between TATA Consultancy Services (TCS) and ABN AMRO bank. A number of theoretical contributions flow from our analysis of the case study, helping to move our understanding beyond the dichotomized views of codification outlined above. First, our study adds to previous work where codification has been seen as a static concept by demonstrating the multiple, coexisting, and complementary roles that codification may play. We examine the dynamic nature of codification and show changes in the relative importance of these different roles in coordinating distributed expertise over time. Second, we reconceptualize the commonly accepted view of codification as focusing on the replication and diffusion of knowledge by developing the notion of the codification of the “knower” as complementary to the codification of knowledge. Unlike previous studies of expertise directories, codification of the knower does not involve representing expertise in terms of occupational skills or competences but enables the reciprocal interrelating of expertise required by more unstructured tasks.