4,470,994 research outputs found
Resource-Based View and SMEs Performance Exporting through Foreign Intermediaries: The Mediating Effect of Management Controls
Following the resource-based view, this research empirically explores the role of formal and informal management control in mobilizing export resources to develop export capabilities, influencing the export performance of small and medium-sized enterprises (SMEs) in an interorganizational relationship context. Empirical data were collected using a survey administrated online to finance managers in Spanish SMEs which use foreign intermediaries to access export markets. In this setting, evidence mainly suggests, first, that management control systems (MCSs) play a relevant mediating role between the effect of, on the one hand, resources on capabilities, and, on the other hand, resources and capabilities on performance. Second, that MCSs and capabilities play a interrelated double mediating effect between the impact of resources on performance; more specifically, a significant double indirect effect is found (1) between financial resources, behavior control, customer relationship building capability and performance, and (2) between physical resources, behavior control, customer relationship building capability and performanc
Traffic Control for Network Protection Against Spreading Processes
Epidemic outbreaks in human populations are facilitated by the underlying
transportation network. We consider strategies for containing a viral spreading
process by optimally allocating a limited budget to three types of protection
resources: (i) Traffic control resources, (ii), preventative resources and
(iii) corrective resources. Traffic control resources are employed to impose
restrictions on the traffic flowing across directed edges in the transportation
network. Preventative resources are allocated to nodes to reduce the
probability of infection at that node (e.g. vaccines), and corrective resources
are allocated to nodes to increase the recovery rate at that node (e.g.
antidotes). We assume these resources have monetary costs associated with them,
from which we formalize an optimal budget allocation problem which maximizes
containment of the infection. We present a polynomial time solution to the
optimal budget allocation problem using Geometric Programming (GP) for an
arbitrary weighted and directed contact network and a large class of resource
cost functions. We illustrate our approach by designing optimal traffic control
strategies to contain an epidemic outbreak that propagates through a real-world
air transportation network.Comment: arXiv admin note: text overlap with arXiv:1309.627
Human resources for control of tuberculosis and HIV-associated tuberculosis.
The global targets for tuberculosis (TB) control were postponed from 2000 to 2005, but on current evidence a further postponement may be necessary. Of the constraints preventing these targets being met, the primary one appears to be the lack of adequately trained and qualified staff. This paper outlines: 1) the human resources and skills for global TB and human immunodeficiency virus (HIV) TB control, including the human resources for implementing the DOTS strategy, the additional human resources for implementing joint HIV-TB control strategies and what is known about human resource gaps at global level; 2) the attempts to quantify human resource gaps by focusing on a small country in sub-Saharan Africa, Malawi; and 3) the main constraints to human resources and their possible solutions, under six main headings: human resource planning; production of human resources; distribution of the work-force; motivation and staff retention; quality of existing staff; and the effect of HIV/AIDS. We recommend an urgent shift in thinking about the human resource paradigm, and exhort international policy makers and the donor community to make a concerted effort to bridge the current gaps by investing for real change
Managing Access to Service Providers in Federated Identity Environments: A Case Study in a Cloud Storage Service
© 2015 IEEE. Currently the diversity of services, which are adhering to Identity Federation, has raised new challenges in the area. Increasingly, service providers need to control the access to their resources by users from the federation as, even though the user is authenticated by the federation, its access to resources cannot be taken for granted. Each Service Provider (SP) of a federation implements their own access control mechanism. Moreover, SPs might need to allow different access control granularity. For instance, all users from a particular Identity Provider (IdP) may access the resources due to some financial agreement. On the other hand, it might be the case that only specific users, or groups of users, have access to the resources. This paper proposes a solution to this problem through a hierarchical authorization system. Our approach, which can be customized to different SPs, allows the SP administrator to manage which IdPs, or users, have access to the provided resources. In order to demonstrate the feasibility of our approach, we present a case study in the context of a cloud storage solution
Chance-Constrained ADMM Approach for Decentralized Control of Distributed Energy Resources
Distribution systems are undergoing a dramatic transition from a passive
circuit that routinely disseminates electric power among downstream nodes to
the system with distributed energy resources. The distributed energy resources
come in a variety of technologies and typically include photovoltaic (PV)
arrays, thermostatically controlled loads, energy storage units. Often these
resources are interfaced with the system via inverters that can adjust active
and reactive power injections, thus supporting the operational performance of
the system. This paper designs a control policy for such inverters using the
local power flow measurements. The control actuates active and reactive power
injections of the inverter-based distributed energy resources. This strategy is
then incorporated into a chance-constrained, decentralized optimal power flow
formulation to maintain voltage levels and power flows within their limits and
to mitigate the volatility of (PV) resources
Overview of increasing the penetration of renewable energy sources in the distribution grid by developing control strategies and using ancillary services
Increasing the renewables energy resources in the distribution network is one of the main challenges of the distributed system operator due to instability, power quality and feeder capacity problems. This paper proposes a solution for further penetration of distributed energy resources, by developing control strategies and using ancillary services. Besides the penetration issues, the control strategies will mitigate power quality problems, voltage unbalance and will increase the immunity of the grid by provision of fault ride through capabilities
End-to-end elasticity control of cloud-network slices
The design of efficient elasticity control mechanisms for dynamic resource allocation is crucial to increase the efficiency of future cloud-network slice-defined systems. Current elasticity control mechanisms proposed for cloud- or network-slicing, only consider cloud- or network-type resources respectively. In this paper, we introduce the elaSticity in cLOud-neTwork Slices (SLOTS) which aims to extend the horizontal elasticity control to multi-providers scenarios in an end-to-end fashion, as well as to provide a novel vertical elasticity mechanism to deal with critical insufficiency of resources by harvesting underused resources on other slices. Finally, we present a preliminary assessment of the SLOTS prototype in a real testbed, revealing outcomes that suggest the viability of the proposal.Peer ReviewedPostprint (published version
Mathematical Modelling of Mosquito Dispersal in a Heterogeneous Environment.
Mosquito dispersal is a key behavioural factor that affects the persistence and resurgence of several vector-borne diseases. Spatial heterogeneity of mosquito resources, such as hosts and breeding sites, affects mosquito dispersal behaviour and consequently affects mosquito population structures, human exposure to vectors, and the ability to control disease transmission. In this paper, we develop and simulate a discrete-space continuous-time mathematical model to investigate the impact of dispersal and heterogeneous distribution of resources on the distribution and dynamics of mosquito populations. We build an ordinary differential equation model of the mosquito life cycle and replicate it across a hexagonal grid (multi-patch system) that represents two-dimensional space. We use the model to estimate mosquito dispersal distances and to evaluate the effect of spatial repellents as a vector control strategy. We find evidence of association between heterogeneity, dispersal, spatial distribution of resources, and mosquito population dynamics. Random distribution of repellents reduces the distance moved by mosquitoes, offering a promising strategy for disease control
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