393 research outputs found
A Generic Network and System Management Framework
Networks and distributed systems have formed the basis of an ongoing communications revolution
that has led to the genesis of a wide variety of services. The constantly increasing size and
complexity of these systems does not come without problems. In some organisations, the
deployment of Information Technology has reached a state where the benefits from downsizing and
rightsizing by adding new services are undermined by the effort required to keep the system
running.
Management of networks and distributed systems in general has a straightforward goal: to provide
a productive environment in which work can be performed effectively. The work required for
management should be a small fraction of the total effort. Most IT systems are still managed in an
ad hoc style without any carefully elaborated plan. In such an environment the success of
management decisions depends totally on the qualification and knowledge of the administrator.
The thesis provides an analysis of the state of the art in the area of Network and System
Management and identifies the key requirements that must be addressed for the provisioning of
Integrated Management Services. These include the integration of the different management related
aspects (i.e. integration of heterogeneous Network, System and Service Management).
The thesis then proposes a new framework, INSMware, for the provision of Management Services.
It provides a fundamental basis for the realisation of a new approach to Network and System
Management. It is argued that Management Systems can be derived from a set of pre-fabricated
and reusable Building Blocks that break up the required functionality into a number of separate
entities rather than being developed from scratch. It proposes a high-level logical model in order to
accommodate the range of requirements and environments applicable to Integrated Network and
System Management that can be used as a reference model.
A development methodology is introduced that reflects principles of the proposed approach, and
provides guidelines to structure the analysis, design and implementation phases of a management
system. The INSMware approach can further be combined with the componentware paradigm for
the implementation of the management system. Based on these principles, a prototype for the
management of SNMP systems has been implemented using industry standard middleware
technologies. It is argued that development of a management system based on Componentware
principles can offer a number of benefits. INSMware Components may be re-used and system
solutions will become more modular and thereby easier to construct and maintain
COMPONENT TECHNOLOGIES AND THEIR IMPACT UPON SOFTWARE DEVELOPMENT
Software development is beset with problems relating to development productivity, resulting in
projects delivered late and over budget. While the term software engineering was first introduced
in the late sixties, its current state reflects no other engineering discipline. Component-orientation
has been proposed as a technique to address the problems of development productivity and much
industrial literature extols the benefits of a component-oriented approach to software
development.
This research programme assesses the use of component technologies within industrial software
development. From this assessment, consideration is given to how organisations can best adopt
such techniques. Initial work focuses upon the nature of component-orientation, drawing from the
considerable body of industrial literature in the area. Conventional wisdom regarding componentorientation
is identified from the review. Academic literature relevant to the research programme
focuses upon knowledge regarding the assessment of software technologies and models for the
adoption of emergent technologies. The method pays particular attention to literature concerning
practitioner focussed research, in particular case studies. The application of the case study method
is demonstrated.
The study of two industrial software development projects enables an examination of specific
propositions related to the effect of using component technologies. Each case study is presented,
and the impact of component-orientation is each case is demonstrated. Theories regarding the
impact of component technologies upon software development are drawn from case study results.
These theories are validated through a survey of practitioners. This enabled further examination
of experience in component-based development and also understanding how developers learn
about the techniques.
A strategy for the transfer of research findings into organisational knowledge focuses upon the
packaging of previous experience in the use of component-orientation in such a way that it was
usable by other developers. This strategy returns to adoption theories in light of the research
findings and identifies a pattern-based approach as the most suitable for the research aims. A
pattern language, placed in the context of the research programme, is developed from this
strategy.
Research demonstrates that component-orientation undoubtedly does affect the development
process, and it is necessary to challenge conventional wisdom regarding their use. While
component-orientation provides the mechanisms for increased productivity in software
development, these benefits cannot be exploited without a sound knowledge base around the
domain
Top-down and bottom-up control of drug-induced sleep and anaesthesia
In recent decades, research has unravelled fascinating detail about the molecular mechanisms underpinning pharmacologic loss of consciousness (LOC). However, the systems-level mechanisms are far less clear. Recent genetic approaches, however, enable unprecedented dissection on neural pathways, and they are paving a way for this line of research. The focus of this thesis is to investigate the neuroanatomical substrates of commonly used drugs which reversibly render us unconscious.
Zolpidem is a positive allosteric modulator (PAM) of the GABAA receptor which binds to the benzodiazepine (BZ) site. Because zolpidem binds 1-3,,2 containing GABAA receptors, which are widespread, it acts virtually everywhere. We do not know if zolpidem causes sleep by enhancing GABAergic inhibition throughout the entire brain, or if the therapeutic sleep-inducing property depends upon specific brain circuitry. 2I77 mice are devoid of zolpidem-sensitivity. But, zolpidem-sensitivity can be restored selectively in brain regions, enabling dissection of the circuitry involved in zolpidem’s effect. To isolate the therapeutic effect of zolpidem we deleted GABAA-2I77-subunits and replaced them with GABAA-2F77-subunits in HDC neurons or frontal-cortex in isolation. We were able to selectively restore zolpidem-sensitivity in target neurons. This conferred zolpidem-enhanced IPSCs locally. Compared with wild-type mice and zolpidem-insensitive 2I77lox mice, we found that GABAA-2F77 receptors in either HDC-neurons or frontal cortex alone were enough to rescue the majority of zolpidem-mediated sleep. The response in HDC-2F77 mice was similar to that of an H1-receptor antagonist. By producing a null effect in a negative-control area – the superior colliculus – we show that HDC neurons and the frontal cortex are both substrates involved in zolpidem-mediated sleep.
We also investigated the role of synaptic-inhibition onto corticothalamic-neurons in anaesthetic-induced LOC and sleep-wake. To do this, we genetically ablated 2-subunits from layer-6 corticothalamic-cells by crossing Ntsr1-Cre mice with GABAA-2I77lox mice. We found this reduced isoflurane sensitivity, but left sleep-wake behaviours virtually unaffected.Open Acces
Redes de telecomunicações móveis em Portugal: análise retrospectiva
Mestrado em Engenharia de Computadores e TelemáticaPortugal é um dos paÃses da União Europeia (UE) com maior taxa de
penetração do Serviço Telefónico Móvel (STM) o que o torna num dos
paÃses mais interessantes para estudos relacionados com redes e serviços
M´oveis.
Neste contexto os estudos de mercado para determinar a taxa de penetração
de um novo serviço / tecnologia tornam-se decisivos para as empresas uma
vez que podem implicar custos elevados por vezes muito difÃceis de rentabilizar.
Apesar de já existir algum software que permite fazer modelação do comportamento
de vários operadores de telecomunicações em determinados
cenários, esses modelos têm em consideração padrões de comportamento
teóricos e podem não estar inteiramente adaptados à realidade de cada
mercado.
Este trabalho procura melhorar esses padrões de comportamento fazendo
uma análise retrospectiva ao mercado do STM desde a sua introdução em
Portugal, em 1989, e assim fornecer dados mais precisos às ferramentas de
modelação.Portugal is one of the European Union (EU) countries with the highest
penetration rate of Mobile Telecommunications Service (MTS) and that
fact makes it one of the most interesting countries for conducting studies
related to mobile networks and services.
In this context, doing market research to determine the penetration rate of
a particular new service / technology becomes crucial for companies, since
it may involve high costs sometimes very difficult to monetize.
Although there is already some software that models the behavior of several
telecom operators in certain scenarios, these models take into account
patterns of behavior based only on theory which may not be fully adapted
to each market reality.
This work seeks to improve those patterns of behavior by a making a retrospective
market analysis of the MTS, since its introduction in Portugal in
1989 thus providing more accurate data for modeling tools
Management And Security Of Multi-Cloud Applications
Single cloud management platform technology has reached maturity and is quite successful in information technology applications. Enterprises and application service providers are increasingly adopting a multi-cloud strategy to reduce the risk of cloud service provider lock-in and cloud blackouts and, at the same time, get the benefits like competitive pricing, the flexibility of resource provisioning and better points of presence. Another class of applications that are getting cloud service providers increasingly interested in is the carriers\u27 virtualized network services. However, virtualized carrier services require high levels of availability and performance and impose stringent requirements on cloud services. They necessitate the use of multi-cloud management and innovative techniques for placement and performance management. We consider two classes of distributed applications – the virtual network services and the next generation of healthcare – that would benefit immensely from deployment over multiple clouds. This thesis deals with the design and development of new processes and algorithms to enable these classes of applications. We have evolved a method for optimization of multi-cloud platforms that will pave the way for obtaining optimized placement for both classes of services. The approach that we have followed for placement itself is predictive cost optimized latency controlled virtual resource placement for both types of applications. To improve the availability of virtual network services, we have made innovative use of the machine and deep learning for developing a framework for fault detection and localization. Finally, to secure patient data flowing through the wide expanse of sensors, cloud hierarchy, virtualized network, and visualization domain, we have evolved hierarchical autoencoder models for data in motion between the IoT domain and the multi-cloud domain and within the multi-cloud hierarchy
- …