1,136,878 research outputs found
Strategy management through quantitative modelling of performance measurement systems
This paper is based on previous works on performance measurement and on quantification of relationships between factors which affect performance. It demonstrates how tools and techniques developed can be used to evaluate the performance of alternative strategic choices through a quantitative approach to modelling of performance measurement systems. The paper provides a brief background to the research problem and preceding works. The tools and techniques used are briefly introduced. Use of these tools and techniques to evaluate the performance of alternative manufacturing strategies is demonstrated. Finally, the capability of the approach to deal with dynamic environments is demonstrated using sensitivity analysis
Query Modification in Object-oriented Database Federation
We discuss the modification of queries against an integrated view in a federation of object-oriented databases. We present a generalisation of existing algorithms for simple global query processing that works for arbitrarily defined integration classes. We then extend this algorithm to deal with object-oriented features such as queries involving path expressions and nesting. We show how properties of the OO-style of modelling relationships through object references can be exploited to reduce the number of subqueries necessary to evaluate such querie
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Enhancing Fault / Intrusion Tolerance through Design and Configuration Diversity
Fault/intrusion tolerance is usually the only viable way of improving the system dependability and security in the presence of continuously evolving threats. Many of the solutions in the literature concern a specific snapshot in the production or deployment of a fault-tolerant system and no immediate considerations are made about how the system should evolve to deal with novel threats. In this paper we outline and evaluate a set of operating systems’ and applications’ reconfiguration rules which can be used to modify the state of a system replica prior to deployment or in between recoveries, and hence increase the replicas chance of a longer intrusion-free operation
After the negotiations: assessing the impact of free trade agreements in Southern Africa
After protracted and difficult negotiations, agreement was recently reached on the dimensions of a South African-EU free trade deal. Because of South Africa's prominence in the sub-region, implementation of this agreement will have an impact not only on South Africa, but on all the SADC economies. This paper traces how this impact may be felt over time, using a multi-region model constructed to focus on the determination of sectoral and geographic trade patterns. By separatelymodeling South Africa and the rest of southern Africa, the model can be used to evaluate how alternative SADC regional trade strategies can influence how the EU deal affects the region's economies; by distinguishing among major trading partners (EU, North America, East Asia), the simulations can help illuminate how the trade deal will likely affect current trade patterns The empirical results lead to a number of conclusions: (1) trade creation dominates trade diversion for the region under all FTA arrangements; (2) the rest of southern Africa benefits from an FTA between the EU and South Africa — the recently signed bilateral agreement is not a “beggar thy neighbor” policy; (3) the rest of southern Africa gains more from zero-tariff access to EU markets than from a partial (50 percent) reduction in global tariffs; and (4) the South African economy is not large enough to serve as a growth pole for the region. Access to EU markets provides substantially bigger gains for the rest of southern Africa than does access to South Africa.Trade policy Africa., Free trade., South Africa.,
Evaluation - the educational context
Evaluation comes in many shapes and sizes. It can be as
simple and as grounded in day to day work as a clinical
teacher refl ecting on a lost teaching opportunity and
wondering how to do it better next time or as complex,
top down and politically charged as a major government
led evaluation of use of teaching funds with the subtext
of re-allocating them. Despite these multiple spectra
of scale, perceived ownership, fi nancial and political
implications, the underlying principles of evaluation are
remarkably consistent. To evaluate well, it needs to be
clear who is evaluating what and why. From this will
come notions of how it needs to be done to ensure the
evaluation is meaningful and useful. This paper seeks to
illustrate what evaluation is, why it matters, where to
start if you want to do it and how to deal with evaluation
that is external and imposed
Using a Bayesian averaging model for estimating the reliability of decisions in multimodal biometrics
The issue of reliable authentication is of increasing importance in modern society. Corporations, businesses and individuals often wish to restrict access to logical or physical resources to those with relevant privileges. A popular method for authentication is the use of biometric data, but the uncertainty that arises due to the lack of uniqueness in biometrics has lead there to be a great deal of effort invested into multimodal biometrics. These multimodal biometric systems can give rise to large, distributed data sets that are used to decide the authenticity of a user. Bayesian model averaging (BMA) methodology has been used to allow experts to evaluate the reliability of decisions made in data mining applications. The use of decision tree (DT) models within the BMA methodology gives experts additional information on how decisions are made. In this paper we discuss how DT models within the BMA methodology can be used for authentication in multimodal biometric systems
Combining Static and Dynamic Features for Multivariate Sequence Classification
Model precision in a classification task is highly dependent on the feature
space that is used to train the model. Moreover, whether the features are
sequential or static will dictate which classification method can be applied as
most of the machine learning algorithms are designed to deal with either one or
another type of data. In real-life scenarios, however, it is often the case
that both static and dynamic features are present, or can be extracted from the
data. In this work, we demonstrate how generative models such as Hidden Markov
Models (HMM) and Long Short-Term Memory (LSTM) artificial neural networks can
be used to extract temporal information from the dynamic data. We explore how
the extracted information can be combined with the static features in order to
improve the classification performance. We evaluate the existing techniques and
suggest a hybrid approach, which outperforms other methods on several public
datasets.Comment: Presented at IEEE DSAA 201
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