Prediction of jet engine parameters for control design using genetic programming

The simulation of a jet engine behavior is widely used in many different aspects of the engine development and maintenance. Achieving high quality jet engine control systems requires the iterative use of these simulations to virtually test the performance of the engine avoiding any possible damage on the real engine. Jet engine simulations involve the use of mathematical models which are complex and may not always be available. This paper introduces an approach based on Genetic Programming (GP) to model different parameters of a small engine for control design such as the Exhaust Gas Temperature (EGT). The GP approach has no knowledge of the characteristics of the engine. Instead, the model is found by the evolution of models based on past measurements of parameters such as the pump voltage. Once the model is obtained, it is used to predict the behaviour of the jet engine one step ahead. The proposed approach is successfully applied for the simulation of a Behotec j66 jet engine and the results are presented

Analysing and attacking the 4-way handshake of IEEE 802.11i standard

The IEEE 802.11i standard has been designed to enhance security in wireless networks. In the 4-way handshake the supplicant and the authenticator use the pairwise master key (PMK) to derive a fresh pairwise transient key (PTK). The PMK is not used directly for security while assuming the supplicant and authenticator have the same PMK before running 4-way handshake. In this paper, the 4-way handshake phase has been analysed using Isabelle tool to identify a new Denial-of-Service (DoS) attack. The attack prevents the authenticator from receiving message 4 after the supplicant sends it out. This attack forces the authenticator to re-send the message 3 until time out and subsequently to de-authenticate supplicant. This paper has proposed improvements to the 4-way handshake to avoid the Denial-of-Service attack

Transform Ranking: a New Method of Fitness Scaling in Genetic Algorithms

The first systematic evaluation of the effects of six existing forms of fitness scaling in genetic algorithms is presented alongside a new method called transform ranking. Each method has been applied to stochastic universal sampling (SUS) over a fixed number of generations. The test functions chosen were the two-dimensional Schwefel and Griewank functions. The quality of the solution was improved by applying sigma scaling, linear rank scaling, nonlinear rank scaling, probabilistic nonlinear rank scaling, and transform ranking. However, this benefit was always at a computational cost. Generic linear scaling and Boltzmann scaling were each of benefit in one fitness landscape but not the other. A new fitness scaling function, transform ranking, progresses from linear to nonlinear rank scaling during the evolution process according to a transform schedule. This new form of fitness scaling was found to be one of the two methods offering the greatest improvements in the quality of search. It provided the best improvement in the quality of search for the Griewank function, and was second only to probabilistic nonlinear rank scaling for the Schwefel function. Tournament selection, by comparison, was always the computationally cheapest option but did not necessarily find the best solutions

BINet: Multi-perspective Business Process Anomaly Classification

In this paper, we introduce BINet, a neural network architecture for real-time multi-perspective anomaly detection in business process event logs. BINet is designed to handle both the control flow and the data perspective of a business process. Additionally, we propose a set of heuristics for setting the threshold of an anomaly detection algorithm automatically. We demonstrate that BINet can be used to detect anomalies in event logs not only on a case level but also on event attribute level. Finally, we demonstrate that a simple set of rules can be used to utilize the output of BINet for anomaly classification. We compare BINet to eight other state-of-the-art anomaly detection algorithms and evaluate their performance on an elaborate data corpus of 29 synthetic and 15 real-life event logs. BINet outperforms all other methods both on the synthetic as well as on the real-life datasets

Enrollers’ perceptions of communication during informed consent at a South African tuberculosis research site

The informed consent process (ICP) in clinical trials is an interaction of communication: one in which important information should be adequately conveyed by the enroller and sufficiently understood by the potential participant. However, barriers to effective communication are often encountered during the process and result in participants’ comprehension of information being compromised. This study aimed to use qualitative methods to explore the reported experiences of thirteen enrollers involved in the ICP pre- and post- the implementation of a communication training programme in a Human Immunodeficiency Virus (HIV) and tuberculosis (TB) research study in Rustenburg, South Africa. The communication training programme aimed to improve communication processes during the ICP and enhance participant comprehension of information. This study used journaling and FGDs as data collection methods. Inductive thematic analysis was used to explore the reported experiences of enrollers during the ICP, and to identify perceived barriers and facilitators to communication during these interactions. Findings revealed language-, procedure- and participant-related facilitators and barriers. Furthermore, communication and language strategies employed by enrollers to overcome reported barriers were discussed. Several strategies paralleled the communication and language skills taught during the communication skills training. Many of these strategies were found to facilitate communication processes within the enroller-participant interaction, improve understandings of the informed consent form (ICF) and obtain proper informed consent. These findings confirm that enrolment is a complex process impacted by many variables. Keywords: informed consent, communication, enrollers, clinical researchGR201

Use of Craigslist.org to Hook Up: Age Differences in Sex Requests, HIV Disclosure and Negotiated Safety among Men-Seeking-Men

Data from 984 “men-seeking-men” Craigslist.org postings in five cities were analyzed to assess differences in sexual requests, HIV status disclosure, and negotiated safety between young (18-24 years) and older (25 years and older) men who have sex with men (MSM). Young MSM were less likely than older MSM to post their HIV status or the preferred status of a partner (p=0.04), disclose and/or request a partner who was disease and drug free (p=.01), and request use of a condom in their posting (p=0.01). Interventions aimed at changing the culture and content of postings on Craigslist.org by encouraging HIV status disclosure and condom use preference are warranted, particularly for young MSM

Die zukünftige Ausgestaltung der Direktzahlungen – Eine quantitative Analyse möglicher Reformen in einer erweiterten Europäischen Union

The introduction of the current Common European Agricultural Policy in ten new member states in central and eastern Europe will be a major financial challenge for the European Union. On the basis of the partial equilibrium model ESIM this article analyses potential consequences of different options for a reformed CAP. While the impact on agricultural markets will be relatively small, the financial burden of a harmonisation of agricultural policies and an introduction of direct payments in the new member states has to be carried mainly by the old member states of the EU-15. The burden of the main net-payers, especially Germany, would be significantly lower, if CAP were reformed according to the proposals of the EU-Commission's Mid-term Report. However, the remaining negative impacts on world agricultural trade and on world market prices for agricultural products, clearly show the necessity of a further reform of the CAP.EU Enlargement, EU Mid-term Report, costs of CAP, partial equilibrium analysis, Agricultural and Food Policy,