M. De Backer

Classification With Ant Colony Optimization

Ant colony optimization (ACO) can be applied to the data mining field to extract rule-based classifiers. The aim of this paper is twofold. On the one hand, we provide an overview of previous ant-based approaches to the classification task and compare them with state-of-the-art classification techniques, such as C4.5, RIPPER, and support vector machines in a benchmark study. On the other hand, a new ant-based classification technique is proposed, named AntMiner+. The key differences between the proposed AntMiner+ and previous AntMiner versions are the usage of the better performing MAX-MIN ant system, a clearly defined and augmented environment for the ants to walk through, with the inclusion of the class variable to handle multiclass problems, and the ability to include interval rules in the rule list. Furthermore, the commonly encountered problem in ACO of setting system parameters is dealt with in an automated, dynamic manner. Our benchmarking experiments show an AntMiner+ accuracy that is superior to that obtained by the other AntMiner versions, and competitive or better than the results achieved by the compared classification techniques.

Twelve weeks of continuous oral therapy for toenail onychomycosis caused by dermatophytes: A double-blind comparative trial of terbinafine 250 mg/day versus itraconazole 200 mg/day

BACKGROUND Dermatophyte infections of the toenail have been difficult to treat, requiring long courses of therapy and having high recurrence rates. New oral antifungal agents with better outcomes and minimal adverse events are needed. OBJECTIVE The purpose of this study was to compare two newer antifungal compounds, terbinafine and itraconazole, for efficacy and safety in toenail onychomycosis caused by dermatophytes. METHODS The study was randomized and double-blind. It compared 12 weeks of continuous oral treatment with terbinafine 250 mg/day or itraconazole 200 mg/day for confirmed toenail dermatophyte onychomycosis. Clinical symptoms and mycologic outcome were assessed at weeks 4, 8, 12, 24, 36, and 48. A total of 372 patients (186 in each group) with dermatophyte infection confirmed by microscopy and culture were included in the intent-to-treat analysis. RESULTS At week 48, a statistically significantly greater percentage of the terbinafine group than itraconazole group showed negative mycology (73% [119 of 163] vs 45.8% [77 of 168]; p < 0.0001) (difference = 27.2%; 95% CI = [17.0%, 37.3%]). The difference was also confirmed clinically (p = 0.001) in the patients who were clinically cured or had only minimal symptoms at the end of the study (76.2% [125 of 164] vs 58.1% [100 of 172]) (difference = 18.1%; 95% CI = [8.24%, 27.9%]). The geometric mean length of healthy nail of the big toe was significantly greater in the terbinafine than itraconazole group (8.1 vs 6.4 mm; p = 0.026). Tolerability was good to very good in almost 90% of patients in both groups, and all reported adverse events were known for these compounds. CONCLUSION Terbinafine produced higher rates of clinical and mycologic cure at follow-up than did itraconazole.

Credit rating prediction using Ant Colony Optimization

The introduction of the Basel II Capital Accord has encouraged financial institutions to build internal rating systems assessing the credit risk of their various credit portfolios. One of the key outputs of an internal rating system is the probability of default (PD), which reflects the likelihood that a counterparty will default on his/her financial obligation. Since the PD modelling problem basically boils down to a discrimination problem (defaulter or not), one may rely on the myriad of classification techniques that have been suggested in the literature. However, since the credit risk models will be subject to supervisory review and evaluation, they must be easy to understand and transparent. Hence, techniques such as neural networks or support vector machines are less suitable due to their black box nature. Building upon previous research, we will use AntMiner+ to build internal rating systems for credit risk. AntMiner+ allows to infer a propositional rule set from a given data set, hereby using the principles from Ant Colony Optimization. Experiments will be conducted using various types of credit data sets (retail, small- and medium-sized enterprises and banks). It will be shown that the extracted rule sets are both powerful in terms of discriminatory power and comprehensibility. Furthermore, a framework will be presented describing how AntMiner+ fits into a global Basel II credit risk management system.

Role Satisfaction Mediates the Relation between Role Ambiguity and Social Loafing among Elite Women Handball Players

The aims of the study were to develop a questionnaire on self-reported social loafing (SRSLQ), and then to examine its relations with role ambiguity and role satisfaction in a sample of 110 women handball players competing at the elite level in Norway. Structural equation modeling analyses indicated that the SRSLQ was a psychometrically sound measure. In line with the expectations, role satisfaction fully mediated the positive relation between role ambiguity and self-reported social loafing: The more players experienced role ambiguity, the less satisfied they were with their role in the team, and the more social loafing they reported.

An Encapsulated Eiffel Education Environment, based on Web Services

This paper explores some requirements for training/education environments for elementary object-oriented programming and discusses the applicability of Web Services for this purpose. It is shown how the encapsulated Web-interfaced nature of Web Services offers a very interesting object-oriented technology platform. This is illustrated by means of an implementation of an education environment for teaching Eiffel to first year Applied Economics Students. The benefits, but also the changes in the teaching process are discussed. The implementation is based on a unique combination of features of ISE Eiffel and Microsoft .NET.

The use of Sandimmun (cyclosporin A) in severe refractory rheumatoid arthritis: the Belgian experience

SummaryObjectiveTo investigate practicability, efficacy and tolerability of low starting doses of Sandimmun® (cyclosporin A) (2.5 mg/kg daily) in patients with severe refractory rheumatoid arthritis in the short (6 months) and middle (12 months) term.MethodsFifty-nine patients, presenting with active and severe rheumatoid arthritis unresponding to conventional DMARDs were allowed to start Sandimmun® at the dose of 2.5 mg/kg daily. This dose was progressively increased by steps of 25 mg daily up to a maximum of 5 mg/kg daily according to the renal function and blood pressure.ResultsA mean maintenance dose of 3.9 mg/kg daily was reached after 5 months and maintained throughout the study. Twenty-one patients (36%) completed the one year study. The reasons for discontinuation were: inefficacy (13), adverse events (17), both inefficacy and adverse events (5) and non-compliance (3). For these patients who completed the trial, clinical relevant improvements were observed within 3 months of treatment and were maintained until the end of the study for the Lee functional and the Ritchie articular index, as well as for the number of tender and swollen joints. No changes for the grip strength, the biological and immunological parameters were observed.Mean serum creatinine values rose from 0.81 mg/dl at start to 1.1 mg/dl after 5 months of therapy and remained at that level throughout the study. In patients who discontinued, the serum creatinine level nearly normalized after one month of Sandimmun® withdrawal.One hundred and sixty-two side effects were reported of which most were minor and known to occur with Sandimmun®. Twenty-two cases (37% of patients) dropped out for adverse events before 1 year treatment. The criteria to withdraw the patients from the study differed greatly from centre to centre.ConclusionsManaging RA patients presenting with very long and severe disease remains difficult. Therefore low dose Sandimmun® (2.5–5 mg/kg daily) appears to be a valuable therapeutic opportunity in RA patients refractory to various other conventional drugs, including methotrexate.