Using Information Retrieval techniques for supporting data mining

The classic two-stepped approach of the Apriori algorithm and its descendants, which consisted of finding all large itemsets and then using these itemsets to generate all association rules has worked well for certain categories of data. Nevertheless for many other data types this approach shows highly degraded performance and proves rather inefficient.

We argue that we need to search all the search space of candidate itemsets but rather let the database unveil its secrets as the customers use it. We propose a system that does not merely scan all possible combinations of the itemsets, but rather acts like a search engine specifically implemented for making recommendations to the customers using techniques borrowed from Information Retrieval.     

Simulation and modelling methods in aluminium rolling industry

Aluminium coil production plants can be described as multi-stage processes which are often characterised by complexity and are expected to manipulate huge amount of data. Effective scheduling is a key issue for these processes since it can improve throughput rates and machine utilisation. This paper studies the production line of companies which produce high-quality rolled aluminium lithographic strips. An efficient representation for such production processes is provided and subsequently used for an extensive analysis and performance evaluation through appropriate metrics. In particular, the work addresses the implementation of an overall model in a simulation environment, capable of integrating the various aspects of the specific production management processes. The model was successfully validated using actual production data, and it was found that it is suitable for the modelling, analysis and performance evaluation of the complex aluminium coils production process. With the aid of the model, various scenarios were investigated via extensive simulation runs, such as installing additional machine centres and reducing pre-set times the products spend in intermediate storage areas.     

Experimental Determination of Energy Content of Unknown Organics in Municipal Wastewater Streams

A bomb calorimetry method has been used for the first time to measure the energy content of raw municipal wastewater. The method was first validated using standard compounds (arginine, glucose, and propionic acid) and then tested with municipal sludge samples, with the results compared to previously published values. By drying a large enough sample to yield approximately 0.5 g of solid residue and using benzoic acid in a 1:1 ratio as a combustion aid, an accurate and precise measurement of the energy content of raw municipal wastewater can be made. The energy content measurements indicate that for the full-scale treatment facility examined, the potential energy available in the raw waste-water exceeds the electricity requirements of the treatment process by a factor of 9.3.     

Combined experimental and computer simulation study of the kinetics of solute release from a relaxing swellable polymer matrix. I. Characterization of non‐Fickian solvent uptake

This article is concerned with a combined experimental and computer modeling study aimed at the characterization of the non‐Fickian absorption of liquid water by cellulose acetate (CA) matrices (in the form of thin films) on the basis of a strictly limited number of parameters. The observed kinetics exhibited two distinct non‐Fickian features, resulting from short‐term and long‐term viscous structural relaxations of the swelling glassy polymeric matrix. These relaxation processes were modeled by the extension of a previous model of micromolecular diffusion in a polymer subject to a single relaxation process. The successful simulation of the experimental kinetic curves then enabled the determination and cross‐checking of the relevant model parameter values. This work had the dual purpose of providing (1) input related to solvent absorption for the quantitative computer simulation (in part II of this series) of a model monolithic, solvent‐activated, controlled‐release device, consisting of a swellable glassy polymeric matrix (CA) loaded with an osmotically active solute (NaCl), and (2) an example of a general strategy of extracting meaningful values of micromolecular diffusivity in glassy polymers from non‐Fickian absorption kinetic data. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2458–2467, 2004     

Performance Constraint Analysis of WDM LANs with Nonzero Propagation Delays and Destination Conflicts

In this paper, we study the effect of the round trip propagation delay on performance measures of wavelength division multiplexing (WDM) networks. Even though the impact of propagation delay is substantial in the optical network's behavior, most of the studies ignore the effect of this time component in throughput and delay evaluation. We assume a WDM local area network (LAN) where the round trip propagation delay is less or equal to a data packet transmission time. The proposed asynchronous transmission policy avoids data channel collision. In the analysis, we take into account the propagation delays and the effect of receiver collision for a system with a finite number of stations.     

Characterization of the Absorption of Theophylline From Immediate- and Controlled-Release Dosage Forms With a Numerical Approach Using the In Vitro Dissolution-Permeation Process Using Caco-2 Cells

After oral administration, drug absorption rate is recognized to be dependent on two major factors: dissolution and intestinal cells permeability. Caco-2 monolayer cells have been largely used as a permeation study model. In this study, a numerical approach funded on an exponential first-order time relationship was tested to compare immediate- and controlled-release tablets of theophylline using a dissolution-permeation system. The dissolution performance using USP II paddle apparatus was coupled to the permeability studies investigated in Caco-2 cell monolayers. The dissolved samples were taken at different times; their pH and osmolarity were adjusted to render them suitable to Caco-2 permeability studies (osmolarity = 300 mosm, pH = 7.4). The experimental data show that the dissolution fits the exponential first-order relationship rate. The permeability values were in a range of 4.45 10^- 6-5.28 10^- 6 cm/s, and percentages of absorbed drug dose were dependent on the fraction initially present in the donor compartment, indicating that absorption of theophylline was dissolution rate limited. Plotting experimental absorbed fractions (F_a) against experimental dissolved fractions (F_d) show that permeation is the rate-limiting step in drug absorption process in the extended release form of theophylline. Our results demonstrate a general agreement between observed F_a/F_d relationships and theoretical F_a/F_d relationships obtained with our approach funded on dissolution and permeation behavior. We concluded that the couple dissolution-caco-2 system could be a useful tool to characterize intestinal permeation for a new formulation of a drug compared with the conventional one.     

Noncontact measurement of breathing function.

This paper aims to open a new line of research by demonstrating the feasibility of monitoring breathing function in a highly automated and noncontact fashion. The method is based on the statistical modeling of dynamic thermal data captured through a highly sensitive infrared imaging system. This method achieved an accuracy of 96.43% on a small set of subjects during rest and after brief exercise. It has the potential to provide a unique capability for sustained monitoring of chronic or acute breathing problems and in sleep studies by overcoming the deficiencies of the existing measurement modalities. The method also opens the way for the next generation contact-free polygraphy that will not affect the subject's psychophysiology.     

Parameter adaptive control techniques for anaerobic digesters—real-life experiments

Different digital control schemes for anaerobic digesters of wastewater treatment plants are proposed. The process dynamics are briefly discussed and a simplified process model is adopted for the specific control purposes. By employing parameter adaptive control techniques, three nonlinear adaptive control algorithms are developed: substrate concentration control, methane production rate control and a strategy which is a combined method of the two previous control schemes. Extensive simulation results are presented. These algorithms are applied on a municipal wastewater treatment plant. The results obtained are discussed.     

A three-phase methodology for developing or evaluating bank networks

One basic characteristic of modern society, besides the fast spread of information, is the increased use of banking services in order to fulfil consumer needs. Apart from their income, modern consumers rely to an increasing extent on banking services and money transactions as well, in order to buy consumer products and cover their financial needs. Thus the new standards of the ‘consumer society’ significantly affect the role and the importance of banking services. The end of the monopoly era characterized by increased competition leads banks to modify their strategies, to provide more and better services, to reorganize their structure and expand or merge their networks. In this context we propose a three‐phase methodology for developing and/or evaluating banking networks. The above methodology calculates an ‘attractiveness index’ for each area, and combines geographic information systems with demand covering models so as to propose the best network structure.