THE EFFECT OF TEMPERATURE TREATMENT ON PENETRANT TRANSPORT IN COAL

The macromolecular structure of coals thermally treated at 35^°C, 100^°C and 150^°C was investigated by dynamic penetrant transport in thin coal sections. The effects of temperature, carbon content in coal, and penetrant type on the transport mechanism were investigated. Dynamic swelling studies showed that penetrant transport into coal is a function of the average molecular weight between crosslinks, M_c. The penetrant transport mechanism at low activity is Fickian diffusion. The transport mechanism deviates from Fickian diffusion to anomalous transport, when the carbon content in coal and penetrant activity increase. Variations of the diffusion coefficients and relaxation constants were determined using a diffusion/relaxation coupled model.     

System level performance evaluation of MIMO and SISO OFDM-based WLANs

In this paper we investigate the system level performance of an Orthogonal Frequency Division Multiplexing (OFDM) Wireless LAN network enhanced through Multiple-Input Multiple-Output (MIMO) techniques and compare it to the performance of the conventional Single-Input Single-Output (SISO) network. The MIMO scheme we apply is closed loop power allocation based on Singular Value Decomposition (SVD). The above investigations are carried out by means of a software based simulation platform. In order to characterize the system level performance accurately, a suitable link-to-system interface based on channel capacity has been developed. The performance evaluation is achieved by monitoring the average system throughput and the percentage of satisfied users. Extensive system level simulations have been carried out that prove the superiority of MIMO techniques especially for heavy traffic load conditions.     

Amphiphilic Interpenetrating Networks for the Delivery of Hydrophobic, Low Molecular Weight Therapeutic Agents

To investigate the delivery of hydrophobic therapeutic agents, a novel class of interpenetrating networks (IPNs) were synthesized and composed of two networks: methacrylic acid grafted with poly(ethylene glycol) tethers, P(MAA-g-EG), and poly(n-butyl acrylate) (PBA). The hydrophilic P(MAA-g-EG) networks are pH-responsive hydrogels capable of triggered release of an encapsulated therapeutic agent, such as a low molecular weight drug or a protein, when it passes from the stomach (low pH) to upper small intestine (neutral pH). PBA is a hydrophobic homopolymer that can affect the IPN swelling behavior, the therapeutic agent loading efficiencies in IPNs, and solute release profiles from IPNs. In dynamic swelling conditions, IPNs had greater swelling ratios than P(MAA-g-EG), but in equilibrium swelling conditions the IPN swelling ratio decreased with increasing PBA content. Loading efficiencies of the model therapeutic agent fluorescein ranged from 21 - 44%. Release studies from neat P(MAA-g-EG) and the ensuing IPNs indicated that the transition from low pH (2.0) to neutral pH (7.0) triggered fluorescein release. Maximum fluorescein release depended on the structure and hydrophilicity of the carriers used in these studies.     

Error rate analysis of threshold-based hybrid selection/maximal-ratio diversity over correlated nakagami-m fading channels

An exact performance analysis of triple-branch threshold-based hybrid selection/maximal-ratio combining (T-HS/MRC) receivers over correlated Nakagami-m fading channels is presented. Our analysis is valid for integer-order fading parameters and an arbitrary covariance matrix. Following the moment-generating function-based approach, the error rate performance of T-HS/MRC receivers for various modulation formats is analytically obtained. Various performance evaluation results are also presented and compared to equivalent simulation ones.     

THE GAIA2JADE PROCESS FOR MULTI-AGENT SYSTEMS DEVELOPMENT

In this paper we present the Gaia2JADE process concerning how one can implement a multi-agent system with the JADE framework using the Gaia methodology for analysis and design purposes. This process is particularly dedicated to the conversion of Gaia models to JADE code. It is described using the Software Process Engineering Metamodel (SPEM) and extends the one proposed by FIPA for describing the Gaia modeling process. Thus, it proposes to potential MAS developers a process that covers the full software development lifecycle. This work is based on the experience we have acquired by applying this process for implementing a real-word multi-agent system conceived for providing e-services to mobile users. With this paper, we share this experience with future multi-agent systems (MAS) developers, who would like to follow this process, taking into account several technical issues that emerged during the implementation phase, helping them to easily model and implement their systems.     

Supporting exact indexing of arbitrarily rotated shapes and periodic time series under Euclidean and warping distance measures

Shape matching and indexing is important topic in its own right, and is a fundamental subroutine in most shape data mining algorithms. Given the ubiquity of shape, shape matching is an important problem with applications in domains as diverse as biometrics, industry, medicine, zoology and anthropology. The distance/similarity measure for used for shape matching must be invariant to many distortions, including scale, offset, noise, articulation, partial occlusion, etc. Most of these distortions are relatively easy to handle, either in the representation of the data or in the similarity measure used. However, rotation invariance is noted in the literature as being an especially difficult challenge. Current approaches typically try to achieve rotation invariance in the representation of the data, at the expense of discrimination ability, or in the distance measure, at the expense of efficiency. In this work, we show that we can take the slow but accurate approaches and dramatically speed them up. On real world problems our technique can take current approaches and make them four orders of magnitude faster without false dismissals. Moreover, our technique can be used with any of the dozens of existing shape representations and with all the most popular distance measures including Euclidean distance, dynamic time warping and Longest Common Subsequence. We further show that our indexing technique can be used to index star light curves, an important type of astronomical data, without modification. Reproducible Research Statement: All datasets and images used in this work are freely available at .     

Error rate performance analysis of dual-hop relaying transmissions over generalized-K fading channels

In this paper we present analytical expressions for the lower bounds of the error performance of dual-hop amplify-and-forward transmissions over independent and not necessarily identical Generalized-K fading channels. Using a tight upper bound for the end-to-end SNR, a novel expression for the probability density function is derived. Based on the abovementioned formula, tight lower bounds for the average bit error probability for a variety of modulation schemes are derived. In order to validate the accuracy of the proposed mathematical analysis, various numerical and computer simulation results are presented.