IJITCS Vol. 4, No. 1, Feb. 2012
Cover page and Table of Contents: PDF (size: 129KB)
This article discusses the problem of an evaluation of the remote access to the resources of a Virtual Research Lab (VRL) and information servicing investigation by using queuing model and program simulation. The results presented here are the final part of general investigation of proposed architecture of the VRL developed in the frame of two years scientific project. Some results from the initial phases of the investigation (functional, deterministic and stochastic modeling) are discussed in other publications of the author. The purpose of this article is to present a simulation organization and performance factors evaluation of the remote access and information servicing in the VRL. In this connection formalization and an abstract model are made. An extension of this formalization based on the queuing theory is made and a general queuing model for the simulation organization is developed. The program realization of the simulation experiments is made by using the system WebGPSS. Object of investigation is the user access to the resources and some variants are evaluated, for example ‘single-user access to a single resource’ and ‘multiple-user access to multiple resources’. Some experimental results are discussed. Different assessments for the components that take part in the remote access are calculated and presented (utilization, workload, waiting time, etc.)[...] Read more.
Identifying customers who are more likely to respond to new product offers is an important issue in direct marketing. In direct marketing, data mining has been used extensively to identify potential customers for a new product (target selection). Using historical purchase data, a predictive response model with data mining techniques was developed to predict a probability that a customer in Ebedi Microfinance bank will respond to a promotion or an offer. To achieve this purpose, a predictive response model using customers’ historical purchase data was built with data mining techniques. The data were stored in a data warehouse to serve as management decision support system. The response model was built from customers’ historic purchases and demographic dataset.
Bayesian algorithm precisely Naïve Bayes algorithm was employed in constructing the classifier system. Both filter and wrapper feature selection techniques were employed in determining inputs to the model.
The results obtained shows that Ebedi Microfinance bank can plan effective marketing of their products and services by obtaining a guiding report on the status of their customers which will go a long way in assisting management in saving significant amount of money that could have been spent on wasteful promotional campaigns.[...] Read more.
Due to the usage of single carrier, the performance of SC-FDMA systems degrades in deep frequency selective fading channels. In this paper, we propose a structure of equalizer based on frequency domain decision feedback which could be used for multi-user SC-FDMA systems. This algorithm is applicable to various carrier allocations in multi-user systems such as localized allocation, distributed allocation, and frequency-hopping (FH) allocation. To reduce the complexity, it is not necessary to derive the inversion of matrix, which is required in the traditional decision feedback equalizer for single carrier frequency domain equalization (SC-FDE-DFE). Simulation results show that equalization has been achieved for FD-LE and FD-DFE with distribution mapping. This structure can be used in the broadcasting uplink channels with SC-FDMA scheme.[...] Read more.
This paper presents the architecture for accessing heterogeneous databases. Two major processes in this architecture which are extracting SQL statement and ontology. The algorithms for extracting SQL statement was created and tested in order to improve time performance during searching and retrieving process. Ontology approach was implemented and combined with these algorithms. In ontology approach, web semantic was implemented in order to retrieve only relevant data from database. A prototype based on this architecture was developed using JAVA technology. JAVA technology was chosen because this technology have Jena library. This library is provide API and support SPARQL. Several experiments have been executed and tested. The result indicates this architecture able to improve web query processing in term of time. The result also indicates this architecture able to retrieve and displayed more relevant data to web users.[...] Read more.
In the present paper, we propose a new scheme for a scalable multicast key distribution scheme. The present scheme is based on the Key Management using Tabulation method of Boolean Function Simplification technique. It explores the use of batching of group membership changes to reduce the frequency, and hence the cost, of key re-distribution operations. It focuses explicitly on the issue of snowballing member removal and presents an algorithm that minimizes the number of messages required to distribute new keys to the remaining group members. The algorithm is used in conjunction with a new scalable multicast key distribution scheme which uses a set of auxiliary keys in order to improve scalability. In contrast to previous schemes which generate a fixed hierarchy of keys, the proposed scheme dynamically generates the most suitable key hierarchy by composing different keys. Our snowballing member removal uses one of the Boolean function simplification techniques called tabulation method, and outperforms all other schemes known to us in terms of message complexity. Most importantly, our technique is superior in minimizing the number of messages when multiple members leave the session in the same round.[...] Read more.
In order to explore the leukocyte distribution of human being to predict the recurrent leukemia, the mouse marrow cells are investigated to get the possible indication of the recurrence. This paper uses the C-mean fuzzy clustering recognition method to identify cells from sliced mouse marrow image. In our image processing, red cells, leukocytes, megakaryocyte, and cytoplasm can not be separated by their staining color, RGB combinations are used to classify the image into 8 sectors so that the searching area can be matched with these sectors. The gray value distribution and the texture patterns are used to construct membership function. Previous work on this project involves the recognition using pixel distribution and probability lays the background of data processing and preprocessing. Constraints based on size, pixel distribution, and grayscale pattern are used for the successful counting of individual cells. Tests show that this shape, pattern and color based method can reach satisfied counting under similar illumination condition.[...] Read more.
Datalog is a widely recognised language for a certain class of deductive databases. Information Content Inclusion Relation (IIR) formulates a general, information theoretic relationship between: data constructs; between data constructs and real world objects, and between real world objects. IIR is particularly concerned with the information that data carry. It would therefore seem desirable to find out whether IIR and reasoning based on IIR may be implemented by using 'safe' Datalog. We present and prove the following theorem:
Any database system that can be modelled using IIR can be represented as a 'safe' Datalog program.}
This paper explores the nature of the relationship between the two frameworks for representing domains of application, in order that such representations of IIR by 'safe' Datalog can then be used as a tool for the analysis of any site that can be approached with the notion of information content, and in particular any given database, and hence how a database works may be approached in terms of information content of events.
A major goal of the next-generation wireless communication systems is the development of a reliable high-speed wireless communication system that supports high user mobility. Orthogonal Frequency Division Multiplexing (OFDM) system is one of the most promising technologies for current and future wireless communications that has drawn a lot of attention. OFDM usually achieved by Fast Fourier Transform (FFT). In this paper, Fast Fourier Transform (FFT) is replaced by SlantLet Transform (SLT) in order to reduce Inter-Carrier Interference (ICI), Inter-symbol Interference (ISI), and to improve the bandwidth efficiency by removing the Guard Interval (GI) needed in FFT-OFDM. The new structure was tested and compared with conventional FFT-based OFDM for Additive White Gaussian Noise (AWGN) channel, Flat Fading Channel (FFC), and multi-path Selective Fading Channel (SFC). Simulation tests were generated for different channels parameters values. The obtained results showed the proposed system has an improved Bit Error Rate (BER) performance compared with the reference system. For SFC the SLT-OFDM performs better than the FFT-OFDM on the lower SNR region, while the situation reverses with increasing SNR values.[...] Read more.