No. 2 (2015)
Published:
2015-06-30
ARTICLES FROM THIS ISSUE
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Supervised Kernel Principal Component Analysis by Most Expressive Feature Reordering
Abstract
The presented paper is concerned with feature space derivation through feature selection. The selection is performed on results of kernel Principal Component Analysis (kPCA) of input data samples. Several criteria that drive feature selection process are introduced and their performance is assessed and compared against the reference approach, which is a combination of kPCA and most expressive feature reordering based on the Fisher linear discriminant criterion. It has been shown that some of the proposed modifications result in generating feature spaces with noticeably better (at the level of approximately 4%) class discrimination properties.
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Analysis of Polymorphic DNA Sequences in the Identification of Individuals and its Possible Use in Biometric Systems
Abstract
The article presents the achievements in DNA forensic science practice, the latest developments as well as future trends. The article concerns also other than forensic DNA applications as well as expectations, concerns and obstacles. DNA identification technology unlike other biometric techniques requires the collection of biological material and the identification is not performed in real time. DNA utilized in most of forensic identification, is present almost in every living cell in the body. What is more, each cell of the same body has the same DNA molecule which means that it is possible to compare the DNA sampled from different sources, for example saliva with blood or semen from the same person. Rapid development and reliability of DNA technology contribute to the fact that the analysis of polymorphic DNA sequences constitutes a very important evidence used in the court. The unique properties of DNA and rapid development of DNA analytical devices allow to claim that DNA may assume a more important position amongst biometric data in the future.
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Biometric Systems Based on Palm Vein Patterns
Abstract
The work covers issues related to the design of biometric systems based on the hand vascular pattern. The study includes analysis of various stages of biometric systems design ranging from acquisition, feature extraction and biometric pattern creation for verification methods. The extraction methods based on two-dimensional density function and the extraction of the characteristic points – minutiae are presented. The article features the results of tests carried out on two different bases of blood vessels in a hand.
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Polish Personal Identity Card as a Tool for Identity Theft
Abstract
This article discusses the changes that are the result of entry the new personal ID card issued in Poland. The new document contains less information about the owner, i.e. height, eye color or signature, so that the risk of identity theft is significantly greater.
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The Practical Implementation of Biometric Technology - Legal Aspects
Abstract
The article refers to legal and social problems, which may occur while implementing a biometric system. The research on biometric regulation made by the author while preparing the Ph.D. thesis resulted in finding general rules, which should be followed by legislator to introduce a wellfunctioning and user’s friendly biometric system.
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Wind Farms Influence on Radiocommunication Systems Operating in the VHF and UHF Bands
Abstract
The following paper discusses several aspects connected with the wind farms’ impact on radiocommunication systems. The first part of this article is filled with the analysis of the ITU-R BT.1893 model, which was originally created for the analysis of the interaction between the wind turbines and digital TV receivers in the UHF band. A measurement campaign carried out by the authors confirmed that this model is also applicable for the lower, maritime VHF band. Utilizing the software implementation of this model, the authors conducted a thorough simulation analysis of the wind turbines’ influence on radio systems working in both VHF and UHF bands. The results of these simulations are presented and discussed in the second part of the paper.
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Measuring Electromagnetic Emissions from Active Landslides
Abstract
The paper describes the mechanism of electromagnetic emission generation in active landslides and measuring techniques. Special attention is given to electromagnetic emission fields. The author proposes an original system for measuring both continuous and pulsed magnetic emission of landslides. For such measurements boreholes must be drilled in the landslide. It is essential that the tubing constituting the borehole’s lining be made of a material which does not attenuate magnetic fields. Besides its primary function, i.e. the registration of landslide magnetic field activity, the system can be used for the structural inhomogeneity of rock strata examination subjected to considerable stresses. The results of examinations of active and inactive landslide in Poland are presented. The post-extraction cave in the SMZ Jelsava Mine in Jelsava, Slovakia, is presented too.
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SAC-OCDMA over Hybrid FTTx Free Space Optical Communication Networks
Abstract
This paper presents an investigation of Spectral Amplitude Coding Optical Code Division Multiple Access (SAC-OCDMA) over hybrid Fiber-to-the-x (FTTx) Free Space Optical (FSO) link under different weather conditions. FTTx and FSO are the last mile technologies that complement each other in delivering secure and high speed communication to customers’ residence or office. SAC-OCDMA is one of the potential multiplexing techniques that has become a research area of interest in optical communications and considered a promising technique for FTTx access networks. It is based on Khazani-Syed (KS) code with Spectral Direct Decoding (SDD) technique. All the components involved in the network were specified according to the available market product in order to simulate the actual environment as close as possible. The result shows that for bit error rate (BER) of 10−9, the network is able to perform with 20 km Single Mode Fiber ( SMF ) spanning from the central office (CO) and 1.48 km FSO range with transmission rate of 1.25 Gb/s during heavy rain.
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Improvement of LTE Downlink Channel Estimation Performance by Using an Adaptive Pilot Pattern
Abstract
This paper proposes an adaptive pilot pattern to improve channel estimation performance for LTE downlink system with high mobility. The downlink pilot positions are predefined in the time and frequency domain with fixed pilot pattern in LTE standard. However, that pilot structure is not efficient in a fast time varying channel, and leads to a decrease of channel estimation performance. The authors propose and evaluate the performance of LTE downlink channel estimation using an adaptive pilot scheme to optimally use pilot tones over time varying channels. It is shown that only seven bits of additional wide-band feedback per frame and per user are required to optimally support adaptive pilot pattern. Simulation results show that the proposed method allows high performance in terms of throughput and channel estimation error. This analysis shows that LTE downlink throughput could be increased over 4%.
