Andrzej Napieralski

A reliable iris recognition algorithm based on reverse biorthogonal wavelet transform

This article describes an iris recognition algorithm designed to analyze noisy iris biometric data. The methods forming part of the authentication process were developed and optimized by the authors using visible wavelength images of an eye taken under unconstrained conditions (at a different perspectives, illuminations, occlusion grades, etc.), mainly contained in the UBIRIS.v2 database. The whole iris authentication system was submitted by the authors to the International Iris Recognition Contest NICE.II, where it took eighth place, while the iris segmentation stage itself took second place in the previous contest - NICE.I. This paper is focused on the iris feature extraction stage - the method developed by the authors to analyze noisy iris biometric data. Several techniques used for more efficient and robust analysis of such images and issues concerning the best wavelet selection are also presented in this paper.

MVC model, struts framework and file upload issues in web applications based on J2EE platform

This work describes the web applications based on the J2EE platform indicating the model-view-controller (MVC) model, struts framework and file upload issues. The development of internet technology and the will to standardize the mechanisms used in implementation of internet applications was the basis background for the development of J2EE platform. The project of international office TUL internet service is an application based on the above mentioned environment. The specification of the project is closely connected with the activities and needs of the staff of the international office. The article presents the use of MVC model on J2EE platform on an example of open source Apache/Tomcat server and the database management system MySql.

Ion sensitive field effect transistor modelling for multidomain simulation purposes

Abstract The proper design and simulation of modern electronic microsystems oriented towards environment monitoring requires accurate models of various ambient sensors. In particular, this paper presents a comprehensive model of an ion sensitive field effect transistor (ISFET). The model can be employed straightforwardly for simulations at device, circuit or system level. First, the model was validated with electrical measurements and simulations of real structures performed for different ion concentration and temperature values. Then, the ISFET sensor model was employed for mixed-signal simulations in VHDL-AMS, when the analysis of a microsystem consisting of the ISFET sensor and a sigma–delta analogue-to-digital converter was carried out. Additionally, the presence of other ions than hydrogen in the measured solution was also taken into account in the simulations.

Thermal analysis of layered electronic circuits with Green's functions

This paper presents a method for thermal simulation of electronic circuits using an analytical solution of the three-dimensional heat equation resulting from an appropriate circuit thermal model. The temperature fields in multilayered structures are computed analytically employing the Greens functions solution method. The entire solution methodology is illustrated in detail on the particular examples of electronic circuits containing multiple heat sources. Compared to the previous papers published by the authors, the method has been extended by including the possibility of simulating imperfect layer contacts. The simulation results are validated with infra-red measurements and results obtained using other methods. Additionally, the discussion of simulation errors caused mainly by different non-linear phenomena is included.

Iris Recognition Algorithm Optimized for Hardware Implementation

Iris recognition is accepted as one of the most efficient biometric method. Implementing this method to the practical system requires the special image preprocessing where the iris feature extraction plays a crucial role. Recognition is preceeded by iris localization which consists in finding the iris boundaries as well as eyelids. In this paper the short introduction into iris localization and wavelet-based iris identification method optimized for embedded systems is described. Proposed solution was applied to high resolution images taken under near infrared light

Hot spots and core-to-core thermal coupling in future multi-core architectures

This paper studies hot spot and thermal coupling problems in future multicore architectures as CMOS technology scales from 65 nm feature size to 15 nm. We demonstrate that the thermal coupling between neighboring cores will dramatically increase as the technology scales to smaller feature sizes. The simulation studies were based on solving the heat equation using the analytical Greens function method. Our simulations indicate that the thermal coupling in the 15 nm feature size just after 100 ms of operation will increase from 20% to 42% and in the steady state might reach even 65%. This finding uncovers a major challenge for the design of future multi-core architectures as the technology keeps scaling down. This will require a holistic approach to the design of future multi-core architectures encompassing low power computing, thermal management technologies and workload distribution.

Hardware Architecture Optimized for Iris Recognition

One of the remaining problems in iris recognition is the implementation of its efficient hardware systems. The difficulty arises from the fact that the methods forming part of this type of authentication process are fairly complex. Furthermore, next generation algorithms for iris recognition will become even more complex to enhance the reliability and functionality of currently used solutions. An example of such an intensive processing task is iris image quality assessment and segmentation using video signal obtained at-a-distance and on-the-move. Thus, processing robustness and predictable analysis time in such dedicated architectures may be particularly important. This paper describes a hardware system designed to analyze iris biometric data developed as a part of the work conducted by the authors on the complete iris identification system (1:N). This specialized architecture is mainly composed of digital signal processors and field-programmable gate arrays. Several issues concerning efficient biometric sample processing are discussed. Algorithms for iris recognition previously developed by the authors on a PC platform were adapted to the described architecture. The obtained results are presented, and the developed system is compared with chosen commercially available iris authentication systems.

Transient thermal analysis of multilayered structures using Green's functions

Abstract This paper presents an approach to the analysis of transient thermal states in electronic circuits using an analytical solution of the heat equation. Fully three-dimensional analytical time dependent solutions are determined for multilayered structures with the help of Greens functions (GFs). The GFs required for the solution are found using a Galerkin-based integral method. The entire solution method is illustrated in detail using a practical example, where the results of transient thermal simulations of a real hybrid power module are compared with infrared measurements.

A Distributed System for Radiation Monitoring at Linear Accelerators

This paper discusses a system for an on-line neutron fluence monitoring at linear accelerators. The system consists of a SRAM-based detector and a radiation-tolerant read-out system. The neutron fluence was measured in several locations of the accelerator. Monitoring of the radiation environment in an accelerator tunnel is necessary to assure reliable long-term operation of electronic systems placed in the tunnel. Monitoring of the chamber is especially important during the design stage of a linear accelerator. The new design of 20 GeV linear accelerator X-ray Free Electron Laser (X-FEL) is currently approved for construction at DESY Research Centre in Hamburg , . The presented paper is based on our research and experimental measurement carried out at 1.2 GeV superconducting electron linac driving the Vacuum UltraViolet Free Electron Laser (VUV-FEL). The application of a pair of TLD-700 and TLD-500 or superheated emulsion (bubble) dosimeters enables the supervision of neutron fluence in accelerators . This process requires continuous and arduous calibration of TLDs, therefore this method is not convenient. Moreover, it is impossible to monitor the radiation environment in real-time. The presented system fills the market niche of real-time neutron monitoring for high-energy accelerators. Neutron fluence and gamma dose measured in this way can be used for the detailed analysis of the VUV-FEL or X-FEL environments. Monitoring of the radioactive area in a linear accelerator tunnel could be helpful to the diagnosis and reduction of beam losses. We have conducted experiments with the distributed system dedicated to neutron flux measurement at the DESY Research Centre in Hamburg. The devices were exposed to a neutron field from an Americium-Beryllium (n,alpha) source 241AmBe. The systems were installed in two accelerators: Linac II and VUV-FEL

Object Oriented Application Cooperation Methods with Relational Database (ORM) based on J2EE Technology

This article describes cooperation methods of object oriented applications with relational databases. Currently there exist many technologies supporting object-relational mapping (ORM) for J2EE technology. The authors made comparison of three popular ones: Hibernate, JPOX and JPA in case of their performance and learning speed.