Pawel Pawlowski

Software defined radio - design and implementation of complete platform

In this paper, a complete architecture of the software defined radio receiver is proposed. First, a precise definition and the discussion of the problem is given. Next, an outline of the system topology is proposed, together with the requirements for each component of the system. Finally, a custom implementation is presented, including specifications, design considerations, and simulations.

Proposal of VLIW Architecture for Application Specific Processors with Built-in-Self-Repair facility via Variable Accuracy Arithmetic

A new proposal of a very long instruction word (VLIW) architecture for application specific processors with the built-in-self-repair (BISR) facility realized by means of the variable accuracy arithmetic has been described in this paper. The proposed idea, which is particularly interesting for the portable embedded systems, is based on a novel two accumulator model, which is used in order to obtain high accuracy of the result of a series of floating-point additions. The goal of the proposed approach consists in ensuring the functionality of the system even in case of permanent faults of particular building blocks, e.g., of one of the floating point adders. Instead of decreasing the performance of the system or providing redundant hardware, as it is typically done in other approaches, in our present concept merely the accuracy of the floating point accumulation is reduced. Therefore, although the quality of service is reduced, the performance and the overall functionality of the system may remain unchanged. By this means we can also control the power consumption, saving the power with the cost of the somehow reduced signal processing accuracy.

Multiphase clock generators with controlled clock impulse width for programmable high order rotator SC FIR filters realized in 0.35 μm CMOS technology

Complexity of clock generator is one of the most important parameters in the design and optimization of switched-capacitor (SC) finite impulse response (FIR) filters. There are different SC FIR filter architectures. Some of them need a simple clock generator but the others require a quite complicated multiphase clock system. In the latter case an external clock system (i.e., outside the integrated circuit) is unrealistic because of a great number of the required external pins. We have implemented various SC FIR filter architectures together with complex internal clock generators in the CMOS 0.8 μm and 0.35 μm technologies. One of the most important problems in the design process was the optimization of waveforms and widths of the clock impulses. SC FIR filters are very sensitive to parameters of clock systems. Thus the clock generators must be designed very precisely. We demonstrate results of the design of the 64-phase clock generator for a programmable rotator SC FIR filter. In our approach the width of the clock impulses is controlled by two external signals. This is a very convenient solution, because optimization of the clock impulses, which was difficult in other approaches, is currently much easier. The internal clock generator area is ca. 0.15 mm2 in the CMOS 0.35 μm technology, i.e., only 7 % of the entire SC FIR filter chip area.

Pedestrian detection in low resolution night vision images

This paper presents a test of pedestrian detection in low resolution night vision infrared images. An image feature extractor based on histograms of oriented gradients followed by a Support Vector Machine (SVM) classifier are evaluated, optimized and used. Tests performed on three different night vision infrared datasets show that the classification quality of the proposed method is very high even in very low resolutions of images. In practice, large frame size for analysis not always improves the classification effectiveness, but always requires more time for processing.

Programmable Clock Signal Generators For SC Structures

This paper discusses possibility of the use of PLD circuits to control switched capacitors (SC) structures. It is well known that several years the SC technique was introduced ago in order to replace resistors by simple configurations of a small capacitor with some switches, which (up to capacitance ratios) may be precisely realized in integrated circuits. The aim of the presented generator of programmable sequences is to show an efficient way of controlling the SC circuits, e.g., the SC delay line with the so-called even-odd delay elements. PLD circuits contained in the ALTERA design kit and the MAX+plusII software kit were used in the presented design. Simulations and measurements presented in this paper prove many important advantages of the programmable logic devices applied for the generation of multiphase synchronous clock signals

Multicriteria Metadata Mechanisms for Fast and Reliable Searching of People Using Databases with Unreliable Records

In this paper an approach to multicriteria search for people is presented using data extracted from telephone calls to emergency services. In the considered application a procedure of searching the most similar object (objects) to the reference object using metadata mechanisms is presented. The proposed solution computes as much reliable result as possible using even unreliable records in the database. In the considered case the commonly used mechanism based on exact matching does not give the best result. Instead, the multicriteria metadata matching mechanisms exploiting weights, probabilities, distances, and correlations among database records are more reliable.

Multi-branch classifiers for pedestrian detection from infrared night and day images

This paper presents a modified multi-branch classifier of pedestrians from far infrared (FIR) night and day images. The solution is accurate, fast, and especially best suited for all realtime applications where pedestrians may appear in many distances to the camera, like in cars and CCTV. Two proposed training methods of the classifier, namely full-scale and partial-scale training were deeply tested. Results show increased efficiency of the classification process (by up to 3 %) with similar processing time in comparison to a single classifier. All tests were conducted using Adaboost classifier, but generally, the results should be consistent for other classifiers.

Evaluation of Five Phase Digitally Controlled Rotating Field Plasma Source for Photochemical Mercury Vapor Generation Optical Emission Spectrometry

A new sensitive method for total mercury determination in reference materials using a 5-phase digitally controlled rotating field plasma source (RFP) for optical emission spectrometry (OES) was developed. A novel synergic effect of ultrasonic nebulization (USN) and ultraviolet-visible light (UV-Vis) irradiation when used in combination was exploited for efficient Hg vapor generation. UV- and Vis-based irradiation systems were studied. It was found that the most advantageous design was an ultrasonic nebulizer fitted with a 6 W mercury lamp supplying a microliter sample to a quartz oscillator, converting liquid into aerosol at the entrance of the UV spray chamber. Optimal conditions involved using a 20% v/v solution of acetic acid as the generation medium. The mercury cold vapor, favorably generated from Hg(2+) solutions by UV irradiation, was rapidly transported into a plasma source with rotating field generated within the five electrodes and detected by digitally controlled rotating field plasma optical emission spectrometry (RFP-OES). Under optimal conditions, the experimental concentration detection limit for the determination, calculated as the concentration giving a signal equal to three times the standard deviation of the blank (LOD, 3σblank criterion, peak height), was 4.1 ng mL(-1). The relative standard deviation for samples was equal to or better than 5% for liquid analysis and microsampling capability. The methodology was validated through determination of mercury in three certified reference materials (corresponding to biological and environmental samples) (NRCC DOLT-2, NRCC PACS-1, NIST 2710) using the external aqueous standard calibration techniques in acetic acid media, with satisfactory recoveries. Mercury serves as an example element to validate the capability of this approach. This is a simple, reagent-saving, cost-effective and green analytical method for mercury determination.

Classification of emergency phone conversations with artificial neural network

This paper presents a series of experiments on the classification of emergency phone conversation records using artificial neural networks (ANNs). Input data which were processed by ANNs were the features of callers and events taken from emergency phone calls. The authors analyzed four variants of classification: the groups of callers which have specified features, the groups of events which have specified features, selected callers, and selected events. Then the efficiency of classification by the ANN (artificial neural network) with various sets of features was compared. Results show that ANNs can properly classify precisely defined callers or events, from e.g. so called ‘black-list’ of callers.

Efficient pedestrian detection with enhanced object segmentation in far IR night vision

This paper presents a pedestrian detection system with enhanced object segmentation procedure working on a far infrared (FIR) video. To make the object detection more accurate on the FIR images, we propose an enhanced segmentation procedure with two thresholds and the region enlargement. This combination allowed a significant reduction of the region of interests (ROIs) for further processing. Experiments performed on demanding public dataset show a significant increase of the pedestrian detection performance (up to 33 frames per second) with the accuracy comparable with state-of-the-art algorithms.