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- 2018
- sodium lighting system
- modeling
- radiation curves
- LED lighting system
- software goniophotometer
- upper half-space
- Electrical Engineering and Automation
- VSB-TU Ostrava
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Characterization and thermoluminescence behavior of beta irradiated NaBaBO3 phosphor synthesized by combustion method
摘要： NaBaBO3 host material was synthesized using the combustion method. In order to optimize the performance of the material, effects of sintering temperatures varying from 600 to 1000 °C were investigated. The sintering temperature and dwell time were found to have pronounced effects on the pure NaBaBO3 material. X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) techniques were used to confirm the phase formation and examine the surface morphology of the prepared powder material, respectively. TL behavior of NaBaBO3 was studied at various beta doses. It is seen that the sample exhibits well resolved TL glow peak at a peak temperature about 175 °C and corresponding TL intensity increases with the increasing beta dose. However, TL glow peak slightly shifts to lower temperature with the increasing beta dose level. This is the first TL report of a phosphor with a NaBaBO3 host. The TL kinetic parameters were estimated by the peak shape (PS) method and CGCD software. TL glow curves of NaBaBO3 consist of several traps and exhibited second order kinetics. A possible TL mechanism was also discussed using the energy level model. The obtained results can provide valuable knowledge related to the investigation of the intrinsic nature characteristics of NaBaBO3 in research fields pertaining to dosimetry.
关键词： TLanal software,XRD,Peak shape method,NaBaBO3,Thermoluminescence,SEM
更新于2025-09-23 15:23:52
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Evaluation of the effect of image noise on CT perfusion measurements using digital perfusion phantoms
摘要： Objectives To assess the influence of image noise on computed tomography (CT) perfusion studies, CT perfusion software algorithms were evaluated for susceptibility to image noise and results applied to clinical perfusion studies. Methods Digital perfusion phantoms were generated using a published deconvolution model to create time-attenuation curves (TACs) for 16 different combinations of blood flow (BF; 30/60/90/120 ml/100 ml/min) and flow extraction product (FEP; 10/20/30/40 ml/100 ml/min) corresponding to values encountered in clinical studies. TACs were distorted with Gaussian noise at 50 different strengths to approximate image noise, performing 200 repetitions for each noise level. A total of 160,000 TACs were evaluated by measuring BF and FEP with CT perfusion software, comparing results for the maximum slope and Patlak models with those obtained with a deconvolution model. To translate results to clinical practice, data of 23 patients from a CT perfusion study were assessed for image noise, and the accuracy of reported CT perfusion measurements was estimated. Results Perfusion measurements depend on image noise as means and standard deviations of BF and FEP over repetitions increase with increasing image noise, especially for low BF and FEP values. BF measurements derived by deconvolution show larger standard deviations than those performed with the maximum slope model. Image noise in the evaluated CT perfusion study was 26.46 ± 3.52 HU, indicating possible overestimation of BF by up to 85% in a clinical setting. Conclusions Measurements of perfusion parameters depend heavily upon the magnitude of image noise, which has to be taken into account during selection of acquisition parameters and interpretation of results, e.g., as a quantitative imaging biomarker.
关键词： Tomography, x-ray computed,Phantoms, imaging,Perfusion imaging,Software,Artifacts
更新于2025-09-23 15:23:52
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The impact of out of band emissions: A measurement based performance comparison of UF-OFDM and CP-OFDM
摘要： Long Term Evolution (LTE) networks, along with their recent releases, rely on the cyclic prefix orthogonal frequency division multiplexing (CP-OFDM) waveform as the foundation. However, high sidelobes, synchronization problems and spectral efficiency constraints of CP-OFDM cannot meet future requirements of cellular network design targets. At this point, universal filtered orthogonal frequency division multiplexing (UF-OFDM) emerges as a strong candidate. Equipped with the advantages of using filters, UF-OFDM provides additional design flexibility to address the fundamental problems of CP-OFDM. In this study, the effect of adjacent channels that causes interference between different frequency channels because of out-of-band (OoB) emissions on UF-OFDM performance is investigated by performing real-time tests on software defined radio (SDR) nodes with multiple reception paths. Frequency domain carrier frequency offset (CFO) and symbol timing offset (STO) correction techniques are used. By the application of the same correction approaches to CP-OFDM, these two waveforms are evaluated in terms of signal to noise ratio (SNR), bit/symbol error rate (BER/SER) and error vector magnitude (EVM). Test results indicate that, based on lower OoB emissions, UF-OFDM uses the spectrum more efficiently and provides better results than CP-OFDM in congested environments.
关键词： synchronization,CP-OFDM,out-of-band emissions,software defined radio nodes,UF-OFDM
更新于2025-09-23 15:23:52
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[IEEE 2018 Seventh Balkan Conference on Lighting (BalkanLight) - Varna (2018.9.20-2018.9.22)] 2018 Seventh Balkan Conference on Lighting (BalkanLight) - Comparison of Experimental and Simulation Data for Daylighting
摘要： The paper detailed information about experimental results, obtained for the Daylight Factor (DF) of an educational facility. The experimental data obtained is compared to computational results, given by different software products for lighting calculations. The correlation between the measured and the simulated data is estimated.
关键词： daylight factor,daylighting,simulation software,daylight factor profile
更新于2025-09-23 15:23:52
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Open-Source Package for PJVS Testing and Calibration
摘要： This paper describes a software package for PJVS automated measurements written in Python, an interpreted programming language widely used in scientific applications. The code is modular and expandable with the support of many libraries allowing easy reconfiguration for different calibration and testing purposes.
关键词： Python,measurement software,programmable Josephson array,Voltage standards,open source
更新于2025-09-23 15:23:52
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Development of the readout system for a time projection chamber prototype
摘要： A new GEM-TPC prototype with a laser calibration system is being designed to study the key issues of high-precision track detection whose aimed spatial resolution is better than 100 μm. Meanwhile, a readout system with scalability for the TPC is also being developed. Design of the readout system is based on the architecture of front-end ASICs and commercial ADCs for its advantages at high count rates. Given the requirement of several hundred channels, the system is composed of multiple front-end cards and DAQ boards. The DAQ boards are daisy-chained via bidirectional optical fibers, which transmit clock, trigger, data and control signals simultaneously. To achieve timing synchronization, the GigaBit Transceiver (GBT) firmware is employed to ensure fixed latency between the boards. This paper is focused on the design and setup of the DAQ system, including clock structure, trigger alignment, high-speed data acquisition, etc. The DAQ system consisting of 512 channels has been built, and tests have proved that the entire system works correctly and meets the expected requirements.
关键词： Trigger concepts and systems (hardware and software),Electronic detector readout concepts (gas, liquid),Modular electronics,Data acquisition concepts
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE International Conference on RFID Technology & Application (RFID-TA) - Macau, Macao (2018.9.26-2018.9.28)] 2018 IEEE International Conference on RFID Technology & Application (RFID-TA) - Perfectly Synchronized Streaming from Digitally Modulated Multiple Backscatter Sensor Tags
摘要： This paper proposes a multiple access method, referred to as Multiple Subcarrier Multiple Access (MSMA), for perfectly synchronized concurrent data collection from a group of passive backscatter wireless sensor tags and its experimental evaluation. By achieving less than 128 micro second synchronization error, backscatter communications can be applied to structural health monitoring of artifacts such as civil structures and machineries. In MSMA, each sensor tag uses a dedicated subcarrier frequency to produce a modulated backscatter. The sensor data is superposed onto the subcarrier either with an analog or a digital modulation. The inevitable harmonics among the subcarriers, stemming from the backscatter principle, can be rejected by numerically calculating the harmonic replicas and subtracting them from the observed signal in a software defined receiver. A frame based signal processing in the receiver results in no relative synchronization error among subcarriers even after the interference rejection. Since the interference rejection can be done before the demodulation and decoding, the concurrency can be secured irrespective to the choice of modulation method. We developed a prototype of MSMA using LabVIEW communications Software Defined Radio environment and prototype sensor tags using discrete electrical parts. The performances and limitation of MSMA using digitally modulated subcarriers are evaluated both in wired and wireless environments with up to four backscatter sensors.
关键词： Structural Health Monitoring,Software Defined Radio,Interference Rejection,Passive backscatter
更新于2025-09-23 15:22:29
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[IEEE 2018 Conference on Design and Architectures for Signal and Image Processing (DASIP) - Porto, Portugal (2018.10.10-2018.10.12)] 2018 Conference on Design and Architectures for Signal and Image Processing (DASIP) - Hardware-Software Implementation of a SFM Module for Navigation an Unmanned Aerial Vehicles-A Demo
摘要： In this paper the design of an embedded vision system for structure from motion (SFM) computation is presented. The solution allows for scene depth reconstruction based on two consecutive video frames registered by a moving camera. The module is developed for a Xilinx Zynq SoC (System on Chip) device and is divided into a hardware and software part. The programmable logic (PL) is used mainly for detect and match features. Fundamental matrix estimation and triangulation are executed in the processing system (PS – ARM based). The module is dedicated to navigation of unmanned aerial vehicles (UAV) – autonomous flight and landing. The system is adapted to process a 1280x720 pixel video stream @60 frames per second in real-time.
关键词： FPGA,Zynq SoC,structure from motion,real-time video processing,hardware-software systems
更新于2025-09-23 15:22:29
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[IEEE 2018 New Trends in Signal Processing (NTSP) - Liptovsky Mikulá?, Slovakia (2018.10.10-2018.10.12)] 2018 New Trends in Signal Processing (NTSP) - Possibilities of Using FSO/RF Technology in Military Communication Systems
摘要： The article presents an overview of selected aspects of wireless communications considering military applications. The main attention is paid to performance analysis of radio and free space optics technologies. There are also presented some activities to get new capabilities of wireless communications using procedure of dynamic spectrum access, wideband and narrowband radio system, and free space optical system operated in infrared spectrum. In the summary, possibilities of radio-optical hybrid communication systems and their application in military areas have been defined.
关键词： hybrid wireless communications,frequency management,software-defined radio,frequency broker,cognitive radio
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE International Conference on Automation/XXIII Congress of the Chilean Association of Automatic Control (ICA-ACCA) - Concepcion, Chile (2018.10.17-2018.10.19)] 2018 IEEE International Conference on Automation/XXIII Congress of the Chilean Association of Automatic Control (ICA-ACCA) - Using clustering algorithms to segment UAV-based RGB images
摘要： This article describes the implementation of two segmentation algorithms in combination with the Triangular Greenness Index (TGI) derived from images obtained from an unmanned aerial vehicle (UAV), with the objective of segmenting shadow, soil and vegetation data obtained from a commercial vineyard cv. Cabernet Sauvignon. The importance of this segmentation lies in the recent development in tools that allow remote monitoring of crops but that nevertheless still have unresolved methodological aspects. The precise differentiation of these classes would allow the development of more complex monitoring techniques based on multispectral and thermal sensors. The results of this investigation showed that both k-means and Clustering Large Applications (CLARA) allowed to differentiate three classes in the images corresponding to soil, shade and vegetation. However, CLARA showed a better performance when differentiating the layer corresponding to vegetation.
关键词： Image processing,Unmanned aerial vehicles,Agricultural engineering,Open source software
更新于2025-09-23 15:22:29