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Number of results: 425
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Abstract

In this work, the design of current mode Fractional order filter using VDTAs (Voltage differencing trans-conductance amplifier) as an active element with grounded capacitors has been proposed. The approximate transfer functions of low and high pass filters of fractional order on the basis of the integer order transfer has been shown and the form of those functions of filters is also implemented using VDTA as an active building block. In this work, filters of the different sequence have been realized. The frequency domain simulation results of the proposed filters are obtained on Matlab and PSPICE with TSMC CMOS 180 nm technology parameters. Stability and sensitivity is also verified.
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Abstract

Nonlinearities in optical fibers deteriorate system performances and become a major performancelimiting issue. This article aims to investigate the compensation of nonlinear distortions in optical communication systems based on different wavelength propagations over few-mode fiber (FMF). The study adopted Space Division Multiplexing (SDM) based on decision feedback equalizer (DFE). Various transmission wavelength of the FMF system is applied to mitigate the attenuation effect on the system. In this paper, different wavelengths (780, 850 and 1550 nm) are used in SDM. Extensive simulation is performed to assess the attenuation and Bit Error Rate (BER) in each case. The results show that the wavelength of 1550 nm produces higher power and less attenuation in the transmission. Furthermore, this wavelength produces the best distance with less BER compared to 780 nm and 850 nm wavelengths. Moreover, the validations show improvement in BER and eye diagram.
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Abstract

This paper presents active inductor based VCO design for wireless applications based on analysis of active inductor models (Weng-Kuo Cascode active inductor & Liang Regular Cascode active inductor) with feedback resistor technique. Embedment of feedback resistor results in the increment of inductance as well as the quality factor whereas the values are 125.6@2.4GHz (Liang) and 98.7@3.4GHz (Weng-Kuo). The Weng-Kuo active inductor based VCO shows a tuning frequency of 1.765GHz ~2.430GHz (31.7%), while consuming a power of 2.60 mW and phase noise of -84.15 dBc/Hz@1MHz offset. On the other hand, Liang active inductor based VCO shows a frequency range of 1.897GHz ~2.522GHz (28.28%), while consuming a power of 1.40 mW and phase noise of -80.79 dBc/Hz@1MHz offset. Comparing Figure-of-Merit (FoM), power consumption, output power and stability in performance, designed active inductor based VCOs outperform with the stateof- the-art.
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Abstract

The paper considers the technique of modeling and formation educational components of the planned training of CDIO Syllabus, realized in the form of the educational adaptive environment of engineering education. The following key concepts of the methodology have been accepted: competence models of the stages of the CDIO initiative, the method of project training, syntax for describing the concepts of the domain, models for mapping support concepts in the form of expressions of knowledge and ontological engineering.
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Abstract

We address one of the weaknesses of the RSA ciphering systems i.e. the existence of the private keys that are relatively easy to compromise by the attacker. The problem can be mitigated by the Internet services providers, but it requires some computational effort. We propose the proof of concept of the GPGPU-accelerated system that can help detect and eliminate users’ weak keys. We have proposed the algorithms and developed the GPU-optimised program code that is now publicly available and substantially outperforms the tested CPU processor. The source code of the OpenSSL library was adapted for GPGPU, and the resulting code can perform both on the GPU and CPU processors. Additionally, we present the solution how to map a triangular grid into the GPU rectangular grid – the basic dilemma in many problems that concern pair-wise analysis for the set of elements. Also, the comparison of two data caching methods on GPGPU leads to the interesting general conclusions. We present the results of the experiments of the performance analysis of the selected algorithms for the various RSA key length, configurations of GPU grid, and size of the tested key set.
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Abstract

A robust and highly imperceptible audio watermarking technique is presented to secure the electronic patient record of Parkinson’s Disease (PD) affected patient. The proposed DCT-SVD based watermarking technique introduces minimal changes in speech such that the accuracy in classification of PD affected person’s speech and healthy person’s speech is retained. To achieve high imperceptibility the voiced part of the speech is considered for embedding the watermark. It is shown that the proposed watermarking technique is robust to common signal processing attacks. The practicability of the proposed technique is tested: by creating an android application to record & watermark the speech signal. The classification of PD affected speech is done using Support Vector Machine (SVM) classifier in cloud server.
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Abstract

The paper presents the use of visual evoked potentials VEP to the objective assessment of visual acuity. Methods of using visual evoked potentials (VEP) rely on the assessment of changes of the electrical action potentials generated within the cortex. To diagnose the degree of weakening eyesight a series of studies on healthy people and visually impaired ones were made. Electrophysiological studies of the eye, using noninvasive VEP examination allow a noninvasive and objective assessment of visual acuity. The use of visual evoked potentials gives the objectivity in assessment of visual acuity what may be very important in ophthalmology. This particularly may concern children examination, people with mental retardation and suspected of simulation.
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Abstract

The paper presents a method for wireless measurement of car wheel air pressure and temperature using the Tire Pressure Monitoring System, or TPMS module - one of the latest safety systems introduced by the automotive industry - with readings taken on a specifically designed test bench. The paper describes the structure and operating principle of the test bench key elements and how they work with the sensors, the TPMS module, and reference instruments, as well as the data format and accuracy of data transmission between TPMS and the host computer. The software designed for an embedded system emulating the real on-board computer allows for observing raw sensor readings and the effect of calibration in two points of the characteristics.
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Abstract

GNSS systems are susceptible to radio interference despite then operating in a spread spectrum. The commerce jammers power up to 2 watts that can block the receiver function at a distance of up to 15 kilometers in free space. Two original methods for GNSS receiver testing were developed. The first method is based on the usage of a GNSS simulator for generation of the satellite signals and a vector signal RF generator for generating different types of interference signals. The second software radio method is based on a software GNSS simulator and a signal processing in Matlab. The receivers were tested for narrowband CW interference, FM modulated signal and chirp jamming signals and scenarios. The signal to noise ratio usually drops down to 27 dBc-Hz while the jamming to signal ratio is different for different types of interference. The chirp signal is very effective. The jammer signal is well propagated in free space while in the real mobile urban and suburban environment it is usually strongly attenuated.
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Abstract

Multiple input multiple output (MIMO) is a multiple antenna technology used extensively in wireless communication systems. With the ever increasing demand in high data rates, MIMO system is the necessity of wireless communication. In MIMO wireless communication system, where the multiple antennas are placed on base station and mobile station, the major problem is the constant power of base station, which has to be allocated to data streams optimally. This problem is referred as a power allocation problem. In this research, singular value decomposition (SVD) is used to decouple the MIMO system in the presence of channel state information (CSI) at the base station and forms parallel channels between base station and mobile station. This practice parallel channel ensures the simultaneous transmission of parallel data streams between base station and mobile station. Along with this, water filling algorithm is used in this research to allocate power to each data stream optimally. Further the relationship between the channel capacity of MIMO wireless system and the number of antennas at the base station and the mobile station is derived mathematically. The performance comparison of channel capacity for MIMO systems, both in the presence and absence of CSI is done. Finally, the effect of channel correlation because of antennas at the base stations and the mobile stations in the MIMO systems is also measured.
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Abstract

A novel non-orthogonal multiple access (NOMA) scheme is proposed to improve the throughput and the outage probability of the cognitive radio (CR) inspired system which has been implemented to adapt multiple services in the nextgeneration network (5G). In the proposed scheme, the primary source (PS) had sent a superposition code symbol with a predefined power allocation to relays, it decoded and forwarded (DF) a new superposition coded symbol to the destination with the other power allocation. By using a dual antenna at relays, it will be improved the bandwidth efficiency in such CR NOMA scheme. The performance of the system is evaluated based on the outage probability and the throughput with the assumption of the Rayleigh fading channels. According to the results obtained, it is shown that the outage probability and throughput of the proposed full-duplex (FD) in CR-NOMA with reasonable parameters can be able deploy in practical design as illustration in numerical results section.
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Abstract

One of the crucial advancements in next-generation 5G wireless networks is the use of high-frequency signals specifically those are in the millimeter wave (mm-wave) bands. Using mmwave frequency will allow more bandwidth resulting higher user data rates in comparison to the currently available network. However, several challenges are emerging (such as fading, scattering, propagation loss etc.), whenever we utilize mm-wave frequency wave bands for signal propagation. Optimizing propagation parameters of the mm-wave channels system are much essential for implementing in the real-world scenario. To keep this in mind, this paper presents the potential abilities of high frequencies signals by characterizing the indoor small cell propagation channel for 28, 38, 60 and 73 GHz frequency band, which is considered as the ultimate frequency choice for many of the researchers. The most potential Close-In (CI) propagation model for mm-wave frequencies is used as a Large-scale path loss model. Results and outcomes directly affecting the user experience based on fairness index, average cell throughput, spectral efficiency, cell-edge user’s throughput and average user throughput. The statistical results proved that these mm-wave spectrum gives a sufficiently greater overall performance and are available for use in the next generation 5G mobile communication network.
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Abstract

Performance of standard Direction of Arrival (DOA) estimation techniques degraded under real-time signal conditions. The classical algorithms are Multiple Signal Classification (MUSIC), and Estimation of Signal Parameters via Rotational Invariance Technique (ESPRIT). There are many signal conditions hamper on its performance, such as closely spaced and coherent signals caused due to the multipath propagations of signals results in a decrease of the signal to noise ratio (SNR) of the received signal. In this paper, a novel DOA estimation technique named CW-PCA MUSIC is proposed using Principal Component Analysis (PCA) to threshold the nearby correlated wavelet coefficients of Dual-Tree Complex Wavelet transform (DTCWT) for denoising the signals before applying to MUSIC algorithm. The proposed technique improves the detection performance under closely spaced, and coherent signals with relatively low SNR conditions. Also, this method requires fewer snapshots, and less antenna array elements compared with standard MUSIC and wavelet-based DOA estimation algorithms.
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Abstract

In this paper, we propose a new algorithm that improves the performance of the operation of Handover (HO) in LTE-Advanced (LTE-A) networks. As recognized, Mobility Management (MM) is an important pillar in LTE/LTE-A systems to provide high quality of service to users on the move. The handover algorithms define the method and the steps to follow to ensure a reliable transfer of the UEs from one cell to another without interruption or degradation of the services offered by the network. In this paper, the authors proposed a new handover algorithm for LTE/LTE-A networks based on the measurement and calculation of two important parameters, namely the available bandwidth and the Received Power (RSRP) at the level of eNodeBs. The proposed scheme named LTE Available Bandwidth and RSRP Based Handover Algorithm (LABRBHA) was tested in comparison with well-known algorithms in the literature as the LHHA, LHHAARC and the INTEGRATOR scheme using the open source simulator LTE-Sim. Finally, the network performances were investigated via three indicators: the number of lost packets during the handover operation, the latency as well as the maximum system throughput. The results reported that our algorithm shows remarkable improvements over other transfer schemes.
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Abstract

This article has two outreach aims. It concisely summarizes the main research and technical efforts in the EC H2020 ARIES Integrating Activity – Accelerator Research and Innovation for European Science and Society [1] during the period 2017/2018. ARIES is a continuation of CARE, TIARA and EuCARD projects [2-3]. The article also tries to show these results as an encouragement for local physics and engineering, research and technical communities to participate actively in such important European projects. According to the author’s opinion this participation may be much bigger [4-27]. All the needed components to participate – human, material and infrastructural are there [4,7]. So why the results are not satisfying as they should be? The major research subjects of ARIES are: new methods of particles acceleration including laser, plasma and particle beam interactions, new materials and accelerator components, building new generations of accelerators, energy efficiency and management of large accelerator systems, innovative superconducting magnets, high field and ultra-high gradient magnets, cost lowering, system miniaturization, promotion of innovation originating from accelerator research, industrial applications, and societal implications. Two institutions from Poland participate in ARIES – these are Warsaw University of Technology and Institute of Nuclear Chemistry and Technology in Warsaw. There are not present some of the key institutes active in accelerator technology in Poland. Let this article be a small contribution why Poland, a country of such big research potential, contributes so modestly to the European accelerator infrastructural projects? The article bases on public and internal documents of ARIES project, including the EU Grant Agreement and P1 report. The views presented in the paper are only by the author and not necessarily by the ARIES.
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Abstract

The article presents the biometeorological impact of thermal and humidity conditions on the human body in the Hornsund area in the southern Spitsbergen, Svalbard. This was determined based on diurnal air temperature range, the day-to-day variation in average diurnal air temperature and the average diurnal relative humidity. The temporal variability of thermal and humidity biometeorological stimuli in Hornsund was examined for the period 01.11.1978–31.12.2017. A lessening of biometeorological impact was found in the southern Spitsbergen region, including a statistically significant negative trend in strongly- and severely-felt stimuli (according to diurnal air temperature range), and in significant and severe stimuli (according to day-to-day variation in average diurnal air temperature). A non-significant positive trend was observed in the number of days of relative humidity with humid and very humid air. To analyse the spatial variability of the stimuli around the Hornsund fjord, data were used from seven year-round measuring stations for the period 01.07.2014–31.06.2015. The most unfavourable conditions were found on the Hans Glacier, on the summit of Fugleberget and inside the fjord. The paper presents the role of atmospheric circulation on thermal and humidity stimuli. In the Hornsund region, the highest probability of unfavourable sensible temperatures for humans occurring during the year was mostly in winter and early spring. This was related to the advection of air masses from the north-east sector, regardless of baric regime type. It was found that very humid air (> 85%) flowed over Hornsund for practically the entire year from the S–SW as part of both cyclonic and anti-cyclonic systems.
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Abstract

Meteorological conditions at Arctowski Station during 2013–2017 were presented against the background of regional climate changes, especially air temperature decline. Air temperature, relative air humidity, air pressure, solar radiation, wind speed and direction, snow cover and precipitation were collected with an automatic weather station and manual measurements and were further analysed. The obtained results were compared with data from previous years and with data from other stations located on King George Island. Our observations confirm that the vicinity of Arctowski Station experienced a decrease in air temperature during summer, which supports the hypothesis of regional cooling.
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Abstract

A novel method to improve the performance of the frequency band is cognitive radio that was introduced in 1999. Due to a lot of advantages of the OFDM, adaptive OFDM method, this technique is used in cognitive radio (CR) systems, widely. In adaptive OFDM, transmission rate and power of subcarriers are allocated based on the channel variations to improve the system performance. This paper investigates adaptive resource allocation in the CR systems that are used OFDM technique to transmit data. The aim of this paper is to maximize the achievable transmission rate for the CR system by considering the interference constraint. Although secondary users can be aware form channel information between each other, but in some wireless standards, it is impossible for secondary user to be aware from channel information between itself and a primary user. Therefore, due to practical limitation, statistical interference channel is considered in this paper. This paper introduces a novel suboptimal power allocation algorithm. Also, this paper introduces a novel bit loading algorithm. In the numerical results sections, the performance of our algorithm is compared by optimal and conventional algorithms. Numerical results indicate our algorithm has better performance than conventional algorithms while its complexity is less than optimal algorithm.
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Abstract

Self-control is a complex and multifaceted construct that can be regarded as an individual trait that follows its own developmental trajectory. In the presented study we used NAS-50 for the assessment of self-control in adolescents and young adults. Since the questionnaire has not been used before in underage participants we tested its reliability in adolescent and adult samples. We also investigated possible age and gender differences in self-control abilities as well as relations between NAS-50 and behavioral measures of cognitive control and impulsivity. Although the sample was quite small, the reliability of the questionnaire was similar to the results achieved by its authors. According to the predictions in the literature we did not find relations between NAS-50 and behavioral measures of cognitive control and impulsivity. We also did not observe significant age differences in the assessment of self-control abilities. The theoretical relevance of our results is discussed.
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Abstract

O b j e c t i v e s: The aim of study was to investigate the association between anxiety, depression, stress and determinants of quality of life among Iranian students. M e t h o d s: The questionnaires were completed by 275 students. The random sampling was conducted in two phases, the stratified sampling which some classes were selected among different classes of faculty of health and at the second phase, in each class the number of students who had the requirements to enter in the study were selected randomly. the logistic regression to find out the association between demographic characteristics with the quality of life was run and according to the normality status of the distribution of data the parametric or non-parametric tests were used. R e s u l t s: In the univariable model, the students that were living in their own homes had the odds of 2.18 times more than the others to have a higher quality of life level (95% CI: 1.07–4.45). In the multi variable model the anxiety and stress were significantly related to the quality of life and for increasing each 1 unit in the amount of anxiety and stress the odds of a better quality of life decreases 0.19 and 0.03 respectively. Even after adjusting for other covariates – in the multivariable model – both anxiety and stress were associated with the quality of life. C o n c l u s i o n: It is useful for the universities to understand different aspects of the students’ lives which are under the influence of stress, anxiety and depression, and also determining the resources from which they are originated.
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Abstract

Virtual reality (VR) technology now provides players with immersive and realistic experiences as never before. Spatial presence plays a crucial role in the introduction of immersive experience in a VR environment. Spatial presence is a special feeling of personal and physical presence in the displayed environment. In this study, we found that the first-person perspective (1PP) was more effective in raising the sense of spatial presence that induces immersive experience compared to the third-person perspective (3PP) in a VR shooting game. Moreover, eye blink rate was significantly higher in the 1PP compared with the 3PP. The 1PP game setting was more realistic than the 3PP setting, and may have raised participants’ sense of immersion and facilitated eye blink. These results indicate that eye blink rate is increased by the sense of spatial presence, and can be a good measure of subjective immersive experience in a VR environment. Neuroscientific evidences suggest that dopaminergic system is involved in such emotional experiences and physiological responses.
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Abstract

Cheerleading is a new sport, practiced in 110 nations; since 2016 enjoys provisional Olympic status. Its leaders claim that it is a “happy” sport, but research on its psychological effects is lacking. In this field-study we examined core-affect, positive-affect, and negative-affect in 65 cheerleaders before, during, after, and one-hour after a cheerleading training. Core-affect was more positive during and immediately after training, but it tapered off one hour following the training when feeling states were still more positive than at baseline. Negative-affect declined linearly from baseline to one-hour following training when it became significantly lower than its previous values. Positive-affect showed quadratic dynamics, in parallel with arousal, being higher during and immediately after training than during baseline, or one-hour after training. These results demonstrate for the first time that cheerleading is a “happy” sport, which apart from the skill-development also yields positive psychological emotions both during and after training.
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Abstract

Studies based on the most common diagnostic categories do not bring conclusive results concerning the overlapping and distinctive features of anxiety and depression, especially in the areas of attentional functioning, structure of affect, and cognitive emotion regulation. However, a new typology has been proposed which treats anxiety and depression as personality types (Fajkowska, 2013). These types – arousal and apprehension anxiety as well as valence and anhedonic depression – are constructed based on two criteria: specific structure and functions (reactive or regulative). The present paper critically examines the empirical evidence related to this approach. The data mostly confirmed the prediction that the similarities and differences in attentional and affective functioning among the anxiety and depression types would be related to their shared and specific structural and functional characteristics. The new typology turned out to be suitable for integrating the existing research findings by relating them to the structure and functions of anxiety and depression. As a result, it is useful in explaining some of the inconsistencies in literature, as it allows to identify the overlapping and distinctive features of the anxiety and depression types. It also helps to understand the mechanisms contributing to the development and maintenance of anxiety and depression, which might be useful in diagnosis and treatment. However, even though Fajkowska’s approach is an important contribution to the understanding of anxiety and depression, it is not exhaustive. Its limitations are discussed, along with proposed modifications of the theory, as well as further research directions.
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Abstract

Previous research reported about high comorbidity between asthma and neurodevelopmental disorders. Recently, asthma was associated also with executive functions poorness. The current study aimed to investigate the verbal and visual memory performances among fifteen asthmatic kindergarten children compared to the performances of other fifteen healthy kindergarten children. The results showed that the asthmatic group revealed poor performances in the immediate short term verbal memory and the verbal working memory tests but not in the verbal learning test as it was compared to the healthy group. In addition, the asthmatic group revealed poor performances in the visual memory tasks compared to the healthy group. The results were explained in light of the assumption that poor executive functions might be interfere the process of managing the attentional resources which are needed through the process of memory encoding and retrieval.
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Abstract

It is nearly impossible to study behaviour effectively without any reference to its context. This is because it is generally known in the psychological literature that behaviour is partially a product of its environment. This suggests that many behavioural processes may be universal but there are significant variations in their manifestations. For instance, love may be a universal process but its manifestation varies from one society to another. Given that ethical decision-making is a behavioural process, it stands to reason that its manifestation will vary from one culture to another. It is against this premise that this paper seeks to demonstrate that despite the existence of the ‘universal’ normative ethical principles, ethical decisions will be expected to vary across cultural space and even evolve with time. This paper achieves this objective by employing typical ethical dilemmas that Ghanaian psychologists and other health professionals encounter to show how and why what is ethical in one culture becomes unethical in the Ghanaian context and what is unethical in the Ghanaian context becomes ethical in another culture.
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