13 research outputs found
Ordinal Regression Model of Parking Search Time
Parking search reduces the quality of parking service, as well as traffic network level of service, due to additionally generated traffic. Parking search also entails other negative effects, primarily ecological, social and economic. Even though the importance of this problem has been noted in the past, there is an impression that this issue has not been sufficiently researched and should be additionally analysed in order to properly understand this phenomenon. Therefore, the aim of this paper is to study the factors affecting parking search time that can be influenced through a set of parking management measures. In this paper, an ordinal regression model was developed to estimate these parameters and it was fitted using empirical data collected by interviewing drivers. Main model results show that parking occupancy has the highest impact upon the value of parking search time, indicating the significance of defining proper policies and measures aimed at reaching targeted parking occupancy. Parking frequency is the second parameter observed to be significant, demonstrating the importance of implementing proper parking information systems
DOHERTY AMPLIFIER LINEARIZATION BY DIGITAL INJECTION METHODS
Verification of two linearization methods, applied on asymmetrical two-way microstrip Doherty amplifier in experiment and on symmetrical two-way Doherty amplifier in simulation, is performed in this paper. The laboratory set-ups are formed to generate the baseband nonlinear linearization signals of the second-order. After being tuned in magnitude and phase in the digital domain the linearization signals modulate the second harmonics of fundamental carrier. In the first method, adequately processed signals are then inserted at the input and output of the main Doherty amplifier transistor, whereas in the second method, they are injected at the outputs of the Doherty main and auxiliary amplifier transistors. The experimental results are obtained for 64QAM digitally modulated signals. As a proof of concept, the linearization methods are also verified in simulation, for Doherty amplifier designed to work in 5G band below 6 GHz, utilizing 20 MHz LTE signal
RF PA LINEARIZATION BY SIGNALS MODIFIED IN BASEBAND DIGITAL DOMAIN
This paper represents the linearization of the RF power amplifier performed by a new approach that combines two different methods exploiting the modified baseband signals. The signals for linearization in both methods are formed and processed in digital domain. The required modified baseband signals for linearization are products of the second order nonlinearity of a nonlinear system fed by the useful baseband signal. In the first method, adequate part of the modified baseband signal is adjusted in amplitude and polarity and injected at the input and output of the amplifier transistor across the DC bias circuits. In the second method, the appropriate modified baseband signal set on the appropriate amplitude and phase modulates the fundamental carrier second harmonic, which is then inserted at the input and output of the amplifier transistor. The effects of the combined linearization method are considered on a single stage power amplifier for quadrature amplitude modulated signals characterized with frequency spacing between spectral components up to 60 MHz for different input power levels, as well as for WCDMA digitally modulated signal
LINEARIZATION OF BROADBAND TWO-WAY MICROSTRIP DOHERTY AMPLIFIER
The linearization of a broadband two-way microstrip Doherty amplifier designed for application in the frequency range 0.9-1.0 GHz is considered in this paper. The amplifier characterized by the maximum output power 8 W is designed in microstrip technique for broadband applications. For linearization purposes, the second- and fourth-order nonlinear signals are extracted at the output of the peaking cell, adjusted in amplitude and phase and fed at the input and output of the carrier transistor over the microstrip hairpin band-pass filters. The effects of the linearization are considered through the simulation for two sinusoidal signals with different frequency interval between them setting on from 5 MHz and going up to30 MHz at different input power levels up to saturation, as well as for an Orthogonal frequency division multiplexing (OFDM) digitally modulated signal
Dactylis glomerata grass pollen from urban area releases more sub- pollen particles and has stronger ige response in allergic individuals than rural counterpart
Background and Aim: Epidemiological studies pointed at the connection betweenpollution (e.g., traffic emissions) and an increased percentage of people suffering fromrespiratory allergies, including the pediatric population. Field studies provided the mostrelevant assessment of the effects of the intensity and variety of urban and industrialcontamination on the structure and allergenic potency of pollen allergens. Therefore, theaim of the present work was to compare allergenic profiles ofDactylis glomerata pollen(DGP) collected in the specific urban and rural areas (Kruševac and suburbs), to assesspollen structures and immunoglobulin E (IgE) reactivity to pollen of school childrenpopulation allergic to grass pollens
Seroprevalence nekih zaraznih bolesti u pasa lutalica u širem području Leskovca
Since the last decade, stray dogs have been significant ecological, economical and sociological problem in the world as well as in the Republic of Serbia. They occupy specifi c place in the ecology of big cities and their contact with human population represents danger since they are carriers of many zoonotic infectious diseases. The goal of this paper is to present epizootiological survey on some diseases of bacterial, viral and parasitic origin through serological investigation of blood sera and full blood. The prevalence of leptospirosis, Tularaemia, West Nile fever and dirofilariosis has been determined in this research. The material included full blood and blood sera of stray dogs in the wider territory of Leskovac city. The research methods encompassed standard serological tests: microscopic agglutination test (MAT) for determination of specific antibodies against Leptospira spp.; slow and fast agglutination test for determination of antibodies against Tularaemia causative agent (Francisella tularensis); agar gel immunodiffusion (AGID) for detection of specific antibodies against West Nile virus -WNV; modified Knot's test for the detection of microfilaria. The results revealed seropositivity for causative agents of Leptospirosis, Tularaemia and dirofilariosis, while there were no positive findings for WNV.Tokom poslednjih deset godina, psi lutalice se smatraju značajnim ekološkim, ekonomskim i socijalnim problemom kako u celom svetu tako i u Republici Srbiji. Psi lutalice zauzimaju posebno mesto u ekologiji velikih gradova i njihov kontakt sa ljudima, predstavlja opasnost, jer oni mogu biti nosioci uzročnika mnogih zoonotskih infektivnih oboljenja. Cilj ovog rada je da se predstavi epizootiološka studija nekih bakterijskih, virusnih i parazitskih oboljenja, pomoću seroloških ispitivanja krvnih seruma i pune krvi pasa. Tokom ovog istraživanja, ispitivana je prevalenca na leptospirozu, tularemiju, groznicu zapadnog Nila i dirofilariozu. Materijal su predstavljali uzorci pune krvi i krvnog seruma pasa lutalica, iz šire okoline grada Leskovca. Metode ispitivanja su obuhvatale standardne serološke testove: test mikroskopske aglutinacije (MAT) za utvrđivanje specifičnih antitela protiv Leptospira spp.; spora i brza aglutinacija za utvrđivanje antitela protiv uzročnika tularaemije (Francisella tularensis); agar gel imunodifuzioni test (AGID) za detekciju specifičnih antitela protiv virusa Zapadnog Nila -WNV; modifikovani Knotov test za detekciju mikrofilarija. Rezultati ispitivanja pokazuju seropozitivnost na uzročnike leptospiroze, tularemije i dirofilarioze, dok nisu dobijeni pozitivni nalazi za WNV. PR Projekat Ministarstva nauke Republike Srbije, br. TR 37015
Dactylis glomerata grass pollen from urban area releases more sub- pollen particles and has stronger ige response in allergic individuals than rural counterpart
Background and Aim: Epidemiological studies pointed at the connection between
pollution (e.g., traffic emissions) and an increased percentage of people suffering from
respiratory allergies, including the pediatric population. Field studies provided the most
relevant assessment of the effects of the intensity and variety of urban and industrial
contamination on the structure and allergenic potency of pollen allergens. Therefore, the
aim of the present work was to compare allergenic profiles of
Dactylis glomerata pollen
(DGP) collected in the specific urban and rural areas (Kruševac and suburbs), to assess
pollen structures and immunoglobulin E (IgE) reactivity to pollen of school children
population allergic to grass pollens
Ordinal Regression Model of Parking Search Time
Parking search reduces the quality of parking service, as well as traffic network level of service, due to additionally generated traffic. Parking search also entails other negative effects, primarily ecological, social and economic. Even though the importance of this problem has been noted in the past, there is an impression that this issue has not been sufficiently researched and should be additionally analysed in order to properly understand this phenomenon. Therefore, the aim of this paper is to study the factors affecting parking search time that can be influenced through a set of parking management measures. In this paper, an ordinal regression model was developed to estimate these parameters and it was fitted using empirical data collected by interviewing drivers. Main model results show that parking occupancy has the highest impact upon the value of parking search time, indicating the significance of defining proper policies and measures aimed at reaching targeted parking occupancy. Parking frequency is the second parameter observed to be significant, demonstrating the importance of implementing proper parking information systems
Doherty Amplifier Linearity Test for Fifth Generation Signals
In this paper, the linearity of a fabricated microstrip Doherty amplifier in asymmetrical topology (ADA) is experimentally tested for the fifth generation signals. The measurement set-up contains a Matlab programming platform, a signal generator, and a vector signal analyzer. The Matlab development platform and the signal generator are used for the generation of the 5G FBMC, UFMC, and FOFDM signals. The 5G signal spectra are measured by the vector signal analyzer at the input and output of the Doherty amplifier. The output spectra of the 5G signals for different input power levels gained in measurements are compared to the simulated results