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Outage Capacity Analysis for Cognitive Non-Orthogonal Multiple Access Downlink Transmissions Systems in the Presence of Channel Estimation Error
Full text linkIn this paper, we propose a downlink cognitive non-orthogonal multiple access (NOMA) network, where the secondary users (SUs) operate in underlay mode. In the network, secondary transmitter employs NOMA signaling for downlink transmission, and the primary user (PU) is interfered by the transmission from SU. The expressions for the outage probabilities are derived in closed-form for both primary and secondary users in the presence of channel estimation error. Numerical simulation results show that the channel estimation error and the inter-network interference cause degradation of the downlink outage performance. Also the power allocation and the location have a significant impact on the outage probability. The numerical experiments demonstrate that the analytic expressions of the outage probabilities match with the simulation results
Analysis of Bus Ride Comfort Using Smartphone Sensor Data
Full text linkPassenger comfort is an important indicator that is often used to measure the quality of public transport services. It may also be a crucial factor in the passenger’s choice of transport mode. The typical method of assessing passenger comfort is through a passenger interview survey which can be tedious. This study aims to investigate the relationship between bus ride comfort based on ride smoothness and the vehicle’s motion detected by the smartphone sensors. An experiment was carried out on a bus fixed route within the University campus where comfort levels were rated on a 3-point scale and recorded at 5-second intervals. The kinematic motion characteristics obtained includes tri-axial linear accelerations, tri-axial rotational velocities, tri-axial inclinations and the latitude and longitude position of the vehicle and the updated speed. The data acquired were statistically analyzed using the Classification & Regression Tree method to correlate ride comfort with the best set of kinematic data. The results indicated that these kinematic changes captured in the smartphone can reflect the passenger ride comfort with an accuracy of about 90%. The work demonstrates that it is possible to make use of larger and readily available kinematic data to assess passenger comfort. This understanding also suggests the possibility of measuring driver behavior and performance
Design of Smith Predictor Based Fractional Controller for Higher Order Time Delay Process
No full textNormally all real world process in a process industry will have time delay. For those processes with time delays, obtaining satisfactory closed loop performances becomes very difficult. In this work, three interacting cylindrical tank process is considered for study and the objective of the work is to compensate for time delays using smith predictor structure and to maintain the level in the third tank. Input/Output data is generated for the three interacting tank process. It is approximated as Integer First Order Plus Dead Time system (IFOPDT) and Fractional First Order Plus Dead Time system (FFOPDT). Smith predictor based fractional order Proportional Integral controller and Integer order Proportional Integral controller is designed for the IFOPDT and FFOPDT model using frequency response technique and their closed loop performance indices are compared and tabulated. The servo and regulatory responses are simulated using Matlab/Simulink
Experimental Study and Finite Element Analysis on Ultimate Strength of Dual-Angle Cross Combined Section Under Compression
No full textThis paper investigates Q420 dual-angle cross combined section columns under axial and eccentric compression by conducting experiments. The specimen parameters, experimental setup, and test results are presented. It showed that local buckling occurred apparently for single internode specimens (λλ), width to thickness ratio of angles (b/t), the number of filled plate (n), load relative eccentricity (e) and the lateral support stiffness on the ultimate strengths of dual-angle cross combined section columns. Based on above analysis, the design equations are proposed by using curve fitting technique. It is shown from comparison between test results, finite element analysis and related specifications that the ultimate strength from theoretical formulas, proposed equations and finite element models are consistent with experiments results
A Self-Organizing Memory Neural Network for Aerosol Concentration Prediction
No full textHaze-fog, which is an atmospheric aerosol caused by natural or man-made factors, seriously affects the physical and mental health of human beings. PM2.5 (a particulate matter whose diameter is smaller than or equal to 2.5 microns) is the chief culprit causing aerosol. To forecast the condition of PM2.5, this paper adopts the related the meteorological data and air pollutes data to predict the concentration of PM2.5. Since the meteorological data and air pollutes data are typical time series data, it is reasonable to adopt a machine learning method called Single Hidden-Layer Long Short-Term Memory Neural Network (SSHL-LSTMNN) containing memory capability to implement the prediction. However, the number of neurons in the hidden layer is difficult to decide unless manual testing is operated. In order to decide the best structure of the neural network and improve the accuracy of prediction, this paper employs a self-organizing algorithm, which uses Information Processing Capability (IPC) to adjust the number of the hidden neurons automatically during a learning phase. In a word, to predict PM2.5 concentration accurately, this paper proposes the SSHL-LSTMNN to predict PM2.5 concentration. In the experiment, not only the hourly precise prediction but also the daily longer-term prediction is taken into account. At last, the experimental results reflect that SSHL-LSTMNN performs the best
Hardware Circuit Implementation and Performance Analysis of Three-Slot NP-CSMA
No full textThe development of wireless communication technology has become increasingly important in the communications industry. How to allocate limited channel resources reasonably and reliably to each competing user is a problem that the access protocol of the MAC (Multiple Access Control) layer needs to solve. As an important way of random access, NP-CSMA (Non Persistent Carrier Sense Multiple Access) has a higher network throughput rate when the arrival rate is higher. This paper analyzes and improves the implemented NP-CSMA model, and obtains a three-slot NP-CSMA model. The mathematical tool MATLAB is used to analyze the network throughput, delay and energy efficiency of the model, and compare several random multiple access protocols adheres to the network throughput, they are NP-CSMA, Three-slot NP-CSMA, 1-persistent CSMA, P-persistent CSMA, and concludes that the three-slot NP-CSMA is significantly letter than several other multiple access protocols. Finally, using Quartus to design the three-slot NP-CSMA circuit, the statistical value of the circuit system is compared with the theoretical value of the model, and the error is less than 0.01, which proves that the system is reasonable in design and can be applied to wireless communication networks
Blend of Polyhydroxyalkanoates Synthesized By Lipase Positive Bacteria From Plant Oils
No full textA total of 5 biochemically characterized lipase positive bacterial strains were screened for Polyhydroxyalkanoates (PHA) production by Nile blue staining and confirmation was done by Sudan Black B. PHA production ability for all strains was optimized followed by time profiling calculation and comparison via using glucose and two plant oils i.e., canola and mustard oil. Quantitative analysis showed that glucose can serve as a carbon source for maximum biomass (2.5 g/L CDW for strain 5) and PHA production (70.3% for strain 2). PHA produced by strain 2 was further analyzed for its chemical composition and type via Fourier Transform Infrared (FT-IR) spectroscopy. It revealed homopolymer (PHB) and copolymer (PHB-co-PHV) production of PHA (peaks at 1743 cm-1 and 2861 cm-1, respectively) with both canola and mustard oil unlike glucose which produced only homopolymer one i.e., PHB (peaks at 1110 cm-1, 1411 cm-1 and 1650 cm-1). Crystallinity of FT-IR analyzed PHA was calculated using mathematical formulas which showed decrease from glucose to canola to mustard oil. This study revealed that plant oils can serve as better carbon source to produce better quality (ductile and copolymer) PHA. Moreover, 16S rRNA gene sequencing analysis showed that strain 1, strain 2, strain 3, strain 4 and strain 5 are Stenotrophomonas sp. N3, Exiguobacterium sp. N4, Exiguobacterium sp. Ch3, Cellulosimicrobium sp. A8 and Klebsiella sp. LFSM2, respectively
Liquefaction of Kraft Lignin at Atmospheric Pressure
No full textKraft lignin was liquefied using polyethylene glycol #400 (PEG) and glycerol (G) in a weight ratio of 80/20 (w/w) and sulphuric acid (SA) as catalyst under atmospheric pressure at 160ºC. The three independent variables: reaction time (60, 80 and 100 min), percentage of lignin (15, 20 and 25%, w/w), and catalyst concentration (0, 3 and 6%, w/w), were varied resulting in 27 experimental runs. The effect of these reaction conditions on the properties of the polyols was evaluated. The statistical analysis showed that only “the percentage of lignin” did not influence the properties of the liquefied products, however, reaction time and catalyst load were important parameters. The resulting liquefied products were characterized by FTIR analysis
Functionalised Poly(Vinyl Alcohol)/Graphene Oxide as Polymer Composite Electrolyte Membranes
No full textCrosslinked poly(vinyl alcohol) (PVA) based composite films were prepared as polyelectrolyte membranes for low temperature direct ethanol fuel cells (DEFC). The membranes were functionalised by means of the addition of graphene oxide (GO) and sulfonated graphene oxide (SGO) and crosslinked with sulfosuccinic acid (SSA). The chemical structure was corroborated and suitable thermal properties were found. Although the addition of GO and SGO slightly decreased the proton conductivity of the membranes, a significant reduction of the ethanol solution swelling and crossover was encountered, more relevant for those functionalised with SGO. In general, the composite membranes were stable under simulated service conditions. The addition of GO and SGO particles permitted to buffer the loss and almost retain similar proton conductivity than prior to immersion. These membranes are alternative polyelectrolytes, which overcome current concerns of actual commercial membranes such as the high cost or the crossover phenomenon
The Effects of Gamma Irradiation on Molecular Weight, Morphology and Physical Properties of PHBV/Cloisite 30B Bionanocomposites
No full textIn this paper, the effects of gamma irradiation on Cast poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and PHBV/Cloisite 30B (C30B) (3 wt%) bionanocomposite prepared by melt compounding, were evaluated at various doses, i.e., 5, 15, 20, 50 and 100 kGy at room temperature in air. Changes in molecular weight, morphology and physical properties were investigated. The study showed that the main degradation mechanism occurring in gamma irradiation in both Cast PHBV and C-PHBV/3C30B bionanocomposite is chain scission, responsible for the decrease of molecular weight. Differential scanning calorimetry (DSC) data indicated a regular decrease in crystallization temperature, melting temperature and crystallinity index for all irradiated samples with increasing the dose. Further, DSC thermograms of both Cast PHBV and PHBV bionanocomposite exhibited double melting peaks due probably to changes in the PHBV crystal structure. Tensile and DMA data showed a reduction in Young’s modulus, strength, elongation at break and storage modulus with the radiation dose; the decrease was however more pronounced for Cast PHBV. The morphological damages were much less pronounced for the PHBV bionanocomposite sample compared to Cast PHBV, for which some irregularities and defects were observed at 100 kGy. This study highlighted the ability of C30B to counterbalance the detrimental effect of radiolytic degradation on the functional properties of PHBV up to 100 kGy, thus acting as a potential anti-rad