Search results for: road transport systems

Authors: Tariq Ahamad, Mohammed S. Al-Kahtani, Taisir Eldos

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Optical communications technology has made enormous and steady progress for several decades, providing the key resource in our increasingly information-driven society and economy. Much of this progress has been in finding innovative ways to increase the data carrying capacity of a single optical fiber. In this research article we have explored basic issues in terms of security and reliability for secure and reliable information transfer through the fiber infrastructure. Conspicuously, one potentially enormous source of improvement has however been left untapped in these systems: fibers can easily support hundreds of spatial modes, but today’s commercial systems (single-mode or multi-mode) make no attempt to use these as parallel channels for independent signals. Bandwidth, performance, reliability, cost efficiency, resiliency, redundancy, and security are some of the demands placed on telecommunications today. Since its initial development, fiber optic systems have had the advantage of most of these requirements over copper-based and wireless telecommunications solutions. The largest obstacle preventing most businesses from implementing fiber optic systems was cost. With the recent advancements in fiber optic technology and the ever-growing demand for more bandwidth, the cost of installing and maintaining fiber optic systems has been reduced dramatically. With so many advantages, including cost efficiency, there will continue to be an increase of fiber optic systems replacing copper-based communications. This will also lead to an increase in the expertise and the technology needed to tap into fiber optic networks by intruders. As ever before, all technologies have been subject to hacking and criminal manipulation, fiber optics is no exception. Researching fiber optic security vulnerabilities suggests that not everyone who is responsible for their networks security is aware of the different methods that intruders use to hack virtually undetected into fiber optic cables. With millions of miles of fiber optic cables stretching across the globe and carrying information including but certainly not limited to government, military, and personal information, such as, medical records, banking information, driving records, and credit card information; being aware of fiber optic security vulnerabilities is essential and critical. Many articles and research still suggest that fiber optics is expensive, impractical and hard to tap. Others argue that it is not only easily done, but also inexpensive. This paper will briefly discuss the history of fiber optics, explain the basics of fiber optic technologies and then discuss the vulnerabilities in fiber optic systems and how they can be better protected. Knowing the security risks and knowing the options available may save a company a lot embarrassment, time, and most importantly money.

Keywords: in-house networks, fiber optics, security risk, money

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Authors: Azzouzi Fadoua

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This study focuses on the diagnosis of the dynamics of natural resources in a semi-arid mountainous weakened by natural vulnerability and anthropogenic action. This is evident in the forms of hydraulic erosion and degradation of agricultural land. The rate of this damaged land is 53%, with a strong presence of concentrated erosion; this shows that balanced and semi-balanced environments are less apparent to the Watershed, representing 47%. The results revealed the crucial role of the slopes and the density of the hydraulic networks to facilitate the transport of fine elements, at the level of the slopes with low vegetation intensity, to the lake of the dam. Something that endangers the siltation of the latter. After the study of natural and anthropogenic elements, it turned out that natural vulnerability is an integral part of the current dynamic, especially when it coincides with the overexploitation of natural resources, in this case, the exploitation of steep slopes for the cultivation of cereals and overgrazing. This causes the soil to pile up and increase the rate of runoff.

Keywords: watershed, erosion, natural vulnerability, anthropogenic

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Authors: Nancy Bartekian, Kaelan Vazquez, Christine Reyna

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Immigrants coming into the United States of America may justify the American system (political, economic, healthcare, criminal justice) and see it as functional. This may be explained because they may come from countries that are even more unstable than the U.S. and/or come here to benefit from the promise of the “American dream” -a narrative that they might be more likely to believe in if they were willing to undergo the costly and sometimes dangerous process to immigrate. Conversely, native-born Americans, as well as immigrants who may have lived in America for a longer period of time, would have more experiences with the various broken systems in America that are dysfunctional, fail to provide adequate services equitably, and/or are steeped in systemic racism and other biases that disadvantage lower-status groups. Thus, our research expects that system justification would decrease, and condemnation would increase with more time spent in the U.S. for immigrant groups. We predict that a) those not born in the U.S. will be more likely to justify the system, b) they will also be less likely to condemn the system, and c) the longer an immigrant has been in the U.S. the less likely they will to justify, and more they will to condemn the system. We will use a mixed-model multivariate analysis of covariance (MANCOVA) and control for race, income, and education. We will also run linear regression models to test if there is a relationship between the length of time in the United States and a decrease in system justification, and length of time and an increase in system condemnation for those not born in the U.S. We will also conduct exploratory analyses to see if the predicted patterns are more likely within certain systems over other systems (political, economic, healthcare, criminal justice).

Keywords: immigration, system justification, system condemnation, system qualification

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Authors: Nahian Salsabeel, Faria Leera

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—“Whoever controls the Indian Ocean, dominates Asia. This ocean is the key to the seven seas. In the 21st century, the destiny of the world will be decided on its waters” -Alfred Mahan South Asia is increasingly becoming a hub for international politics. Numerous ventures are taking place in the strategic region. Of them, the most prominent is the Belt and Road Initiative (BRI). Originating from the concept of ancient Silk Route, the Chinese Xi Jin Ping regime looks to reestablish the vast connectivity project to connect the world through infrastructure and trade. On the other hand, the US, teamed up with India, Australia and Japan, thereby forming the Quad, have launched their own foreign policy, the Indo-Pacific Strategy. The ambitious 21st century initiative for the development of maritime trade, security and governance focuses critical importance to the Indo-Pacific region, especially to South Asia. Against the backdrop of contemporary political scenario, both the Quad and China airs to establish their own footprint across the region through respective mega projects, the Indo-Pacific Strategy and the BRI. This research employs a comparative case study research method, using a secondary research design. The paper looks at the variety of opportunities and challenges posed by the BRI and the Indo Pacific, and gives the comparative study on both ends.

Keywords: BRI, Foreign Policy, Indo-Pacific, South Asia

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Authors: Muhammad Nuqman Bin Anuar, Dalila Mat Said

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The integration of photovoltaic (PV) systems in government buildings represents a crucial step toward enhancing energy efficiency and promoting sustainability. However, the adoption of PV systems can introduce challenges in maintaining power quality due to the intermittent nature of solar generation. The effect of a self-consumption photovoltaic system on the power quality characteristics of a Malaysian government building is examined in this study. Total harmonic distortion of current (THDi), total harmonic distortion of voltage (THDv), voltage (Vrms), current (Irms), and power factors are among the important parameters that were examined both before and after the PV system was installed. Power quality data were collected over several weeks by using a power quality analyzer Fluke 1750, and a comparative analysis was conducted to evaluate changes in these parameters. The results show significant fluctuations in the power factor, particularly during periods of high solar generation, with notable variations in THDi across the three phases. These fluctuations highlight the potential interactions between solar generation and load demand, emphasizing the need for harmonic mitigation. Despite these issues, Vrms and THDv remained within acceptable limits, ensuring compliance with power quality standards. This study provides insights into the power quality behaviour of self-consumption PV systems before and after the installation of photovoltaics.

Keywords: power quality, power factor, harmonics, photovoltaic

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Authors: Wahab Ali Shah, Junjia He

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Transferring electrical power without any wiring has been a dream since late 19^th century. There were some advances in this area as to know more about microwave systems. However, this subject has recently become very attractive due to their practiScal systems. There are low power applications such as charging the batteries of contactless tooth brushes or implanted devices, and higher power applications such as charging the batteries of electrical automobiles or buses. In the first group of applications operating frequencies are in microwave range while the frequency is lower in high power applications. In the latter, the concept is also called inductive power transfer. The aim of the paper is to have an overview of the inductive power transfer for electrical vehicles with a special concentration on coil design and power converter simulation for static charging. Coil design is very important for an efficient and safe power transfer. Coil design is one of the most critical tasks. Power converters are used in both side of the system. The converter on the primary side is used to generate a high frequency voltage to excite the primary coil. The purpose of the converter in the secondary is to rectify the voltage transferred from the primary to charge the battery. In this paper, an inductive power transfer system is studied. Inductive power transfer is a promising technology with several possible applications. Operation principles of these systems are explained, and components of the system are described. Finally, a single phase 2 kW system was simulated and results were presented. The work presented in this paper is just an introduction to the concept. A reformed compensation network based on traditional inductor-capacitor-inductor (LCL) topology is proposed to realize robust reaction to large coupling variation that is common in dynamic wireless charging application. In the future, this type compensation should be studied. Also, comparison of different compensation topologies should be done for the same power level.

Keywords: coil design, contactless charging, electrical automobiles, inductive power transfer, operating frequency

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Authors: Abid Ali Abid

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Electromagnetic ion cyclotron waves have been playing a significant role in inner magnetosphere, and their proton band has been detected using the Magnetospheric-Multiscale (MMS) satellite observations in the inner magnetosphere. It has been examined that the intensity of EMIC waves gradually increases by decreasing the L shell. Thermal anisotropy of hot protons initiates the waves. The low-energy cold protons (ions) can be activated by the EMIC waves when the EMIC wave intensity is high. As a result, these formerly invisible protons are now visible. The EMIC waves, whose frequency ranges from 0.001 Hz to 5 Hz in the inner magnetosphere and received considerable attention for energy transport across the magnetosphere. Since these waves act as a mechanism for the loss of energetic electrons from the Van Allen radiation belt to the atmosphere, therefore, it is necessary to understand how and where they can be produced, as well as the direction of waves along the magnetic field lines. It is demonstrated that throughout the energy range of 1 eV to 100 eV, the number density and temperature anisotropy of the protons likewise rise as the intensity of the EMIC waves increases.

Keywords: electromagnetic ion cyclotron waves, magnetospheric-multiscale (MMS) satellite, cold protons, inner magnetosphere

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Authors: Jin Liang, James H. Liu, Ti-Jun Xiao

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It is known that there exist many physical phenomena where abrupt or impulsive changes occur either in the system dynamics, for example, ad-hoc network, or in the input forces containing impacts, for example, the bombardment of space antenna by micrometeorites. There are many other examples such as ultra high-speed optical signals over communication networks, the collision of particles, inventory control, government decisions, interest changes, changes in stock price, etc. These are impulsive phenomena. Hence, as a combination of the traditional initial value problems and the short-term perturbations whose duration can be negligible in comparison with the duration of the process, the systems with impulsive conditions (i.e., impulsive systems) are more realistic models for describing the impulsive phenomenon. Such a situation is also suitable for the delay systems, which include some of the past states of the system. So far, there have been a lot of research results in the study of impulsive systems with delay both in finite and infinite dimensional spaces. In this paper, we investigate the periodicity of solutions to the nonautonomous impulsive evolution equations with infinite delay in Banach spaces, where the coefficient operators (possibly unbounded) in the linear part depend on the time, which are impulsive systems in infinite dimensional spaces and come from the optimal control theory. It was indicated that the study of periodic solutions for these impulsive evolution equations with infinite delay was challenging because the fixed point theorems requiring some compactness conditions are not applicable to them due to the impulsive condition and the infinite delay. We are happy to report that after detailed analysis, we are able to combine the techniques developed in our previous papers, and some new ideas in this paper, to attack these impulsive evolution equations and derive periodic solutions. More specifically, by virtue of the related transition operator family (evolution family), we present a Poincaré operator given by the nonautonomous impulsive evolution system with infinite delay, and then show that the operator is a condensing operator with respect to Kuratowski's measure of non-compactness in a phase space by using an Amann's lemma. Finally, we derive periodic solutions from bounded solutions in view of the Sadovskii fixed point theorem. We also present a relationship between the boundedness and the periodicity of the solutions of the nonautonomous impulsive evolution system. The new results obtained here extend some earlier results in this area for evolution equations without impulsive conditions or without infinite delay.

Keywords: impulsive, nonautonomous evolution equation, optimal control, periodic solution

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Authors: Fahad Alhussein, Huaping Liu

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This paper compares the multipath mitigation performance of code correlation reference waveform receivers with variable and fixed window width, for binary offset carrier and multiplexed binary offset carrier signals typically used in global navigation satellite systems. In the variable window width method, such width is iteratively reduced until the distortion on the discriminator with multipath is eliminated. This distortion is measured as the Euclidean distance between the actual discriminator (obtained with the incoming signal), and the local discriminator (generated with a local copy of the signal). The variable window width have shown better performance compared to the fixed window width. In particular, the former yields zero error for all delays for the BOC and MBOC signals considered, while the latter gives rather large nonzero errors for small delays in all cases. Due to its computational simplicity, the variable window width method is perfectly suitable for implementation in low-cost receivers.

Keywords: correlation reference waveform receivers, binary offset carrier, multiplexed binary offset carrier, global navigation satellite systems

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Authors: Burak Yildirim, Muhsin Tunay Gencoglu

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This publication shows the effects of Microgrid (MG) integration on the power systems oscillating stability. Generated MG model power systems were applied to the IEEE 14 bus test system which is widely used in stability studies. Stability studies were carried out with the help of eigenvalue analysis over linearized system models. In addition, Hopf bifurcation point detection was performed to show the effect of MGs on the system loadability margin. In the study results, it is seen that MGs affect system stability positively by increasing system loadability margin and has a damper effect on the critical modes of the system and the electromechanical local modes, but they make the damping amount of the electromechanical interarea modes reduce.

Keywords: Eigenvalue analysis, microgrid, Hopf bifurcation, oscillatory stability

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Authors: HyunSu Seo, HoYoung Son, Sungjin Kim, WooYoung Jung

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In order to understand the seismic behavior of steel frame structure with infill FRP composite panel, simple models for simulation on the steel frame with the panel systems were developed in this study. To achieve the simple design method of the steel framed structure with the damping panel system, 2-D finite element analysis with the springs and dashpots models was conducted in ABAQUS. Under various applied spring stiffness and dashpot coefficient, the expected hysteretic energy responses of the steel frame with damping panel systems we re investigated. Using the proposed simple design method which decides the stiffness and the damping, it is possible to decide the FRP and damping materials on a steel frame system.

Keywords: numerical analysis, FEM, infill, GFRP, damping

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Authors: Andrey V. Timofeev, Viktor M. Denisov

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A robust sequential nonparametric method is proposed for adaptation to background noise parameters for real-time. The distribution of background noise was modelled like to Huber contamination mixture. The method is designed to operate as an adaptation-unit, which is included inside a detection subsystem of an integrated multichannel monitoring system. The proposed method guarantees the given size of a nonasymptotic confidence set for noise parameters. Properties of the suggested method are rigorously proved. The proposed algorithm has been successfully tested in real conditions of a functioning C-OTDR monitoring system, which was designed to monitor railways.

Keywords: guaranteed estimation, multichannel monitoring systems, non-asymptotic confidence set, contamination mixture

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Authors: Ramana Reddy, Vijay Kothari

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Aircraft provide a fast, reliable mode of transport with no comparable alternative for long distance travel. Throughout the years, technology improvements have been made to aircraft and engines to make them more fuel efficient. Air traffic continues to grow around the world and needs more aircrafts to accommodate such rapid growth. This has direct consequences on two of the most important environmental factors i.e. emissions and noise. Aviation contributes about 2% of global greenhouse gas emissions. Aviation emits a number of pollutants that alter the chemical composition of the atmosphere, changing its radiative balance and hence influencing the climate. In order to reduce or if possible eliminate potential harm to the environment and also make air travel efficient and economical, an environmentally beneficial concept called “Green Aviation System” is required. This is a structured frame work with elements like innovative technologies/tools in engineering design, manufacturing, airport and fleet operations.

Keywords: air traffic, environment, emissions, noise, green aviation system

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Authors: Sigal Portnoy, Jason Friedman, Eitan Raveh

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Introduction: Sensory substitution is possible due to the capacity of our brain to adapt to information transmitted by a synthetic receptor via an alternative sensory system. Practical sensory substitution systems are being developed in order to increase the functionality of individuals with sensory loss, e.g. amputees. For upper limb prosthetic-users the loss of tactile feedback compels them to allocate visual attention to their prosthesis. The effect of adding vibrotactile feedback (VTF) to the applied force has been studied, however its effect on the allocation if visual attention during dual-tasking and the response during misleading visual feedback have not been studied. We hypothesized that VTF will improve the performance and reduce visual attention during dual-task assignments in healthy individuals using a robotic hand and improve the performance in a standardized functional test, despite the presence of misleading visual feedback. Methods: For the dual-task paradigm, twenty healthy subjects were instructed to toggle two keyboard arrow keys with the left hand to retain a moving virtual car on a road on a screen. During the game, instructions for various activities, e.g. mix the sugar in the glass with a spoon, appeared on the screen. The subject performed these tasks with a robotic hand, attached to the right hand. The robotic hand was controlled by the activity of the flexors and extensors of the right wrist, recorded using surface EMG electrodes. Pressure sensors were attached at the tips of the robotic hand and induced VTF using vibrotactile actuators attached to the right arm of the subject. An eye-tracking system tracked to visual attention of the subject during the trials. The trials were repeated twice, with and without the VTF. Additionally, the subjects performed the modified box and blocks, hidden from eyesight, in a motion laboratory. A virtual presentation of a misleading visual feedback was be presented on a screen so that twice during the trial, the virtual block fell while the physical block was still held by the subject. Results: This is an ongoing study, which current results are detailed below. We are continuing these trials with transradial myoelectric prosthesis-users. In the healthy group, the VTF did not reduce the visual attention or improve performance during dual-tasking for the tasks that were typed transfer-to-target, e.g. place the eraser on the shelf. An improvement was observed for other tasks. For example, the average±standard deviation of time to complete the sugar-mixing task was 13.7±17.2s and 19.3±9.1s with and without the VTF, respectively. Also, the number of gaze shifts from the screen to the hand during this task were 15.5±23.7 and 20.0±11.6, with and without the VTF, respectively. The response of the subjects to the misleading visual feedback did not differ between the two conditions, i.e. with and without VTF. Conclusions: Our interim results suggest that the performance of certain activities of daily living may be improved by VTF. The substitution of visual sensory input by tactile feedback might require a long training period so that brain plasticity can occur and allow adaptation to the new condition.

Keywords: prosthetics, rehabilitation, sensory substitution, upper limb amputation

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Authors: Felipe M. de Freitas, Ícaro V. Soares, Lucas L. L. Fortes, Sandro T. M. Gonçalves, Úrsula D. C. Resende

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There is a dispersed energy in Radio Frequencies (RF) that can be reused to power electronics circuits such as: sensors, actuators, identification devices, among other systems, without wire connections or a battery supply requirement. In this context, there are different types of energy harvesting systems, including rectennas, coil systems, graphene and new materials. A secondary step of an energy harvesting system is the rectification of the collected signal which may be carried out, for example, by the combination of one or more Schottky diodes connected in series or shunt. In the case of a rectenna-based system, for instance, the diode used must be able to receive low power signals at ultra-high frequencies. Therefore, it is required low values of series resistance, junction capacitance and potential barrier voltage. Due to this low-power condition, voltage multiplier configurations are used such as voltage doublers or modified bridge converters. Lowpass filter (LPF) at the input, DC output filter, and a resistive load are also commonly used in the rectifier design. The electronic circuits projects are commonly analyzed through simulation in SPICE (Simulation Program with Integrated Circuit Emphasis) environment. Despite the remarkable potential of SPICE-based simulators for complex circuit modeling and analysis of quasi-static electromagnetic fields interaction, i.e., at low frequency, these simulators are limited and they cannot model properly applications of microwave hybrid circuits in which there are both, lumped elements as well as distributed elements. This work proposes, therefore, the electromagnetic modelling of electronic components in order to create models that satisfy the needs for simulations of circuits in ultra-high frequencies, with application in rectifiers coupled to antennas, as in energy harvesting systems, that is, in rectennas. For this purpose, the numerical method FDTD (Finite-Difference Time-Domain) is applied and SPICE computational tools are used for comparison. In the present work, initially the Ampere-Maxwell equation is applied to the equations of current density and electric field within the FDTD method and its circuital relation with the voltage drop in the modeled component for the case of lumped parameter using the FDTD (Lumped-Element Finite-Difference Time-Domain) proposed in for the passive components and the one proposed in for the diode. Next, a rectifier is built with the essential requirements for operating rectenna energy harvesting systems and the FDTD results are compared with experimental measurements.

Keywords: energy harvesting system, LE-FDTD, rectenna, rectifier, wireless power systems

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Authors: Gabriel Fernando Talero Rojas, Vladimir Silva Leal, Camilo Bayona-Roa, Juan Pava, Mauricio Lopez Gomez

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The substitution of conventional aviation fuels with biomass-derived alternative fuels is an emerging field of study in the aviation transport, mainly due to its energy consumption, the contribution to the global Greenhouse Gas - GHG emissions and the fossil fuel price fluctuations. Nevertheless, several challenges remain as the biofuel production cost and its degradative effect over the fuel systems that alter the operating safety. Moreover, experimentation on full-scale aeronautic turbines are expensive and complex, leading to most of the research to the testing of small-size turbojets with a major absence of information regarding the effects in the energy performance and the emissions. The main purpose of the current study is to present the results of experimentation in a full-scale military turbojet engine J69-T-25A (presented in Fig. 1) with 640 kW of power rating and using blends of Jet A1 with oil palm biodiesel. The main findings are related to the thrust specific fuel consumption – TSFC, the engine global efficiency – η, the air/fuel ratio – AFR and the volume fractions of O2, CO2, CO, and HC. Two fuels are used in the present study: a commercial Jet A1 and a Colombian palm oil biodiesel. The experimental plan is conducted using the biodiesel volume contents - w_BD from 0 % (B0) to 50 % (B50). The engine operating regimes are set to Idle, Cruise, and Take-off conditions. The turbojet engine J69 is used by the Colombian Air Force and it is installed in a testing bench with the instrumentation that corresponds to the technical manual of the engine. The increment of w_BD from 0 % to 50 % reduces the η near 3,3 % and the thrust force in a 26,6 % at Idle regime. These variations are related to the reduction of the 〖HHV〗_ad of the fuel blend. The evolved CO and HC tend to be reduced in all the operating conditions when increasing w_BD. Furthermore, a reduction of the atomization angle is presented in Fig. 2, indicating a poor atomization in the fuel nozzle injectors when using a higher biodiesel content as the viscosity of fuel blend increases. An evolution of cloudiness is also observed during the shutdown procedure as presented in Fig. 3a, particularly after 20 % of biodiesel content in the fuel blend. This promotes the contamination of some components of the combustion chamber of the J69 engine with soot and unburned matter (Fig. 3). Thus, the substitution of biodiesel content above 20 % is not recommended in order to avoid a significant decrease of η and the thrust force. A more detail examination of the mechanical wearing of the main components of the engine is advised in further studies.

Keywords: aviation, air to fuel ratio, biodiesel, energy performance, fuel atomization, gas turbine

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Authors: Surajit Chakrabarty, Piyush Chauhan, Subhasis Panda, Sujoy Bhattacharya

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A large proportion of roads in India are not well maintained as per the laid down public safety guidelines leading to loss of direction control and fatal accidents. We propose a technique to detect speed breakers and potholes using mobile sensor data captured from multiple vehicles and provide a profile of the road. This would, in turn, help in monitoring roads and revolutionize digital maps. Incorporating randomness in the model formulation for detection of speed breakers and potholes is crucial due to substantial heterogeneity observed in data obtained using a mobile application from multiple vehicles driven by different drivers. This is accomplished with Hidden Markov Models, whose hidden state sequence is found for each time step given the observables sequence, and are then fed as input to LSTM network with peephole connections. A precision score of 0.96 and 0.63 is obtained for classifying bumps and potholes, respectively, a significant improvement from the machine learning based models. Further visualization of bumps/potholes is done by converting time series to images using Markov Transition Fields where a significant demarcation among bump/potholes is observed.

Keywords: deep learning, hidden Markov model, pothole, speed breaker

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Authors: Juan Carlos Aguirre Pabon, Stephen Sabatino, James Morris, Khor Waiho, Antonio Murias

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The tiger shrimp Penaeus monodon is one of the most important species in aquaculture and is native to the Indo-Pacific Ocean. During its greatest success in world production (70s and 80s) was introduced in many Atlantic Ocean countries for cultivation purposes and is currently reported as established in several countries of this area. Because there are no studies to understand the magnitude of the invasion process, this is an exciting opportunity to test evolutionary hypotheses in the context of marine invasions mediated by culture systems; therefore, the purpose of this study was to reconstruct the scenario of invasion of P. monodon in the Atlantic Ocean, by using mitochondrial DNA and eight loci microsatellites. In addition, samples of the invasion area in the Atlantic Ocean (US, Colombia, Venezuela, Brazil, Guienne Bissau, Senegal), the Indo-Pacific Ocean (Indonesia, India, Mozambique), and some cultivation systems (India, Bangladesh, Madagascar) were collected; and analysis of phylogenetic relationships (using some species of the family), genetic diversity, structure population, and demographic changes were performed. High intraspecific divergence in P. semisulcatus and P. monodon were found, high genetic variability in all sites (especially with microsatellites) and the presence of three clusters or populations. In addition, signs of demographic expansion in the culture population and bottlenecks in the invasive and native populations were found, as well as evidence of gene mixtures from all of the populations studied, implying that cropping systems play an essential role in mitigating the negative effects of the founder effect and providing a source of genetic variability that can ensure the success of the invasion.

Keywords: species introduction, increased variability, demographic changes, promoting invasion.

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Authors: Victoria Appatova

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internal and external, that are largely shaped by the student’s perceptions. Since 2006, the ELE concept has been studied by an international group of scholars through the creation of an ELE survey which was administered in nine countries and translated into five languages. The survey compares students’ perceptions of their learning environments and self-efficacy across A student’s effective learning environment (ELE) is comprised of multiple factors, both cultures as well as distinguishes similarities and differences in the students’ needs related to their learning. The main objectives of this international project include the following: Determine a system of components constituting ELE from the perspective of students and other academic populations Analyze students’ expectations, and their chances to succeed in college based on their expectations Conceptualize a comprehensive approach for assessing the effectiveness of a learning environment Compare the actualization of the ELE concept in American schools versus other national educational systems Compare student perceptions of ELE with those of faculty, administrators, and professional staff Four major factors influencing student learning across cultures and various national educational systems were determined: students’ initiative in using support services; learning skills; external comfort; and curriculum. Recent changes in the students’ perceptions, resulting from technology advances and a rapid shift to online learning, are being explored. The findings call for administrative and pedagogical actions which would cultivate more equitable education systems.

Keywords: learning environment, student perception, global perspectives, self-efficacy

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Authors: Onder Yakut, Serdar Solak, Emine Dogru Bolat

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Measuring the Electrocardiogram (ECG) signal is an essential process for the diagnosis of the heart diseases. The ECG signal has the information of the degree of how much the heart performs its functions. In medical diagnosis and treatment systems, Decision Support Systems processing the ECG signal are being developed for the use of clinicians while medical examination. In this study, a modular wireless ECG (WECG) measuring and recording system using a single board computer and e-Health sensor platform is developed. In this designed modular system, after the ECG signal is taken from the body surface by the electrodes first, it is filtered and converted to digital form. Then, it is recorded to the health database using Wi-Fi communication technology. The real time access of the ECG data is provided through the internet utilizing the developed web interface.

Keywords: ECG, e-health sensor shield, Raspberry Pi, wiFi technology

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Authors: Burak Erkayman, Emin Gundogar, Hayrettin Evirgen, Murat Sarı

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With the increasing competition in recent years, airline companies tend to manage their operations aiming fewer losses in a robust manner. Airline operations are complex operations and have the necessity of being performed just in time and more knock-on relevant elements in the event of a disruption. In this study a knowledge based decision support system is suggested and software is developed. The developed software includes knowledge bases which are based on expert experience and government regulations, model bases and data bases. The results of the suggested approach are presented and improvable aspects of the approach are discussed.

Keywords: knowledge based systems, irregular operations, decision support systems, flight disruptions management

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Authors: Jan Busch, Peter Nyhuis

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Considering the challenges of short product life cycles and growing variant diversity, cost minimization and manufacturing flexibility increasingly gain importance to maintain a competitive edge in today’s global and dynamic markets. In this context, an aerodynamic part feeding system for high-speed industrial assembly applications has been developed at the Institute of Production Systems and Logistics (IFA), Leibniz Universitaet Hannover. The aerodynamic part feeding system outperforms conventional systems with respect to its process safety, reliability, and operating speed. In this paper, a multi-objective optimisation of the aerodynamic feeding system regarding the orientation rate, the feeding velocity and the required nozzle pressure is presented.

Keywords: aerodynamic feeding system, genetic algorithm, multi-objective optimization, workpiece orientation

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Authors: Serban Stere, Stefan Burciu

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The challenging and continuously growing competition in the urban freight transport market emphasizes the need for optimal planning of transportation processes in terms of identifying the solution of consolidating traffic flows in congested urban areas. The aim of the present paper is to present the mathematical framework and propose a methodology of combining urban traffic flows between the distribution centers located at the boundary of a congested urban area. The three scenarios regarding traffic flow between consolidation centers that are taken into consideration in the paper are based on the same characteristics of traffic flows. The scenarios differ in terms of the accessibility of the four consolidation centers given by the infrastructure, the connections between them, and the possibility of consolidating traffic flows for one or multiple destinations. Also, synthetical indicators will allow us to compare the scenarios considered and chose the indicated for our distribution system.

Keywords: distribution system, single and multiple destinations, urban consolidation centers, traffic flow consolidation schemes

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Authors: M. Kowalski, M. Kastek, M. Szustakowski

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Multispectral screening systems are becoming more popular because of their very interesting properties and applications. One of the most significant applications of multispectral screening systems is prevention of terrorist attacks. There are many kinds of threats and many methods of detection. Visual detection of objects hidden under clothing of a person is one of the most challenging problems of threats detection. There are various solutions of the problem; however, the most effective utilize multispectral surveillance imagers. The development of imaging devices and exploration of new spectral bands is a chance to introduce new equipment for assuring public safety. We investigate the possibility of long lasting detection of potentially dangerous objects covered with various types of clothing. In the article we present the results of comparative studies of passive imaging in three spectrums – visible, infrared and terahertz

Keywords: terahertz, infrared, object detection, screening camera, image processing

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Authors: Mary Butler

Abstract:

Background: Screening programmes for older drivers in Europe (though not the UK), and in many states in the US and in Australia are based on medical assessment of fitness to drive. These programmes require physicians (including general practitioners) to carry out an assessment of fitness to drive in their offices. In 2006, New Zealand changed from doing on-road driving tests with all older drivers from the age of 80, to a screening programme that uses medical assessment of fitness to drive only. Aim: This study set out to understand the experience of New Zealand GPs as they manage the process of medical assessment of fitness to drive assessments for older people. In particular, it aimed to establish how GPs understand the role of specialist driving assessment and rehabilitation carried out by occupational therapists. Design and setting: The study used an interpretive descriptive approach to analyze data from ten interviews with GPs in New Zealand. Results: The results indicated that GPs lack understanding about how occupational therapists can assist their patients, and tend to refer only when there is a disagreement with the patient. Conclusion: There are problems with the medical assessment of fitness to drive carried out by GPs, and there is a need for a more comprehensive community approach to driving cessation. Patients, families and the multidisciplinary team all have a role in deciding when driving cessation should occur. Occupational therapists have a particular responsibility for strategic leadership in this area of practice.

Keywords: assessment, driving, older people, occupational therapy

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Authors: Sarwar Beg, Gajanand Sharma, O. P. Katare, Bhupinder Singh

Abstract:

The current studies entail development of self-nano emulsifying drug delivery systems (SNEDDS) of rosuvastatin, employing rational QbD-based approach for enhancing its oral bioavailability. SNEDDS were prepared using the blend of lipidic and emulsifying excipients, i.e., Peceol, Tween 80, and Transcutol HP. The prepared formulations evaluated for in vitro drug release, ex vivo permeation, in situ perfusion studies and in vivo pharmacokinetic studies in rats, which demonstrated 3-4 fold improvement in biopharmaceutical performance of the developed formulations. Cytotoxicity studies using MTT assay and histopathological studies in intestinal cells revealed the lack of cytotoxicity and thereby safety and efficacy of the developed formulations.

Keywords: SNEDDS, bioavailability, solubility, Quality by Design (QbD)

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Authors: G. Obregon-Pulido , G. C. Solis-Perales, J. A. Meda-Campaña

Abstract:

In this paper, we present a sliding mode controller in discrete time. The design of the controller is based on the theory of regulation for nonlinear systems. In the problem of disturbance rejection and/or output tracking, it is known that in discrete time, a controller that uses the zero-order holder only guarantees tracking at the sampling instances but not between instances. It is shown that using the so-called exponential holder, it is possible to guarantee asymptotic zero output tracking error, also between the sampling instant. For stabilizing the problem of close loop system we introduce the sliding mode approach relaxing the requirements of the existence of a linear stabilizing control law.

Keywords: regulation theory, sliding modes, discrete controller, ripple-free tracking

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Authors: Dilara Usta, Fatos Korkmaz

Abstract:

Background: Individuals who utilise health services maintain relationships with health professionals, insurers and institutions. The nature of these relationships requires service receivers to have trust in the service providers because maintaining health services without reciprocal trust is very difficult. Therefore, individual evaluations of trust within the scope of health services have become increasingly important. Objective: To investigate patients’ trust in the health-care system and their relevant socio-demographical characteristics. Methods: This research was conducted using a descriptive design which included 493 literate patients aged 18-65 years who were hospitalised for a minimum of two days at public university and training&research hospitals in Ankara, Turkey. Patients’ trust in health-care professionals, insurers, and institutions were investigated. Data were collected using a demographic questionnaire and the Multidimensional Trust in Health-Care Systems Scale between September 2015 and April 2016. Results: The participants’ mean age was 47.7±13.1; 70% had a moderate income and 69% had a prior hospitalisation and 63.5% of the patients were satisfied with the health-care services. The mean Multidimensional Trust in Health-Care Systems Scale score for the sample was 61.5±8.3; the provider subscale had a mean of 38.1±5, the insurers subscale had a mean of 12.9±3.7, and institutions subscale had a mean of 10.6±1.9. Conclusion: Patients’ level of trust in the health-care system was above average and the trust level of the patients with higher educational and socio-economic levels was lower compared to the other patients. Health-care professionals should raise awareness about the significance of trust in the health-care system.

Keywords: delivery of health care, health care system, nursing, patients, trust

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Authors: Emre Kara, Ahmet Fatih Geylan, Kadir Koç, Şura Karakuzu, Metehan Demir, Halil Aykul

Abstract:

The structures obtained with the use of sandwich technologies combine low weight with high energy absorbing capacity and load carrying capacity. Hence, there is a growing and markedly interest in the use of sandwiches with aluminium foam core because of very good properties such as flexural rigidity and energy absorption capability. The static (bending and penetration) and dynamic (dynamic bending and low velocity impact) tests were already performed on the aluminum foam cored sandwiches with different types of outer skins by some of the authors. In the current investigation, the static three-point bending tests were carried out on the sandwiches with aluminum foam core and glass fiber reinforced polymer (GFRP) skins at different values of support span distances (L= 55, 70, 80, 125 mm) aiming the analyses of their flexural performance. The influence of the core thickness and the GFRP skin type was reported in terms of peak load, energy absorption capacity and energy efficiency. For this purpose, the skins with two different types of fabrics ([0°/90°] cross ply E-Glass Woven and [0°/90°] cross ply S-Glass Woven which have same thickness value of 1.5 mm) and the aluminum foam core with two different thicknesses (h=10 and 15 mm) were bonded with a commercial polyurethane based flexible adhesive in order to combine the composite sandwich panels. The GFRP skins fabricated via Vacuum Assisted Resin Transfer Molding (VARTM) technique used in the study can be easily bonded to the aluminum foam core and it is possible to configure the base materials (skin, adhesive and core), fiber angle orientation and number of layers for a specific application. The main results of the bending tests are: force-displacement curves, peak force values, absorbed energy, energy efficiency, collapse mechanisms and the effect of the support span length and core thickness. The results of the experimental study showed that the sandwich with the skins made of S-Glass Woven fabrics and with the thicker foam core presented higher mechanical values such as load carrying and energy absorption capacities. The increment of the support span distance generated the decrease of the mechanical values for each type of panels, as expected, because of the inverse proportion between the force and span length. The most common failure types of the sandwiches are debonding of the upper or lower skin and the core shear. The obtained results have particular importance for applications that require lightweight structures with a high capacity of energy dissipation, such as the transport industry (automotive, aerospace, shipbuilding and marine industry), where the problems of collision and crash have increased in the last years.

Keywords: aluminum foam, composite panel, flexure, transport application

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Authors: Roya Moradifar, Bijan Honarvar, Masoumeh Zabihi

Abstract:

The personal residential camps of South Pars gas complex are one of the few places where electric energy is used for the bath water heating. The widespread use of these devices is mainly responsible for the high peak of the electricity demand in the residential sector. In an attempt to deal with this issue, to reduce the electricity usage of the hot water, as an option, solar hot water systems have been proposed. However, despite the high incidence of solar radiation on the Assaloyeh about 20 MJ/m²/day, currently, there is no technical assessment quantifying the economic benefits on the region. The present study estimates the economic impacts resulting by the deployment of solar hot water systems in residential camp. Hence, the feasibility study allows assessing the potential of solar water heating as an alternative to reduce the peak on the electricity demand. In order to examine the potential of using solar energy in Bidkhoon residential camp two solar water heater packages as pilots were installed for restaurant and building. Restaurant package was damaged due to maintenance problems, but for the building package, we achieved the result of the solar fraction total 83percent and max energy saving 2895 kWh, the maximum reduction in CO₂ emissions calculated as 1634.5 kg. The results of this study can be used as a support tool to spread the use solar water heaters and create policies for South Pars Gas Complex.

Keywords: electrical energy, hot water, solar, South Pars Gas complex

Procedia PDF Downloads 205