International Science Index

International Journal of Electronics and Communication Engineering

Dynamics of Mach Zehnder Modulator in Open and Closed Loop Bias Condition
Numerous efforts have been done in the past decade to develop the methods of secure communication that are free from interception and eavesdropping. In fiber optic communication, chaotic optical carrier signals are used for data encryption in secure data transmission. Mach-Zehnder Modulators (MZM) are the key components for generating the chaotic signals to be used as optical carriers. This paper presents the dynamics of a lithium niobate MZM modulator under various biasing conditions. The chaotic fluctuations of the intensity of a laser diode have been generated using the electro-optic MZM modulator operating in a highly nonlinear regime. The modulator is driven in closed loop by its own output at an earlier time. When used as an electro-optic oscillator employing delayed feedback, the MZM displays a wide range of output waveforms of varying complexity. The dynamical behavior of the system ranges from periodic to nonlinear oscillations. The nonlinearity displayed by the system is reproducible and is easily controllable. In this paper, we demonstrate a wide variety of optical signals generated by MZM using easily controllable device parameters in both open and close loop bias conditions.
Analysis of Fixed Beamforming Algorithms for Smart Antenna Systems
The smart antenna is the prominent technology that has become known in recent years to meet the growing demands of wireless communications. In an overcrowded atmosphere, its application is growing gradually. A methodical evaluation of the performance of Fixed Beamforming algorithms for smart antennas such as Multiple sidelobe canceller (MSC), Maximum Signal-to-interference ratio (MSIR) and minimum variance (MVDR) has been comprehensively presented in this paper. Simulation results show that beamforming is helpful in providing optimized response towards desired directions. MVDR beamformer provides the most optimal solution.
A Motion Dictionary to Real-Time Recognition of Sign Language Alphabet Using Dynamic Time Warping and Artificial Neural Network
Computacional recognition of sign languages aims to allow a greater social and digital inclusion of deaf people through interpretation of their language by computer. This article presents a model of recognition of two of global parameters from sign languages; hand configurations and hand movements. Hand motion is captured through an infrared technology and its joints are built into a virtual three-dimensional space. A Multilayer Perceptron Neural Network (MLP) was used to classify hand configurations and Dynamic Time Warping (DWT) recognizes hand motion. Beyond of the method of sign recognition, we provide a dataset of hand configurations and motion capture built with help of fluent professionals in sign languages. Despite this technology can be used to translate any sign from any signs dictionary, Brazilian Sign Language (Libras) was used as case study. Finally, the model presented in this paper achieved a recognition rate of 80.4%.
The Design of Broadband 8x2 Phased Array 5G Antenna MIMO 28 GHz for Base Station
This paper proposed a new design of 16 elements, 8x2 linear fed patch antenna array with 16 ports, for 28 GHz, mm-wave band 5G for base station. The phased array covers along the azimuth plane to provide the coverage to the users in omnidirectional. The proposed antenna is designed RT Duroid 5880 substrate with the overall size of 85x35.6x0.787 mm³. The array is operating from 27.43 GHz to 28.34 GHz with a 910 MHz impedance bandwidth. The gain of the array is 18.3 dB while the suppression of the side lobes is -1.0 dB. The main lobe direction of the array is 15 deg. The array shows a high array gain throughout the impedance bandwidth with overall of VSWR is below 1.12. The design will be proposed in single element and 16 elements antenna.
Specific Absorption Rate Reduction of a Biomedical Implantable Printed Monopole Antenna Using Ferrite Sheet
Specific Absorption Rate (SAR) is one of the most important aspects of biomedical implantable antenna radiation. It provides the measure of the rate at which energy is absorbed by the human body when exposed to a radio frequency (RF) electromagnetic field. Despite of having the hazards of damaging human tissues due to power absorption and heating, the implantable antennas are of utmost necessity for recent bio-telemetry applications. Hence, the challenge is to reduce the SAR without affecting the normal antenna parameters and keep it inside a IEEEC95.1-1999 specified value (1.6 W/Kg for 1 g tissue model). In pursuit of that, ferrite sheet has been used to reduce the SAR value of a compact, Co-Planar Waveguide (CPW)-fed printed monopole implantable antenna, in this paper. SAR of an implantable antenna depends on the electric field in near field. For an antenna, the near-field component of an electric field can be mathematically established by the divergence equation of magnetic vector potential. So, the slope discontinuities of the magnetic vector potential (A) can cause an increase in SAR value. Consequently, it can be stated that the uniformity of the current distribution leads to lowering the SAR value. Generally, Ferrimagnetic materials can be used to reduce the discontinuities in current distribution for an antenna. The most important group of ferrimagnetic materials are the ferrites. In ferrites, the conductivity is low which results in much smaller induced currents in the material when electromagnetic waves are applied. The ferrite sheet suppressed the current density on that part attached, which resulted in reducing the corresponding surface SAR. With the aid of knowledge about the SAR reduction mechanism described above, a ferrite sheet has been designed to obtain the maximum reduction in SAR value. SAR reduction using ferrite sheet has been achieved previously in non-implantable antennas. In this paper, we are proposing this SAR reduction technique for an antenna implanted inside the human body. We have attached a ferrite sheet above the proposed monopole Implantable antenna. We have used polymeric ferrite sheet (Ԑr = 220). Ferrite sheet suppresses the surface current density which resulted in reducing surface SAR. The antenna prototype with ferrite sheet placed over the superstrate is simulated inside a single layer human skin model (Ԑr = 42.92, σ = 1.562 S/m at 2.4 GHz). The measurement has been performed and validates with the simulated results. The impedance bandwidth of the proposed antenna with ferrite sheet is 30% (1.9 – 2.7GHz). The maximum simulated SAR value without ferrite sheet is at 2.45 GHz is 31.5 W/Kg, and maximum SAR value with ferrite sheet is 18.5W/Kg. About 42% SAR reduction has been obtained in this proposed design by using ferrite sheet.
Application of the Micropolar Beam Theory for the Construction of the Discrete-Continual Model of Carbon Nanotubes
Together with the study of electron-optical properties of nanostructures and proceeding from experiment-based data, the study of the mechanical properties of nanostructures has become quite actual. For the study of the mechanical properties of fullerene, carbon nanotubes, graphene and other nanostructures one of the crucial issues is the construction of their adequate mathematical models. Among all mathematical models of graphene or carbon nano-tubes, this so-called discrete-continuous model is specifically important. It substitutes the interactions between atoms by elastic beams or springs. The present paper demonstrates the construction of the discrete-continual beam model for carbon nanotubes or graphene, where the micropolar beam model based on the theory of moment elasticity is accepted. With the account of the energy balance principle, the elastic moment constants for the beam model, expressed by the physical and geometrical parameters of carbon nanotube or graphene, are determined. By switching from discrete-continual beam model to the continual, the models of micropolar elastic cylindrical shell and micropolar elastic plate are confirmed as continual models for carbon nanotube and graphene respectively.
Automatic Vehicle Detection Using Circular Synthetic Aperture Radar Image
Automatic vehicle detection using synthetic aperture radar (SAR) image has been widely researched, as well as using optical remote sensing images. However, most researches treat the detection as an independent problem, failing to make full use of SAR data information. In circular SAR (CSAR), the two long borders of vehicle will shrink if the imaging surface is set higher than the reference one. Based on above variance, an automatic vehicle detection using CSAR image is proposed to enhance detection ability under complex environment, such as vehicles’ closely packing, which confuses the detector. The detection method uses the multiple images generated by different height plane to obtain an energy-concentrated image for detecting and then uses the maximally stable extremal regions method (MSER) to detect vehicles. A result of vehicles’ detection is given to verify the effectiveness and correctness of proposed method.
Acoustics Barrier Design to Reduce Railway Noise by Using Maekawa's Method
Railway noise generated by pass-by train has been described as a form of environmental pollutants especially for the residential area near the railway. Many studies have shown, that environmental noise particularly transportation noise has negative effects on people which resulting in annoyance and specific health problems such as cardiovascular disease, cognitive impairment and sleep disturbance. Therefore, various attempts are made to reduce the noise. One method of reducing such noise to acceptable noise levels is to build acoustically barrier walls. The objective of this study was to review the method of reducing railway noise and obtain the preliminary design of the acoustics barrier on the edge of railway tracks close to the residential area. The design of this barrier is using the Maekawa's method. Measurements have been performed in residential areas around the railroads in the Karawang - Indonesia with the absence of an acoustical barrier. From the observation, it was found that the railway was passed by five trains within thirty minutes. With the limited distance between the railway tracks and the location of the residential area as well as the street of residents, then it was obtained that a reduction in sound pressure level is 25 dBA. Maximum sound pressure level obtained is 86.9 dBA then by setting the barrier as high as 4 m at a distance, 2.5 m from the railway, the noise level received by residents in the settlement around the railway line becomes 61.9 dBA.
Interpreting the Conflicted Self: A Reading of Agha Shahid Ali' Verses
The aim of this study is to bring forth the interpretation that Agha Shahid Ali in his verses exhibits. The study will focus on the conflict and chaos in his verses reflecting the sense of identity attached to Kashmir. His verse advertently depicts the political turmoil and social dissent in the ‘un-silent’ valley, and ultimately it expresses the chaos, anguish, and suffering, a sense of longing and belonging to this conflicted state of ‘being’ as well as ‘mind.’ Agha Shahid Ali, Kashmiri- American poet who writes of Kashmiri tragedies that continue to remain unarticulated and unheard to the major parts of the world, articulates the narrative that showcases the conflicted self of Kashmiris in general and Ali’s in particular. The focus of the paper will be his poetry that debunks the claims of civility and how Kashmiri identity is kept either maligned or obscured in the major narratives that arise from the mainstream writers. However, Ali’s verses are substantially broad and clear and very brilliantly, he rewrites Kashmir in his avid and novel voice; his verses embracing the Kashmiri self, effectively anew in English language. The paper will clearly indicate how Ali remains true to his name, ‘shaheed’ and ‘shahid,’ both a martyr and witness. Ali’s fate has been intricately entangled with Kashmir, even after his untimely death. He has fully and beautifully immersed himself in the surreal world of the conflict prevalent in the Valley, and this paper will examine the grotesque and gory history that has been spanning over the years in Kashmir with never-ending cycle of conflict. The originality and innovation of his poetry surfaces from the anarchy of Kashmir, spanning between its culture, historical context, the art of memory and imagery.
Induction Heating and Electromagnetic Stirring of Bi-Phasic Metal/Glass Molten Bath for Mixed Nuclear Waste Treatment
For nuclear waste treatment and confinement, a specific IN-CAN melting module based on low-frequency induction heating have been designed. The frequency of 50Hz has been chosen to improve penetration length through metal. In this design, the liquid metal, strongly stirred by electromagnetic effects, presents shape of a dome caused by strong Laplace forces developing in the bulk of bath. Because of a lower density, the glass phase is located above the metal phase and is heated and stirred by metal through interface. Electric parameters (Intensity, frequency) give precious information about metal load and composition (resistivity of alloy) through impedance modification. Then, power supply can be adapted to energy transfer efficiency for suitable process supervision. Modeling of this system allows prediction of metal dome shape (in agreement with experimental measurement with a specific device), glass and metal velocity, heat and motion transfer through interface. MHD modeling is achieved with COMSOL and Fluent. First, a simplified model is used to obtain the shape of the metal dome. Then the shape is fixed to calculate the fluid flow and the thermal part.
Extended and Unscented Kalman Filters in a Cells-Covering Method for Environment Reconstruction
We compare the effectiveness of two widely used filters for nonlinear systems, i.e., the Extended Kalman Filter (EKF) and the Unscented Kalman Filter (UKF), in reconstructing the unknown environment where a mobile robot moves. The reconstruction is obtained by a novel cells-covering algorithm that only uses distance measurements taken from robot's on-board sonar sensors. We show that, despite the superior theoretical properties of the UKF, both filters perform comparably well, providing good localization performance and ensuring a reliable environment reconstruction.
Rendering of Indian History: A Study Based on Select Graphic Novels
In the postmodern society, visual narratives became an emerging genre in the field of literature. Graphic literature focuses on the literal and symbolic layer of interpretation. The most salient feature of graphic literature is its exploration of the public history of events and life narratives. The Indian graphic literature re-interprets the canon, style and the form of texts in Indian Writing in English and it demands a new literacy and the structure of the English literature. With the help of visual-verbal language, the graphic narratives discuss various facets of contemporary India. Graphic novels have firmly identified itself with the art of storytelling because of its capability of expressing human experiences to the most. In the textual novels, the author usually deserts the imagination of the readers, but in the case of graphic narratives, due to the presence of visual elements, the interpretation becomes simpler. India is the second most populous country in the world with a long tradition of history and culture. Indian literature always tries to reconstruct Indian history in various modes of representation. The present paper focuses on the fictional articulation of Indian history through the graphic narratives and analyses how some historical events in India portrays. The paper also traces the differences in rendering the history in graphic novels with that of textual novels. The paper discusses how much the blending of words and images helps in represent the Indian history by analyzing the graphic novels like Kashmir Pending by Naseer Ahmed, Delhi Calm by Vishwajyoti Ghosh and Munnu by Malik Sajad.
Elaboration of Composites with Thermoplastic Matrix Polypropylene Charged by the Polyaniline Synthesized by the Self-Curling Method
This work is dedicated to the elaboration of composites (PP/PANI) with Polypropylene (PP) as thermoplastic polymer and the polyaniline (PANI) as electric charge doped with sulfanilic acid (PANI-As). These realized formulations are intended for the antistatic domain. The used conductive polymer is synthesized by the method self-curling which proved the obtaining of the nanoparticles of PANI in regular morphological forms. The PANI and PP composites are fabricated into a film by a twin-screw extruding. Several methods of characterization are proposed: spectroscopic, thermal, and electric. The realized composites proved a pseudo-homogeneous aspect and the threshold percolation study, showed that the formulation with 7% of PANI presents a better formulation which can be used in the antistatic domain.
Crossover Memories and Code-Switching in the Narratives of Arabic-Hebrew and Hebrew-English Bilingual Adults in Israel
This study examines two bilingual phenomena in the narratives of Arabic Hebrew and Hebrew-English bilingual adults in Israel: Crossover memories and code-switching (CS). The study examined these phenomena in the context of autobiographical memory, using a cue word technique. Student experimenters held two sessions in the homes of the participants. In separate language sessions, the participant was asked to look first at each of 16 cue words and then to state a concrete memory. After stating the memory, participants reported whether their memories were in the same language of the experiment session or different. Memories were classified as ‘Crossovers’ (CO) or ‘Same Language’ (SL) according to participants' self-reports. Participants were also required to elaborate about the setting, interlocutors and other languages involved in the specific memory. Beyond replicating the procedure of cuing technique, one memory from a specific lifespan period was chosen per participant, and the participant was required to provide further details about it. For the more detailed memories, code-switching (CS) count was conducted. Both bilingual groups confirmed the Reminiscence Bump phenomenon, retrieving more memories in the 10-30 age period. Crossover memories prevailed in second language sessions (L2). Same Language memories were more abundant in first language sessions (L1). Higher code-switching frequency was found in L2 sessions. Finally, as predicted, 'individual' code-switching was prevalent in L2 sessions, but 'community-based' code-switching was not higher in L1 sessions. The two bilingual measures in this study, crossovers, and code-switching came from different research traditions, the former from an experimental paradigm in the psychology of autobiographical memory based on self-reported judgments, the latter a behavioral measure from linguistics. This merger of approaches offers new insight into the field of bilingual autobiographical memory. In addition, the study attempted to shed light on the investigation of motivations for code-switching, beginning with Walters’ SPPL Model and concluding with a distinction between ‘community-based’ and individual motivations.
On ‘Freaks’ and the Feminine in Margaret Atwood’s ‘Lusus Naturae’
This paper considers one of Margaret Atwood’s short stories ‘Lusus Naturae'. Through a critical lens that makes use of Julia Kristeva’s work on Powers of Horror and abjection, this paper suggests that the monstrous girl is the disabled woman, the abject in society. The monster is used as a metaphor for the unknown, the misunderstood, and the ‘different’ woman. Culturally Relevant Teaching (CRT) is a pedagogy that calls for making course material accessible and relevant to students. Through the study of literary texts, we are able to help create agency inside and outside the classroom. Stories are a necessary part of establishing connections across borders and boundaries. Stories are meant to raise awareness both inside and outside the classroom. The discussion is equally important, and the text is meant to facilitate relevant questions that the students need to consider when it comes to identity. Questions to consider are: what does it mean to be a ‘girl’ today, and what implications and consequences are at hand when you fail to perform this gendered identity? Gender is sometimes a fatal bond in the Middle East, and even more so, is the disability. In the case of our unnamed protagonist, she undergoes a process of un-becoming, a non-linear process of growing up. In a sense, it is a counter-Bildungsroman. The reading of this text emphasizes that a non-linear narrative is sometimes necessary for the female protagonist’s self-awareness and development. Discussion in class facilitates this sense of agency and questioning of gender and disability.
Highly Sensitive and Selective H2 Gas Sensor Based on Pd-Pt Decorated Nanostructured Silicon Carbide Thin Films for Extreme Environment Application
Present work describes the fabrication and sensing characteristics of the Pd-Pt decorated nanostructured silicon carbide (SiC) thin films on anodized porous silicon (PSi) substrate by RF magnetron sputtering. The gas sensing performance of Pd-Pt/SiC/PSi sensing electrode towards H2 gas under low (10–400 ppm) detection limit and high operating temperature regime (25–600 °C) were studied in detail. The chemiresistive sensor exhibited high selectivity, good sensing response, fast response/recovery time with excellent stability towards H2 at high temperature. The selectivity measurement of the sensing electrode was done towards different oxidizing and reducing gases and proposed sensing mechanism discussed in detail. Therefore, the investigated Pd-Pt/SiC/PSi structure may be a highly sensitive and selective hydrogen gas sensing electrode for deployment in extreme environment applications.
A Facile and Room Temperature Growth of Pd-Pt Decorated Hexagonal-ZnO Framework and Their Selective H₂ Gas Sensing Properties
The attractive and multifunctional properties of ZnO make it a promising material for the fabrication of highly sensitive and selective efficient gas sensors at room temperature. This presented article focuses on the development of highly selective and sensitive H₂ gas sensor based on the Pd-Pt decorated ZnO framework and its sensing mechanisms. The gas sensing performance of sputter made Pd-Pt/ZnO electrode on anodized porous silicon (PSi) substrate toward H₂ gas is studied under low detection limit (2–500 ppm) of H₂ in the air. The chemiresistive sensor demonstrated sublimate selectivity, good sensing response, and fast response/recovery time with excellent stability towards H₂ at low temperature operation under ambient environment. The elaborate selective measurement of Pd-Pt/ZnO/PSi structure was performed towards different oxidizing and reducing gases. This structure exhibited advance and reversible response to H₂ gas, which revealed that the acquired architecture with ZnO framework is a promising candidate for H₂ gas sensor.
A Fast Chemiresistive H₂ Gas Sensor Based on Sputter Grown Nanocrystalline P-TiO₂ Thin Film Decorated with Catalytic Pd-Pt Layer on P-Si Substrate
In the present work, we have fabricated and studied a resistive H₂ gas sensor based on Pd-Pt decorated room temperature sputter grown nanocrystalline porous titanium dioxide (p-TiO₂) thin film on porous silicon (p-Si) substrate for fast H₂ detection. The gas sensing performance of Pd-Pt/p-TiO₂/p-Si sensing electrode towards H₂ gas under low (10-500 ppm) detection limit and operating temperature regime (25-200 °C) was discussed. The sensor is highly sensitive even at room temperature, with response (Ra/Rg) reaching ~102 for 500 ppm H₂ in dry air and its capability of sensing H₂ concentrations as low as ~10 ppm was demonstrated. At elevated temperature of 200 ℃, the response reached more than ~103 for 500 ppm H₂. Overall the fabricated resistive gas sensor exhibited high selectivity, good sensing response, and fast response/recovery time with good stability towards H₂.
Distributed Optical Fiber Vibration Sensing Using Phase Generated Carrier Demodulation Algorithm
Distributed fiber-optic vibration sensors are gaining extensive attention, for the advantages of high sensitivity, accurate location, light weight, large-scale monitoring, good concealment, and etc. In this paper, a novel optical fiber distributed vibration sensing system is proposed, which is based on self-interference of Rayleigh backscattering with phase generated carrier (PGC) demodulation algorithm. Pulsed lights are sent into the sensing fiber and the Rayleigh backscattering light from a certain position along the sensing fiber would interfere through an unbalanced Michelson Interferometry (MI) to generate the interference light. An improved PGC demodulation algorithm is carried out to recover the phase information of the interference signal, which carries the sensing information. Three vibration events were applied simultaneously to different positions over 2000m sensing fiber and demodulated correctly. Experiments show that the spatial resolution of is 10 m, and the noise level of the Φ-OTDR system is about 10-3 rad/√Hz, and the signal to noise ratio (SNR) is about 30.34dB. This vibration measurement scheme can be applied at surface, seabed or downhole for vibration measurements or distributed acoustic sensing (DAS).
Estimation of Mobility Parameters and Threshold Voltage of an Organic Thin Film Transistor Using an Asymmetric Capacitive Test Structure
Carrier mobility at the organic/insulator interface is essential to the performance of organic thin film transistors (OTFT). The present work describes estimation of field dependent mobility (FDM) parameters and the threshold voltage of an OTFT using a simple, easy to fabricate two terminal asymmetric capacitive test structure using admittance measurements. Conventionally, transfer characteristics are used to estimate the threshold voltage in an OTFT with field independent mobility (FIDM). Yet, this technique breaks down to give accurate results for devices with high contact resistance and having field dependent mobility. In this work, a new technique is presented for characterization of long channel organic capacitor (LCOC). The proposed technique helps in the accurate estimation of mobility enhancement factor (γ), the threshold voltage (V_th) and band mobility (µ₀) using capacitance-voltage (C-V) measurement in OTFT. This technique also helps to get rid of making short channel OTFT or metal-insulator-metal (MIM) structures for making C-V measurements. To understand the behavior of devices and ease of analysis, transmission line compact model is developed. The 2-D numerical simulation was carried out to illustrate the correctness of the model. Results show that proposed technique estimates device parameters accurately even in the presence of contact resistance and field dependent mobility. Pentacene/Poly (4-vinyl phenol) based top contact bottom-gate OTFT’s are fabricated to illustrate the operation and advantages of the proposed technique. Small signal of frequency varying from 1 kHz to 5 kHz and gate potential ranging from +40 V to -40 V have been applied to the devices for measurement.
Preparation and Characterization of Organic Silver Precursors for Conductive Ink
Low ink sintering temperature is desired for flexible electronics as it would widen the application of the ink on temperature-sensitive substrates, where the selection of silver precursor is very critical. In this paper, four types of organic silver precursors, silver carbonate, silver oxalate, silver tartrate and silver itaconate, were synthesized using an ion exchange method firstly. Various characterization methods were employed to investigate their physical phase, chemical composition, morphologies and thermal decomposition behavior. It was found that silver oxalate has the ideal thermal property and showed the lowest decomposition temperature. An ink was then formulated by complexing the as-prepared silver oxalate with ethylenediamine in organic solvents. The result shows that a favorable conductive film with uniform surface structure consisting of spherical silver nanoparticles and few voids could be produced from the ink at a sintering temperature of 150°C.
Fully Printed Strain Gauges: A Comparison of Aerosoljet-Printing and Micropipette-Dispensing
Strain sensors based on a change in resistance are well established for the measurement of forces, stresses, or material fatigue. Within the scope of this paper, fully additive manufactured strain sensors were produced using ink of silver nanoparticles. Their linearity and long-term stability were evaluated by periodic tensile tests. Printed strain sensors exhibit two advantages: Their measuring grid is adaptable to the use case and they do not need a carrier-foil as the measuring structure can be printed directly onto a thin sprayed varnish layer on the aluminium specimen. A full Wheatstone bridge was implemented for temperature compensation and the reduction of external components. In order to compare quality characteristics, the sensors have been manufactured using two different technologies, namely aerosoljet-printing and micropipette-dispensing. Both processes produce structures which exhibit continuous features (in contrast to what can be achieved with droplets during inkjet printing). The results clearly show that aerosoljet-printing is the preferred technology for the specimen with non-planar surfaces whereas both technologies are equally well suitable for the flat specimen.
Utilization of Cloud-Based Learning Platform for the Enhancement of IT Onboarding System
The study aims to define the efficiency of e-Trainings by the use of cloud platform as part of the onboarding process for IT support engineers. Traditional lecture based trainings involves human resource to guide and assist new hires as part of onboarding which takes time and effort. The use of electronic medium as a platform for training provides a two-way basic communication that can be done in a repetitive manner. The study focuses on determining the most efficient manner of learning the basic knowledge on IT support in the shortest time possible. This was determined by conducting the same set of knowledge transfer categories in two different approaches, one being the e-Training and the other using the traditional method. Performance assessment will be done by the use of Service Tracker Assessment (STA) Tool and Service Manager. Data gathered from this ongoing study will promote the utilization of e-Trainings in the IT onboarding process.
Faculty Members' Acceptance of Mobile Learning in Kingdom of Saudi Arabia: Case Study of a Saudi University
It is difficult to find an aspect of our modern lives that has been untouched by mobile technology. Indeed, the use of mobile learning in Saudi Arabia may enhance students’ learning and increase overall educational standards. However, within tertiary education, the success of e-learning implementation depends on the degree to which students and educators accept mobile learning and are willing to utilise it. Therefore, this research targeted the factors that influence Hail University instructors’ intentions to use mobile learning. An online survey was completed by eighty instructors and it was found that their use of mobile learning was heavily predicted by performance experience, effort expectancy, social influence, and facilitating conditions; the multiple regression analysis revealed that 67% of the variation was accounted for by these variables. From these variables, effort expectancy was shown to be the strongest predictor of intention to use e-learning for instructors.
Applicability of Fuzzy Logic for Intrusion Detection in Mobile Adhoc Networks
Mobile Adhoc Networks (MANETs) are gaining popularity due to their potential of providing low-cost mobile connectivity solutions to real-world communication problems. Integrating Intrusion Detection Systems (IDS) in MANETs is a tedious task by reason of its distinctive features such as dynamic topology, de-centralized authority and highly controlled/limited resource environment. IDS primarily use automated soft-computing techniques to monitor the inflow/outflow of traffic packets in a given network to detect intrusion. Use of machine learning techniques in IDS enables system to make decisions on intrusion while continuous keep learning about their dynamic environment. An appropriate IDS model is essential to be selected to expedite this application challenges. Thus, this paper focused on fuzzy-logic based machine learning IDS technique for MANETs and presented their applicability for achieving effectiveness in identifying the intrusions. Further, the selection of appropriate protocol attributes and fuzzy rules generation plays significant role for accuracy of the fuzzy-logic based IDS, have been discussed. This paper also presents the critical attributes of MANET’s routing protocol and its applicability in fuzzy logic based IDS.
Low-Profile Meander-Line Yagi-Uda Antenna with High Directive Gain and Printed Configuration for 915MHz ISM Band Applications
Recently, wireless systems operating in the 915 MHz industrial, science, and medical (ISM) band applications, such as LoRA, Sigfox, LTE-M, and UHF RFID, are expanding due to the development of Internet of Thing (IoT) and wireless sensor technologies. This paper presents a low-profile meander-line Yagi-Uda antenna with high directive gain and printed antenna configuration for 915 MHz ISM band applications. The proposed antenna, which adapted the meander line for the antenna miniaturization, consists of a driven antenna element with a microstrip balun, a director, and a reflector. For the advantages of low cost and low profile, the antenna is fabricated on 1.2 mm FR-4 substrate with a size of approximately 0.24λ₀ × 0.37λ₀ × 0.0037λ₀ at 915 MHz, and test to experimentally validate the proposed design. The impedance bandwidth and peak gain of the proposed antenna achieve approximately 4% and 5 dBi at the operating frequency (902-928 MHz), respectively. Therefore, the performance of the proposed antenna is attractive for wireless sensor of IoTs and wireless energy harvesting applications.
Quantitative Phase Imaging System Based on a Three-Lens Common-Path Interferometer
White-light quantitative phase imaging is an effective technique for achieving sub-nanometer phase sensitivity. Highly stable interferometers based on common-path geometry have been developed in recent years to solve this task. Some of these methods also apply multispectral approach. The purpose of this research is to suggest a simple and effective interferometer for such systems. We developed a three-lens common-path interferometer, which can be used for quantitative phase imaging with or without multispectral modality. The lens system consists of two components, the first one of which is a compound lens, consisting of two lenses. A pinhole is placed between the components. The lens-in-lens approach enables effective light transmission and high stability of the interferometer. The multispectrality is easily implemented by placing a tunable filter in front of the interferometer. In our work, we used an acousto-optical tunable filter. Some design considerations are discussed and multispectral quantitative phase retrieval is demonstrated.
A Parallel-Processing Framework for Adaptive Filtering of Large-Scale Data
This paper proposes a parallel-processing framework for adaptive filtering of large-scale data. In this framework, largescale data is divided into several sub-blocks to reduce the computational cost. Based on each data sub-block, a normalized least-mean-square algorithm estimates the parameters of interest at each sub-filter. Furthermore, the mean-square deviation analysis of the estimation result at each sub-filter leads to a variable step-size method and an intermittent-update method. These methods provide not only fast convergence rate and small steady-state error but also high computational efficiency. Finally, the estimation results of each sub-filter are combined through a combination method by determining the weights for each estimation result based on their error variance. The proposed combination method provides robustness to abnormalities of the data. Simulation results show that the proposed framework performs well for estimation with large-scale data.
A Method for Time Synchronization between the eNodeBs in Evolved Universal Terrestrial Radio Access Network under the Asymmetric Network
In this paper, we present a method for time synchronization between the two eNodeBs (eNBs) in E-UTRAN (Evolved Universal Terrestrial Radio Access) network. The two eNBs are cooperating in so-called inter eNB CA (Carrier Aggregation) case and connected via asymmetrical IP network. We solve the problem by using broadcasting signals generated in E-UTRAN as synchronization signals. The results show that the time synchronization with the proposed method is possible with the error significantly less than 1 ms which is sufficient considering the time transmission interval is 1 ms in E-UTRAN. This makes this method (with low complexity) more suitable than Network Time Protocol (NTP) in the mobile applications with generated broadcasting signals where time synchronization in asymmetrical network is required.
Simulation and Experimentation Investigation of Infrared Non-Destructive Testing on Thermal Insulation Material
The heat-resistant material has important application in the aerospace field. The reliability of the connection between the heat-resisting material and the body determines the success or failure of the project. In this paper, lock-in infrared thermography non-destructive testing technology is used to detect the stability of the thermal-resistant structure. The phase relationship between the temperature and the heat flow is calculated by the numerical method, and the influence of the heating frequency and power is obtained. The correctness of the analysis is verified by the experimental method. Through the research, it can provide the basis for the parameter setting of heat flux including frequency and power, improve the efficiency of detection and the reliability of connection between the heat-resisting material and the body.