Search results for: continuously variable transmission
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 4756

Search results for: continuously variable transmission

4456 Prey-Predator Eco-Epidemiological Model with Nonlinear Transmission Disease

Authors: Qamar J. A. Khan, Fatma Ahmed Al Kharousi

Abstract:

A prey-predator eco-epidemiological model is studied where transmission of the disease between infected and uninfected prey is nonlinear. The interaction of the predator with infected and uninfected prey species depend on their numerical superiority. Harvesting of both uninfected and infected prey is considered. Stability analysis is carried out for equilibrium values. Using the parameter µ, the death rate of infected prey as a bifurcation parameter it is shown that Hopf bifurcation could occur. The theoretical results are compared with numerical results for different set of parameters.

Keywords: bifurcation, optimal harvesting, predator, prey, stability

Procedia PDF Downloads 282
4455 Flexible Alternative Current Transmission System Impact on Grid Stability and Power Markets

Authors: Abdulrahman M. Alsuhaibani, Martin Maken

Abstract:

FACTS devices have great influence on the grid stability and power markets price. Recently, there is intent to integrate a large scale of renewable energy sources to the power system which in turn push the power system to operate closer to the security limits. This paper discusses the power system stability and reliability improvement that could be achieved by using FACTS. There is a comparison between FACTS devices to evaluate their performance for different functions. A case study has also been made about its effect on reducing generation cost and minimizing transmission losses which have good impact on efficient and economic operation of electricity markets

Keywords: FACTS, grid stability, spot price, OPF

Procedia PDF Downloads 131
4454 Effect of the Aluminium Concentration on the Laser Wavelength of Random Trimer Barrier AlxGa1-xAs Superlattices

Authors: Samir Bentata, Fatima Bendahma

Abstract:

We have numerically investigated the effect of Aluminium concentration on the the laser wavelength of random trimer barrier AlxGa1-xAs superlattices (RTBSL). Such systems consist of two different structures randomly distributed along the growth direction, with the additional constraint that the barriers of one kind appear in triply. An explicit formula is given for evaluating the transmission coefficient of superlattices (SL's) with intentional correlated disorder. The method is based on Airy function formalism and the transfer-matrix technique. We discuss the impact of the Aluminium concentration associate to the structure profile on the laser wavelengths.

Keywords: superlattices, correlated disorder, transmission coefficient, laser wavelength

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4453 Estimating X-Ray Spectra for Digital Mammography by Using the Expectation Maximization Algorithm: A Monte Carlo Simulation Study

Authors: Chieh-Chun Chang, Cheng-Ting Shih, Yan-Lin Liu, Shu-Jun Chang, Jay Wu

Abstract:

With the widespread use of digital mammography (DM), radiation dose evaluation of breasts has become important. X-ray spectra are one of the key factors that influence the absorbed dose of glandular tissue. In this study, we estimated the X-ray spectrum of DM using the expectation maximization (EM) algorithm with the transmission measurement data. The interpolating polynomial model proposed by Boone was applied to generate the initial guess of the DM spectrum with the target/filter combination of Mo/Mo and the tube voltage of 26 kVp. The Monte Carlo N-particle code (MCNP5) was used to tally the transmission data through aluminum sheets of 0.2 to 3 mm. The X-ray spectrum was reconstructed by using the EM algorithm iteratively. The influence of the initial guess for EM reconstruction was evaluated. The percentage error of the average energy between the reference spectrum inputted for Monte Carlo simulation and the spectrum estimated by the EM algorithm was -0.14%. The normalized root mean square error (NRMSE) and the normalized root max square error (NRMaSE) between both spectra were 0.6% and 2.3%, respectively. We conclude that the EM algorithm with transmission measurement data is a convenient and useful tool for estimating x-ray spectra for DM in clinical practice.

Keywords: digital mammography, expectation maximization algorithm, X-Ray spectrum, X-Ray

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4452 Efficiently Silicon Metasurfaces at Visible Light

Authors: Juntao Li

Abstract:

The metasurfaces for beam deflecting with gradient silicon posts in the square lattices were fabricated on the thin film crystal silicon with quartz substrate. By using the crystals silicon with high refractive index and high transmission to control the phase over 2π coverage, we demonstrated the polarization independent beam deflecting at wavelength of 532nm with 45% transmission in experiment and 70% in simulation into the desired angle. This simulation efficiency is almost close to the TiO2 metasurfaces but has higher refractive index and lower aspect ratio to reduce fabrication complexity. The result can extend the application of silicon metalsurfaces from 700 nm to 500 nm hence open a new way to use metasurfaces efficiently in visible light regime.

Keywords: metasurfaces, crystal silicon, light deflection, visible light

Procedia PDF Downloads 261
4451 Study on the OTP Authentication Method and Security for User Mobility in the Cloud

Authors: Jong-Won Lee

Abstract:

Since Cloud environment has appeared as the most powerful keyword in the computing industry, the growth in VDI (Virtual Desktop Infrastructure) became remarkable in domestic market. In recent years, with the trend that mobile devices such as smartphones and pads spread so rapidly, the strengths of VDI that allows people to access and perform business on the move along with companies' office needs expedite more rapid spread of VDI. However, although this enhanced accessibility and mobility can bring the enhanced productivity, it sometimes conflicts with the security, so there should be more detailed security solution, which is user authentication. In this paper, mobile OTP (One-Time Password) authentication method is proposed to secure mobile device portability through rapid and secure authentication using mobile devices such as mobile phones or pads, which does not require additional purchase or possession of OTP tokens of users. However, in order to use the service continuously and reliably in the cloud environment, both service provider and user have to prepare for security awareness and security threats, and continuously study the conflicting aspect between the improving user convenience and the security and supplement so that cloud service can provide opportunities to develop as a new growth industry in the future and create a new market in IT industry.

Keywords: cloud, OTP, mobility, security, authentication

Procedia PDF Downloads 334
4450 Contemplating Charge Transport by Modeling of DNA Nucleobases Based Nano Structures

Authors: Rajan Vohra, Ravinder Singh Sawhney, Kunwar Partap Singh

Abstract:

Electrical charge transport through two basic strands thymine and adenine of DNA have been investigated and analyzed using the jellium model approach. The FFT-2D computations have been performed for semi-empirical Extended Huckel Theory using atomistic tool kit to contemplate the charge transport metrics like current and conductance. The envisaged data is further evaluated in terms of transmission spectrum, HOMO-LUMO Gap and number of electrons. We have scrutinized the behavior of the devices in the range of -2V to 2V for a step size of 0.2V. We observe that both thymine and adenine can act as molecular devices when sandwiched between two gold probes. A prominent observation is a drop in HLGs of adenine and thymine when working as a device as compared to their intrinsic values and this is comparative more visible in case of adenine. The current in the thymine based device exhibit linear increase with voltage in spite of having low conductance. Further, the broader transmission peaks represent the strong coupling of electrodes to the scattering molecule (thymine). Moreover, the observed current in case of thymine is almost 3-4 times than that of observed for adenine. The NDR effect has been perceived in case of adenine based device for higher bias voltages and can be utilized in various future electronics applications.

Keywords: adenine, DNA, extended Huckel, thymine, transmission spectra

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4449 Wireless Integrated Switched Oscillator Impulse Generator with Application in Wireless Passive Electric Field Sensors

Authors: S. Mohammadzamani, B. Kordi

Abstract:

Wireless electric field sensors are in high demand in the number of applications that requires measuring electric field such as investigations of high power systems and testing the high voltage apparatus. Passive wireless electric field sensors are most desired since they do not require a source of power and are interrogated wirelessly. A passive wireless electric field sensor has been designed and fabricated by our research group. In the wireless interrogation system of the sensor, a wireless radio frequency impulse generator needs to be employed. A compact wireless impulse generator composed of an integrated resonant switched oscillator (SWO) and a pulse-radiating antenna has been designed and fabricated in this research. The fundamental of Switched Oscillators was introduced by C.E.Baum. A Switched Oscillator consists of a low impedance transmission line charged by a DC source, through large impedance at desired frequencies and terminated to a high impedance antenna at one end and a fast closing switch at the other end. Once the line is charged, the switch will close and short-circuit the transmission line. Therefore, a fast transient wave will be generated and travels along the transmission line. Because of the mismatch between the antenna and the transmission line, only a part of fast transient wave will be radiated, and a portion of the fast-transient wave will reflect back. At the other end of the transmission line, there is a closed switch. Consequently, a second reflection with a reversed sign will propagate towards the antenna and the wave continues back and forth. hence, at the terminal of the antenna, there will be a series of positive and negative pulses with descending amplitude. In this research a single ended quarter wavelength Switched Oscillator has been designed and simulated at 800MHz. The simulation results show that the designed Switched Oscillator generates pulses with decreasing amplitude at the frequency of 800MHz with the maximum amplitude of 10V and bandwidth of about 10MHz at the antenna end. The switched oscillator has been fabricated using a 6cm long coaxial cable transmission line which is charged by a DC source and an 8cm monopole antenna as the pulse radiating antenna. A 90V gas discharge switch has been employed as the fast closing switch. The Switched oscillator sends a series of pulses with decreasing amplitude at the frequency of 790MHz with the maximum amplitude of 0.3V in the distance of 30 cm.

Keywords: electric field measurement, impulse radiating antenna, switched oscillator, wireless impulse generator

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4448 Controller Design and Experimental Evaluation of a Motorized Assistance for a Patient Transfer Floor Lift

Authors: Donatien Callon, Ian Lalonde, Mathieu Nadeau, Alexandre Girard

Abstract:

Patient transfer is a challenging, critical task because it exposes caregivers to injury risks. Available transfer devices, like floor lifts, lead to improvements but are far from perfect. They do not eliminate the caregivers’ risk of musculoskeletal disorders, and they can be burdensome to use due to their poor maneuverability. This paper presents a new motorized floor lift with a single central motorized wheel connected to an instrumented handle. Admittance controllers are designed to 1) improve the device maneuverability, 2) reduce the required caregiver effort, and 3) ensure the security and comfort of patients. Two controller designs, one with a linear admittance law and a non-linear admittance law with variable damping, were developed and implemented on a prototype. Tests were performed on seven participants to evaluate the performance of the assistance system and the controllers. The experimental results show that 1) the motorized assistance with the variable damping controller improves maneuverability by 28%, 2) reduces the amount of effort required to push the lift by 66%, and 3) provides the same level of patient comfort compared to a standard unassisted floor lift.

Keywords: floor lift, human robot interaction, admittance controller, variable admittance

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4447 Species Composition and Plasmodium Infection Rates of Anopheles Mosquitoes in Kilosa, Tanzania

Authors: Amina R. Issae, Godfrey C. Katusi, Beda J. Mwang’Onde, Ladslaus L. Mnyone, Allen L. Malisa

Abstract:

Background: The fluctuating composition of mosquito species over time, driven by ecological changes in specific regions, plays a pivotal role in the transmission of malaria. Grasping these dynamics is fundamental for establishing a baseline understanding and is crucial for identifying transmission patterns. This knowledge is essential in devising effective strategies for managing and controlling vector populations. Our study focused on examining the species composition and Plasmodium infection rates of malaria vectors, aiming to enhance the health and well-being of communities affected by malaria. Methods: Species composition was determined through a cross-sectional collection of mosquitoes, conducted once in the village, in four selected villages of Kilosa district, Tanzania. Mosquitoes were collected indoors and outdoors using CDC light traps. A sub-sample of all collected mosquitoes was subjected to PCR identification and assayed for Plasmodium porozoites. Results: A total of 6493 female Anophelines mosquitoes were collected, of which eight species were identified as Anopheles gambiaes.l., An. funestus group, An. coustani, An. pharoensis, An. squamosus, and An. rufipes. The abundance of the Anopheles gambiaes.s.and An. funestuss.s. varied with location and village. A total of 5 sporozoite-positive mosquitoes were found, of which 4 were An. funestuss.s. and 1 was An. gambiaes.s. Conclusions: Anopheles gambiaes.s.and An. funestuss.s. were identified as the most abundant malaria vectors, respectively. Sporozoite analysis indicated this for An. funestuss.s. contribute to most of the malaria transmission in the area. Further studies are required to assess the role of seasonal shifts in vector abundance, insecticide resistance and malaria transmission of the vectors.

Keywords: mosquito, composition, malaria, sporozoites

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4446 New Result for Optical OFDM in Code Division Multiple Access Systems Using Direct Detection

Authors: Cherifi Abdelhamid

Abstract:

In optical communication systems, OFDM has received increased attention as a means to overcome various limitations of optical transmission systems such as modal dispersion, relative intensity noise, chromatic dispersion, polarization mode dispersion and self-phase modulation. The multipath dispersion limits the maximum transmission data rates. In this paper we investigate OFDM system where multipath induced intersymbol interference (ISI) is reduced and we increase the number of users by combining OFDM system with OCDMA system using direct detection Incorporate OOC (orthogonal optical code) for minimize a bit error rate.

Keywords: OFDM, OCDMA, OOC (orthogonal optical code), (ISI), prim codes (Pc)

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4445 Design of Photonic Crystal with Defect Layer to Eliminate Interface Corrugations for Obtaining Unidirectional and Bidirectional Beam Splitting under Normal Incidence

Authors: Evrim Colak, Andriy E. Serebryannikov, Pavel V. Usik, Ekmel Ozbay

Abstract:

Working with a dielectric photonic crystal (PC) structure which does not include surface corrugations, unidirectional transmission and dual-beam splitting are observed under normal incidence as a result of the strong diffractions caused by the embedded defect layer. The defect layer has twice the period of the regular PC segments which sandwich the defect layer. Although the PC has even number of rows, the structural symmetry is broken due to the asymmetric placement of the defect layer with respect to the symmetry axis of the regular PC. The simulations verify that efficient splitting and occurrence of strong diffractions are related to the dispersion properties of the Floquet-Bloch modes of the photonic crystal. Unidirectional and bi-directional splitting, which are associated with asymmetric transmission, arise due to the dominant contribution of the first positive and first negative diffraction orders. The effect of the depth of the defect layer is examined by placing single defect layer in varying rows, preserving the asymmetry of PC. Even for deeply buried defect layer, asymmetric transmission is still valid even if the zeroth order is not coupled. This transmission is due to evanescent waves which reach to the deeply embedded defect layer and couple to higher order modes. In an additional selected performance, whichever surface is illuminated, i.e., in both upper and lower surface illumination cases, incident beam is split into two beams of equal intensity at the output surface where the intensity of the out-going beams are equal for both illumination cases. That is, although the structure is asymmetric, symmetric bidirectional transmission with equal transmission values is demonstrated and the structure mimics the behavior of symmetric structures. Finally, simulation studies including the examination of a coupled-cavity defect for two different permittivity values (close to the permittivity values of GaAs or Si and alumina) reveal unidirectional splitting for a wider band of operation in comparison to the bandwidth obtained in the case of a single embedded defect layer. Since the dielectric materials that are utilized are low-loss and weakly dispersive in a wide frequency range including microwave and optical frequencies, the studied structures should be scalable to the mentioned ranges.

Keywords: asymmetric transmission, beam deflection, blazing, bi-directional splitting, defect layer, dual beam splitting, Floquet-Bloch modes, isofrequency contours, line defect, oblique incidence, photonic crystal, unidirectionality

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4444 Mycobacterium tuberculosis and Molecular Epidemiology: An Overview

Authors: Asho Ali

Abstract:

Tuberculosis is a disease of grave concern which infects one-third of the global population. The high incidence of tuberculosis is further compounded by the increasing emergence of drug resistant strains including multi drug resistant (MDR). Global incidence MDR-TB is ~4%. Molecular epidemiological studies, based on the assumption that patients infected with clustered strains are epidemiologically linked, have helped understand the transmission dynamics of disease. It has also helped to investigate the basis of variation in Mycobacterium tuberculosis (MTB) strains, differences in transmission, and severity of disease or drug resistance mechanisms from across the globe. This has helped in developing strategies for the treatment and prevention of the disease including MDR.

Keywords: Mycobcaterium tuberculosis, molecular epidemiology, drug resistance, disease

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4443 The Implantable MEMS Blood Pressure Sensor Model With Wireless Powering And Data Transmission

Authors: Vitaliy Petrov, Natalia Shusharina, Vitaliy Kasymov, Maksim Patrushev, Evgeny Bogdanov

Abstract:

The leading worldwide death reasons are ischemic heart disease and other cardiovascular illnesses. Generally, the common symptom is high blood pressure. Long-time blood pressure control is very important for the prophylaxis, correct diagnosis and timely therapy. Non-invasive methods which are based on Korotkoff sounds are impossible to apply often and for a long time. Implantable devices can combine longtime monitoring with high accuracy of measurements. The main purpose of this work is to create a real-time monitoring system for decreasing the death rate from cardiovascular diseases. These days implantable electronic devices began to play an important role in medicine. Usually implantable devices consist of a transmitter, powering which could be wireless with a special made battery and measurement circuit. Common problems in making implantable devices are short lifetime of the battery, big size and biocompatibility. In these work, blood pressure measure will be the focus because it’s one of the main symptoms of cardiovascular diseases. Our device will consist of three parts: the implantable pressure sensor, external transmitter and automated workstation in a hospital. The Implantable part of pressure sensors could be based on piezoresistive or capacitive technologies. Both sensors have some advantages and some limitations. The Developed circuit is based on a small capacitive sensor which is made of the technology of microelectromechanical systems (MEMS). The Capacitive sensor can provide high sensitivity, low power consumption and minimum hysteresis compared to the piezoresistive sensor. For this device, it was selected the oscillator-based circuit where frequency depends from the capacitance of sensor hence from capacitance one can calculate pressure. The external device (transmitter) used for wireless charging and signal transmission. Some implant devices for these applications are passive, the external device sends radio wave signal on internal LC circuit device. The external device gets reflected the signal from the implant and from a change of frequency is possible to calculate changing of capacitance and then blood pressure. However, this method has some disadvantages, such as the patient position dependence and static using. Developed implantable device doesn’t have these disadvantages and sends blood pressure data to the external part in real-time. The external device continuously sends information about blood pressure to hospital cloud service for analysis by a physician. Doctor’s automated workstation at the hospital also acts as a dashboard, which displays actual medical data of patients (which require attention) and stores it in cloud service. Usually, critical heart conditions occur few hours before heart attack but the device is able to send an alarm signal to the hospital for an early action of medical service. The system was tested with wireless charging and data transmission. These results can be used for ASIC design for MEMS pressure sensor.

Keywords: MEMS sensor, RF power, wireless data, oscillator-based circuit

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4442 On Estimating the Low Income Proportion with Several Auxiliary Variables

Authors: Juan F. Muñoz-Rosas, Rosa M. García-Fernández, Encarnación Álvarez-Verdejo, Pablo J. Moya-Fernández

Abstract:

Poverty measurement is a very important topic in many studies in social sciences. One of the most important indicators when measuring poverty is the low income proportion. This indicator gives the proportion of people of a population classified as poor. This indicator is generally unknown, and for this reason, it is estimated by using survey data, which are obtained by official surveys carried out by many statistical agencies such as Eurostat. The main feature of the mentioned survey data is the fact that they contain several variables. The variable used to estimate the low income proportion is called as the variable of interest. The survey data may contain several additional variables, also named as the auxiliary variables, related to the variable of interest, and if this is the situation, they could be used to improve the estimation of the low income proportion. In this paper, we use Monte Carlo simulation studies to analyze numerically the performance of estimators based on several auxiliary variables. In this simulation study, we considered real data sets obtained from the 2011 European Union Survey on Income and Living Condition. Results derived from this study indicate that the estimators based on auxiliary variables are more accurate than the naive estimator.

Keywords: inclusion probability, poverty, poverty line, survey sampling

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4441 Variability Management of Contextual Feature Model in Multi-Software Product Line

Authors: Muhammad Fezan Afzal, Asad Abbas, Imran Khan, Salma Imtiaz

Abstract:

Software Product Line (SPL) paradigm is used for the development of the family of software products that share common and variable features. Feature model is a domain of SPL that consists of common and variable features with predefined relationships and constraints. Multiple SPLs consist of a number of similar common and variable features, such as mobile phones and Tabs. Reusability of common and variable features from the different domains of SPL is a complex task due to the external relationships and constraints of features in the feature model. To increase the reusability of feature model resources from domain engineering, it is required to manage the commonality of features at the level of SPL application development. In this research, we have proposed an approach that combines multiple SPLs into a single domain and converts them to a common feature model. Extracting the common features from different feature models is more effective, less cost and time to market for the application development. For extracting features from multiple SPLs, the proposed framework consists of three steps: 1) find the variation points, 2) find the constraints, and 3) combine the feature models into a single feature model on the basis of variation points and constraints. By using this approach, reusability can increase features from the multiple feature models. The impact of this research is to reduce the development of cost, time to market and increase products of SPL.

Keywords: software product line, feature model, variability management, multi-SPLs

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4440 Design and Construction of Models of Sun Tracker or Sun Tracking System for Light Transmission

Authors: Mohsen Azarmjoo, Yasaman Azarmjoo, Zahra Alikhani Koopaei

Abstract:

This article introduces devices that can transfer sunlight to buildings that do not have access to direct sunlight during the day. The transmission and reflection of sunlight are done through the movement of movable mirrors. The focus of this article is on two models of sun tracker systems designed and built by the Macad team. In fact, this article will reveal the distinction between the two Macad devices and the previously built competitor device. What distinguishes the devices built by the Macad team from the competitor's device is the different mode of operation and the difference in the location of the sensors. Given that the devices have the same results, the Macad team has tried to reduce the defects of the competitor's device as much as possible. The special feature of the second type of device built by the Macad team has enabled buildings with different construction positions to use sun tracking systems. This article will also discuss diagrams of the path of sunlight transmission and more details of the device. It is worth mentioning that fixed mirrors are also placed next to the main devices. So that the light shining on the first device is reflected to these mirrors, this light is guided within the light receiver space and is transferred to the different parts around by steel sheets built in the light receiver space, and finally, these spaces benefit from sunlight.

Keywords: design, construction, mechatronic device, sun tracker system, sun tracker, sunlight

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4439 Medical Image Compression Based on Region of Interest: A Review

Authors: Sudeepti Dayal, Neelesh Gupta

Abstract:

In terms of transmission, bigger the size of any image, longer the time the channel takes for transmission. It is understood that the bandwidth of the channel is fixed. Therefore, if the size of an image is reduced, a larger number of data or images can be transmitted over the channel. Compression is the technique used to reduce the size of an image. In terms of storage, compression reduces the file size which it occupies on the disk. Any image is based on two parameters, region of interest and non-region of interest. There are several algorithms of compression that compress the data more economically. In this paper we have reviewed region of interest and non-region of interest based compression techniques and the algorithms which compress the image most efficiently.

Keywords: compression ratio, region of interest, DCT, DWT

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4438 Transmission Loss Analysis for Panels Laminated with Felt and Film

Authors: Yoshio Kurosawa

Abstract:

To reduce the interior noise of cars in high-frequency region, sound proof materials are laminated with the body panels and the interior trims. Therefore, sound proof properties of the laminates play an important role for the efficient acoustical design. A program code which predicts both sound absorption properties and sound insulation properties of the laminates are developed. This program code is used for transfer matrix method by Biot theory. This report described the outline of this program code, and the calculation results almost agreed with the experimental results.

Keywords: porous media, transmission loss, Biot theory, transfer matrix method

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4437 The Development of Encrypted Near Field Communication Data Exchange Format Transmission in an NFC Passive Tag for Checking the Genuine Product

Authors: Tanawat Hongthai, Dusit Thanapatay

Abstract:

This paper presents the development of encrypted near field communication (NFC) data exchange format transmission in an NFC passive tag for the feasibility of implementing a genuine product authentication. We propose a research encryption and checking the genuine product into four major categories; concept, infrastructure, development and applications. This result shows the passive NFC-forum Type 2 tag can be configured to be compatible with the NFC data exchange format (NDEF), which can be automatically partially data updated when there is NFC field.

Keywords: near field communication, NFC data exchange format, checking the genuine product, encrypted NFC

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4436 Effective Practical Proceedings in Breaking the Respiratory Infections Transmission Chain in the Community with the Emphasis on SARS-COV-2 Control

Authors: Fatemeh Aghamohammadzadeh, Mahdi Asghari Ozma

Abstract:

SARS-CoV-2 was transmitted from animals to humans in China and through air transport to almost all world countries, including Iran, creating the first pandemic of the 21st century. The virus was spread through droplets from sneezing, coughing, loud talking, and exhalation of sick and asymptomatic people, even during incubation. It was transmitted from human to human directly by inhalation of viruses in droplets or indirectly through contact with infected surfaces, resulting in the death of a significant number of patients, especially the elderly and those with underlying diseases. The virus is more likely to be transmitted in places with high population densities. The chain of transmission of infection can be broken by observing the following: risk perception, reduced travel, complete quarantine in a particular area, home quarantine, social distancing, use of personal protective equipment (PPE), prevention of gatherings, cleaning and disinfection of public utilities and busy places, identifying, isolating and treating infected people, tracking calls, continuing health education, following health principles by people, especially in poor areas, and washing their hands frequently with soap and water or disinfecting them with 70% ethanol.

Keywords: COVID-19, transmission, population density, home quarantine, social distancing

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4435 Adaptive Transmission Scheme Based on Channel State in Dual-Hop System

Authors: Seung-Jun Yu, Yong-Jun Kim, Jung-In Baik, Hyoung-Kyu Song

Abstract:

In this paper, a dual-hop relay based on channel state is studied. In the conventional relay scheme, a relay uses the same modulation method without reference to channel state. But, a relay uses an adaptive modulation method with reference to channel state. If the channel state is poor, a relay eliminates latter 2 bits and uses Quadrature Phase Shift Keying (QPSK) modulation. If channel state is good, a relay modulates the received symbols with 16-QAM symbols by using 4 bits. The performance of the proposed scheme for Symbol Error Rate (SER) and throughput is analyzed.

Keywords: adaptive transmission, channel state, dual-hop, hierarchical modulation, relay

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4434 Elimination of Mother to Child Transmission of HIV/AIDS: A Study of the Knowledge, Attitudes and Perceptions of Healthcare Workers in Abuja Nigeria

Authors: Ezinne K. Okoro, Takahiko Katoh, Yoko Kawamura, Stanley C. Meribe

Abstract:

HIV infection in children is largely as a result of vertical transmission (mother to child transmission [MTCT]). Thus, elimination of mother to child transmission of HIV/AIDS is critical in eliminating HIV infection in children. In Nigeria, drawbacks such as; limited pediatric screening, limited human capital, insufficient advocacy and poor understanding of ART guidelines, have impacted efforts at combating the disease, even as treatment services are free. Prevention of Mother to Child Transmission (PMTCT) program relies on health workers who not only counsel pregnant women on first contact but can competently provide HIV-positive pregnant women with accurate information about the PMTCT program such as feeding techniques and drug adherence. In developing regions like Nigeria where health care delivery faces a lot of drawbacks, it becomes paramount to address these issues of poor PMTCT coverage by conducting a baseline assessment of the knowledge, practices and perceptions related to HIV prevention amongst healthcare workers in Nigeria. A descriptive cross-sectional study was conducted amongst 250 health workers currently employed in health facilities in Abuja, Nigeria where PMTCT services were offered with the capacity to carry out early infant diagnosis testing (EID). Data was collected using a self-administered, pretested, structured questionnaire. This study showed that the knowledge of PMTCT of HIV was poor (30%) among healthcare workers who offer this service day-to-day to pregnant women. When PMTCT practices were analyzed in keeping with National PMTCT guidelines, over 61% of the respondents reported observing standard practices and the majority (58%) had good attitudes towards caring for patients with HIV/AIDS. Although 61% of the respondents reported being satisfied with the quality of service being rendered, 63% reported not being satisfied with their level of knowledge. Predictors of good knowledge were job designation and level of educational attainment. Health workers who were more satisfied with their working conditions and those who had worked for a longer time in the PMTCT service were more likely to observe standard PMTCT practices. With over 62% of the healthcare workers suggesting that more training would improve the quality of service being rendered, this is a strong pointer to stakeholders to consider a ‘healthcare worker-oriented approach’ when planning and conducting PMTCT training for healthcare workers. This in turn will increase pediatric ARV coverage, the knowledge and effectiveness of the healthcare workers in carrying out appropriate PMTCT interventions and culminating in the reduction/elimination of HIV transmission to newborns.

Keywords: attitudes, HIV/AIDS, healthcare workers, knowledge, mother to child transmission, Nigeria, perceptions

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4433 Effect of Hill Interval Training on VO₂ Max among Filed Hockey Players

Authors: Sujay Bisht

Abstract:

The purpose of the study was to evaluate and find out the effect of Hill interval training on VO₂ MAX among field Hockey players. Thirty male field hockey players were selected from LNIPE, Guwahati who were studied in B.P.Ed course. The selected subjects were aged between 18 to 23 years. The VO₂ MAX was calculated and they were divided into two group. One group (N=15) considered as control group that did not participated in any special training apart from regular scheduled/curriculum and another group (N=15) considered as an experimental group which underwent four week Hill Training program. The selected criterion variable such VO₂ Max was measured by the cooper 12min/run/walk test and scores was recorded in ml/kg/min. The subjects were tested on selected criterion variable such as VO₂ Max prior and immediately after the training program. The pretest and posttest data were evaluate by the Analysis of Covariance (ANCOVA) to find out the significance difference if any between the experimental and control group on selected criterion variable. The level of significance was set at 0.05 level of confidence. After applied ANCOVA it was revealed that there was a significant different among the experimental and control group on VO₂ Max. Finally it was concluded that 4 week of Hill interval training effect the VO₂ max performance of field hockey players.

Keywords: VO₂ max, hill interval training, ANCOVA, experimental group

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4432 Prediction on the Pursuance of Separation of Catalonia from Spain

Authors: Francis Mark A. Fernandez, Chelca Ubay, Armithan Suguitan

Abstract:

Regions or provinces in a definite state certainly contribute to the economy of their mainland. These regions or provinces are the ones supplying the mainland with different resources and assets. Thus, with a certain region separating from the mainland would indeed impinge the heart of an entire state to develop and expand. With these, the researchers decided to study on the effects of the separation of one’s region to its mainland and the consequences that will take place if the mainland would rule out the region to separate from them. The researchers wrote this paper to present the causes of the separation of Catalonia from Spain and the prediction regarding the pursuance of this region to revolt from its mainland, Spain. In conducting this research, the researchers utilized two analyses, namely: qualitative and quantitative. In qualitative, numerous of information regarding the existing experiences of the citizens of Catalonia were gathered by the authors to give certainty to the prediction of the researchers. Besides this undertaking, the researchers will also gather needed information and figures through books, journals and the published news and reports. In addition, to further support this prediction under qualitative analysis, the researchers intended to operate the Phenomenological research in which the examiners will exemplify the lived experiences of each citizen in Catalonia. Moreover, the researchers will utilize one of the types of Phenomenological research which is hermeneutical phenomenology by Van Manen. In quantitative analysis, the researchers utilized the regression analysis in which it will ascertain the causality in an underlying theory in understanding the relationship of the variables. The researchers assigned and identified different variables, wherein the dependent variable or the y which represents the prediction of the researchers, the independent variable however or the x represents the arising problems that grounds the partition of the region, the summation of the independent variable or the ∑x represents the sum of the problem and finally the summation of the dependent variable or the ∑y is the result of the prediction. With these variables, using the regression analysis, the researchers will be able to show the connections and how a single variable could affect the other variables. From these approaches, the prediction of the researchers will be specified. This research could help different states dealing with this kind of problem. It will further help certain states undergoing this problem by analyzing the causes of these insurgencies and the effects on it if it will obstruct its region to consign their full-pledge autonomy.

Keywords: autonomy, liberty, prediction, separation

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4431 Effect of Aging Condition on Semisolid Cast 2024 Aluminum Alloy

Authors: S. Wisutmethangoon, S. Pannaray, T. Plookphol, J. Wannasin

Abstract:

2024 Aluminium alloy was squeezed cast by the Gas Induced Semi Solid (GISS) process. Effect of artificial aging on microstructure and mechanical properties of this alloy was studied in the present work. The solutionized specimens were aged hardened at temperatures of 175°C, 200°C, and 225°C under various time durations. The highest hardness of about 77.7 HRE was attained from specimen aged at the temperature of 175 °C for 36 h. Upon investigation the microstructure by using Transmission Electron Microscopy (TEM), the phase was mainly attributed to the strengthening effect in the aged alloy. The apparent activation energy for precipitation hardening of the alloy was calculated as 133,805 J/mol.

Keywords: 2024 aluminium alloy, gas induced semi solid, T6 heat treatment, aged hardening, transmission electron microscopy

Procedia PDF Downloads 285
4430 Secure Message Transmission Using Meaningful Shares

Authors: Ajish Sreedharan

Abstract:

Visual cryptography encodes a secret image into shares of random binary patterns. If the shares are exerted onto transparencies, the secret image can be visually decoded by superimposing a qualified subset of transparencies, but no secret information can be obtained from the superposition of a forbidden subset. The binary patterns of the shares, however, have no visual meaning and hinder the objectives of visual cryptography. In the Secret Message Transmission through Meaningful Shares a secret message to be transmitted is converted to grey scale image. Then (2,2) visual cryptographic shares are generated from this converted gray scale image. The shares are encrypted using A Chaos-Based Image Encryption Algorithm Using Wavelet Transform. Two separate color images which are of the same size of the shares, taken as cover image of the respective shares to hide the shares into them. The encrypted shares which are covered by meaningful images so that a potential eavesdropper wont know there is a message to be read. The meaningful shares are transmitted through two different transmission medium. During decoding shares are fetched from received meaningful images and decrypted using A Chaos-Based Image Encryption Algorithm Using Wavelet Transform. The shares are combined to regenerate the grey scale image from where the secret message is obtained.

Keywords: visual cryptography, wavelet transform, meaningful shares, grey scale image

Procedia PDF Downloads 430
4429 Optical Characterization and Surface Morphology of SnO2 Thin Films Prepared by Spin Coating Technique

Authors: J. O. Ajayi, S. S. Oluyamo, D. B. Agunbiade

Abstract:

In this work, tin oxide thin films (SnO2) were prepared using the spin coating technique. The effects of precursor concentration on the thin film properties were investigated. Tin oxide was synthesized from anhydrous Tin (II) Chloride (SnCl2) dispersed in Methanol and Acetic acid. The metallic oxide (SnO2) films deposited were characterized using the UV Spectrophotometer and the Scanning Electron Microscope (SEM). From the absorption spectra, absorption increases with decrease in precursor concentration. Absorbance in the VIS region is lower than 0 % at higher concentration. The optical transmission spectrum shows that transmission increases as the concentration of precursor decreases and the maximum transmission in visible region is about 90% for films prepared with 0.2 M. Also, there is increase in the reflectance of thin films as concentration of precursor increases. The films have high transparency (more than 85%) and low reflectance (less than 40%) in the VIS region. Investigation showed that the direct band gap value increased from 3.79eV, to 3.82eV as the precursor concentration decreased from 0.6 M to 0.2 M. Average direct bandgap energy for all the tin oxide films was estimated to be 3.80eV. The effect of precursor concentration was directly observed in crystal outgrowth and surface particle densification. They were found to increase proportionately with higher concentration.

Keywords: anhydrous TIN (II) chloride, densification, NIS- VIS region, spin coating technique

Procedia PDF Downloads 246
4428 A Cooperative Transmission Scheme Using Two Sources Based on OFDM System

Authors: Bit-Na Kwon, Dong-Hyun Ha, Hyoung-Kyu Song

Abstract:

In wireless communication, space-time block code (STBC), cyclic delay diversity (CDD) and space-time cyclic delay diversity (STCDD) are used as the spatial diversity schemes and have been widely studied for the reliable communication. If these schemes are used, the communication system can obtain the improved performance. However, the quality of the system is degraded when the distance between a source and a destination is distant in wireless communication system. In this paper, the cooperative transmission scheme using two sources is proposed and improves the performance of the wireless communication system.

Keywords: OFDM, Cooperative communication, CDD, STBC, STCDD

Procedia PDF Downloads 450
4427 Relation between Properties of Internally Cured Concrete and Water Cement Ratio

Authors: T. Manzur, S. Iffat, M. A. Noor

Abstract:

In this paper, relationship between different properties of IC concrete and water cement ratio, obtained from a comprehensive experiment conducted on IC using local materials (Burnt clay chips- BC) is presented. In addition, saturated SAP was used as an IC material in some cases. Relationships have been developed through regression analysis. The focus of this analysis is on developing relationship between a dependent variable and an independent variable. Different percent replacements of BC and water cement ratios were used. Compressive strength, modulus of elasticity, water permeability and chloride permeability were tested and variations of these parameters were analyzed with respect to water cement ratio.

Keywords: compressive strength, concrete, curing, lightweight, aggregate, superabsorbent polymer, internal curing

Procedia PDF Downloads 445