Search results for: hyperbolic sine function
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 5066

Search results for: hyperbolic sine function

4076 Systems Engineering Management Using Transdisciplinary Quality System Development Lifecycle Model

Authors: Mohamed Asaad Abdelrazek, Amir Taher El-Sheikh, M. Zayan, A.M. Elhady

Abstract:

The successful realization of complex systems is dependent not only on the technology issues and the process for implementing them, but on the management issues as well. Managing the systems development lifecycle requires technical management. Systems engineering management is the technical management. Systems engineering management is accomplished by incorporating many activities. The three major activities are development phasing, systems engineering process and lifecycle integration. Systems engineering management activities are performed across the system development lifecycle. Due to the ever-increasing complexity of systems as well the difficulty of managing and tracking the development activities, new ways to achieve systems engineering management activities are required. This paper presents a systematic approach used as a design management tool applied across systems engineering management roles. In this approach, Transdisciplinary System Development Lifecycle (TSDL) Model has been modified and integrated with Quality Function Deployment. Hereinafter, the name of the systematic approach is the Transdisciplinary Quality System Development Lifecycle (TQSDL) Model. The QFD translates the voice of customers (VOC) into measurable technical characteristics. The modified TSDL model is based on Axiomatic Design developed by Suh which is applicable to all designs: products, processes, systems and organizations. The TQSDL model aims to provide a robust structure and systematic thinking to support the implementation of systems engineering management roles. This approach ensures that the customer requirements are fulfilled as well as satisfies all the systems engineering manager roles and activities.

Keywords: axiomatic design, quality function deployment, systems engineering management, system development lifecycle

Procedia PDF Downloads 364
4075 Message Authentication Scheme for Vehicular Ad-Hoc Networks under Sparse RSUs Environment

Authors: Wen Shyong Hsieh, Chih Hsueh Lin

Abstract:

In this paper, we combine the concepts of chameleon hash function (CHF) and identification based cryptography (IBC) to build a message authentication environment for VANET under sparse RSUs. Based on the CHF, TA keeps two common secrets that will be embedded to all identities to be as the evidence of mutual trusting. TA will issue one original identity to every RSU and vehicle. An identity contains one public ID and one private key. The public ID, includes three components: pseudonym, random key, and public key, is used to present one entity and can be verified to be a legal one. The private key is used to claim the ownership of the public ID. Based on the concept of IBC, without any negotiating process, a CHF pairing key multiplied by one private key and other’s public key will be used for mutually trusting and to be utilized as the session key of secure communicating between RSUs and vehicles. To help the vehicles to do message authenticating, the RSUs are assigned to response the vehicle’s temple identity request using two short time secretes that are broadcasted by TA. To light the loading of request information, one day is divided into M time slots. At every time slot, TA will broadcast two short time secretes to all valid RSUs for that time slot. Any RSU can response the temple identity request from legal vehicles. With the collected announcement of public IDs from the neighbor vehicles, a vehicle can set up its neighboring set, which includes the information about the neighbor vehicle’s temple public ID and temple CHF pairing key that can be derived by the private key and neighbor’s public key and will be used to do message authenticating or secure communicating without the help of RSU.

Keywords: Internet of Vehicles (IOV), Vehicular Ad-hoc Networks (VANETs), Chameleon Hash Function (CHF), message authentication

Procedia PDF Downloads 392
4074 Systematic Discovery of Bacterial Toxins Against Plants Pathogens Fungi

Authors: Yaara Oppenheimer-Shaanan, Nimrod Nachmias, Marina Campos Rocha, Neta Schlezinger, Noam Dotan, Asaf Levy

Abstract:

Fusarium oxysporum, a fungus that attacks a broad range of plants and can cause infections in humans, operates across different kingdoms. This pathogen encounters varied conditions, such as temperature, pH, and nutrient availability, in plant and human hosts. The Fusarium oxysporum species complex, pervasive in soils globally, can affect numerous plants, including key crops like tomatoes and bananas. Controlling Fusarium infections can involve biocontrol agents that hinder the growth of harmful strains. Our research developed a computational method to identify toxin domains within a vast number of microbial genomes, leading to the discovery of nine distinct toxins capable of killing bacteria and fungi, including Fusarium. These toxins appear to function as enzymes, causing significant damage to cellular structures, membranes and DNA. We explored biological control using bacteria that produce polymorphic toxins, finding that certain bacteria, non-pathogenic to plants, offer a safe biological alternative for Fusarium management, as they did not harm macrophage cells or C. elegans. Additionally, we elucidated the 3D structures of two toxins with their protective immunity proteins, revealing their function as unique DNases. These potent toxins are likely instrumental in microbial competition within plant ecosystems and could serve as biocontrol agents to mitigate Fusarium wilt and related diseases.

Keywords: microbial toxins, antifungal, Fusarium oxysporum, bacterial-fungal intreactions

Procedia PDF Downloads 60
4073 Simulation of Utility Accrual Scheduling and Recovery Algorithm in Multiprocessor Environment

Authors: A. Idawaty, O. Mohamed, A. Z. Zuriati

Abstract:

This paper presents the development of an event based Discrete Event Simulation (DES) for a recovery algorithm known Backward Recovery Global Preemptive Utility Accrual Scheduling (BR_GPUAS). This algorithm implements the Backward Recovery (BR) mechanism as a fault recovery solution under the existing Time/Utility Function/ Utility Accrual (TUF/UA) scheduling domain for multiprocessor environment. The BR mechanism attempts to take the faulty tasks back to its initial safe state and then proceeds to re-execute the affected section of the faulty tasks to enable recovery. Considering that faults may occur in the components of any system; a fault tolerance system that can nullify the erroneous effect is necessary to be developed. Current TUF/UA scheduling algorithm uses the abortion recovery mechanism and it simply aborts the erroneous task as their fault recovery solution. None of the existing algorithm in TUF/UA scheduling domain in multiprocessor scheduling environment have considered the transient fault and implement the BR mechanism as a fault recovery mechanism to nullify the erroneous effect and solve the recovery problem in this domain. The developed BR_GPUAS simulator has derived the set of parameter, events and performance metrics according to a detailed analysis of the base model. Simulation results revealed that BR_GPUAS algorithm can saved almost 20-30% of the accumulated utilities making it reliable and efficient for the real-time application in the multiprocessor scheduling environment.

Keywords: real-time system (RTS), time utility function/ utility accrual (TUF/UA) scheduling, backward recovery mechanism, multiprocessor, discrete event simulation (DES)

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4072 Approximation of a Wanted Flow via Topological Sensitivity Analysis

Authors: Mohamed Abdelwahed

Abstract:

We propose an optimization algorithm for the geometric control of fluid flow. The used approach is based on the topological sensitivity analysis method. It consists in studying the variation of a cost function with respect to the insertion of a small obstacle in the domain. Some theoretical and numerical results are presented in 2D and 3D.

Keywords: sensitivity analysis, topological gradient, shape optimization, stokes equations

Procedia PDF Downloads 539
4071 Prototype Development of Knitted Buoyant Swimming Vest for Children

Authors: Nga-Wun Li, Chu-Po Ho, Kit-Lun Yick, Jin-Yun Zhou

Abstract:

The use of buoyant vests incorporated with swimsuits can develop children’s confidence in the water, particularly for novice swimmers. Consequently, parents intend to purchase buoyant swimming vests for the children to reduce their anxiety to water. Although the conventional buoyant swimming vests can provide the buoyant function to the wearer, their bulkiness and hardness make children feel uncomfortable and not willing to wear. This study aimed to apply inlay knitting technology to design new functional buoyant swimming vests for children. This prototype involved a shell and a buoyant knitted layer, which is the main media to provide buoyancy. Polypropylene yarn and 6.4 mm of Expandable Polyethylene (EPE) foam were fabricated in Full needle stitch with inlay knitting technology and were then linked by sewing to form the buoyant layer. The shell of the knitted buoyant vest was made of Polypropylene circular knitted fabric. The structure of knitted fabrics of the buoyant swimsuit makes them inherently stretchable, and the arrangement of the inlaid material was designed based on the body movement that can improve the ease with which the swimmer moves. Further, the shoulder seam is designed at the back to minimize the irritation of the wearer. Apart from maintaining the buoyant function to them, this prototype shows its contribution in reducing bulkiness and improving softness to the conventional buoyant swimming vest by taking the advantages of a knitted garment. The results in this study are significant to the development of the buoyant swimming vest for both the textile and the fast-growing sportswear industry.

Keywords: knitting technology, buoyancy, inlay, swimming vest, functional garment

Procedia PDF Downloads 112
4070 Study on the Effect Cabbage (Brassica oleracea) and Ginger (Zingiber officinale) Extracts on Rat Liver Injuries Induced by Carbon tetrachloride (CCl4)

Authors: Asmaa F. Hamouda, Randa M Shrourou

Abstract:

Cabbage (Brassica oleracea) and Ginger (Zingiber officinale) constitute apportion of regular human diet. The effect of Cabbage(CE) and Ginger extracts(GE) separately on liver nitric oxide (NO), malondialdehyde (MDA), as well as serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin, total cholesterol(TC), triglyceride(T.G), high density lipoprotein(HDL cholesterol), low density lipoprotein (LDL cholesterol), thyroid-stimulating hormone (TSH), Triiodothyronine (T3), Thyroxine (T4) in rats treated and untreated with carbon tetrachloride (CCl4) was studied. The levels of NO, MDA, as well as serum AST, ALT, total bilirubin, TC, T.G, LDLand TSH showed an elevation and decline in HDL, T3, and T4 in rats treated with CCl4 as compared to control. Treatment of rats with GE pre, during, and post CCl4 administration improved NO, MDA, as well as serum AST, ALT, total bilirubin, TC, T.G, HDL, LDL, TSH, T3, T4 as compared to CCl4, indicates that GE improve thyroid function and reduced oxidative stress as well as injuries induced by CCl4. Treatment of rats with CE pre, during, and post CCl4 administration did not improved in the thyroid hormones and lipid profile levels as compared to CCl4. These findings suggest that ginger treatment exerts a protective effect on metabolic disorders by decreasing oxidative stress.

Keywords: liver injuries, carbon tetrachloride (CCl4), cabbage (Brassica oleracea), ginger (Zingiber officinale), thyroid function

Procedia PDF Downloads 265
4069 The Effect of Degraded Shock Absorbers on the Safety-Critical Tipping and Rolling Behaviour of Passenger Cars

Authors: Tobias Schramm, Günther Prokop

Abstract:

In Germany, the number of road fatalities has been falling since 2010 at a more moderate rate than before. At the same time, the average age of all registered passenger cars in Germany is rising continuously. Studies show that there is a correlation between the age and mileage of passenger cars and the degradation of their chassis components. Various studies show that degraded shock absorbers increase the braking distance of passenger cars and have a negative impact on driving stability. The exact effect of degraded vehicle shock absorbers on road safety is still the subject of research. A shock absorber examination as part of the periodic technical inspection is only mandatory in very few countries. In Germany, there is as yet no requirement for such a shock absorber examination. More comprehensive findings on the effect of degraded shock absorbers on the safety-critical driving dynamics of passenger cars can provide further arguments for the introduction of mandatory shock absorber testing as part of the periodic technical inspection. The specific effect chains of untripped rollover accidents are also still the subject of research. However, current research results show that the high proportion of sport utility vehicles in the vehicle field significantly increases the probability of untripped rollover accidents. The aim of this work is to estimate the effect of degraded twin-tube shock absorbers on the safety-critical tipping and rolling behaviour of passenger cars, which can lead to untripped rollover accidents. A characteristic curve-based five-mass full vehicle model and a semi-physical phenomenological shock absorber model were set up, parameterized and validated. The shock absorber model is able to reproduce the damping characteristics of vehicle twin-tube shock absorbers with oil and gas loss for various excitations. The full vehicle model was validated with steering wheel angle sinus sweep driving maneuvers. The model was then used to simulate steering wheel angle sine and fishhook maneuvers, which investigate the safety-critical tipping and rolling behavior of passenger cars. The simulations were carried out in a realistic parameter space in order to demonstrate the effect of various vehicle characteristics on the effect of degraded shock absorbers. As a result, it was shown that degraded shock absorbers have a negative effect on the tipping and rolling behavior of all passenger cars. Shock absorber degradation leads to a significant increase in the observed roll angles, particularly in the range of the roll natural frequency. This superelevation has a negative effect on the wheel load distribution during the driving maneuvers investigated. In particular, the height of the vehicle's center of gravity and the stabilizer stiffness of the vehicles has a major influence on the effect of degraded shock absorbers on the overturning and rolling behaviour of passenger cars.

Keywords: numerical simulation, safety-critical driving dynamics, suspension degradation, tipping and rolling behavior of passenger cars, vehicle shock absorber

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4068 Computerized Analysis of Phonological Structure of 10,400 Brazilian Sign Language Signs

Authors: Wanessa G. Oliveira, Fernando C. Capovilla

Abstract:

Capovilla and Raphael’s Libras Dictionary documents a corpus of 4,200 Brazilian Sign Language (Libras) signs. Duduchi and Capovilla’s software SignTracking permits users to retrieve signs even when ignoring the gloss corresponding to it and to discover the meaning of all 4,200 signs sign simply by clicking on graphic menus of the sign characteristics (phonemes). Duduchi and Capovilla have discovered that the ease with which any given sign can be retrieved is an inverse function of the average popularity of its component phonemes. Thus, signs composed of rare (distinct) phonemes are easier to retrieve than are those composed of common phonemes. SignTracking offers a means of computing the average popularity of the phonemes that make up each one of 4,200 signs. It provides a precise measure of the degree of ease with which signs can be retrieved, and sign meanings can be discovered. Duduchi and Capovilla’s logarithmic model proved valid: The degree with which any given sign can be retrieved is an inverse function of the arithmetic mean of the logarithm of the popularity of each component phoneme. Capovilla, Raphael and Mauricio’s New Libras Dictionary documents a corpus of 10,400 Libras signs. The present analysis revealed Libras DNA structure by mapping the incidence of 501 sign phonemes resulting from the layered distribution of five parameters: 163 handshape phonemes (CherEmes-ManusIculi); 34 finger shape phonemes (DactilEmes-DigitumIculi); 55 hand placement phonemes (ArtrotoToposEmes-ArticulatiLocusIculi); 173 movement dimension phonemes (CinesEmes-MotusIculi) pertaining to direction, frequency, and type; and 76 Facial Expression phonemes (MascarEmes-PersonalIculi).

Keywords: Brazilian sign language, lexical retrieval, libras sign, sign phonology

Procedia PDF Downloads 346
4067 Investigating the Influence of Activation Functions on Image Classification Accuracy via Deep Convolutional Neural Network

Authors: Gulfam Haider, sana danish

Abstract:

Convolutional Neural Networks (CNNs) have emerged as powerful tools for image classification, and the choice of optimizers profoundly affects their performance. The study of optimizers and their adaptations remains a topic of significant importance in machine learning research. While numerous studies have explored and advocated for various optimizers, the efficacy of these optimization techniques is still subject to scrutiny. This work aims to address the challenges surrounding the effectiveness of optimizers by conducting a comprehensive analysis and evaluation. The primary focus of this investigation lies in examining the performance of different optimizers when employed in conjunction with the popular activation function, Rectified Linear Unit (ReLU). By incorporating ReLU, known for its favorable properties in prior research, the aim is to bolster the effectiveness of the optimizers under scrutiny. Specifically, we evaluate the adjustment of these optimizers with both the original Softmax activation function and the modified ReLU activation function, carefully assessing their impact on overall performance. To achieve this, a series of experiments are conducted using a well-established benchmark dataset for image classification tasks, namely the Canadian Institute for Advanced Research dataset (CIFAR-10). The selected optimizers for investigation encompass a range of prominent algorithms, including Adam, Root Mean Squared Propagation (RMSprop), Adaptive Learning Rate Method (Adadelta), Adaptive Gradient Algorithm (Adagrad), and Stochastic Gradient Descent (SGD). The performance analysis encompasses a comprehensive evaluation of the classification accuracy, convergence speed, and robustness of the CNN models trained with each optimizer. Through rigorous experimentation and meticulous assessment, we discern the strengths and weaknesses of the different optimization techniques, providing valuable insights into their suitability for image classification tasks. By conducting this in-depth study, we contribute to the existing body of knowledge surrounding optimizers in CNNs, shedding light on their performance characteristics for image classification. The findings gleaned from this research serve to guide researchers and practitioners in making informed decisions when selecting optimizers and activation functions, thus advancing the state-of-the-art in the field of image classification with convolutional neural networks.

Keywords: deep neural network, optimizers, RMsprop, ReLU, stochastic gradient descent

Procedia PDF Downloads 128
4066 Thermodynamic and Magnetic Properties of Heavy Fermion UTE₂ Superconductor

Authors: Habtamu Anagaw Muluneh, Gebregziabher Kahsay, Tamiru Negussie

Abstract:

Theoretical study of the density of state, condensation energy, specific heat, and magnetization in a spin-triplet superconductor are the main goals of this work. Utilizing the retarded double-time temperature-dependent Green's function formalism and building a model Hamiltonian for the system at hand, we were able to derive the expressions for the parameters mentioned above. The phase diagrams are plotted using MATLAB scripts. From the phase diagrams, the density of electrons increases as the excitation energy increases, and the maximum excitation energy is equal to the superconducting gap, but it decreases when the value exceeds the gap and finally becomes the same as the density of the normal state. On the other hand, the condensation energy decreases with the increase in temperature and attains its minimum value at the superconducting transition temperature but increases with the increase in superconducting transition temperature (TC) and finally becomes zero, implying the superconducting energy is equal to the normal state energy. The specific heat increases with the increase in temperature, attaining its maximum value at the TC and then undergoing a jump, showing the presence of a second-order phase transition from the superconducting state to the normal state. Finally, the magnetization of both the itinerant and localized electrons decreases with the increase in temperature and finally becomes zero at TC = 1.6 K and magnetic phase transition temperature T = 2 K, respectively, which results in a magnetic phase transition from a ferromagnetic to a paramagnetic state. Our finding is in good agreement with the previous findings.

Keywords: spin triplet superconductivity, Green’s function, condensation energy, density of state, specific heat, magnetization

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4065 The Importance of Anthropometric Indices for Assessing the Physical Development and Physical Fitness of Young Athletes

Authors: Akbarova Gulnozakhon

Abstract:

Relevance. Physical exercises can prolong the function of the growth zones of long tubular bones, delay the fusion of the epiphyses and diaphyses of bones and, thus, increase the growth of the body. At the same time, intensive strength exercises can accelerate the process of ossification of bone growth zones and slow down their growth in length. The influence of physical exercises on the process of biological maturation is noted. Gymnastics, which requires intense speed and strength loads, delays puberty. On the other hand, it is indicated that the relatively slow puberty of gymnasts is associated with the selection of girls with a special somatotype in this sport. It was found that the later onset of menstruation in female athletes does not have a negative effect on the maturation process and fertility (the ability to procreate). Observations are made about the normalizing influence of sports on the puberty of girls. The purpose of the study. Our goal is to study physical activity of varying intensity on the formation of secondary sexual characteristics and hormonal status of girls in adolescence. Each biological process peculiar to a given organism is not in a stationary state, but fluctuates with a certain frequency. According to the duration, there are, for example, circadian cycles, and infradian cycles, a typical example of which is the menstrual cycle. Materials and methods, results. Violations of menstrual function in athletes were detected by applying a questionnaire survey that contains several paragraphs and sub-paragraphs where passport data, anthropometric indicators, taking into account anthropometric indices, information about the menstrual cycle are indicated. Of 135 female athletes aged 1-3 to 16 years engaged in various sports - gymnasts, menstrual function disorders were noted in 86.7% (primary or secondary amenorrhea, irregular MC), in swimming-in 57.1%. The general condition also changes during the menstrual cycle. In a large percentage of cases, athletes indicate an increase in irritability in the premenstrual (45%) and menstrual (36%) phases. During these phases, girls note an increase in fatigue of 46.5% and 58% (respectively). In girls, secondary sexual characteristics continue to form during puberty and the clearest indicator of the onset of puberty is the age of the onset of the first menstruation - menarche. Conclusions. 1. Physical exercise has a positive effect on all major systems of the body and thus promotes health.2. Along with a beneficial effect on human health, physical exercise, if the requirements of sports are not observed, can be harmful.

Keywords: girls health, anthropometric, physical development, reproductive health

Procedia PDF Downloads 104
4064 A Generalised Propensity Score Analysis to Investigate the Influence of Agricultural Research Systems on Greenhouse Gas Emissions

Authors: Spada Alessia, Fiore Mariantonietta, Lamonaca Emilia, Contò Francesco

Abstract:

Bioeconomy can give the chance to face new global challenges and can move ahead the transition from a waste economy to an economy based on renewable resources and sustainable consumption. Air pollution is a grave issue in green challenges, mainly caused by anthropogenic factors. The agriculture sector is a great contributor to global greenhouse gases (GHGs) emissions due to lacking efficient management of the resources involved and research policies. In particular, livestock sector contributes to emissions of GHGs, deforestation, and nutrient imbalances. More effective agricultural research systems and technologies are crucial in order to improve farm productivity but also to reduce the GHGs emissions. Using data from FAOSTAT statistics and concern the EU countries; the aim of this research is to evaluate the impact of ASTI R&D (Agricultural Science and Technology Indicators) on GHGs emissions for countries EU in 2015 by generalized propensity score procedures, estimating a dose-response function, also considering a set of covariates. Expected results show the existence of the influence of ASTI R&D on GHGs across EU countries. Implications are crucial: reducing GHGs emissions by means of R&D based policies and correlatively reaching eco-friendly management of required resources by means of green available practices could have a crucial role for fair intra-generational implications.

Keywords: agricultural research systems, dose-response function, generalized propensity score, GHG emissions

Procedia PDF Downloads 278
4063 Mild Auditory Perception and Cognitive Impairment in mid-Trimester Pregnancy

Authors: Tahamina Begum, Wan Nor Azlen Wan Mohamad, Faruque Reza, Wan Rosilawati Wan Rosli

Abstract:

To assess auditory perception and cognitive function during pregnancy is necessary as the pregnant women need extra effort for attention mainly for their executive function to maintain their quality of life. This study aimed to investigate neural correlates of cognitive and behavioral processing during mid trimester pregnancy. Event-Related Potentials (ERPs) were studied by using 128-sensor net and PAS or COWA (controlled Oral Word Association), WCST (Wisconsin Card Sorting Test), RAVLTIM (Rey Auditory Verbal and Learning Test: immediate or interference recall, delayed recall (RAVLT DR) and total score (RAVLT TS) were tested for neuropsychology assessment. In total 18 subjects were recruited (n= 9 in each group; control and pregnant group). All participants of the pregnant group were within 16-27 (mid trimester) weeks gestation. Age and education matched control healthy subjects were recruited in the control group. Participants were given a standardized test of auditory cognitive function as auditory oddball paradigm during ERP study. In this paradigm, two different auditory stimuli (standard and target stimuli) were used where subjects counted silently only target stimuli with giving attention by ignoring standard stimuli. Mean differences between target and standard stimuli were compared across groups. N100 (auditory sensory ERP component) and P300 (auditory cognitive ERP component) were recorded at T3, T4, T5, T6, Cz and Pz electrode sites. An equal number of electrodes showed non-significantly shorter amplitude of N100 component (except significantly shorter at T3, P= 0.05) and non-significant longer latencies (except significantly longer latency at T5, P= 0.008) of N100 component in pregnant group comparing control. In case of P300 component, maximum electrode sites showed non-significantly higher amplitudes and equal number of sites showed non-significant shorter latencies in pregnant group comparing control. Neuropsychology results revealed the non-significant higher score of PAS, lower score of WCST, lower score of RAVLTIM and RAVLTDR in pregnant group comparing control. The results of N100 component and RAVLT scores concluded that auditory perception is mildly impaired and P300 component proved very mild cognitive dysfunction with good executive functions in second trimester of pregnancy.

Keywords: auditory perception, pregnancy, stimuli, trimester

Procedia PDF Downloads 385
4062 Prevalence of Occupational Asthma Diagnosed by Specific Challenge Test in 5 Different Working Environments in Thailand

Authors: Sawang Saenghirunvattana, Chao Saenghirunvattana, Maria Christina Gonzales, Wilai Srimuk, Chitchamai Siangpro, Kritsana Sutthisri

Abstract:

Introduction: Thailand is one of the fastest growing countries in Asia. It has emerged from agricultural to industrialized economy. Work places have shifted from farms to factories, offices and streets were employees are exposed to certain chemicals and pollutants causing occupational diseases particularly asthma. Work-related diseases are major concern and many studies have been published to demonstrate certain professions and their exposures that elevate the risk of asthma. Workers who exhibit coughing, wheezing and difficulty of breathing are brought to a health care setting where Pulmonary Function Test (PFT) is performed and based from results, they are then diagnosed of asthma. These patients, known to have occupational asthma eventually get well when removed from the exposure of the environment. Our study, focused on performing PFT or specific challenge test in diagnosing workers of occupational asthma with them executing the test within their workplace, maintaining the environment and their daily exposure to certain levels of chemicals and pollutants. This has provided us with an understanding and reliable diagnosis of occupational asthma. Objective: To identify the prevalence of Thai workers who develop asthma caused by exposure to pollutants and chemicals from their working environment by conducting interview and performing PFT or specific challenge test in their work places. Materials and Methods: This study was performed from January-March 2015 in Bangkok, Thailand. The percentage of abnormal symptoms of 940 workers in 5 different areas (factories of plastic, fertilizer, animal food, office and streets) were collected through a questionnaire. The demographic information, occupational history, and the state of health were determined using a questionnaire and checklists. PFT was executed in their work places and results were measured and evaluated. Results: Pulmonary Function test was performed by 940 participants. The specific challenge test was done in factories of plastic, fertilizer, animal food, office environment and on the streets of Thailand. Of the 100 participants working in the plastic industry, 65% complained of having respiratory symptoms. None of them had an abnormal PFT. From the participants who worked with fertilizers and are exposed to sulfur dioxide, out of 200 participants, 20% complained of having symptoms and 8% had abnormal PFT. The 300 subjects working with animal food reported that 45% complained of respiratory symptoms and 15% had abnormal PFT results. From the office environment where there is indoor pollution, Out of 140 subjects, 7% had symptoms and 4% had abnormal PFT. The 200 workers exposed to traffic pollution, 24% reported respiratory symptoms and 12% had abnormal PFT. Conclusion: We were able to identify and diagnose participants of occupational asthma through their abnormal lung function test done at their work places. The chemical agents and exposures were determined therefore effective management of workers with occupational asthma were advised to avoid further exposure for better chances of recovery. Further studies identifying the risk factors and causative agents of asthma in workplaces should be developed to encourage interventional strategies and programs that will prevent occupation related diseases particularly asthma.

Keywords: occupational asthma, pulmonary function test, specific challenge test, Thailand

Procedia PDF Downloads 304
4061 Survey of the Relationship between Functional Movement Screening Tests and Anthropometric Dimensions in Healthy People, 2018

Authors: Akram Sadat Jafari Roodbandi, Parisa Kahani, Fatollah Rahimi Bafrani, Ali Dehghan, Nava Seyedi, Vafa Feyzi, Zohreh Forozanfar

Abstract:

Introduction: Movement function is considered as the ability to produce and maintain balance, stability, and movement throughout the movement chain. Having a score of 14 and above on 7 sub-tests in the functional movement screening (FMS) test shows agility and optimal movement performance. On the other hand, the person's body is an important factor in physical fitness and optimal movement performance. The aim of this study was to identify effective anthropometric dimensions in increasing motor function. Methods: This study was a descriptive-analytical and cross-sectional study using simple random sampling. FMS test and 25 anthropometric dimensions and subcutaneous in five body regions measured in 139 healthy students of Bam University of Medical Sciences. Data analysis was performed using SPSS software and univariate tests and linear regressions at a significance level of 0.05. Results: 139 students were enrolled in the study, 51.1% (71 subjects) and the rest were female. The mean and standard deviation of age, weight, height, and arm subcutaneous fat were 21.5 ± 1.45, 12.6 ± 64.3, 168.7 ± 9.8, 15.3 ± 7, respectively. 17 subjects (12.2%) of the participants in the study have a score of less than 14, and the rest were above 14. Using regression analysis, it was found that exercise and arm subcutaneous fat are predictive variables associated with obtaining a high score in the FMS test. Conclusion: Exercise and weight loss are effective factors for increasing the movement performance of individuals, and this factor is independent of the size of other physical dimensions.

Keywords: functional movement, screening test, anthropometry, ergonomics

Procedia PDF Downloads 149
4060 Applying (1, T) Ordering Policy in a Multi-Vendor-Single-Buyer Inventory System with Lost Sales and Poisson Demand

Authors: Adel Nikfarjam, Hamed Tayebi, Sadoullah Ebrahimnejad

Abstract:

This paper considers a two-echelon inventory system with a number of warehouses and a single retailer. The retailer replenishes its required items from warehouses, and assembles them into a single final product. We assume that each warehouse supplies only one kind of the raw material for the retailer. The demand process of the final product is assumed to be Poissson, and unsatisfied demand of the final product will be lost. The retailer applies one-for-one-period ordering policy which is also known as (1, T) ordering policy. In this policy the retailer orders to each warehouse a fixed quantity of each item at fixed time intervals, which the fixed quantity is equal to the utilization of the item in the final product. Since, this policy eliminates all demand uncertainties at the upstream echelon, the standard lot sizing model can be applied at all warehouses. In this paper, we calculate the total cost function of the inventory system. Then, based on this function, we present a procedure to obtain the optimal time interval between two consecutive order placements from retailer to the warehouses, and the optimal order quantities of warehouses (assuming that there are positive ordering costs at warehouses). Finally, we present some numerical examples, and conduct numerical sensitivity analysis for cost parameters.

Keywords: two-echelon supply chain, multi-vendor-single-buyer inventory system, lost sales, Poisson demand, one-for-one-period policy, lot sizing model

Procedia PDF Downloads 313
4059 Comparative Evaluation of EBT3 Film Dosimetry Using Flat Bad Scanner, Densitometer and Spectrophotometer Methods and Its Applications in Radiotherapy

Authors: K. Khaerunnisa, D. Ryangga, S. A. Pawiro

Abstract:

Over the past few decades, film dosimetry has become a tool which is used in various radiotherapy modalities, either for clinical quality assurance (QA) or dose verification. The response of the film to irradiation is usually expressed in optical density (OD) or net optical density (netOD). While the film's response to radiation is not linear, then the use of film as a dosimeter must go through a calibration process. This study aimed to compare the function of the calibration curve of various measurement methods with various densitometer, using a flat bad scanner, point densitometer and spectrophotometer. For every response function, a radichromic film calibration curve is generated from each method by performing accuracy, precision and sensitivity analysis. netOD is obtained by measuring changes in the optical density (OD) of the film before irradiation and after irradiation when using a film scanner if it uses ImageJ to extract the pixel value of the film on the red channel of three channels (RGB), calculate the change in OD before and after irradiation when using a point densitometer, and calculate changes in absorbance before and after irradiation when using a spectrophotometer. the results showed that the three calibration methods gave readings with a netOD precision of doses below 3% for the uncertainty value of 1σ (one sigma). while the sensitivity of all three methods has the same trend in responding to film readings against radiation, it has a different magnitude of sensitivity. while the accuracy of the three methods provides readings below 3% for doses above 100 cGy and 200 cGy, but for doses below 100 cGy found above 3% when using point densitometers and spectrophotometers. when all three methods are used for clinical implementation, the results of the study show accuracy and precision below 2% for the use of scanners and spectrophotometers and above 3% for precision and accuracy when using point densitometers.

Keywords: Callibration Methods, Film Dosimetry EBT3, Flat Bad Scanner, Densitomete, Spectrophotometer

Procedia PDF Downloads 135
4058 Unveiling the Impact of Ultra High Vacuum Annealing Levels on Physico-Chemical Properties of Bulk ZnSe Semiconductor

Authors: Kheira Hamaida, Mohamed Salah Halati

Abstract:

In this current paper, our aim work is to link as possible the obtained simulation results and the other experimental ones, just focusing on the electronic and optical properties of ZnSe. The predictive spectra of the total and partial densities of states using the Full Potential Linearized/Augmented Plane Wave method with the newly Tran-Blaha (TB) modified Becke-Johnson (mBJ) exchange-correlation potential (EXC). So the upper valence energy (UVE) levels contain the relative contribution of Se-(4p and 3d) states with considerable contribution from the electrons of Zn-2s orbital. The dielectric function of w-ZnSe, with its two parts, appears with a noticeable anisotropy character. The microscopic origins of the electronic states that are responsible for the observed peaks in the spectrum are determined through the decomposition of the spectrum to the individual contributions of the electronic transitions between the pairs of bands, where Vi is an occupied state in the valence band, and Ci is an unoccupied state in the conduction band. X-PES (X Ray-Photo Electron Spectroscopy) is an important technique used to probe the homogeneity, stoichiometry, and purity state of the title compound. In order to check the electron transitions derived from simulations and the others from Reflected Electron Energy Loss Spectroscopy (REELS) technique which was of great sensitivity, is used to determine the interband electronic transitions. In the optical window (Eg), all the electron energy states created were also determined through the specific gaussian deconvolution of the photoluminescence spectrum (PLS) that probed under a room temperature (RT).

Keywords: spectroscopy, WIEN2K, IIB-VIA semiconductors, dielectric function

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4057 Comparing Xbar Charts: Conventional versus Reweighted Robust Estimation Methods for Univariate Data Sets

Authors: Ece Cigdem Mutlu, Burak Alakent

Abstract:

Maintaining the quality of manufactured products at a desired level depends on the stability of process dispersion and location parameters and detection of perturbations in these parameters as promptly as possible. Shewhart control chart is the most widely used technique in statistical process monitoring to monitor the quality of products and control process mean and variability. In the application of Xbar control charts, sample standard deviation and sample mean are known to be the most efficient conventional estimators in determining process dispersion and location parameters, respectively, based on the assumption of independent and normally distributed datasets. On the other hand, there is no guarantee that the real-world data would be normally distributed. In the cases of estimated process parameters from Phase I data clouded with outliers, efficiency of traditional estimators is significantly reduced, and performance of Xbar charts are undesirably low, e.g. occasional outliers in the rational subgroups in Phase I data set may considerably affect the sample mean and standard deviation, resulting a serious delay in detection of inferior products in Phase II. For more efficient application of control charts, it is required to use robust estimators against contaminations, which may exist in Phase I. In the current study, we present a simple approach to construct robust Xbar control charts using average distance to the median, Qn-estimator of scale, M-estimator of scale with logistic psi-function in the estimation of process dispersion parameter, and Harrell-Davis qth quantile estimator, Hodge-Lehmann estimator and M-estimator of location with Huber psi-function and logistic psi-function in the estimation of process location parameter. Phase I efficiency of proposed estimators and Phase II performance of Xbar charts constructed from these estimators are compared with the conventional mean and standard deviation statistics both under normality and against diffuse-localized and symmetric-asymmetric contaminations using 50,000 Monte Carlo simulations on MATLAB. Consequently, it is found that robust estimators yield parameter estimates with higher efficiency against all types of contaminations, and Xbar charts constructed using robust estimators have higher power in detecting disturbances, compared to conventional methods. Additionally, utilizing individuals charts to screen outlier subgroups and employing different combination of dispersion and location estimators on subgroups and individual observations are found to improve the performance of Xbar charts.

Keywords: average run length, M-estimators, quality control, robust estimators

Procedia PDF Downloads 191
4056 Quantifying Meaning in Biological Systems

Authors: Richard L. Summers

Abstract:

The advanced computational analysis of biological systems is becoming increasingly dependent upon an understanding of the information-theoretic structure of the materials, energy and interactive processes that comprise those systems. The stability and survival of these living systems are fundamentally contingent upon their ability to acquire and process the meaning of information concerning the physical state of its biological continuum (biocontinuum). The drive for adaptive system reconciliation of a divergence from steady-state within this biocontinuum can be described by an information metric-based formulation of the process for actionable knowledge acquisition that incorporates the axiomatic inference of Kullback-Leibler information minimization driven by survival replicator dynamics. If the mathematical expression of this process is the Lagrangian integrand for any change within the biocontinuum then it can also be considered as an action functional for the living system. In the direct method of Lyapunov, such a summarizing mathematical formulation of global system behavior based on the driving forces of energy currents and constraints within the system can serve as a platform for the analysis of stability. As the system evolves in time in response to biocontinuum perturbations, the summarizing function then conveys information about its overall stability. This stability information portends survival and therefore has absolute existential meaning for the living system. The first derivative of the Lyapunov energy information function will have a negative trajectory toward a system's steady state if the driving force is dissipating. By contrast, system instability leading to system dissolution will have a positive trajectory. The direction and magnitude of the vector for the trajectory then serves as a quantifiable signature of the meaning associated with the living system’s stability information, homeostasis and survival potential.

Keywords: meaning, information, Lyapunov, living systems

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4055 A Mixing Matrix Estimation Algorithm for Speech Signals under the Under-Determined Blind Source Separation Model

Authors: Jing Wu, Wei Lv, Yibing Li, Yuanfan You

Abstract:

The separation of speech signals has become a research hotspot in the field of signal processing in recent years. It has many applications and influences in teleconferencing, hearing aids, speech recognition of machines and so on. The sounds received are usually noisy. The issue of identifying the sounds of interest and obtaining clear sounds in such an environment becomes a problem worth exploring, that is, the problem of blind source separation. This paper focuses on the under-determined blind source separation (UBSS). Sparse component analysis is generally used for the problem of under-determined blind source separation. The method is mainly divided into two parts. Firstly, the clustering algorithm is used to estimate the mixing matrix according to the observed signals. Then the signal is separated based on the known mixing matrix. In this paper, the problem of mixing matrix estimation is studied. This paper proposes an improved algorithm to estimate the mixing matrix for speech signals in the UBSS model. The traditional potential algorithm is not accurate for the mixing matrix estimation, especially for low signal-to noise ratio (SNR).In response to this problem, this paper considers the idea of an improved potential function method to estimate the mixing matrix. The algorithm not only avoids the inuence of insufficient prior information in traditional clustering algorithm, but also improves the estimation accuracy of mixing matrix. This paper takes the mixing of four speech signals into two channels as an example. The results of simulations show that the approach in this paper not only improves the accuracy of estimation, but also applies to any mixing matrix.

Keywords: DBSCAN, potential function, speech signal, the UBSS model

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4054 Servant Leadership and Organisational Climate in South African Private Schools: A Qualitative Study

Authors: Christo Swart, Lidia Pottas, David Maree

Abstract:

Background: It is a sine qua non that the South African educational system finds itself in a profound crisis and that traditional school leadership styles are outdated and hinder quality education. New thinking is mandatory to improve the status quo and school leadership has an immense role to play to improve the current situation. It is believed that the servant leadership paradigm, when practiced by school leadership, may have a significant influence on the school environment in totality. This study investigates the private school segment in search of constructive answers to assist with the educational crises in South Africa. It is assumed that where school leadership can augment a supportive and empowering environment for teachers to constructively engage in their teaching and learning activities - then many challenges facing by school system may be subjugated in a productive manner. Aim: The aim of this study is fourfold. To outline the constructs of servant leadership which are perceived by teachers of private schools as priorities to enhance a successful school environment. To describe the constructs of organizational climate which are observed by teachers of private schools as priorities to enhance a successful school environment. To investigate whether the participants perceived a link between the constructs of servant leadership and organizational climate. To consider the process to be followed to introduce the constructs of SL and OC the school system in general as perceived by participants. Method: This study utilized a qualitative approach to explore the mediation between school leadership and the organizational climate in private schools in the search for amicable answers. The participants were purposefully selected for the study. Focus group interviews were held with participants from primary and secondary schools and a focus group discussion was conducted with principals of both primary and secondary schools. The interview data were transcribed and analyzed and identical patterns of coded data were grouped together under emerging themes. Findings: It was found that the practice of servant leadership by school leadership indeed mediates a constructive and positive school climate. It was found that the constructs of empowerment, accountability, humility and courage – interlinking with one other - are prominent of servant leadership concepts that are perceived by teachers of private schools as priorities for school leadership to enhance a successful school environment. It was confirmed that the groupings of training and development, communication, trust and work environment are perceived by teachers of private schools as prominent features of organizational climate as practiced by school leadership to augment a successful school environment. It can be concluded that the participants perceived several links between the constructs of servant leadership and organizational climate that encourage a constructive school environment and that there is a definite positive consideration and motivation that the two concepts be introduced to the school system in general. It is recommended that school leadership mentors and guides teachers to take ownership of the constructs of servant leadership as well as organizational climate and that public schools be researched and consider to implement the two paradigms. The study suggests that aspirant teachers be exposed to leadership as well as organizational paradigms during their studies at university.

Keywords: empowering environment for teachers and learners, new thinking required, organizational climate, school leadership, servant leadership

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4053 Contribution of Home Gardens to Rural Household Income in Raymond Mhlaba Local Municipality, Eastern Cape Province, South Africa

Authors: K. Alaka, A. Obi

Abstract:

Home garden has proved to be significant to rural inhabitants by providing a wide range of useful products such as fruits, vegetables and medicine. There is need for quantitative information on its benefits and contributions to rural household. The main objective of this study is to investigate contributions of home garden to income of rural households in Raymond Mhlaba Local Municipality, formerly Nkonkobe Local Municipality of Eastern Cape Province South Africa. The stratified random sampling method was applied in order to choose a sample of 160 households.The study was conducted among 80 households engaging in home gardens and 80 non- participating households in the study area. Data analysis employed descriptive statistics with the use of frequency table and one way sample T test to show actual contributions. The overall model shows that social grant has the highest contribution to total household income for both categories while income generated from home garden has the second largest share to total household income, this shows that the majority of rural households in the study area rely on social grant as their source of income. However, since most households are net food buyers, it is essential to have policies that are formulated with an understanding that household food security is not only a function of the food that farming households produce for their own consumption but more so a function of total household income. The results produced sufficient evidence that home gardens contribute significantly to income of rural household.

Keywords: food security, home gardening, household, income

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4052 Chronic Cognitive Impacts of Mild Traumatic Brain Injury during Aging

Authors: Camille Charlebois-Plante, Marie-Ève Bourassa, Gaelle Dumel, Meriem Sabir, Louis De Beaumont

Abstract:

To the extent of our knowledge, there has been little interest in the chronic effects of mild traumatic brain injury (mTBI) on cognition during normal aging. This is rather surprising considering the impacts on daily and social functioning. In addition, sustaining a mTBI during late adulthood may increase the effect of normal biological aging in individuals who consider themselves normal and healthy. The objective of this study was to characterize the persistent neuropsychological repercussions of mTBI sustained during late adulthood, on average 12 months prior to testing. To this end, 35 mTBI patients and 42 controls between the ages of 50 and 69 completed an exhaustive neuropsychological assessment lasting three hours. All mTBI patients were asymptomatic and all participants had a score ≥ 27 at the MoCA. The evaluation consisted of 20 standardized neuropsychological tests measuring memory, attention, executive and language functions, as well as information processing speed. Performance on tests of visual (Brief Visuospatial Memory Test Revised) and verbal memory (Rey Auditory Verbal Learning Test and WMS-IV Logical Memory subtest), lexical access (Boston Naming Test) and response inhibition (Stroop) revealed to be significantly lower in the mTBI group. These findings suggest that a mTBI sustained during late adulthood induces lasting effects on cognitive function. Episodic memory and executive functions seem to be particularly vulnerable to enduring mTBI effects.

Keywords: cognitive function, late adulthood, mild traumatic brain injury, neuropsychology

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4051 Preliminary Study Investigating Trunk Muscle Fatigue and Cognitive Function in Event Riders during a Simulated Jumping Test

Authors: Alice Carter, Lucy Dumbell, Lorna Cameron, Victoria Lewis

Abstract:

The Olympic discipline of eventing is the triathlon of equestrian sport, consisting of dressage, cross-country and show jumping. Falls on the cross-country are common and can be serious even causing death to rider. Research identifies an increased risk of a fall with an increasing number of obstacles and for jumping efforts later in the course suggesting fatigue maybe a contributing factor. Advice based on anecdotal evidence suggests riders undertake strength and conditioning programs to improve their ‘core’, thus improving their ability to maintain and control their riding position. There is little empirical evidence to support this advice. Therefore, the aim of this study is to investigate truck muscle fatigue and cognitive function during a simulated jumping test. Eight adult riders participated in a riding test on a Racewood Event simulator for 10 minutes, over a continuous jumping programme. The SEMG activity of six trunk muscles were bilaterally measured at every minute, and normalised root mean squares (RMS) and median frequencies (MDF) were computed from the EMG power spectra. Visual analogue scales (VAS) measuring Fatigue and Pain levels and Cognitive Function ‘tapping’ tests were performed before and after the riding test. Average MDF values for all muscles differed significantly between each sampled minute (p = 0.017), however a consistent decrease from Minute 1 and Minute 9 was not found, suggesting the trunk muscles fatigued and then recovered as other muscle groups important in maintaining the riding position during dynamic movement compensated. Differences between the MDF and RMS of different muscles were highly significant (H=213.01, DF=5, p < 0.001), supporting previous anecdotal evidence that different trunk muscles carry out different roles of posture maintenance during riding. RMS values were not significantly different between the sampled minutes or between riders, suggesting the riding test produced a consistent and repeatable effect on the trunk muscles. MDF values differed significantly between riders (H=50.8, DF = 5, p < 0.001), suggesting individuals may experience localised muscular fatigue of the same test differently, and that other parameters of physical fitness should be investigated to provide conclusions. Lumbar muscles were shown to be important in maintaining the position, therefore physical training program should focus on these areas. No significant differences were found between pre- and post-riding test VAS Pain and Fatigue scores or cognitive function test scores, suggesting the riding test was not significantly fatiguing for participants. However, a near significant correlation was found between time of riding test and VAS Pain score (p = 0.06), suggesting somatic pain may be a limiting factor to performance. No other correlations were found between the factors of participant riding test time, VAS Pain and Fatigue, however a larger sample needs to be tested to improve statistical analysis. The findings suggest the simulator riding test was not sufficient to provoke fatigue in the riders, however foundations for future studies have been laid to enable methodologies in realistic eventing settings.

Keywords: eventing, fatigue, horse-rider, surface EMG, trunk muscles

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4050 Displacement Solution for a Static Vertical Rigid Movement of an Interior Circular Disc in a Transversely Isotropic Tri-Material Full-Space

Authors: D. Mehdizadeh, M. Rahimian, M. Eskandari-Ghadi

Abstract:

This article is concerned with the determination of the static interaction of a vertically loaded rigid circular disc embedded at the interface of a horizontal layer sandwiched in between two different transversely isotropic half-spaces called as tri-material full-space. The axes of symmetry of different regions are assumed to be normal to the horizontal interfaces and parallel to the movement direction. With the use of a potential function method, and by implementing Hankel integral transforms in the radial direction, the government partial differential equation for the solely scalar potential function is transformed to an ordinary 4th order differential equation, and the mixed boundary conditions are transformed into a pair of integral equations called dual integral equations, which can be reduced to a Fredholm integral equation of the second kind, which is solved analytically. Then, the displacements and stresses are given in the form of improper line integrals, which is due to inverse Hankel integral transforms. It is shown that the present solutions are in exact agreement with the existing solutions for a homogeneous full-space with transversely isotropic material. To confirm the accuracy of the numerical evaluation of the integrals involved, the numerical results are compared with the solutions exists for the homogeneous full-space. Then, some different cases with different degrees of material anisotropy are compared to portray the effect of degree of anisotropy.

Keywords: transversely isotropic, rigid disc, elasticity, dual integral equations, tri-material full-space

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4049 Electronic Spectral Function of Double Quantum Dots–Superconductors Nanoscopic Junction

Authors: Rajendra Kumar

Abstract:

We study the Electronic spectral density of a double coupled quantum dots sandwich between superconducting leads, where one of the superconducting leads (QD1) are connected with left superconductor lead and (QD1) also connected right superconductor lead. (QD1) and (QD2) are coupling to each other. The electronic spectral density through a quantum dots between superconducting leads having s-wave symmetry of the superconducting order parameter. Such junction is called superconducting –quantum dot (S-QD-S) junction. For this purpose, we have considered a renormalized Anderson model that includes the double coupled of the superconducting leads with the quantum dots level and an attractive BCS-type effective interaction in superconducting leads. We employed the Green’s function technique to obtain superconducting order parameter with the BCS framework and Ambegaoker-Baratoff formalism to analyze the electronic spectral density through such (S-QD-S) junction. It has been pointed out that electronic spectral density through such a junction is dominated by the attractive the paring interaction in the leads, energy of the level on the dot with respect to Fermi energy and also on the coupling parameter of the two in an essential way. On the basis of numerical analysis we have compared the theoretical results of electronic spectral density with the recent transport existing theoretical analysis. QDs is the charging energy that may give rise to effects based on the interplay of Coulomb repulsion and superconducting correlations. It is, therefore, an interesting question to ask how the discrete level spectrum and the charging energy affect the DC and AC Josephson transport between two superconductors coupled via a QD. In the absence of a bias voltage, a finite DC current can be sustained in such an S-QD-S by the DC Josephson effect.

Keywords: quantum dots, S-QD-S junction, BCS superconductors, Anderson model

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4048 A Microwave and Millimeter-Wave Transmit/Receive Switch Subsystem for Communication Systems

Authors: Donghyun Lee, Cam Nguyen

Abstract:

Multi-band systems offer a great deal of benefit in modern communication and radar systems. In particular, multi-band antenna-array radar systems with their extended frequency diversity provide numerous advantages in detection, identification, locating and tracking a wide range of targets, including enhanced detection coverage, accurate target location, reduced survey time and cost, increased resolution, improved reliability and target information. An accurate calibration is a critical issue in antenna array systems. The amplitude and phase errors in multi-band and multi-polarization antenna array transceivers result in inaccurate target detection, deteriorated resolution and reduced reliability. Furthermore, the digital beam former without the RF domain phase-shifting is less immune to unfiltered interference signals, which can lead to receiver saturation in array systems. Therefore, implementing integrated front-end architecture, which can support calibration function with low insertion and filtering function from the farthest end of an array transceiver is of great interest. We report a dual K/Ka-band T/R/Calibration switch module with quasi-elliptic dual-bandpass filtering function implementing a Q-enhanced metamaterial transmission line. A unique dual-band frequency response is incorporated in the reception and calibration path of the proposed switch module utilizing the composite right/left-handed meta material transmission line coupled with a Colpitts-style negative generation circuit. The fabricated fully integrated T/R/Calibration switch module in 0.18-μm BiCMOS technology exhibits insertion loss of 4.9-12.3 dB and isolation of more than 45 dB in the reception, transmission and calibration mode of operation. In the reception and calibration mode, the dual-band frequency response centered at 24.5 and 35 GHz exhibits out-of-band rejection of more than 30 dB compared to the pass bands below 10.5 GHz and above 59.5 GHz. The rejection between the pass bands reaches more than 50 dB. In all modes of operation, the IP1-dB is between 4 and 11 dBm. Acknowledgement: This paper was made possible by NPRP grant # 6-241-2-102 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors.

Keywords: microwaves, millimeter waves, T/R switch, wireless communications, wireless communications

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4047 Interaction Between Gut Microorganisms and Endocrine Disruptors - Effects on Hyperglycaemia

Authors: Karthika Durairaj, Buvaneswari G., Gowdham M., Gilles M., Velmurugan G.

Abstract:

Background: Hyperglycaemia is the primary cause of metabolic illness. Recently, researchers focused on the possibility that chemical exposure could promote metabolic disease. Hyperglycaemia causes a variety of metabolic diseases dependent on its etiologic conditions. According to animal and population-based research, individual chemical exposure causes health problems through alteration of endocrine function with the influence of microbial influence. We were intrigued by the function of gut microbiota variation in high fat and chemically induced hyperglycaemia. Methodology: C57/Bl6 mice were subjected to two different treatments to generate the etiologic-based diabetes model: I – a high-fat diet with a 45 kcal diet, and II - endocrine disrupting chemicals (EDCs) cocktail. The mice were monitored periodically for changes in body weight and fasting glucose. After 120 days of the experiment, blood anthropometry, faecal metagenomics and metabolomics were performed and analyzed through statistical analysis using one-way ANOVA and student’s t-test. Results: After 120 days of exposure, we found hyperglycaemic changes in both experimental models. The treatment groups also differed in terms of plasma lipid levels, creatinine, and hepatic markers. To determine the influence on glucose metabolism, microbial profiling and metabolite levels were significantly different between groups. The gene expression studies associated with glucose metabolism vary between hosts and their treatments. Conclusion: This research will result in the identification of biomarkers and molecular targets for better diabetes control and treatment.

Keywords: hyperglycaemia, endocrine-disrupting chemicals, gut microbiota, host metabolism

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