Search results for: mobility assistive device

Authors: Jonghoon Kim, Gilwon Yoon

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A wrist-band type biosignal measurement system and its data transfer through human body communication (HBC) were investigated. An HBC method based on pulses of ultra-wide band instead of using frequency or amplitude modulations was studied and implemented since the system became very compact and it was more suited for personal or mobile health monitoring. Our system measured photo-plethysmogram (PPG) and measured PPG signals were transmitted through a finger to a monitoring PC system. The device was compact and low-power consuming. HBC communication has very strong security measures since it does not use wireless network. Furthermore, biosignal monitoring system becomes handy because it does not need to have wire connections.

Keywords: biosignal, human body communication, mobile health, PPG, ultrawide band

Procedia PDF Downloads 476

Authors: Sorayya Kazemi, Hamed Kharrati, Mehdi Abedinpour Fallah

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This paper presents the design and implementation of a novel electric pressure-sensitive toothbrush, capable of measuring the forces applied to the head of the brush. The developed device is used for gum recession measurement. In particular, the percentage of gum recession is measured by a Programmable Automation controller (PAC). Moreover, the brushing forces are measured by a Force Sensing Resistor (FSR) sensor. These forces are analog inputs of PAC. According to the applied forces during patient’s brushing and the patient’s percentage of gum recession, dentist sets the standard force range. The instrument alarms when the patient applies a force over the set range.

Keywords: gum recession, force sensing resistor, controller, toothbrush

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Authors: Alaa Al Hawari, Mohammad Khader, Tarek Zayed, Osama Moselhi

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In this paper, an effective non-destructive, non-invasive approach for leak detection was proposed. The process relies on analyzing thermal images collected by an IR viewer device that captures thermo-grams. In this study a statistical analysis of the collected thermal images of the ground surface along the expected leak location followed by a visual inspection of the thermo-grams was performed in order to locate the leak. In order to verify the applicability of the proposed approach the predicted leak location from the developed approach was compared with the real leak location. The results showed that the expected leak location was successfully identified with an accuracy of more than 95%.

Keywords: thermography, leakage, water pipelines, thermograms

Procedia PDF Downloads 355

Authors: Jae-Soo Do, Kyoung-Seok Kim

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The crisis theory of Samsung Electronics is becoming a hot topic today. Due to its performance deterioration, the share of Samsung Electronics lost its driving power. Considering the public opinion about the bad rumors circulating within the company, it is quite probable that the company is currently facing crisis. Then, what company has challenged the stronghold of Samsung Electronics? At the core of the crisis is 'Xiaomi' who snatched the first place of the market share, pushing Samsung Electronics aside in the Chinese market. In June 2010, Xiaomi, established by eight co-founders, has been showing a miraculous growth as the smart device manufacturer, taking the first place in the Chinese market and coming in fifth worldwide in just four years after its establishment. How did Xiaomi instantaneously achieve enough growth to overtake Samsung? Thus, we have conducted a comparative analysis on the competitive strategies of Samsung and Xiaomi.

Keywords: Samsung, Xiaomi, industrial attractiveness, VIRO

Procedia PDF Downloads 396

Authors: Naim Suleyman Ting, Yakup Sahin, Ismail Aksoy

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This paper presents a zero voltage transition-zero current transition (ZVT-ZCT)-PWM DC-DC boost converter with direct power transfer. In this converter, the main switch turns on with ZVT and turns off with ZCT. The auxiliary switch turns on and off with zero current switching (ZCS). The main diode turns on with ZVS and turns off with ZCS. Besides, the additional current or voltage stress does not occur on the main device. The converter has features as simple structure, fast dynamic response and easy control. Also, the proposed converter has direct power transfer feature as well as excellent soft switching techniques. In this study, the operating principle of the converter is presented and its operation is verified for 1 kW and 100 kHz model.

Keywords: direct power transfer, boost converter, zero-voltage transition, zero-current transition

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Authors: Heba M. Wagih, Hoda M. O. Mokhtar

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Social Network has recently played a significant role in both scientific and social communities. The growing adoption of social network applications has been a relevant source of information nowadays. Due to its popularity, several research trends are emerged to service the huge volume of users including, Location-Based Social Networks (LBSN), Recommendation Systems, Sentiment Analysis Applications, and many others. LBSNs applications are among the highly demanded applications that do not focus only on analyzing the spatiotemporal positions in a given raw trajectory but also on understanding the semantics behind the dynamics of the moving object. LBSNs are possible means of predicting human mobility based on users social ties as well as their spatial preferences. LBSNs rely on the efficient representation of users’ trajectories. Hence, traditional raw trajectory information is no longer convenient. In our research, we focus on studying human behavior trajectory which is the major pillar in location recommendation systems. In this paper, we propose an ontology design patterns with their underlying description logics to efficiently annotate human behavior trajectories.

Keywords: human behavior trajectory, location-based social network, ontology, social network

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Authors: Nagaraju Jarugu, B. R. Narendra

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This paper focused on boost rectification by Single Phase Matrix Converter with fewer numbers of switches. The conventional matrix converter consists of 4 bidirectional switches, i.e. 8 set of IGBT/MOSFET with anti-parallel diodes. In this proposed matrix converter, only six switches are used. The switch commutation arrangements are also carried out in this work. The SPMC topology has many advantages as a minimal passive device use. It is very flexible and it can be used as a lot of converters. The gate pulses to the switches are provided by the PWM techniques. The duty ratio of the switches based on Pulse Width Modulation (PWM) technique was used to produce the output waveform of the circuit, simply by turning ON and OFF the switches. The simulation results using MATLAB/Simulink were provided to validate the feasibility of this proposed method.

Keywords: single phase matrix converter, reduced switches, AC voltage regulators, boost rectifier operation

Procedia PDF Downloads 1188

Authors: Ioannis Andrianakis, Manolis Falelakis, Maria Pavlidou, Konstantinos Papakonstantinou, Ermioni Avramidou, Dimitrios Kalogiannis, Nikolaos Milios, Katerina Bountakidou, Kiriakos Chatzidimitriou, Panagiotis Panagiotopoulos

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Artistic events, such as concerts and performances, are challenging to organize because they involve many people with different skill sets. Small and medium venues often struggle to afford the costs and overheads of booking and hosting remote artists, especially if they lack sponsors or subsidies. This limits the opportunities for both venues and artists, especially those outside of big cities. However, more and more research shows that audiences prefer smaller-scale events and concerts, which benefit local economies and communities. To address this challenge, our project “PerformAnts: Digital Event Manager-Organizer” aims to develop a smart digital tool that automates and optimizes the processes and costs of live shows and tours. By using machine learning, applying best practices and training users through workshops, our platform offers a comprehensive solution for a growing market, enhances the mobility of artists and the accessibility of venues and allows professionals to focus on the creative aspects of concert production.

Keywords: event organization, creative industries, event promotion, machine learning

Procedia PDF Downloads 87

Authors: Alaa El-Din Rezk

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For organic xenobiotics, sorption to Aldrich humic acid is a key process controlling their mobility, bioavailability, toxicity and fate in the soil. Hydrophobic organic compounds possessing either acid or basic groups can be partially ionized (deprotonated or protonated) within the range of natural soil pH. For neutral and ionogenicxenobiotics including (neutral, acids and bases) sorption coefficients normalized to organic carbon content, Koc, have measured at different pH values. To this end, the batch equilibrium technique has been used, employing SPME combined with GC-MSD as an analytical tool. For most ionogenic compounds, sorption has been affected by both pH and pKa and can be explained through Henderson-Hasselbalch equation. The results demonstrate that when assessing the environmental fate of ionogenic compounds, their pKa and speciation under natural conditions should be taken into account. A new model has developed to predict the relationship between log Koc and pH with full statistical evaluation against other existing predictive models. Neutral solutes have displayed a good fit with the classical model using log Kow as log Koc predictor, whereas acidic and basic compounds have displayed a good fit with the LSER approach and the new proposed model. Measurement limitations of the Batch technique and SPME-GC-MSD have been found with ionic compounds.

Keywords: humic acid, log Koc, pH, pKa, SPME-GCMSD

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Authors: H. Zengin, M. E. Turan, Y. Turen, H. Ahlatci, Y. Sun

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This study aimed for improving wear resistance of AM60 magnesium alloy by Ti addition (0, 0.2, 0.5, 1wt%Ti). An electric resistance furnace was used to produce alloys. Pure Mg together with Al, Al-Ti and Al-Mn were melted at 750 ⁰C in a stainless steel crucible under controlled Ar gas atmosphere and then poured into a metal mould preheated at 250 ⁰C. Microstructure characterizations were performed by light optical (LOM) and scanning electron microscope (SEM) after the wear test. Wear rates and friction coefficients were measured with a pin-on-disk type UTS-10 Tribometer test device under a load of 20N. The results showed that Ti addition altered the morphology and the amount of b-Mg₁₇Al₁₂ phase in the microstructure of AM60 alloy. b-Mg₁₇Al₁₂ phases on the grain boundaries were refined with increasing amount of Ti. An improvement in wear resistance of AM60 alloy was observed due to the alteration in the microstructure by Ti addition.

Keywords: magnesium alloy, titanium, SEM, wear

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Authors: Mehrnaz Mostafavi

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Recent advances in single-molecule protein identification (ID) and quantification techniques are poised to revolutionize proteomics, enabling researchers to delve into single-cell proteomics and identify low-abundance proteins crucial for biomedical and clinical research. This paper introduces a different approach to single-molecule protein ID and quantification using tri-color amino acid tags and a plasmonic nanopore device. A comprehensive simulator incorporating various physical phenomena was designed to predict and model the device's behavior under diverse experimental conditions, providing insights into its feasibility and limitations. The study employs a whole-proteome single-molecule identification algorithm based on convolutional neural networks, achieving high accuracies (>90%), particularly in challenging conditions (95–97%). To address potential challenges in clinical samples, where post-translational modifications affecting labeling efficiency, the paper evaluates protein identification accuracy under partial labeling conditions. Solid-state nanopores, capable of processing tens of individual proteins per second, are explored as a platform for this method. Unlike techniques relying solely on ion-current measurements, this approach enables parallel readout using high-density nanopore arrays and multi-pixel single-photon sensors. Convolutional neural networks contribute to the method's versatility and robustness, simplifying calibration procedures and potentially allowing protein ID based on partial reads. The study also discusses the efficacy of the approach in real experimental conditions, resolving functionally similar proteins. The theoretical analysis, protein labeler program, finite difference time domain calculation of plasmonic fields, and simulation of nanopore-based optical sensing are detailed in the methods section. The study anticipates further exploration of temporal distributions of protein translocation dwell-times and the impact on convolutional neural network identification accuracy. Overall, the research presents a promising avenue for advancing single-molecule protein identification and quantification with broad applications in proteomics research. The contributions made in methodology, accuracy, robustness, and technological exploration collectively position this work at the forefront of transformative developments in the field.

Keywords: nano proteomics, nanopore-based optical sensing, deep learning, artificial intelligence

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Authors: Maja Čović, Josipa Bojčić, Bruna Bacalja, Gorana Jelić Mrčelić

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The appearance of the COVID-19 disease and its fast-spreading brought global pandemic and health crisis. In order to prevent the further spreading of the virus, the governments had implemented mobility restriction rules which left a negative mark on the world’s economy. Although there is numerous research on the impact of COVID-19 on marine traffic around the world, the objective of this paper is to consider the impact of COVID-19 on passenger and cargo traffic in Port of Split, in the Republic of Croatia. Methods used to make the theoretical and research part of the paper are descriptive method, comparative method, compilation, inductive method, deductive method, and statistical method. Paper relies on data obtained via Port of Split Authority and analyses trends in passenger and cargo traffic, including the year 2020, when the pandemic broke. Significant reductions in income, disruptions in transportation and traffic, as well as other maritime services are shown in the paper. This article also observes a significant decline in passenger traffic, cruising traffic and also observes the dynamic of cargo traffic inside the port of Split.

Keywords: COVID-19, pandemic, passenger traffic, ports, trends, cargo traffic

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Authors: K. K. Saju, A. R. Reghuraj

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High reflectance of surgical instruments under bright light hinders the visual clarity during laparoscopic surgical procedures leading to loss of precision and device control and creates strain and undesired difficulties to surgeons. Majority of the surgical instruments are made of surgical grade steel. Instruments with a non reflective surface can enhance the visual clarity during precision surgeries. A conversion coating of black oxide has been successfully developed 410 grade surgical stainless steel .The characteristics of the developed coating suggests the application of this technique for developing 410 grade surgical instruments with minimal reflectance.

Keywords: conversion coatings, 410 stainless steel, black oxide, reflectance

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Authors: C. L. Wu, W. W. Tseng

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From the National Health Insurance (NHI) system was introduced in Taiwan in 2000, there have been some problems in transformed small-scale hospitals, such as mobility of patients, shortage of nursing staff, medical pipelines breaking fire compartments and insufficient fire protection systems. Due to shrinking of the funding scale and the aging society, fire safety in small-scale hospitals has recently given cause for concern. The aim of this study is to determine fire risk index for small-scale hospital through a systematic approach The selection of fire safety mitigation methods can be regarded as a multi-attribute decision making process which must be guaranteed by expert groups. First of all, identify and select safety related factors and identify evaluation criteria through literature reviews and experts group. Secondly, application of the Fuzzy Analytic Hierarchy Process method is used to ascertain a weighted value which enables rating of the importance each of the selected factors. Overall, Sprinkler type and Compartmentation are the most crucial indices in mitigating fire, that is to say, structural approach play an important role to decrease losses in fire events.

Keywords: Fuzzy Delphi Method, fuzzy analytic hierarchy, process risk assessment, fire events

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Authors: Alaa Eldien Sarhaan, Rania A. Galil, Yasmina Youssef

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Vital streets transfer a totally different message from the lifeless streets; vitality is considered as the mobility dynamism for the city’s streets. The quality of a street is integral to the vitality. However, most efforts have focused on the requirements of cars resulting in the loss many qualities. A successful street is related to the needs and expectations of pedestrians. The amount of activity held in a place is one of the measures of vitality; hence the meaning of a vital street may be the result of a number of people engaged in various activities meeting their needs and expectations. Consequently, it varies from one city to another. This research focuses on vitality in commercial streets. It studies commercial streets in the Egyptian context, which have developed into a chaotic environment due to inefficiency and high-density activities. The first part identifies the meaning of vitality in the frame of its physical, social and economic dimensions, then determines the methods used in measuring vitality across commercial streets. Secondly, an application on one of the most important commercial streets in Alexandria ‘El-Attareen’ street is chosen as a case study to measure its vitality. The study contributes to a greater understanding of how theories on vital urban life contribute to the development of vital commercial streets in the Egyptian and similar contexts.

Keywords: footfall measurement, vitality, urban commercial streets, yield factor

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Authors: Soungwan Kim

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This study identifies factors underlying the digital divide that is faced by the disabled. The results of its analysis showed that the digital divide in PC use is affected by age, number of years of education, employment status, and household income of more than KRW 3 million. The digital divide in smart device use is affected by sex, age, number of years of education, time when disability struck, and household income of more than KRW 3 million. Based on these results, this study proposes methods for bridging the digital divide faced by the disabled.

Keywords: digital divide, digital divide for the disabled, information accessibility for PCs and smart devices, information accessibility

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Authors: C. Yagci, F. Iscan

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In this study, spatial differences of Power Transmission Line (PTL) and effects of the situation before and after the urban regeneration are studied by using Geographical Information System (GIS). In addition, a questionable and analyzable structure is acquired by developed system. In the study area many parcels on the PTL were analyzed. The amount of the parcels, which are affected by the negativity of PTL is clearly seen with the aid of generated maps. Some kind of changes are exhibited in the system, which are created by GIS, for instance before urban regeneration PTL was very close to people’s private properties and huge parts of PTL were among the buildings, however; after urban regeneration electricity lines were changed their locations to the underground. According to the results, GIS can be used as a device in planning and managing of PTL in urban regeneration projects and can be used for analyses. By the help of GIS technology, necessary investigations should be carried out in urban regeneration applications for creating sustainable cities.

Keywords: GIS, power transmission line, technology, urban regeneration

Procedia PDF Downloads 766

Authors: Khaled Shaaban

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Distracted driving, which includes anything that distracts a driver from the main task of driving, is one of the main causes of traffic accidents in modern societies. The objective of this research was to understand the type of activities that young drivers perform while driving in Qatar and to identify which activities cause the most distraction to the driver based on their experience. The data was collected through administered questionnaires in the city of Doha, Qatar. According to the participants, the majority reported that they use their cell phone all the time or occasionally while driving. Other significantly cited activities while driving included listening to music or radio, talking with passengers, and eating, drinking or smoking. When asked about the activities that distract the driver, using cell phone was listed as the most distracting activity followed by mental activities and adjusting GPS and audio device vehicle.

Keywords: driver distraction, young drivers, cell phone use, Qatar

Procedia PDF Downloads 492

Authors: Majed M. Mustafa, Abdulrahman A. Altassan

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In recent years, ensuring accessibility for all individuals, particularly those with mobility impairments, has gained significant attention in Saudi Arabia. This research aims to evaluate wheelchair accessibility in shopping centers, malls, and stores across the kingdom, highlighting its critical role in promoting inclusivity and equal access. The study will focus on the availability and quality of ramps, automatic doors, lifts, accessible restrooms, and overall ease of navigation for wheelchair users. Utilizing a mixed-methods approach, the research will employ site assessments, user surveys, and interviews with facility managers to gather comprehensive data. Preliminary findings indicate that while some facilities have made strides in accessibility, there are still numerous areas requiring improvement. The study will provide targeted recommendations to enhance accessibility, ensuring that all users can navigate shopping environments with ease and dignity. Conclusively, this research underscores the need for continuous efforts and policy enhancements to achieve universal design standards in public spaces within Saudi Arabia.

Keywords: automatic doors, equal access, ramp quality, wheelchair accessibility

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Authors: Aisha Maroof

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Introduction: Coronavirus Disease 2019 (COVID-19) is spreading rapidly around the world with devastating consequences on patients, health care workers and health systems. Severe 2019 novel coronavirus infectious disease (COVID-19) with pneumonia is associated with high rates of admission to the intensive care unit (ICU) and they are at high risk to obtain the hospital acquire bloodstream infection (HAIs) such as central line associated bloodstream infection (CLABSI), catheter associated urinary tract infections (CAUTI) and laboratory confirm bloodstream infection (LCBSI). The chances of infection transmission increase when healthcare worker’s (HCWs) practice is inappropriate. Risk related to hand hygiene (HH) and personal protective equipment (PPE) as regards multidrug-resistant organism transmission: use of multiple gloving instead of HH and incorrect use of PPE can lead to a significant increase of device-related infections. As it reaches low- and middle-income countries, its effects could be even more, because it will be difficult for them to react aggressively to the pandemic. HAIs are one of the biggest medical concerns, resulting in increased mortality rates. Objective: To assess the effect of intervention on compliance of hand hygiene and PPE among HCWs reduce the rate of HAI in COVID-19 patients. Method: An interventional study was done between July to December, 2020. CLABSI, CAUTI and LCBSI data were collected from the medical record and direct observation. There were total of 50 Nurses, 18 doctors and all patients with laboratory-confirmed severe COVID-19 admitted to the hospital were included in this research study. Respiratory tract specimens were obtained after the first 48 h of ICU admission. Practices were observed after and before intervention. Education was provided based on WHO guidelines. Results: During the six months of study July to December, the rate of CLABSI, CAUTI and LCBSI pre and post intervention was reported. CLABSI rate decreasedd from 22.7 to 0, CAUTI rate was decreased from 1.6 to 0, LCBSI declined from 3.3 to 0 after implementation of intervention. Conclusion: HAIs are an important cause of morbidity and mortality. Most of the device related infections occurs due to lack of correct use of PPE and hand hygiene compliance. Hand hygiene and PPE is the most important measure to protect patients, through education it can be improved the correct use of PPE and hand hygiene compliance and can reduce the bacterial infection in COVID-19 patients.

Keywords: hospital acquire infection, healthcare workers, hand hygiene, personal protective equipment

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Authors: Ahmed Nassim Moulai Khatir

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Fin field effect transistors (FinFETs) deliver superior levels of scalability than the classical structure of MOSFETs by offering the elimination of short channel effects. Modern FinFETs are 3D structures that rise above the planar substrate, but some of these structures have inclined surfaces, which results in trapezoidal cross sections instead of rectangular sections usually used. Fin cross section shape of FinFETs results in some device issues, like potential distribution performance. This work analyzes that impact with three-dimensional numeric simulation of several triple-gate FinFETs with various top and bottom widths of fin. Results of the simulation show that the potential distribution and the electrical field in the fin depend on the sidewall inclination angle.

Keywords: FinFET, cross section shape, SILVACO, trapezoidal FinFETs

Procedia PDF Downloads 47

Authors: Wilai Masanga, Chirapha Tannanonta, Sangutid Thongsawad, Sasikarn Chamchod, Todsaporn Fuangrod

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The major factors of radiotherapy for head and neck (HN) cancers include patient’s anatomical changes and tumour shrinkage. These changes can significantly affect the planned dose distribution that causes the treatment plan deterioration. A measured transit EPID images compared to a predicted EPID images using gamma analysis has been clinically implemented to verify the dose accuracy as part of adaptive radiotherapy protocol. However, a global gamma analysis dose not sensitive to some critical organ changes as the entire treatment field is compared. The objective of this feasibility study is to evaluate the dosimetric response to patient anatomical changes during the treatment course in HN IMRT (Head and Neck Intensity-Modulated Radiation Therapy) using a novel comparison method; organ-of-interest gamma analysis. This method provides more sensitive to specific organ change detection. Random replanned 5 HN IMRT patients with causes of tumour shrinkage and patient weight loss that critically affect to the parotid size changes were selected and evaluated its transit dosimetry. A comprehensive physics-based model was used to generate a series of predicted transit EPID images for each gantry angle from original computed tomography (CT) and replan CT datasets. The patient structures; including left and right parotid, spinal cord, and planning target volume (PTV56) were projected to EPID level. The agreement between the transit images generated from original CT and replanned CT was quantified using gamma analysis with 3%, 3mm criteria. Moreover, only gamma pass-rate is calculated within each projected structure. The gamma pass-rate in right parotid and PTV56 between predicted transit of original CT and replan CT were 42.8%( ± 17.2%) and 54.7%( ± 21.5%). The gamma pass-rate for other projected organs were greater than 80%. Additionally, the results of organ-of-interest gamma analysis were compared with 3-dimensional cone-beam computed tomography (3D-CBCT) and the rational of replan by radiation oncologists. It showed that using only registration of 3D-CBCT to original CT does not provide the dosimetric impact of anatomical changes. Using transit EPID images with organ-of-interest gamma analysis can provide additional information for treatment plan suitability assessment.

Keywords: re-plan, anatomical change, transit electronic portal imaging device, EPID, head, and neck

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Authors: Reem Al-Garni

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Malnutrition is a global epidemic, but the under-weight or Failure-To-Thrive risk is increasing in rehabilitation setting and considered one of the contribution factor for developmental delay. Beside the consequences of malnutrition on children growth and development, there are other side-effects that might delay or hold the progress of rehabilitation. The awareness for malnutrition must be raised and discussed by the rehabilitation team, to promote the treatment and to optimize the client care. The solution can start from food supplements intake and / or Enteral Nutrition plan, depending on the malnutrition level and to reach the goal, the medical team should to work together in order to provide comprehensive treatment and to help the family to be able to manage their child condition. We have explore the outcomes of rehabilitation between the children with CP whose diagnosed with malnutrition and children with normal body Wight Over a period of 4 months who received 4-6 weeks of rehabilitation two hours daily by using WeeFIM score to measure rehabilitation outcomes. WeeFIM measures and covers various domains, such as: self-care, mobility, locomotion, communication and other psycho-social aspects. Our findings reported that children with normal body Wight has better outcomes and improvement comparing with children with malnutrition for the entire study sample.

Keywords: Cerebral Palsy (CP), pediatric Functional Independent Measure (WeeFIM), rehabilitation, malnutrition

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Authors: H. Nematifar, D. Sanavi Khoshnoud, S. Feyz

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Bi0.82La0.2Fe1-xCrxO3 (BLFCxO, x = 0.0, 0.02, 0.05 and 0.08) nanoparticles were successfully synthesized by a sol-gel method. The X-ray diffraction (XRD) patterns indicate that the lattice parameters decrease for x ≤ 0.05, firstly, and then they increase for x > 0.05. A transformation from rhombohedral structure to orthorhombic structure occurs at x = 0.08. The transmission electron microscopy (TEM) analysis shows that the average nanoparticle size is about 60-70 nm. The remnant magnetisation (Mr) increases gradually with x to 0.02, then decreases with further increasing x up to 0.05, and finally enchases abruptly in x = 0.08. The coercivity (HC) increases gradually with x to 0.05, and then significantly reduced with increasing Cr substitution. The magnetic ordering temperature (TN) decreases with Cr doping concentration. The M-H curves of all samples exhibit a wasp-waist hysteresis loop in low magnetic region. This property can play an important role for the applications of some multiferroic nano-device.

Keywords: BiFeO3, sol-gel preparation, nanoparticles, magnetic materials, thermal analysis

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Authors: Jade Martínez-Llinàs, Pere Colet

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By exploring the possible dynamical regimes in a prototypical model for mutually delay-coupled OEOs, here it is shown that two mutually coupled non-identical OEOs, besides in- and out-of-phase square-waves, can generate stable square-wave pulses synchronized at a quarter of the period (T/4) in a broad parameter region. The key point to obtain T/4 solutions is that the two OEO operate with mixed feedback, namely with negative feedback in one and positive in the other. Furthermore, the coexistence of multiple solutions provides a large degree of flexibility for tuning the frequency in the GHz range without changing any parameter. As a result the two coupled OEOs system is good candidate to be implemented for information encoding as a high-capacity memory device.

Keywords: nonlinear optics, optoelectronic oscillators, square waves, synchronization

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Authors: F. Pedro, S. Dias, A. Tadeu, J. António, Ó. López, A. Coelho

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Railway transportation is considered the most economical and sustainable way to travel. However, future mobility brings important challenges to railway operators. The main target is to develop solutions that stimulate sustainable mobility. The research and innovation goals for this domain are efficient solutions, ensuring an increased level of safety and reliability, improved resource efficiency, high availability of the means (train), and satisfied passengers with the travel comfort level. These requirements are in line with the European Strategic Agenda for the 2020 rail sector, promoted by the European Rail Research Advisory Council (ERRAC). All these aspects involve redesigning current equipment and, in particular, the interior of the carriages. Recent studies have shown that two of the most important requirements for passengers are reasonable ticket prices and comfortable interiors. Passengers tend to use their travel time to rest or to work, so train interiors and their systems need to incorporate features that meet these requirements. Among the various systems that integrate train interiors, the flooring system is one of the systems with the greatest impact on passenger safety and comfort. It is also one of the systems that takes more time to install on the train, and which contributes seriously to the weight (mass) of all interior systems. Additionally, it presents a strong impact on manufacturing costs. The design of railway floor, in the development phase, is usually made relying on a design software that allows to draw and calculate several solutions in a short period of time. After obtaining the best solution, considering the goals previously defined, experimental data is always necessary and required. This experimental phase has such great significance, that its outcome can provoke the revision of the designed solution. This paper presents the methodology and some of the results of an experimental characterisation of composite panels for railway application. The mechanical tests were made for unaged specimens and for specimens that suffered some type of aging, i.e. heat, cold and humidity cycles or freezing/thawing cycles. These conditionings aim to simulate not only the time effect, but also the impact of severe environmental conditions. Both full solutions and separated components/materials were tested. For the full solution, (panel) these were: four-point bending tests, tensile shear strength, tensile strength perpendicular to the plane, determination of the spreading of water, and impact tests. For individual characterisation of the components, more specifically for the covering, the following tests were made: determination of the tensile stress-strain properties, determination of flexibility, determination of tear strength, peel test, tensile shear strength test, adhesion resistance test and dimensional stability. The main conclusions were that experimental characterisation brings a huge contribution to understand the behaviour of the materials both individually and assembled. This knowledge contributes to the increase the quality and improvements of premium solutions. This research work was framed within the POCI-01-0247-FEDER-003474 (coMMUTe) Project funded by Portugal 2020 through the COMPETE 2020.

Keywords: durability, experimental characterization, mechanical tests, railway flooring system

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Authors: Abdeljalil Metioui

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The purpose of this article is to present the results of two-stage qualitative research. The first involved the identification of the alternative conceptions of 80 elementary pre-service teachers from Quebec in Canada about the operation of simple electrical circuits. To do this, they completed a two-choice questionnaire (true or false) with justification. Data analysis identifies many conceptual difficulties. For example, for their majority, whatever the electrical device that composes an electrical circuit, the current source (power supply), and the generated electrical power is constant. The second step was to develop a double multiple-choice questionnaire based on the identified designs. It allows teachers to quickly diagnose their students' conceptions and take them into account in their teaching.

Keywords: development, electrical circuits, two-tier diagnostic test, secondary and high school

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Authors: Mohammad Rostami, Mohammad Reza Forghani, Elahe Neshat, Fatemeh Yaghoobi

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An Ad Hoc network consists of wireless mobile equipment which connects to each other without any infrastructure, using connection equipment. The best way to form a hierarchical structure is clustering. Various methods of clustering can form more stable clusters according to nodes' mobility. In this research we propose an algorithm, which allocates some weight to nodes based on factors, i.e. link stability and power reduction rate. According to the allocated weight in the previous phase, the cellular learning automaton picks out in the second phase nodes which are candidates for being cluster head. In the third phase, learning automaton selects cluster head nodes, member nodes and forms the cluster. Thus, this automaton does the learning from the setting and can form optimized clusters in terms of power consumption and link stability. To simulate the proposed algorithm we have used omnet++4.2.2. Simulation results indicate that newly formed clusters have a longer lifetime than previous algorithms and decrease strongly network overload by reducing update rate.

Keywords: mobile Ad Hoc networks, clustering, learning automaton, cellular automaton, battery power

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Authors: Esraa Moustafa, Gaetan Rey, Stephane Lavirotte, Jean-Yves Tigli

Abstract:

With the development of Internet of Things and Web of Things, computing becomes more pervasive, invisible and present everywhere. In fact, in our environment, we are surrounded by multiple devices that deliver (web) services that meet the needs of the users. However, the mobility of these devices as the users has important repercussions that challenge software design of these applications because the variability of the environment cannot be anticipated at the design time. Thus, it will be interesting to dynamically discover the environment and adapt the application during its execution to the new contextual conditions. We, therefore, propose a model of a context-aware middleware that can address this issue through a monitoring service that is capable of reasoning and observation channels capable of calculating the context during the runtime. The monitoring service evaluates the pre-defined X-Query predicates in the context manager and uses Prolog to deduce the services needed to respond back. An independent Observation Channel for each different predicate is then dynamically generated by the monitoring service depending on the current state of the environment. Each channel sends its result directly to the context manager which consequently calculates the context based on all the predicates’ results while preserving the reactivity of the self-adaptive system.

Keywords: auto-adaptation, context-awareness, middleware, reasoning engine

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Authors: Stepan Papacek, Jiri Jablonsky, Radek Kana, Ctirad Matonoha, Stefan Kindermann

Abstract:

FRAP (Fluorescence Recovery After Photobleaching) is a widely used measurement technique to determine the mobility of fluorescent molecules within living cells. While the experimental setup and protocol for FRAP experiments are usually fixed, data processing part is still under development. In this paper, we formulate and solve the problem of data selection which enhances the processing of FRAP images. We introduce the concept of the irrelevant data set, i.e., the data which are almost not reducing the confidence interval of the estimated parameters and thus could be neglected. Based on sensitivity analysis, we both solve the problem of the optimal data space selection and we find specific conditions for optimizing an important experimental design factor, e.g., the radius of bleach spot. Finally, a theorem announcing less precision of the integrated data approach compared to the full data case is proven; i.e., we claim that the data set represented by the FRAP recovery curve lead to a larger confidence interval compared to the spatio-temporal (full) data.

Keywords: FRAP, inverse problem, parameter identification, sensitivity analysis, optimal experimental design

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