Abstract: Interoperable medical devices (IMDs) face threats due to the increased attack surface accessible by interoperability and the corresponding infrastructure. Initiating networking and coordination functionalities primarily modify medical systems' security properties. Understanding the threats is a vital first step in ultimately crafting security solutions for such systems. The key to this problem is coming up with some common types of threats or attacks with those of security and privacy, and providing this information as a roadmap. This paper analyses the security issues in interoperability of devices and presents the main types of threats that have to be considered to build a secured system.
Abstract: Housings in developing countries have often inadequate
seismic protection, particularly for masonry. People choose this type
of structure since the cost and application are relatively cheap.
Seismic protection of masonry remains an interesting issue among
researchers. In this study, we develop a low-cost seismic isolation
system for masonry using fiber reinforced elastomeric isolators. The
elastomer proposed consists of few layers of rubber pads and fiber
lamina, making it lower in cost comparing to the conventional
isolators. We present a finite element (FE) analysis to predict the
behavior of the low cost rubber isolators undergoing moderate
deformations. The FE model of the elastomer involves a hyperelastic
material property for the rubber pad. We adopt a Yeoh hyperelasticity
model and estimate its coefficients through the available experimental
data. Having the shear behavior of the elastomers, we apply that
isolation system onto small masonry housing. To attach the isolators
on the building, we model the shear behavior of the isolation system
by means of a damped nonlinear spring model. By this attempt, the
FE analysis becomes computationally inexpensive. Several ground
motion data are applied to observe its sensitivity. Roof acceleration
and tensile damage of walls become the parameters to evaluate
the performance of the isolators. In this study, a concrete damage
plasticity model is used to model masonry in the nonlinear range.
This tool is available in the standard package of Abaqus FE software.
Finally, the results show that the low-cost isolators proposed are
capable of reducing roof acceleration and damage level of masonry
housing. Through this study, we are also capable of monitoring the
shear deformation of isolators during seismic motion. It is useful to
determine whether the isolator is applicable. According to the results,
the deformations of isolators on the benchmark one story building are
relatively small.
Abstract: Non-parametric reliability technique is useful for assessment of reliability of systems for which failure rates are not available. This is useful when detection of malfunctioning of any component is the key purpose during ongoing operation of the system. The main purpose of the Heat Exchanger Cycle discussed in this paper is to provide hot water at a constant temperature for longer periods of time. In such a cycle, certain components play a crucial role and this paper presents an effective way to predict the malfunctioning of the components by determination of system reliability. The method discussed in the paper is feasible and this is clarified with the help of various test cases.
Abstract: Fabric as the first and most common layer that is in permanent contact with human skin is a very good interface to provide coverage, as well as heat and cold insulation. Phase change materials (PCMs) are organic and inorganic compounds which have the capability of absorbing and releasing noticeable amounts of latent heat during phase transitions between solid and liquid phases at a low temperature range. PCMs come across phase changes (liquid-solid and solid-liquid transitions) during absorbing and releasing thermal heat; so, in order to use them for a long time, they should have been encapsulated in polymeric shells, so-called microcapsules. Microencapsulation and nanoencapsulation methods have been developed in order to reduce the reactivity of a PCM with outside environment, promoting the ease of handling, decreasing the diffusion and evaporation rates. Methods of incorporation of PCMs in textiles such as electrospinning and determining thermal properties had been summarized. Paraffin waxes catch a lot of attention due to their high thermal storage density, repeatability of phase change, thermal stability, small volume change during phase transition, chemical stability, non-toxicity, non-flammability, non-corrosive and low cost and they seem to play a key role in confronting with climate change and global warming. In this article, we aimed to review the researches concentrating on the characteristics of PCMs and new materials and methods of microencapsulation.
Abstract: The Gravity Recovery and Climate Experiment (GRACE) has been a very successful project in determining math redistribution within the Earth system. Large deformations caused by earthquakes are in the high frequency band. Unfortunately, GRACE is only capable to provide reliable estimate at the low-to-medium frequency band for the gravitational changes. In this study, we computed the gravity changes after the 2012 Mw8.6 Indian Ocean earthquake off-Sumatra using the GRACE Level-2 monthly spherical harmonic (SH) solutions released by the University of Texas Center for Space Research (UTCSR). Moreover, we calculated gravity changes using different fault models derived from teleseismic data. The model predictions showed non-negligible discrepancies in gravity changes. However, after removing high-frequency signals, using Gaussian filtering 350 km commensurable GRACE spatial resolution, the discrepancies vanished, and the spatial patterns of total gravity changes predicted from all slip models became similar at the spatial resolution attainable by GRACE observations, and predicted-gravity changes were consistent with the GRACE-detected gravity changes. Nevertheless, the fault models, in which give different slip amplitudes, proportionally lead to different amplitude in the predicted gravity changes.
Abstract: A simple design of array antenna is presented in this paper, supporting millimeter wave applications which can be used in short range wireless communications such as 5G applications. This design enhances the use of V-band, according to IEEE standards, as the antenna works in the 70 GHz band with bandwidth more than 11 GHz and peak gain more than 13 dBi. The design is simulated using different numerical techniques achieving a very good agreement.
Abstract: The preservation of historical Italian heritage, at the urban and architectural scale, has to consider restrictions and requirements connected with conservation issues and usability needs, which are often at odds with historical heritage preservation. Recent decades have been marked by the search for increased accessibility not only of public and private buildings, but to the whole historical city, also for people with disability. Moreover, in the last years the concepts of Smart City and Healthy City seek to improve accessibility both in terms of mobility (independent or assisted) and fruition of goods and services, also for historical cities. The principles of Inclusive Design have introduced new criteria for the improvement of public urban space, between current regulations and best practices. Moreover, they have contributed to transforming “special needs” into an opportunity of social innovation. These considerations find a field of research and analysis in the historical city of Venice, which is at the same time a site of UNESCO world heritage, a mass tourism destination bringing in visitors from all over the world and a city inhabited by an aging population. Due to its conformation, Venetian urban fabric is only partially accessible: about four thousand bridges divide thousands of islands, making it almost impossible to move independently. These urban characteristics and difficulties were the base, in the last 20 years, for several researches, experimentations and solutions with the aim of eliminating architectural barriers, in particular for the usability of bridges. The Venetian Municipality with the EBA Office and some external consultants realized several devices (e.g. the “stepped ramp” and the new accessible ramps for the Venice Marathon) that should determine an innovation for the city, passing from the use of mechanical replicable devices to specific architectural projects in order to guarantee autonomy in use. This paper intends to present the state-of-the-art in bridges accessibility, through an analysis based on Inclusive Design principles and on the current national and regional regulation. The purpose is to evaluate some possible strategies that could improve performances, between limits and possibilities of interventions. The aim of the research is to lay the foundations for the development of a strategic program for the City of Venice that could successfully bring together both conservation and improvement requirements.
Abstract: Air pollution and climate warming become more and more intensified in many areas, especially in urban areas. Environmental parameters are critical information to air pollution and weather monitoring. Thus, it is necessary to develop a suitable air pollution and weather monitoring system for urban areas. In this study, a vehicle monitoring system (VMS) based on the IoT technique is developed. Cars are selected as the research tool because it can reach a greater number of streets to collect data. The VMS can monitor different environmental parameters, including ambient temperature and humidity, and air quality parameters, including PM2.5, NO2, CO, and O3. The VMS can provide other information, including GPS signals and the vibration information through driving a car on the street. Different sensor modules are used to measure the parameters and collect the measured data and transmit them to a cloud server through the LoRa protocol. A user interface is used to show the sensing data storing at the cloud server. To examine the performance of the system, a researcher drove a Nissan x-trail 1998 to the area close to the Da’an District office in Taipei to collect monitoring data. The collected data are instantly shown on the user interface. The four kinds of information are provided by the interface: GPS positions, weather parameters, vehicle information, and air quality information. With the VMS, users can obtain the information regarding air quality and weather conditions when they drive their car to an urban area. Also, government agencies can make decisions on traffic planning based on the information provided by the proposed VMS.
Abstract: Power failure resulting from tower collapse due to violent seismic events might bring enormous and inestimable losses. The Chi-Chi earthquake, for example, strongly struck Taiwan and caused huge damage to the power system on September 21, 1999. Nearly 10% of extra high voltage (EHV) transmission towers were damaged in the earthquake. Therefore, seismic hazards of EHV transmission towers should be monitored and evaluated. The ultimate goal of this study is to establish a damage level assessment model for EHV transmission towers. The data of earthquakes provided by Taiwan Central Weather Bureau serve as a reference and then lay the foundation for earthquake simulations and analyses afterward. Some parameters related to the damage level of each point of an EHV tower are simulated and analyzed by the data from monitoring stations once an earthquake occurs. Through the Fourier transform, the seismic wave is then analyzed and transformed into different wave frequencies, and the data would be shown through a response spectrum. With this method, the seismic frequency which damages EHV towers the most is clearly identified. An estimation model is built to determine the damage level caused by a future seismic event. Finally, instead of relying on visual observation done by inspectors, the proposed model can provide a power company with the damage information of a transmission tower. Using the model, manpower required by visual observation can be reduced, and the accuracy of the damage level estimation can be substantially improved. Such a model is greatly useful for health and construction monitoring because of the advantages of long-term evaluation of structural characteristics and long-term damage detection.
Abstract: In this paper, we present a vocal ontology of
OpenStreetMap data for the apprehension of space by visually
impaired people. Indeed, the platform based on produsage gives a
freedom to data producers to choose the descriptors of geocoded
locations. Unfortunately, this freedom, called also folksonomy leads
to complicate subsequent searches of data. We try to solve this issue
in a simple but usable method to extract data from OSM databases in
order to send them to visually impaired people using Text To Speech
technology. We focus on how to help people suffering from visual
disability to plan their itinerary, to comprehend a map by querying
computer and getting information about surrounding environment in
a mono-modal human-computer dialogue.
Abstract: Redundancy requirements for UAV (Unmanned Aerial
Vehicle) are hardly faced due to the generally restricted amount
of available space and allowable weight for the aircraft systems,
limiting their exploitation. Essential equipment as the Air Data,
Attitude and Heading Reference Systems (ADAHRS) require several
external probes to measure significant data as the Angle of Attack
or the Sideslip Angle. Previous research focused on the analysis
of a patented technology named Smart-ADAHRS (Smart Air Data,
Attitude and Heading Reference System) as an alternative method to
obtain reliable and accurate estimates of the aerodynamic angles.
This solution is based on an innovative sensor fusion algorithm
implementing soft computing techniques and it allows to obtain a
simplified inertial and air data system reducing external devices.
In fact, only one external source of dynamic and static pressures
is needed. This paper focuses on the benefits which would be
gained by the implementation of this system in UAV applications.
A simplification of the entire ADAHRS architecture will bring to
reduce the overall cost together with improved safety performance.
Smart-ADAHRS has currently reached Technology Readiness Level
(TRL) 6. Real flight tests took place on ultralight aircraft equipped
with a suitable Flight Test Instrumentation (FTI). The output of
the algorithm using the flight test measurements demonstrates the
capability for this fusion algorithm to embed in a single device
multiple physical and virtual sensors. Any source of dynamic and
static pressure can be integrated with this system gaining a significant
improvement in terms of versatility.
Abstract: The present paper investigates the effect of linear
thermal gradient on the steady-state creep behavior of rotating
isotropic disc using threshold stress based Sherby’s creep law.
The composite discs made of aluminum matrix reinforced with
silicon carbide particulate has been taken for analysis. The stress
and strain rate distributions have been calculated for discs rotating
at linear thermal gradation using von Mises’ yield criterion. The
material parameters have been estimated by regression fit of the
available experimental data. The results are displayed and compared
graphically in designer friendly format for the above said temperature
profile with the disc operating under uniform temperature profile. It is
observed that radial and tangential stresses show minor variation and
the strain rates vary significantly in the presence of thermal gradation
as compared to disc having uniform temperature.
Abstract: Two-wheel tractor (power tiller) is a common tillage tool in Bangladesh agriculture for easy access in fragmented land with affordable price of small farmers. Traditional maize sheller needs to be carried from place to place by hooking with two-wheel tractor (2WT) and set up again for shelling operation which takes longer time for preparation of maize shelling. The mobile maize sheller eliminates the transportation problem and can start shelling operation instantly any place as it is attached together with 2WT. It is counterclockwise rotating cylinder, axial flow type sheller, and grain separated with a frictional force between spike tooth and concave. The maize sheller is attached with nuts and bolts in front of the engine base of 2WT. The operating power of the sheller comes from the fly wheel of the engine of the tractor through ‘V” belt pulley arrangement. The average shelling capacity of the mobile sheller is 2.0 t/hr, broken kernel 2.2%, and shelling efficiency 97%. The average maize shelling cost is Tk. 0.22/kg and traditional custom hire rate is Tk.1.0/kg, respectively (1 US$=Tk.78.0). The service provider of the 2WT can transport the mobile maize sheller long distance in operator’s seating position. The manufacturers started the fabrication of mobile maize sheller. This mobile maize sheller is also compatible for the other countries where 2WT is available for farming operation.
Abstract: Goals and Objectives: A typical analysis of survival data involves the modeling of time-to-event data, such as the time till death. A frailty model is a random effect model for time-to-event data, where the random effect has a multiplicative influence on the baseline hazard function. This article aims to investigate the use of gamma frailty model with concomitant variable in order to individualize the prognostic factors that influence the liver cirrhosis patients’ survival times. Methods: During the one-year study period (May 2008-May 2009), data have been used from the recorded information of patients with liver cirrhosis who were scheduled for liver transplantation and were followed up for at least seven years in Imam Khomeini Hospital in Iran. In order to determine the effective factors for cirrhotic patients’ survival in the presence of latent variables, the gamma frailty distribution has been applied. In this article, it was considering the parametric model, such as Exponential and Weibull distributions for survival time. Data analysis is performed using R software, and the error level of 0.05 was considered for all tests. Results: 305 patients with liver cirrhosis including 180 (59%) men and 125 (41%) women were studied. The age average of patients was 39.8 years. At the end of the study, 82 (26%) patients died, among them 48 (58%) were men and 34 (42%) women. The main cause of liver cirrhosis was found hepatitis 'B' with 23%, followed by cryptogenic with 22.6% were identified as the second factor. Generally, 7-year’s survival was 28.44 months, for dead patients and for censoring was 19.33 and 31.79 months, respectively. Using multi-parametric survival models of progressive and regressive, Exponential and Weibull models with regard to the gamma frailty distribution were fitted to the cirrhosis data. In both models, factors including, age, bilirubin serum, albumin serum, and encephalopathy had a significant effect on survival time of cirrhotic patients. Conclusion: To investigate the effective factors for the time of patients’ death with liver cirrhosis in the presence of latent variables, gamma frailty model with parametric distributions seems desirable.
Abstract: Resilience is an important system property that relies
on the ability of a system to automatically recover from a degraded
state so as to continue providing its services. Resilient systems have
the means of detecting faults and failures with the added capability of
automatically restoring their normal operations. Mastering resilience
in the domain of Cyber-Physical Systems is challenging due to the
interdependence of hybrid hardware and software components, along
with physical limitations, laws, regulations and standards, among
others. In order to overcome these challenges, this paper presents a
modeling approach, based on the concept of Dynamic Cells, tailored
to the management of Smart Grids. Additionally, a heuristic algorithm
that works on top of the proposed modeling approach, to find resilient
configurations, has been defined and implemented. More specifically,
the model supports a flexible representation of Smart Grids and
the algorithm is able to manage, at different abstraction levels, the
resource consumption of individual grid elements on the presence of
failures and faults. Finally, the proposal is evaluated in a test scenario
where the effectiveness of such approach, when dealing with complex
scenarios where adequate solutions are difficult to find, is shown.
Abstract: This study investigated the effects of Ag nanoparticle polyethylene film and active modified atmosphere on the postharvest quality of tomatoes stored at 6 ºC. The atmosphere composition used in the packaging was 7% O2 + 7% CO2 + 86% N2, and synthetic air (control). The variables measured were weight loss, firmness, color and respiration rate over 21 days. The results showed that the combination of Ag nanoparticle polyethylene film and modified atmosphere could extend the shelf life of tomatoes to 21 days and could influence the postharvest quality of tomatoes. Also, existence of Ag nanoparticles caused preventing from increasing weight loss, a*, b*, Chroma, Hue angle and reducing firmness and L*. As well as, tomatoes at Ag nanoparticle polyethylene films had lower respiration rate than Polyethylene and paper bags to 13.27% and 23.50%, respectively. The combination of Ag nanoparticle polyethylene film and active modified atmosphere was effective with regard to delaying maturity during the storage period, and preserving the quality of tomatoes.
Abstract: This paper investigates and evaluates experimentally the structural behavior of high strength concrete (HSC) beams under fire and compares it with that of Normal strength concrete (NSC) beams. The main investigated parameters are: concrete compressive strength (300 or 600 kg/cm2); the concrete cover thickness (3 or 5 cm); the degree of temperature (room temperature or 600 oC); the type of cooling (air or water); and the fire exposure time (3 or 5 hours). Test results showed that the concrete compressive strength decreases significantly as the exposure time to fire increases.
Abstract: Rayleigh-B´enard convection of a nanoliquid in shallow, square and tall enclosures is studied using the Khanafer-Vafai-Lightstone single-phase model. The thermophysical properties of water, copper, copper-oxide, alumina, silver and titania at 3000 K under stagnant conditions that are collected from literature are used in calculating thermophysical properties of water-based nanoliquids. Phenomenological laws and mixture theory are used for calculating thermophysical properties. Free-free, rigid-rigid and rigid-free boundary conditions are considered in the study. Intractable Lorenz model for each boundary combination is derived and then reduced to the tractable Ginzburg-Landau model. The amplitude thus obtained is used to quantify the heat transport in terms of Nusselt number. Addition of nanoparticles is shown not to alter the influence of the nature of boundaries on the onset of convection as well as on heat transport. Amongst the three enclosures considered, it is found that tall and shallow enclosures transport maximum and minimum energy respectively. Enhancement of heat transport due to nanoparticles in the three enclosures is found to be in the range 3% - 11%. Comparison of results in the case of rigid-rigid boundaries is made with those of an earlier work and good agreement is found. The study has limitations in the sense that thermophysical properties are calculated by using various quantities modelled for static condition.
Abstract: Sulfur dioxide (SO2) is a very toxic air pollutant gas and it causes the greenhouse effect, photochemical smog, and acid rain, which threaten human health severely. Thus, the capture of SO2 gas is very important for the environment. Graphene which is two-dimensional material has excellent mechanical, chemical, thermal properties, and many application areas such as energy storage devices, gas adsorption, sensing devices, and optical electronics. Further, graphene oxide (GO) is examined as a good adsorbent because of its important features such as functional groups (epoxy, carboxyl and hydroxyl) on the surface and layered structure. The SO2 adsorption properties of the fibers are usually investigated on carbon fibers. In this study, potential adsorption capacity of GO fibers was researched. GO dispersion was first obtained with Hummers’ method from graphite, and then GO fibers were obtained via wet spinning process. These fibers were converted into a disc shape, dried, and then subjected to SO2 gas adsorption test. The SO2 gas adsorption capacity of GO fiber discs was investigated in the fields of utilization of different coagulation baths and reduction by hydrazine hydrate. As coagulation baths, single and triple baths were used. In single bath, only ethanol and CaCl2 (calcium chloride) salt were added. In triple bath, each bath has a different concentration of water/ethanol and CaCl2 salt, and the disc obtained from triple bath has been called as reference disk. The fibers which were produced with single bath were flexible and rough, and the analyses show that they had higher SO2 adsorption capacity than triple bath fibers (reference disk). However, the reduction process did not increase the adsorption capacity, because the SEM images showed that the layers and uniform structure in the fiber form were damaged, and reduction decreased the functional groups which SO2 will be attached. Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD) analyzes were performed on the fibers and discs, and the effects on the results were interpreted. In the future applications of the study, it is aimed that subjects such as pH and additives will be examined.
Abstract: Sentiment analysis and opinion mining have become
emerging topics of research in recent years but most of the work
is focused on data in the English language. A comprehensive
research and analysis are essential which considers multiple
languages, machine translation techniques, and different classifiers.
This paper presents, a comparative analysis of different approaches
for multilingual sentiment analysis. These approaches are divided
into two parts: one using classification of text without language
translation and second using the translation of testing data to a
target language, such as English, before classification. The presented
research and results are useful for understanding whether machine
translation should be used for multilingual sentiment analysis or
building language specific sentiment classification systems is a better
approach. The effects of language translation techniques, features,
and accuracy of various classifiers for multilingual sentiment analysis
is also discussed in this study.