45 research outputs found
Middleware Technologies for Cloud of Things - a survey
The next wave of communication and applications rely on the new services
provided by Internet of Things which is becoming an important aspect in human
and machines future. The IoT services are a key solution for providing smart
environments in homes, buildings and cities. In the era of a massive number of
connected things and objects with a high grow rate, several challenges have
been raised such as management, aggregation and storage for big produced data.
In order to tackle some of these issues, cloud computing emerged to IoT as
Cloud of Things (CoT) which provides virtually unlimited cloud services to
enhance the large scale IoT platforms. There are several factors to be
considered in design and implementation of a CoT platform. One of the most
important and challenging problems is the heterogeneity of different objects.
This problem can be addressed by deploying suitable "Middleware". Middleware
sits between things and applications that make a reliable platform for
communication among things with different interfaces, operating systems, and
architectures. The main aim of this paper is to study the middleware
technologies for CoT. Toward this end, we first present the main features and
characteristics of middlewares. Next we study different architecture styles and
service domains. Then we presents several middlewares that are suitable for CoT
based platforms and lastly a list of current challenges and issues in design of
CoT based middlewares is discussed.Comment: http://www.sciencedirect.com/science/article/pii/S2352864817301268,
Digital Communications and Networks, Elsevier (2017
Middleware Technologies for Cloud of Things - a survey
The next wave of communication and applications rely on the new services
provided by Internet of Things which is becoming an important aspect in human
and machines future. The IoT services are a key solution for providing smart
environments in homes, buildings and cities. In the era of a massive number of
connected things and objects with a high grow rate, several challenges have
been raised such as management, aggregation and storage for big produced data.
In order to tackle some of these issues, cloud computing emerged to IoT as
Cloud of Things (CoT) which provides virtually unlimited cloud services to
enhance the large scale IoT platforms. There are several factors to be
considered in design and implementation of a CoT platform. One of the most
important and challenging problems is the heterogeneity of different objects.
This problem can be addressed by deploying suitable "Middleware". Middleware
sits between things and applications that make a reliable platform for
communication among things with different interfaces, operating systems, and
architectures. The main aim of this paper is to study the middleware
technologies for CoT. Toward this end, we first present the main features and
characteristics of middlewares. Next we study different architecture styles and
service domains. Then we presents several middlewares that are suitable for CoT
based platforms and lastly a list of current challenges and issues in design of
CoT based middlewares is discussed.Comment: http://www.sciencedirect.com/science/article/pii/S2352864817301268,
Digital Communications and Networks, Elsevier (2017
Z-path trajectory mechanism for mobile beacon-assisted localization in wireless sensor networks
A wireless sensor network consists of many sensors that communicate wirelessly to monitor a physical region. In many applications such as warning systems or healthcare services, it is necessary to enhance the captured data with location information. Determining the coordinates of the randomly deployed sensors is known as the problem of localization. A promising solution for statically deployed sensors is to benefit from a mobile beacon-assisted localization. The main challenge is planning an optimum path for the mobile beacon to ensure the full coverage, increase the accuracy of the estimated position and decrease the required time for localization of resource-constrained sensors. So, this research aims at developing a superior trajectory mechanism for mobile beacon-assisted localization to help unknown sensors to efficiently localize themselves. To achieve this purpose; first, a novel trajectory named Z-path is proposed to guarantee fully localized deployed sensors with higher precision since the path reduces collinear beacon positions and promises shorter localization time; second, Z-path transmission power adjustment scheme named Zpower is developed to dynamically and optimally adjust the transmission power for a reliable transmission while conserving the energy consumption for localization by mobile beacon and unknown sensors; third, Z-path obstacle-handling trajectory mechanism is designed to improve the effectiveness of the proposed path toward obstacles which obstruct the path. Finally, the proposed Z-path obstacle handling mechanism is integrated with the developed power adjustment scheme to improve the energy efficiency of the designed obstacle tolerance mechanism. The performance of the proposed trajectory is evaluated by comparing the efficiency with five benchmark trajectories in terms of localization success, accuracy, energy efficiency, time and ineffective position rate, which is a newly introduced metric by this research to measure the collinearity of the trajectories. Simulation results show that Z-path has successfully localized all 250 deployed sensors with higher precision by at least 5.88% improvement than Localization with a Mobile Anchor based on Trilateration (LMAT) trajectory and 58% improvement than random way point. It also serves as a benchmark path with 93 ineffective positions per node localization as compared with LMAT as a second efficient path by 100 collinear positions and faster trajectory for localization. Furthermore, results revealed that Z-power accomplishes better performance in terms of energy consumption as an average 34% for unknown sensors and 25% for mobile beacon than Z-path. In case of obstacle tolerance mechanism, it ensures higher localization performance in terms of accuracy, time and success around 37.5%, 13% and 11% respectively, as compared to Z-path at the presence of obstacles. The handling mechanism integrated with the power control scheme has reduced energy consumption and improved ineffective position rate compared with Z-path handling trajectory by 35.7% and 54.4%, respectively
Investigating the influencing factors on trust and professional skepticism in the relationship between the auditor and the client firms’ managers
The current study investigates how interpersonal trust between the auditor and the client firms’ managers affects the auditor's professional skepticism in Iraq. In the qualitative part of the research, 20 auditors and client firms’ managers were interviewed. In the qualitative section, the interviews conducted were analyzed using MAXQDA software. The statistical population includes two groups: all auditors, 1735 participants until the end of 2022, and all senior managers and managers of public companies, private companies, and other organizations. The statistical sample size is 314. The data collection instrument was Aschauer et al.'s (2017) questionnaire, which was analyzed using PLS3 software. The findings support the idea that there is a positive correlation between the degree of skepticism towards the auditing profession and the degree to which corporate managers and auditors are trusted. Perceived trust between auditors and managers and skepticism of auditors' professions are not significantly correlated with the length of the auditor's contact with the client. The relationship between auditors' and managers' trust in them and their skepticism of the auditing profession is not also significantly impacted by the supply of non-audit services
Fundamental Metrics for Wireless Sensor Networks localization
During the last decade, Localization in wireless sensor networks (WSNs) is a broad topic that has received considerable attention from the research community. The approaches suggested to estimate location are implemented with different concepts, functionalities, scopes and technologies. This paper introduces a methodological approach to the evaluation of localization algorithms and contains a discussion of evaluation criteria and performance metrics followed by statistical/ empirical simulation models and metrics that affect the performance of the algorithms and hence their assessment. The major contribution of this paper is to analyze and identify relevant metrics to compare different approaches on the evaluation of localization schemes.DOI:http://dx.doi.org/10.11591/ijece.v2i4.24
Analytical model to predict dilation behavior of FRP confined circular concrete columns subjected to axial compressive loading
Experimental research and real-case applications are demonstrating that the use of fiber–reinforced polymer (FRP) composite materials can be a solution to substantially improve circular cross section concrete columns in terms of strength, ductility, and energy dissipation. The present study is dedicated to developing a new model for estimating the dilation behavior of fully and partially FRP-based confined concrete columns under axial compressive loading. By considering experimental observations and results, a new relation between secant Poisson's ratio and axial strain is proposed. In order for the model to be applicable to partial confinement configurations, a confinement stiffness index is proposed based on the concept of confinement efficiency factor. A new methodology is also developed to predict the ultimate condition of partially FRP confined concrete taking into account the possibility of concrete crushing and FRP rupture failure modes. By comparing the results from experimental tests available in the literature with those determined with the model, the reliability and the good predictive performance of the developed model are demonstrated.project ‘‘StreColesf_Innovative technique using effectively composite
materials for the strengthening of rectangular cross section reinforced concrete columns exposed to seismic loadings and fire’’, with the reference POCI-01-0145-FEDER-029485
A new dilation model for FRP fully/partially confined concrete column under axial loading
Experimental research has confirmed that the usage of fiber reinforced
polymer (FRP) composite materials can be a reliable solution to substantially improve axial and dilation behavior of confined concrete columns. In this regard,
FRP partial confinement system is a good compromise from the cost competitiveness point of the view, while the application of discrete FRP strips provides
less confinement efficiency compared to full confinement system. Experimental
observations demonstrated that the concrete at the middle distance between the
FRP strips experiences more transversal expansion compared to concrete at the
strip regions. It can result in a considerable decrease in the confinement performance in curtailing concrete transversal expansion, overwhelming the activation
of FRP confining pressure. The present study is dedicated to the development of
a new dilation model for both full and partial confinement systems, which takes
into account the substantial impact of non-uniform distribution of concrete transversal expansion, a scientific topic not yet addressed comprehensibly in existing
formulations. For this purpose, a reduction factor was developed in the determination of the efficiency confinement parameter, by considering available experimental results. Furthermore, based on a database of FRP fully/partially confined
concrete, a new analytical relation between secant Poisson’s ratio and axial strain
was proposed. To evaluate the reliability and predictive performance of the developed dilation model, it was applied on the simulation of experimental tests
available in the literature. The results revealed that the developed model is capable of predicting the experimental counterparts with acceptable accuracy in a design context.The study reported in this paper is part of the project ‘‘StreColesf_Innovative technique
using effectively composite materials for the strengthening of rectangular cross section
reinforced concrete columns exposed to seismic loadings and fire’’, with the reference
POCI-01-0145-FEDER-029485. The forth author also acknowledges the grant provided by PufProtec project with the reference POCI-01-0145-FEDER-028256
Evaluation of the Ki-67 and MCM3 Expression in Cytologic Smear of Oral Squamous Cell Carcinoma
Statement of the Problem: Squamous cell carcinoma (SCC) is the most frequent
oral cancer whose 5-year survival rate is 80% for early-detected lesions and nearly
30-50% for advanced lesions. Early detection of oral cancers and precancerous lesions
can improve the patient’s survival and decrease the morbidity.
Purpose: This study aimed to evaluate and compare the Ki-67 and MCM3 expression
in cytologic smear of oral SCC (OSCC).
Materials and Method: We examined 48 oral brush biopsies including 28 OSCC
and 20 healthy non-smoking samples. Immunocytochemistry staining was performed
for Ki-67 and MCM3 by using an EnVision-labeled peroxidase system, and labeling
index (LI) was calculated.
Results: Out of 28 OSCC cases, 27(96.4%) cases contained MCM3 positive cells
and 22(78%) cases contained Ki-67 positive cells. All normal mucosa were Ki-67
and MCM3 negative. MCM3 and Ki-67 LI were significantly higher in OSCC than
normal mucosa (p< 0.001). MCM3 LI was significantly higher than Ki-67 LI in
OSCC group (p< 0.001).
Conclusion: Immunocytologic evaluation of Ki-67 and MCM3 can be used for early
detection of OSCC. Furthermore, MCM3 may be a more sensitive cytologic biomarker
than Ki-67 in SCC patients
Distribution of Total Volatile Organic Compounds at taxi drivers in Tehran
Air pollution is currently the most serious environmental health threat worldwide. Volatile Organic Compounds (VOC) are considered as the main effective factors in causing air pollution. Vehicles are among the major sources which emit these compounds, so it seems that automobiles’ microenvironment is one of the places where people are exposed to high concentration of VOC. Evaluating the exposure amount of Total Volatile Organic Compounds (TVOC) can indeed be used as an indicator to estimate the amount of exposure to every individual VOC. This study was conducted on the concentration of TVOC inside Tehran taxies for a period of one year. For this purpose, a real time instrument equipped with photo-ionization detector (PID) was used. Consequently, the highest and the lowest measured TVOC in taxies equaled 3.33 ppm and 0.72 ppm, respectively. In addition, the arithmetic mean of TVOC concentration was 1.77±0.53 ppm inside the examined taxies. In this study, the parameters like measurement time, climate and vehicle conditions were found to have significant effect on the amount of exposure to TVOC