Room Temperature Conductance of Graphene Sheet as a Function of Some Variables Using LAD/SZ Method

Current study deals with the room temperature conductance of Graphene Sheets as a function of their binding energy and lengths. The structural properties of each sheet were calculated after the relax of the structures by performing the SIESTA-trunk-462 program. The results showed that the electric conductivity is inversely proportional to the theoretical separation of the gold electrode. The increase of the angle C-C-Au effects on the electric properties of the Graphene Sheet, the Sheet is became much conductive and effectient electrically at large angles. This may refers to that the electron transmission coefficient of the Graphene Sheet depends on the type of the contact of the top gold atoms of the pyramids with the anchor atoms in the Sheet

Balancing Compression and Encryption of Satellite Imagery

With the rapid developments in the remote sensing technologies and services, there is a necessity for combined compression and encryption of satellite imagery. The onboard satellite compression is used to minimize storage and communication bandwidth requirements of high data rate satellite applications. While encryption is employed to secure these resources and prevent illegal use of image sensitive information. In this paper, we propose an approach to address these challenges which raised in the highly dynamic satellite based networked environment. This approach combined compression algorithms (Huffman and SPIHT) and encryptions algorithms (RC4, blowfish and AES) into three complementary modes: (1) secure lossless compression, (2) secure lossy compression and (3) secure hybrid compression. The extensive experiments on the 126 satellite images dataset showed that our approach outperforms traditional and state of art approaches by saving approximately (53%) of computational resources. In addition, the interesting feature of this approach is these three options that mimic reality by imposing every time a different approach to deal with the problem of limited computing and communication resources

Evaluation of Parking Demand and Future Requirement in the Urban Area

Whatever vehicle is traveling, it needs to stop in order to arrive road users their different goals. In most universities, parking becomes an important campus resource, for being as a place to come frequently and to spend long period. Now days parking problems increase with repaid growth of car ownership. So traffic and parking impact can be consider as a major source of contention within any community and can raise additional costs for universities, as well as urban areas facilities. The study aims to evaluate the current parking situation on the university campus in terms of the available supply and required demand of parking spaces in order to recommend future parking spaces need for the next five years. Data has had been collected according to field traffic and engineering survey, Videography method was used for this purpose. Inventories, Interviews and questionnaires included. Data analysis conducted with the aided of AASHTO and equation methods. The study concluded future parking required is 140 vehicle- spaces for the year 2026, according to population rate of growth also illegal parking leads to interference with the movements of pedestrians and their crossing, as well as reducing the capacity of the roads in the study area. Doi: 10.28991/cej-2021-03091767 Full Text: PD

Seismic response analysis of linked twin tall buildings with structural coupling

Effect of structural links on seismic responses for a linked building system has been investigated in this paper by using finite element modeling technique. The linked building system in this study is represented by twin 40-story reinforced concrete frame-wall structures horizontally coupled by structural links. It is assumed that the two adjacent buildings were similar in this linked building system, so the two adjacent stories could be linked at the same height by an inter-building link. The linked building system is modeled as a rigid floor diaphragm for towers and as a beam for each link fixedly linked to the perimeter structural framework of the buildings. By employing earthquake time history excitation, the seismic responses of the twin towers were computed at different locations for the link. The responses of structures were evaluated and compared. The analysis outcomes indicated that the link could effectively change the structural responses of the linked building system. The structural responses have been decreased in some cases compared to the single tower, referring to the extra link stiffness as gathering the single tower to withstand seismic excitation. While the responses have been increased in other cases, attributing to the additional mass of link. Thus, in the design of seismic-resistant linked building systems, care must be taken. Particularly regarding properties of the link, specifically mass, stiffness, and location, as well as the link resistance with respect to the strength of the link and/or the structural elements composing the link to obviate undesired structural responses

Modeling of the axial crumpling of conical shells

The axial crumpling of frusta in the axisymmetric "concertina" mode is examined. A new theoretical model is developed in which the inward folding in both cylinders and frusta is addressed. The results were compared with previous relevant models as well as experimental findings. The flexibility of the model was substantiated by its capability of describing and estimating the inward folding in frusta in general as well as in cylinders as a special case. A declining trend of the eccentricity dependence with the D/t ratio was found in contrast with a previous theory which suggests total independency. ABAQUS 14-2 finite element software was employed to simulate the thin tube as a 3-D thin shell part. Numerical simulations of the process were found to, firstly, underestimate the theoretical values of inward folding in general, secondly anticipate more underestimations as the tubes become thinner and/or have larger apex angle, and finally anticipate as low as 300 apical angle frusta to revert its mode of deformation to global inversion

A review of forest fire surveillance technologies: Mobile ad-hoc network routing protocols perspective

Mobile Ad-Hoc Network (MANET) is a type of structure-less wireless mobile network, in which each node plays the role of the router and host at the same time. MANET has gained increased interest from researchers and developers for various applications such as forest fire detection. Forest fires require continuous monitoring and effective communication, technology, due to the big losses are brought about by this event. As such, disaster response and rescue applications are considered to be a key application of the MANET. This paper gives an extensive review of the modern techniques used in the forest fire detection based on recent MANET routing protocols such as reactive Location-Aided Routing (LAR), proactive Optimized Link State Routing (OLSR) and LAR-Based Reliable Routing Protocol (LARRR)

Machine Learning for Health: Algorithm Auditing & Quality Control

Developers proposing new machine learning for health (ML4H) tools often pledge to match or even surpass the performance of existing tools, yet the reality is usually more complicated. Reliable deployment of ML4H to the real world is challenging as examples from diabetic retinopathy or Covid-19 screening show. We envision an integrated framework of algorithm auditing and quality control that provides a path towards the effective and reliable application of ML systems in healthcare. In this editorial, we give a summary of ongoing work towards that vision and announce a call for participation to the special issue Machine Learning for Health: Algorithm Auditing & Quality Control in this journal to advance the practice of ML4H auditing