Sharif Digital Repository

Deep learning-based graph generation approaches have remarkable capacities for graph data modeling, allowing them to solve a wide range of real-world problems. Making these methods able to consider different conditions during the generation procedure even increases their effectiveness by empowering them to generate new graph samples that meet the desired criteria. This paper presents a conditional deep graph generation method called SCGG that considers a particular type of structural conditions. Specifically, our proposed SCGG model takes an initial subgraph and autoregressively generates new nodes and their corresponding edges on top of the given conditioning substructure. The architecture... 

The current study presents a numerical investigation on turbulent hydrothermal characteristics in a wavy passage equipped with discontinuous twisted tapes. The working fluid is water and passage walls are kept under constant wall temperature. The effect of Reynolds number (Re = 2500, 4500, 6500, 8500 and 10500), twist angle (TA = 90∘ and 180∘) and inclination angle (IA = 15∘ and 30∘) on velocity fields and streamlines, temperature contours, Nusselt number, friction factor, turbulent kinetic energy (TKE), thermal performance factor (TPF), energy efficiency factor (EEF) and entropy generation rate are evaluated. More uniform temperature and velocity fields can be found as both wavy passage and... 

After a significant earthquake, the updated status of the structural elements is usually determined based on a qualitative visual inspection. Although visual inspection provides a prompt assessment of the damaged elements, the output of this subjective method is influenced by the experience and decision of a trained inspector, which may vary from case to case. In this study, an innovative machine learning-based procedure is developed to automate damage state identification of non-ductile reinforced concrete moment frames (RCMFs) utilizing visual indices of crack patterns of the concrete surface. An extensive database including 264 surface crack patterns is constructed corresponding to 61... 

In the absence of effective and adequate vaccines, healthcare decision-makers must rely on non-pharmaceutical interventions (NPIs), such as lockdown, testing, hospital capacity building, and increasing the number of medical staff to control the outbreak of an infectious disease like COVID-19. This manuscript presents a System Dynamics (SD) model to analyze the healthcare system performance under various NPIs during a pandemic. The proposed model, which extends the commonly-used Susceptible-Exposed-Infectious-Recovered (SEIR) model, comprises four sub-models: outbreak, hospital performance, medicine supply, and staff functionality. These sub-models work in harmony to stimulate the impact of... 

Although Unmanned Aerial Vehicles (UAVs) are capable of significantly improving the information security by detecting the eavesdropper's location, their limited energy motivates our research to propose a secure and energy efficient scheme. Thanks to the common-message philosophy introduced by Rate-Splitting (RS), we no longer have to allocate a portion of the transmit power to radiate Artificial Noise (AN), and yet both the Energy Efficiency (EE) and secrecy can be improved. Hence we define and study the Secrecy Energy Efficiency (SEE) of a multi-carrier multi-UAV network, in which Cooperative Rate-Splitting (CRS) is employed by each multi-antenna UAV Base-Station (UAV-BS) for protecting... 

In this paper, the elastic solution to the problem of an isotropic bi-material full-space reinforced by a perfectly bonded thin film across the media interface and subjected to arbitrary asymmetric interfacial loading is addressed. To not include any simplifications, the thin film is first considered as a layer having a finite thickness, and with the aid of Fourier expansion of Muki's potential functions in Hankel transformed space, the formulation of the problem is obtained for a tri-material full-space. Then, knowing that the flexural stiffness of the thin film is negligible, its thickness and shear modulus are assumed to tend to zero and infinity, respectively, such that its in-plane... 

Regression testing activities greatly reduce the risk of faulty software release. However, the size of the test suites grows throughout the development process, resulting in time-consuming execution of the test suite and delayed feedback to the software development team. This has urged the need for approaches such as test case prioritization (TCP) and test-suite reduction to reach better results in case of limited resources. In this regard, proposing approaches that use auxiliary sources of data such as bug history can be interesting. We aim to propose an approach for TCP that takes into account test case coverage data, bug history, and test case diversification. To evaluate this approach we... 

A comprehensive investigation of historical hydro-climatic changes at a county level is an essential prerequisite of developing any adaptation or mitigation strategies to deal with the destructive impacts of climate change. In this study, spatial distributions and trends in thirty-seven hydro-climatic mean and extreme indices across Iran were analyzed based on the state-of-the-art reanalysis datasets (ERA5-Land and AgERA5) at the county level from 1986 to 2015 using several nonparametric approaches such as multiple modified Mann–Kendall statistical tests and Sen’s Slope estimator. Their interannual oscillations were also examined using continuous wavelet transform to portray a complete... 

In the present contribution, visible-near infrared hyperspectral imaging (Vis-NIR-HSI) combined with a novel chemometric approach based on mean-filed independent component analysis (MF-ICA) followed by multivariate classification techniques is proposed for saffron authentication and adulteration detection. First, MF-ICA was used to exploit pure spatial and spectral profiles of the components. Then, principal component analysis (PCA) and hierarchical cluster analysis (HCA) were used to find patterns of authentic samples based on their distribution maps. Then, detection of five common plant-derived adulterants of saffron including safflower, saffron style, calendula, rubia and turmeric were... 

Lithium-ion batteries should continuously be operated at the optimum temperature range (15∼40∘C) for the best performance. Surface temperature monitoring is critical for the safe and efficient operation of the battery. In this study, initially, the electrical parameters of the battery are determined by applying a second-order equivalent circuit model. This model then is integrated with a thermal model based on the temperature dependent behavior of the electrical parameters and the heat generated. The input parameters to the electro-thermal model include the current, the ambient fluid temperature and the output parameters include the terminal voltage, state of charge, cell core temperature... 

In this study, polyvinyl alcohol hydrogel chains were crosslinked by polyurethane in order to synthesize a suitable substrate for cartilage lesions. The substrate was fully characterized, and in vitro and in vivo investigations were conducted based on a sheep model. In vitro tests were performed based on the chondrocyte cells with the Alcian Blue and safranin O staining in order to prove the presence of proteoglycan on the surface of the synthesized substrate, which has been secreted by cultures of chondrocytes. Furthermore, the expression of collagen type I, collagen type II, aggrecan, and Sox9 was presented in the chondrocyte cultures on the synthesized substrate through RT-PCR. In... 

Despite complex fluctuations, missing data, and maintenance costs of detectors, traffic volume forecasting at intersections is still a challenge. Moreover, most existing forecasting methods consider an isolated intersection instead of multiple adjacent ones. By accurately forecasting the volume of short-term traffic, a low-cost method can be provided to solve the problems of congestion, delay, and breakdown of detectors in the road transport system. This paper outlines a novel hybrid method based on deep learning to estimate short-term traffic volume at three adjacent intersections. The gated recurrent unit (GRU) and long short-term memory (LSTM) bilayer network with wavelet transform (WL)... 

Microarchitectural attacks utilize the performance optimization constructs that have been studied over decades in computer architecture research and show the vulnerability of such optimizations in a realistic framework. One such highly performance driven vulnerable construct is speculative execution. In this paper, we focus on the problem of breaking the kernel address-space layout randomization (KASLR) on modern mobile devices without using cache memory as a medium of observation. However, there are some challenges to breaking KASLR on ARM CPUs. The first challenge is that eviction strategies on ARM CPUs are slow, and the microarchitectural attacks exploiting the cache as a covert channel... 

Humans have a unique ability to use language for social communication. The neural architecture for language comprehension and production may have prominently emerged in the brain areas that were originally involved in social cognition. Here, we directly tested the fundamental link between language and social processing using functional magnetic resonance data (MRI) data from over 1,000 human subjects. Cortical activations in language and social tasks showed a striking similarity with a complementary hemispheric lateralization. Within core language areas, left-lateralized activations in the language task were mirrored by right-lateralized activations in the social task. Outside these areas,... 

Localization of radio-frequency (RF) transmitters using time difference of arrival (TDOA)-based methods is one of the conventional passive techniques that admits noncooperative source position finding, but suffers from challenging requirements such as precise intersensor synchronization and high-throughput transmission data links. A tradeoff governing the TDOA systems is in the sensor placement configuration. The more distance the sensors are placed, the more accurate localization is carried out, while the cost for the synchronization and data link increases, at the same time. In this work, a novel reconfigurable intelligent surface (RIS)-aided localization system is proposed that enjoys... 

Supply Chain (SC) coordination, quality requirements, and environmental issues are the main areas of interest within the field of inventory management. Few studies have integrated these concepts into an inventory problem despite its overwhelming necessity. In this direction, this paper deals with a vendor-buyer SC under the Vendor-Managed Inventory with Consignment Stock (VMI-CS) agreement. According to the agreement, the vendor bears the buyer's financial holding cost in return for the storage of products in the buyer's warehouse. Further, each shipment involves a random fraction of repairable items, which need to be withdrawn from the inventory system. Unlike the existing literature, when... 

Social media usage is one of the most popular online activities and people shares millions of message in a short time; however this information rarely goes viral. The diffusion process begins with an initial set of source nodes and continues with other nodes. In addition, the viral cascade is triggered when the number of infected nodes exceeds a specific threshold. Then, we find an initial set of source nodes that maximizes the number of infected nodes given the source nodes. This study aims to answer the following questions: how does a spread like a viral cascade propagate in a network? Do the structural properties of the propagation pattern play an important role in virality? If so, can we... 

Untethered small-scale robots can accomplish tasks which are not feasible by conventional macro robots. In the current research, we have designed and fabricated a miniature magnetic robot actuated by an external magnetic field. The proposed robot has two coaxial wheels and one magnetic dipole which is capable of rolling and moving on the surface by variation in the direction of magnetic field. To generate the desired magnetic field, a Helmholtz electromagnetic coil is manufactured. To steer the robot to the desired position, at first the robot dynamics is investigated, and subsequently a controller based on a neuro-fuzzy network has been designed. Finally, the proposed controller is... 

The original version of this Article contained an error in the spelling of the author Mohammad Hossein Modarressi, which was incorrectly given as Mohammad‑Hossein Modarresi. The original Article has been corrected. © 2022, The Author(s)