Sharif Digital Repository

IP core reuse is popular for designing and implementing complex systems, because reuse of already provided blocks decreases design time and so diminishes productivity gap. Moreover, as system-level design methodologies and tools emerge for embedded system design, it is useful to have a shift from Register Transfer Level to system-level models for IP cores employed for implementation of hardware parts of the system. In this paper, we propose a C++ model for hardware IP cores that can be adopted as a standard for delivering IPs at a high level of abstraction, suitable for object-oriented system-level design methodologies. Next, we extend our system-level synthesizer in order to integrate IP... 

Hantzsch 1, 4-dihydropyridines (1,4-DHPs) can be oxidized to the corresponding pyridine derivatives by thallium triacetate in high yields  

Alterations in the structure of a magnetron, e.g., the A6 relativistic magnetron, are proposed, which considerably increase the device's build-up speed. We cover the magnetron vane surfaces with semiconductor layers of nonzero electric conductivity, with an exact geometrical design. Semiconductor layers with considerable mechanical strength also provide excellent shielding for the vanes against the high-energy relativistic electrons' bombardment. The novel structure introduces several new free parameters to the magnetron design procedure and considerably increases the design flexibility. A multistage exact optimization procedure, performed by extensive computer simulations, shows that... 

The preparation of microcapsules containing perphenazine by solvent evaporation using ethyl cellulose is described. The microparticles are formed after solvent evaporation and polymer precipitation. The drug was dissolved in a polymer solution and emulsified into an aqueous phase to form microcapsules. To study the effects on particle size, encapsulation efficiency and morphology, three different molecular weights of ethyl cellulose (Mw=47000, 71000 and 99000) were used. Covalent bonding of drugs to polymers via hydrolytically or enzymatically cleavable covalent bond was achieved for sustained drug delivery. The release rate of perphenazine from these systems was investigated  

Considering the lipid concentration and side effects regarding the stents used by surgeons, a new heart stent model is proposed. In the new stent, a few piezo plates are designed and attached to the stents by which release of the lipids can take place due to the applied alternative voltages. Due to the vibrations of small-scale piezoelectric plates, the deposition of low-density-lipoproteins (LDL) floating in the blood flow in the coronary arteries is prevented. Small-scale effects are considered using nonlocal elasticity theory, and the interaction between fluid and solid is modeled using the Navier-Stokes equation. The effect of fluid parameters as well as applied voltage and geometry... 

Business intelligence (BI) is a managerial concept helping managers and organizations to manage information and make factual decisions. Some have introduced Business Intelligence as a process of turning data into information and then into knowledge. This concept has become a popular trend for businesses interested in adding value to their decision making processes. Measurement of maturity in implementing Business Intelligence process in organizations is considered a critical issue. Business intelligence like software development is a process, which expressed in terms of components such as artifacts and workflows. Capability Maturity Model Integrated (CMMI) is developed to define different... 

A continuum theory is employed to numerically study the equilibrium orientation and defect structures of a circular cylindrical particle with flat ends under a homeotropic anchoring condition in a uniform nematic medium. Different aspect ratios of this colloidal geometry from thin discotic to long rodlike shapes and several colloidal length scales ranging from mesoscale to nanoscale are investigated. We show that the equilibrium state of this colloidal geometry is sensitive to the two geometrical parameters: aspect ratio and length scale of the particle. For a large enough mesoscopic particle, there is a specific asymptotic equilibrium angle associated to each aspect ratio. Upon reducing the... 

Given a social network modeled as a weighted graph GG, the influence maximization problem seeks kk vertices to become initially influenced, to maximize the expected number of influenced nodes under a particular diffusion model. The influence maximization problem has been proven to be NP-hard, and most proposed solutions to the problem are approximate greedy algorithms, which can guarantee a tunable approximation ratio for their results with respect to the optimal solution. The state-of-the-art algorithms are based on Reverse Influence Sampling (RIS) technique, which can offer both computational efficiency and non-trivial (1-1/e-ϵ)-approximation ratio guarantee for any epsilon >0ϵ>0.... 

We study the problem of experiment design to learn causal structures from interventional data. We consider an active learning setting in which the experimenter decides to intervene on one of the variables in the system in each step and uses the results of the intervention to recover further causal relationships among the variables. The goal is to fully identify the causal structures with minimum number of interventions. We present the first deep reinforcement learning based solution for the problem of experiment design. In the proposed method, we embed input graphs to vectors using a graph neural network and feed them to another neural network which outputs a variable for performing... 

One of the key objectives in many fields in machine learning is to discover causal relationships among a set of variables from observational data. In linear non-Gaussian acyclic models (LiNGAM), it can be shown that the true underlying causal structure can be identified uniquely from merely observational data. The DirectLiNGAM algorithm is a well-known solution to learn the true causal structure in a high dimensional setting. DirectLiNGAM algorithm executes in a sequence of iterations and it performs a set of comparisons between pairs of variables in each iteration. Unfortunately, the runtime of this algorithm grows significantly as the number of variables increases. In this paper, we... 

In this paper a novel algorithm for detection, parameter estimation, and image formation of a moving target in ground-based circular strip-map synthetic aperture radar (GBCSAR) is proposed. Because multiple similar scans of the scene with short revisit time are possible, moving target detection is performed by clutter cancellation. Despite of the frequency-domain or multi-antenna clutter cancellation methods, this system has the capability of removing the clutter completely regardless of the target speed or the signal to clutter ratio (SCR). Estimation of target parameters and range-cell migration correction (RCMC) is based on comparing two consecutive target images. Finally the azimuth... 

Many mobile applications running on smartphones and wear- able devices would potentially benefit from the accuracy and scalability of deep CNN-based machine learning algorithms. However, performance and energy consumption limitations make the execution of such computationally intensive algorithms on mobile devices prohibitive. We present a GPU- accelerated library, dubbed CNNdroid [1], for execution of trained deep CNNs on Android-based mobile devices. Empirical evaluations show that CNNdroid achieves up to 60X speedup and 130X energy saving on current mobile devices. The CNNdroid open source library is available for download at https://github.com/ENCP/CNNdroid  

Neurological diseases have different etiological causes. Contemporary, developing an ef-fective treatment for these diseases is an ongoing challenge. Cell therapy is recognized as one of the promising solutions for the treatment of these diseases. Amongst various types of stem cells, bone marrow-derived mesenchymal stem cells (BM-MSC) are known to be the most widely used stem cells. These cells are endowed with appealing properties such as the ability to differentiate into other cell types, including the muscle, liver, glial, and nerve cells. In this review study, we have systematically evaluated the ability of a variety of chemical compounds used in the last ten years to differentiate... 

Kinetics of oxidation of MgO-C refractory bricks containing 14.3% graphite, 80.9% magnesia, and 4.8% phenolic resin is investigated comprehensively. Effect of temperature and grain size distribution on the rate of oxidation of graphite is evaluated by application of a mathematical model developed on the basis of shrinking core/progressive conversion regime to the gas-solid processes involved. Incorporation of the experimental data into the mathematical model indicates that a mixed controlling mechanism governs the oxidation rate. Three activation energies were recognized: (a) 68 kJ/mol for chemical adsorption of gas on the surface of the graphite flakes, (b) 22 kJ/mol for pore diffusion of... 

In this study, sandwich beam model (SM) is proposed for free vibration analysis of bilayer graphene nanoribbons (BLGNRs) with interlayer shear effect. This model also takes into account the intralayer (in-plane) stretch of graphene nanoribbons. The molecular dynamics (MD) simulations using the software LAMMPS and Adaptive Intermolecular Reactive Empirical Bond Order (AIREBO) potential are done to validate the accuracy of the sandwich model results. The MD simulation results include the two first frequencies of cantilever BLGNRs with different lengths and two interlayer shear moduli, i.e., 0.25 and 4.6GPa. These two interlayer shear moduli, 0.25 and 4.6GPa, can be obtained by sliding a small... 

The Ugi reaction goes fast with high yields in a recyclable and biodegradable low-melting mixture of choline chloride and urea (DES) as a novel and efficient reaction medium. The DES is applicable to a wide range of aldehydes, amines, isocyanides, and acids in good to excellent isolated yields (60-92%) and short reaction times (2-5 h) and can be reused four times without any loss of activity  

We study the trade-off between throughput and memory footprint of embedded software that is synthesized from acyclic static dataflow (task graph) specifications targeting distributed memory multiprocessors. We identify iteration overlapping as a knob in the synthesis process by which one can trade application throughput for its memory requirement. Given an initial processor assignment and non-overlapped task schedule, we formally present underlying properties of the problem, such as constraints on a valid iteration overlapping, maximum possible throughput, and minimum memory footprint. Moreover, we develop an effective algorithm for generation of a rich set of design points that provide a... 

A chemoselective synthesis of tetraketone and xanthene derivatives, by means of tandem Knoevenagel condensation and Michael addition in choline chloride-based deep eutectic solvents (DESs), is presented. The reaction of readily available aldehydes and active methylene compounds in malonic acid- and ZnCl2-based DES gives various xanthenes derivatives with good to excellent yields under mild reaction conditions. On the other hand, tetraketones were synthesized in almost quantitative yields by simple condensation of an aldehyde and active methylene compounds in milder deep eutectic solvents of urea and SnCl2. In addition, the reaction of other types of choline chloride-based DES leads to a... 

In this paper, Virtual Cathode Oscillator as a microwave generator is studied concentrating on the nonlinear behavior of the microwave-plasma interaction that introduces chaos to the output voltage and power of the generator. It is shown that periodic oscillations of the electron beam strictly depend on the two most critical characteristics of the VCO, the input maximum voltage and the cathode radius. The chaos caused by the critical values of these two parameters, could restrict the maximum possible values of the input parameters, reducing the overall maximum output values. The effects of these two parameters are studied trough PIC-code simulations. The simulation results were used to... 

In this paper, the effect of repetitive corrugation and straightening (RCS) process on hardness of Duratherm 600 superalloy has been investigated. To do so, the RCS was carried out until 25 cycles using multiple teeth corrugative setup that the rotation of sample with 90° between cycles was utilized. The results show that the increasing of cycle number enhances the value of hardness. Also, the microstructures of samples are an evidence of slipbands formation during RCS showing the applied strain on the material. As a result, the increasing of hardness can be attributed to formation of subgrains, LAGBs and hcp martensitic plates at large strains