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... 

We have observed that a rotating liquid soap film generates electricity when placed between two non-contact electrodes with a sufficiently large potential difference. In our experiments, suspended liquid film (water + soap film) is formed on the surface of a circular frame, which is forced to rotate in the x−y horizontal plane by a motor. This system is located at the center of two capacitor-like vertical plates to apply an external electric voltage difference in the x-direction. The produced electric current is collected from the liquid film using two conducting electrodes that are separated in the y-direction. We previously reported that a liquid film in an external electric field rotates... 

Hybrid renewable energy heat sources provide more sustainable energy resources with high maintenance for high-efficient power plants. Multigeneration systems driven by a hybrid renewable source are proved as cutting-edge technologies in recent studies. In this study, a novel multigeneration system driven by a hybrid biogas-geothermal heat source is proposed and simulated. To demonstrate the feasibility of the proposed multigeneration system, first and second laws analysis are employed as the most effective tools for performance assessment of the systems. It is found that the proposed multigeneration system can produce overall heating capacity, overall cooling capacity, net output power,... 

Hybridization of biogas and geothermal energies for power plants can present a promising way to resolve drawbacks of each individual heat source from economic viewpoint, especially when low-temperature geothermal heat source is posited. Concerning this aspect of hybrid renewable heat sources, a novel hybrid biogas-geothermal multigeneration system was proposed in the first part of our study, which was modeled under privilege of thermodynamic laws. In continuation of our previous study, the current study is performed to investigate economic, environmental, and enviroeconomical aspects of the introduced system. Furthermore, single and multi-criteria optimizations of this integrated system are... 

When a high voltage is applied between two beakers filled with deionized water, a floating bridge of water is formed in between exceeding the length of 2 cm when the beakers are pulled apart. Currently two theories regarding the stability of the floating water bridge exist, one suggesting that the tension caused by electric field in the dielectric medium is holding the bridge and the other suggesting surface tension to be responsible for the vertical equilibrium. We construct experiments in which the electric field and the geometry of the bridge are measured and compared with predictions of theories of the floating water bridge stability. We use a numerical simulation for estimation of the... 

The main goal of environmental education program developers is to train resourceful experts to work, study and solve environmental issues. Thus, it is essential to conform educational knowledge and skills according to countries needs along with scientific and technological progress. The present study aimed to assess needs of educational programs by considering climate change issues in Iranian Universities. Therefore, needs of higher education sector have been identified and some recommendations were given in line with objectives of training programs. The study applied random selection method to determine a number of environmental professionals to answer the designed questioner. Delphi method... 

The main goal of environmental education program developers is to train resourceful experts to work, study and solve environmental issues. Thus, it is essential to conform educational knowledge and skills according to countries needs along with scientific and technological progress. The present study aimed to assess needs of educational programs by considering climate change issues in Iranian Universities. Therefore, needs of higher education sector have been identified and some recommendations were given in line with objectives of training programs. The study applied random selection method to determine a number of environmental professionals to answer the designed questioner. Delphi method... 

The main goal of environmental education program developers is to train resourceful experts to work, study and solve environmental issues. Thus, it is essential to conform educational knowledge and skills according to countries needs along with scientific and technological progress. The present study aimed to assess needs of educational programs by considering climate change issues in Iranian Universities. Therefore, needs of higher education sector have been identified and some recommendations were given in line with objectives of training programs. The study applied random selection method to determine a number of environmental professionals to answer the designed questioner. Delphi method... 

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... 

Feasibility investigation of a humidification dehumidification (HDH) desalination system driven by an absorption-compression heat pump cycle (ACHPC) is carried out in this paper. The proposed hybrid desalination system uses both heating capacity of the discharged brine as a waste heat for the ACHPC and mechanical power of the ACHPC for the HDH system. The system's performance is investigated under different optimal design modes, using genetic algorithm (GA) as the most robust tool for optimization. A steady-state mathematical model based on the mass, energy, exergy, and exergoeconomic balance equations for components of the proposed system is developed and the predicted results are validated...