Sharif Digital Repository

Motivated by security issues in networks, we study the problem of incentive mechanism design for dynamic resource allocation in a multi-agent networked system. Each strategic agent has a private security state which can be safe or unsafe and is only known to him. At every time, each agent faces security threats from outside as well as from his unsafe neighbors. Therefore, the agents’ states are correlated and have interdependent stochastic dynamics. Agents have interdependent valuations, as each agent’s instantaneous utility depends on his own security state as well as his neighbors’ security states. There is a network manager that can allocate a security resource to one agent at each time... 

one of the important issues of construction industry today, is providing a meaningful interconnectivity between Architecture and its technical and technological aspects. In construction projects aesthetic and form is habitually crucial for the architect while structural designers aim for efficiency and stability of the structure. This research is concerned with the design of an urban footbridge located in Tehran-Iran with social and cultural spaces in which the form of the bridge is obtained by the use of topology optimization process. The objective of this study is to investigate the utilization of topology optimization process in architecture in order to achieve a beneficial design... 

one of the important issues of construction industry today, is providing a meaningful interconnectivity between Architecture and its technical and technological aspects. In construction projects aesthetic and form is habitually crucial for the architect while structural designers aim for efficiency and stability of the structure. This research is concerned with the design of an urban footbridge located in Tehran-Iran with social and cultural spaces in which the form of the bridge is obtained by the use of topology optimization process. The objective of this study is to investigate the utilization of topology optimization process in architecture in order to achieve a beneficial design... 

In this study an experimental design was developed to optimize the performance and structure of a membrane-based parallel-plate liquid desiccant dehumidifier used in air conditioning regeneration system which operates under high humidity weather conditions. We conducted a series of polymeric porous membranes with different compositions fabricated that were prepared with various weight percentages of polysulfone (PSU), mixed with N-methyl-2-pyrrolidone (NMP) and dimethyl form amide (DMF) solvents. Furthermore, the designed experiments were performed under various operating conditions, indicating that the dehumidification efficiency declines with increasing flow rate, temperature, and... 

The proper design of the urban infrastructure is crucial to develop civilization in a developing area. While there are dozens of managerial suggestions to go along with the static aspects of components in urban infrastructure design, hardly any piece of advice may be found to ensure dynamic outcomes of the whole design in advance. In this paper, a novel system dynamics model is introduced and applied in this context as a contribution to fill the research gap. The modular nature of the model development helps to alleviate the challenge of simultaneous design of components and system, with the potential capability of both static and dynamic verification. It allows the decision aider to observe... 

Medical waste management (MWM) is an important and necessary problem in the COVID-19 situation for treatment staff. When the number of infectious patients grows up, the amount of MWMs increases day by day. We present medical waste chain network design (MWCND) that contains health center (HC), waste segregation (WS), waste purchase contractor (WPC), and landfill. We propose to locate WS to decrease waste and recover them and send them to the WPC. Recovering medical waste like metal and plastic can help the environment and return to the production cycle. Therefore, we proposed a novel viable MWCND by a novel two-stage robust stochastic programming that considers resiliency (flexibility and... 

We leverage the crucial hyperelastic properties of a multifunctional structured surface to optimize the reconfigurability of the electromagnetic transmission under large nonlinear mechanical deformations. This multiphysics, multifunctional, hyperelastic structured surface (HSS) offers two simultaneous intriguing functionalities; tunability and switchability. It is made of copper reso-nators and a Polydimethylsiloxane (PDMS) substrate, which is one of the most favorable deformable substrates due to its hyperelastic behavior. The proposed HSS is fabricated via an original cost-effective technique and the multiphysics functionalities are captured in both experimental tests and numerical... 

An integrated probabilistic framework is proposed with a set of probabilistic models that are compatible with the reliability methods used in resilience-based design (RBD). Previous seismic resilience estimation frameworks primarily have used conditional probabilities and total probability integration to compute the expected seismic resilience index while considering the effects of only a few types of uncertainty. However, a high level of uncertainty is associated with seismic resilience estimation. This study presents a probabilistic framework and models that can consider the effect of unlimited uncertainties when calculating the probability distribution of the seismic resilience index for... 

To study of vibration effect on fluidization behaviour of high moisture materials, a laboratory vibro-fluidized bed dryer was designed and fabricated. The blower was selected based on transferring velocity of particles and pressure drop caused by airflow through the bedplate and the channels. It was centrifugal type with backward blades, static pressure of 3.5 kPa, flow rate of 0.4 m 3/s and impeller diameter of 0.4 m. The dryer was constructed with 4.9 kW electrical heater capacity, bed plate with holes diameter of I mm and 140626 holes/m 2. The dryer chamber was made of Plexiglass with 0.16×0.16 m square section and 0.5 m height The bedplate was vibrated mechanically, which was adjustable... 

In this paper, results of a preliminary study on the feasibility of using an Active Tendon Control (ATC) mechanism for frame structures subject to earthquakes is presented. So far, the ATC mechanism has mainly been considered as a means for installation on structures to mitigate their response under severe loading. In this study, it is desired to evaluate the possibility of using the ATC mechanism to serve as the main means for the stability of frames against earthquakes. Hence, a methodology is presented for the integrated design of frames with ATC mechanisms, which is tested numerically. A number of five-, ten-, fifteen- and twenty-story steel frames are used for this purpose. To this end,... 

In this paper, heat effects due to powerful pump beam in the lens duct delivery system is investigated and subsequent thermal effects are described. Temperature raise in the device, thermal loading, and material considerations for the lens ducts fabrication are reported. For an absorbed intensity of 10 W/cm2 in a 4 cm-long lens duct, the temperature difference between the midpoint and its faces, for a lens duct made from borosilicate is 7.05°C, for sapphire 4.01°C, and for synthetic fused silica is the smallest value of 0.54°C. For a typical absorbed intensity of 1.4 W/cm2 in a 4 cm-long lens duct, with a steady-state time constant of 120 s, the fractional thermal loading is 1.98% for BK-7,... 

A low voltage bandgap reference (BGR) in CMOS technology, with high power supply rejection ratio (PSRR) is presented. The proposed circuit uses a regulated current mode structure and some feedback loops to reach a low voltage, low power and high PSRR voltage reference. The circuit was designed and simulated in 0.25um CMOS technology, with a power supply of 1 volt. The results show PSRR is below -70dB at 1MHz and the output voltage variation versus temperature (0-70) is less than 0.3%. This circuit shows robustness against process variation  

In order to get better understanding on the response of floating bodies, different design aspects of mooring lines has been investigated in this paper. Mooting lines are categerized into two types; the catenary settling on the sea floor (type 1) and the limited one which has no dead-length on sea floor (type 2). It has been observed that the stiffness of both types may be well predicted by Jain's formulation and in the design process of floating bodies the mooring lines may be replaced by uncoupled horizontal and vertical springs. On the other hand, the anchor capacity against sliding and release from the mean still water has been studied in this paper. From the results of a parametric... 

This paper presents an analytical approach to estimate the speedup in a simulation-emulation cooperation environment. The speedup of this approach as compared with the speedup of a pure simulation is analyzed. Also, an analysis of the speedup is given when different types of application instructions are utilized. The analysis is based on using both Verilog and VHDL. The results show that when only the simulation part of the simulation-emulation co-operation is used, the speedup is higher, than when the pure simulation is used. The total speedup is also depended on the type of application instructions and the communication cycle time between the simulator and the emulator. © 2002 IEEE  

A novel procedure for fingerprint enhancement filter design is described. Fingerprints are best used as unique and invariant identifiers of individuals. Identification of fingerprint images is based on matching the features obtained from a query image against those stored in a database. Poor quality of fingerprint images makes serious problems in the performance of subsequent matching process. The main contribution of this work is to quantify and justify the functional relationship between image features and filter parameters. In this work, the enhancement process is adapted to the input image characteristics to improve its efficiency. Experimental results show the superiority of the... 

In this paper, a practical method is developed for performance-based design of RC structures subjected to seismic excitations. More efficient design is obtained by redistributing material from strong to weak parts of a structure until a state of uniform deformation or damage prevails. By applying the design algorithm on 5, 10 and 15-storey RC frames, the efficiency of the proposed method is initially demonstrated for specific synthetic and real seismic excitations. The results indicate that, for similar structural weight, designed structures experience up to 30% less global damage compared with code-based design frames. The method is then developed to consider multiple performance objectives...