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Axiomatic Design Science: Application in reducing Design Complexities of Special Structures
, Ph.D. Dissertation Sharif University of Technology ; Abedian, Ali (Supervisor) ; Malaek, Mohammad Bagher (Supervisor)
Abstract
This research aims to study fundamentals of design as a science for possible use in special structures. Special structures are referred to those structures that designers’ knowledge for which are insufficient. Designs of such structures are complex in the sense that we lack all necessary elements of design matrix; as well as proper steps to reach the unknowns. Introducing appropriate design strategy for such structures; we show how a design could be developed without specific needs for trial and errors. In this work, various design methodologies and especially “Axiomatic Design” have been examined. In addition, functional requirement and associated design parameters for structural design are...
A UHF micro-power CMOS rectifier using a novel diode connected CMOS transistor for micro-sensor and RFID applications
, Article International Conference on Electronic Devices, Systems, and Applications ; 2012 , Pages 234-238 ; 21592047 (ISSN) ; 9781467321631 (ISBN) ; Hamidon, M. N ; Khoddam, M ; Najafi, V ; Sharif University of Technology
2012
Abstract
The design strategy and efficiency optimization of UHF micro-power rectifiers using a novel diode connected MOS transistor is presented. The proposed diode connected MOS transistor uses a new bulk connection which leads to reduce the threshold voltage and leakage current in compare to conventional diode connected transistors. Using the proposed diode in typical rectifiers makes a significant improvement in output voltage and current therefore the efficiency is increased comparing to the same rectifier architectures using conventional diodes. Also a design procedure for efficiency optimization is presented and a superposition method is used to optimize the performance of multiple output...
Sliding mode leader following control for autonomous air robots
, Article 2011 IEEE/SICE International Symposium on System Integration, SII 2011, 20 December 2011 through 22 December 2011 ; December , 2011 , Pages 972-977 ; 9781457715235 (ISBN) ; Saghafi, F ; Sharif University of Technology
2011
Abstract
In this paper, we propose a leader following control for autonomous air robots. The separated design strategy with kinematic acceleration commands is used. The location of the robot with respect to the leader is specified by a range and two angles. We obtain the kinematic model of the system represented by the state-space equations. The controller is designed based on the sliding mode control which asymptotically stabilizes the tracking errors in presence of uncertainties and disturbances. In order to implement the leader following controller in the air robots, a control system is introduced which converts the acceleration commands to the actuator commands. Simulations are provided to show...
Various coupling configurations on the performance of two-dimensional coupled oscillator arrays
, Article IET Microwaves, Antennas and Propagation ; Volume 11, Issue 3 , 2017 , Pages 426-432 ; 17518725 (ISSN) ; Banai, A ; Sharif University of Technology
Institution of Engineering and Technology
2017
Abstract
Coupled oscillator arrays (COAs) can be used to control the phase distribution across the aperture of an array antenna in such a manner as to affect steering of the beam without the use of phase shifters. Given the various possible planar configurations of COAs, a systematic design approach is necessary. In this study, the authors present a comprehensive comparison of various configurations of planar COAs based on their sensitivity to random errors in their free running frequencies. The parameters considered are (a) the beam pointing error of the array, (b) the locking probability, (c) the side lobe level, and (d) the beam width of the radiation pattern. These results can serve as a design...
Robust and efficient zero liquid discharge design strategy using four novel desalination systems: A comprehensive 4E assessment
, Article Journal of Cleaner Production ; Volume 310 , 2021 ; 09596526 (ISSN) ; Moosavi, A ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
Discharging unconventional water sources having a high content of inorganic compounds is extremely destructive to the environment. In this research, four novel semi-open-air and closed-air configurations of brine-recycle humidification-dehumidification (BRHDH) systems with zero liquid discharge (ZLD) approach are presented to treat unconventional waters cost-effectively. Bubble-column humidifiers and dehumidifiers are used to have a low initial expenditure, and system multi-staging is implemented to reduce the operating expense of the configurations. The configurations are evaluated for high saline brine treatment using comprehensive energy, exergy, exergoeconomic, and exergoenvironmental...
Design of tensegrity structures for supporting deployable mesh antennas
, Article Scientia Iranica ; Volume 18, Issue 5 , October , 2011 , Pages 1078-1087 ; 10263098 (ISSN) ; Abedian, A ; Sharif University of Technology
2011
Abstract
This paper is an attempt to develop a design methodology for a special deployable structure for potential use in micro-satellites. The basic form of this structure is a hexagonal prismatic tensegrity structure, which, after being rigidified, is used as the supporting structure of a mesh-like antenna. Here, the objectives of presenting the design methodology are to prevent structural elements from failure, while maintaining the structural natural frequency and mesh tension above an intended value and in addition, to minimize the overall mass. Here, the suggested design strategy combines the need for a behavioral study (i.e. fast and wide range evaluation) at the beginning of the design, with...
Compensation of channel and noise distortions combining maximum likelihood based spectral subtraction and Normalization
, Article 2007 IEEE International Conference on Signal Processing and Communications, ICSPC 2007, Dubai, 14 November 2007 through 27 November 2007 ; 2007 , Pages 508-511 ; 9781424412365 (ISBN) ; Babaali, B ; Manzuri Shalmani, M. T ; Sameti, H ; Khaleghi, S ; Sharif University of Technology
2007
Abstract
Channel distortion may dramatically degrade speech recognition performance in a distant environment. Authors in their recent work [1] proposed a novel spectral subtraction method which they named it maximum likelihood based spectral subtraction (MLBSS). They indicated that recognition performance could be improved dramatically by adjusting filter parameters based on recognition results. Previous results show effectiveness of this method in dealing with additive distortion. In this paper we propose an approach for increasing robustness of this method against channel distortion in distant talking environment. We add Cepstral Mean Normalization (CMN) in designing MLBSS filter and show that by...
An imprinted interpenetrating polymer network for microextraction in packed syringe of carbamazepine
, Article Journal of Chromatography A ; Volume 1491 , 2017 , Pages 1-8 ; 00219673 (ISSN) ; Bagheri, H ; Es haghi, A ; Amini Tabrizi, R ; Sharif University of Technology
Abstract
An imprinted interpenetrating polymer network (IPN) was synthesized and used as a medium for isolation of carbamazepine from urine samples. The polymer network consisted of a homogeneous polystyrene–sol gel hybrid constructed by in–situ radical polymerization method. In this process, within the sol–gel reaction duration, styrene monomer could penetrate into the reaction mixture and after the polymerization initiation, a monolithic IPN structure was prepared. The scanning electron microscopy (SEM) image and energy dispersive spectroscopy (EDX) are indications of the polystyrene dispersion at nano- to micro-meter level in the sol gel matrix. Eventually, the synthesized IPN was used as a...