Design and Analysis of Internal Model Principle Based Linear Time Invariant Fractional Order Regulators

, M.Sc. Thesis Sharif University of Technology Niroomand, Mahdi (Author) ; Haeri, Mohammad (Supervisor)

Abstract

In this thesis, two essential issues are investigated. The first issue is, when a general incommensurate fractional-order controller would be a stabilizing controller for an incommensurate fractional-order system in the standard feedback structure, and how one can possibly construct such closed-loop stabilizing controller. The second issue is to synthesize internal model principle based fractional-order controllers. These controllers consist of two main parts: the internal model corresponding to exogenous signals and an arbitrary fractional order controller. The main objective in the internal model principle based controllers, is to synthesize the second part of the controller such that the...

Studying Time Perception in Musician and Non-musician Using Auditory Stimuli

, M.Sc. Thesis Sharif University of Technology Niroomand, Niavash (Author) ; Hajipour, Sepideh (Supervisor)

Abstract

Time perception is a concept that describes how a person interprets the duration of an event. Depending on the circumstances, people may feel that time passes quickly or slowly. So far, the understanding, comparison, and estimation of the time interval have been described using a simple model, a pacemaker accumulator, that is powerful in explaining behavioral and biological data. Also, the role of the frequency band, Contingent Negative Variation (CNV), and Event-Related Potential (ERP) components have been investigated in the passage of time and the perception of time duration. Still, the stimuli used in these studies were not melodic. Predicting is one of the main behaviors of the brain....

A quasi-three-dimensional thermal model for multi-stream plate fin heat exchangers

, Article Applied Thermal Engineering ; Volume 157 , 2019 ; 13594311 (ISSN) Niroomand, R ; Saidi, M. H ; Hannani, S. K ; Sharif University of Technology

Elsevier Ltd 2019

Abstract

In this study, a novel pseudo-three-dimensional model is developed to find out both fluid and solid temperature distributions in multi-stream plate fin heat exchangers. In this simulation algorithm, heat exchangers can be in either parallel flow or cross flow configuration. The model considerations include: heat leakage of cap plates and side plates, conduction throughout the solid matrix of the heat exchanger, variable physical properties, and inlet mass flow rate maldistribution. Using the computational code, the effects of different factors such as: the number of layers, mass flow variation, inlet mass flow rate maldistribution, and stacking pattern on the thermal performance of the heat...

A general multi-scale modeling framework for two-phase simulation of multi-stream plate-fin heat exchangers

, Article International Journal of Heat and Mass Transfer ; Volume 156 , 2020 Niroomand, R ; Saidi, M. H ; Hannani, S. K ; Sharif University of Technology

Elsevier Ltd 2020

Abstract

Compact heat exchangers are among the vital components used in various industries. In this study, a general framework has been developed with a multi-scale point of view for three-dimensional simulation of multi-stream plate-fin heat exchangers. The most important features in the MSPFHEs simulation, such as phase change phenomena, multi-component mixtures, multiple streams, transversal, lateral and longitudinal conduction, non-uniformity of inlet flow, variable fluid properties, and heat leakage are simultaneously considered in this model. The modular form of the model structure has facilitated layer-by-layer simulation of cross flow heat exchangers as well as parallel flow ones. Our model...

A new multiscale modeling framework for investigating thermally-induced flow maldistribution in multi-stream plate-fin heat exchangers

, Article International Journal of Heat and Mass Transfer ; Volume 180 , 2021 ; 00179310 (ISSN) Niroomand, R ; Saidi, M. H ; Hannani, S. K ; Sharif University of Technology

Elsevier Ltd 2021

Abstract

Multi-stream Plate-fin heat exchangers (MSPFHEs) are among the most efficient heat exchangers in energy-based industries. They should be carefully designed to have maximum effectiveness and to avoid wasting energy. Flow maldistribution could significantly degrade the performance of heat exchangers. This study presents a novel modeling framework to capture the thermally-induced maldistribution in two-phase MSPFHEs. The developed model is used to show how thermally-induced flow maldistribution affects the performance of the heat exchanger, and some possible modifications are investigated to reduce its consequences. Our case study results show that thermally-induced maldistribution decreases...

Cross-Platform Software Testing

, M.Sc. Thesis Sharif University of Technology Niroomand, Mohammad Hassan (Author) ; Mirian Hosseinabadi, Hassan (Supervisor)

Abstract

According to expanding penetration of Internet and the increased power of processing devices in the recent years, softwares are incisingly used for daily acitivies. The variety of hardware configuration and operating system of such devices leds the companies to take advantage of cross-platform software development methods. Although the production of cross platform software, resude development costs, it results in an specific type of faults known as platform-specific failures. These faults occur when software is running on specific platforms, and therefore, to identify and resolve them, the software test process should be performed on different platforms. To deal with this problem, we present...

OPAIC: An optimization technique to improve energy consumption and performance in application specific network on chips

, Article Measurement: Journal of the International Measurement Confederation ; Volume 74 , 2015 , Pages 208-220 ; 02632241 (ISSN) Taassori, M ; Taassori, M ; Niroomand, S ; Vizvári, B ; Uysal, S ; Hadi Vencheh, A ; Sharif University of Technology

Elsevier 2015

Abstract

Abstract Network on Chip (NoC) is an appropriate and scalable solution for today's System on Chips (SoCs) with the high communication demands. Application specific NoCs is preferable since they can be customized to optimize all requirements of the specific applications. This paper presents an OPtimization technique for Application specifIC NoCs (OPAIC), which aims not only to decrease the energy consumption but also to improve the area of NoCs. OPAIC is composed of three stages to find the optimum NoC; in the first stage, it uses a linearized form of a Quadratic Assignment Problem (QAP) to map tasks on cores to minimize the energy. In the second stage, a Mixed Integer Linear Problem (MILP)...

Simulation of Cooling System for ER24PC Locomotive Diesel Engine and Investigation of the Effect of Ambient Condition on the Cooling System Performance

, M.Sc. Thesis Sharif University of Technology Niroomand, Reza (Author) ; Saeedi, Mohammad Hassan (Supervisor) ; Kazemzadeh Hannani, Siamak (Co-Advisor)

Abstract

Nowadays, computer simulations have an important role in the investigation of the thermal performance of the systems. In this thesis, a software program was developed for simulation of cooling system of an ER24PC Locomotive diesel engine. For this purpose, the C + + programming language is applied. One of the most important components in the cooling system is the radiator. In order to model the radiator, a relationship must be used to determine the heat transfer coefficient for coolant side and air side of the radiator. This relationship can be based on experimental, analytical, or numerical solutions. Offset strip fins are used in radiator of ER24PC locomotives. With application of...

Cycloplatinated(II) complexes containing bridging bis(diphenylphosphino)acetylene: Photophysical study

, Article Journal of Luminescence ; Volume 179 , 2016 , Pages 222-229 ; 00222313 (ISSN) Jamshidi, M ; Nabavizadeh, S. M ; Sepehrpour, H ; Niroomand Hosseini, F ; Kia, R ; Rashidi, M ; Sharif University of Technology

Elsevier 2016

Abstract

Reaction of the known cycloplatinated (II) complexes [PtAr(C^N)(SMe2)], in which Ar=p–MeC6H4 or p–MeOC6H4 and C^N= 2-phenylpyridinate (ppy) or benzo[h]quinolinate (bhq), with 0.5 equivalent of the bidentate phosphine ligand 1,1′–bis(diphenylphosphino)acetylene, dppac, in acetone at room temperature gave the symmetrical binuclear cycloplatinated(II) complexes [Pt2Ar2(C^N)2(μ–dppac)], 1–4, in which dppac acts as a bridging bidentate ligand. All the complexes were fully characterized using multinuclear (1H, 31P and 195Pt) NMR spectroscopy and the complex [Pt2(p–MeC6H4)2(ppy)2(μ–dppac)], 1, was further identified by single crystal X-ray structure determination. Additional information about the...