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Customer Needs: Finding the Relationship Gaps Between IRAN Digital Print Industrry and Its Individual/Industrial Customers
, M.Sc. Thesis Sharif University of Technology ; Najmi, Manoochehr (Supervisor)
Abstract
Customer needs of Iran Print Industry have permanently been a secret for all producers, print centers and even many of the customers themselves. This research tries to find the relationship gaps between Iran Print Industry and its Individual /Industrial Customers, by identifying their needs. This will give recommendations on how manufacturers can increase their customers' satisfaction by providing them with what they need. Also it helps find the customers` satisfaction coefficient of the needs, which is a good guide for Customer Relationship Management in this industry.Therefore, manufacturers can spot these results by providing appropriate machines which can achieve these goals and offer...
The Effect of Surfactant Agents on the Superhydrophobic Properties of Silica Coatings Synthesis by Sol-gel
, M.Sc. Thesis Sharif University of Technology ; Dolati, Abolghasem (Supervisor)
Abstract
The purpose of this research is producing one phase silica superhydrophobic coating by sol-gel method and drying temperature less than 200 degrees. For preparing micrometer and nanometer scaled hierarchical structure based on silica, TEOS precursor and Fumed Silica nanoparticles were used by density of 43/30 cc/lit and 6/52 gr/lit in order to provide desired roughness in the range of 40 nm. Moreover, HMDS surface modifying agent was used for reducing the surface energy of coating, which is not a danger to the environment in comparison to the same substances. The best Contact Angle is 155 degree and the best Sliding Angle is less than 5 degree. For instance, it was created with the...
Biodesulfurization of dibenzothiophene by a newly isolated Rhodococcus erythropolis strain
, Article Bioresource Technology ; Volume 101, Issue 3 , 2010 , Pages 1102-1105 ; 09608524 (ISSN) ; Vosoughi, M ; Ziaee, A. A ; Sharif University of Technology
2010
Abstract
A new dibenzothiophene (DBT) desulfurizing bacterium was isolated from oil-contaminated soils in Iran. HPLC analysis and PCR-based detection of the presence of the DBT desulfurization genes (dszA, dszB and dszC) indicate that this strain converts DBT to 2-hydroxybiphenyl (2-HBP) via the 4S pathway. The strain, identified as Rhodococcus erythropolis SHT87, can utilize DBT, dibenzothiophene sulfone, thiophene, 2-methylthiophene and dimethylsulfoxide as a sole sulfur source for growth at 30 °C. The maximum specific desulfurization activity of strain SHT87 resting cells in aqueous and biphasic organic-aqueous systems at 30 °C was determined to be 0.36 and 0.47 μmol 2-HBP min-1 (g dry cell)-1,...
Comparative Study on Effect of Metallic Yield Dampers and Friction Devices on Response of Steel Structure
, M.Sc. Thesis Sharif University of Technology ; Kazemi, Mohammad Taghi (Supervisor)
Abstract
Passive energy dissipation systems are mechanical devices which could spread input energy, reduce response and decrease possible damage of the structure. Dampers were identified as a strong energy dissipation devices with cost efficiency and easy installation and maintanance. In this study, effects of using friction and metallic yield dampers to reduce structural responses are investigated. In addition, a comparison between these devices for reducing responses are conducted. Two 5 and 10 stories buildings with intermediate steel moment frames with and without damper are modeled and designed. It is seen, using of dampers could be reduce sections’ sizes. Seven pairs of earthquake records...
Gender Earnings Gap Among Tapsi Ride-share Drivers
, M.Sc. Thesis Sharif University of Technology ; Madanizadeh, Ali (Supervisor) ; Joshaghani, Hossein (Co-Supervisor)
Abstract
Some have argued that two-way markets, such as the online rideshar-ing platforms, which divide their services into different segments and provides each of these segments to the independent workforce based on an articulate and transparent income criterion, are more attrac-tive to women, which in turn, can reduce income disparities. This is due to the flexibility in working hours as well as the transparency of the labor payment process. In this study, using micro-data related to the trips of male and female drivers of Tap30, we find out that there is a 2.2 % gender earning gap between drivers. Furthermore, the fac-tors affecting the possible income difference are identified. On the one hand,...
Enhancing the Accuracy of Automotive Integrated Navigation System Using High-Order Error Model of Inertial Sensors Utilizing Auxiliary Sensors
, M.Sc. Thesis Sharif University of Technology ; Salarieh, Hassan (Supervisor)
Abstract
Navigation in various systems for land, air and sea movement has been of special importance for a long time. Determining the location, direction, speed and acceleration of moving has been a vital issue for mankind and it is also a basic prerequisite for starting the control process. Various methods have been used for this problem, the most important of which is the global positioning system. This method is satellite-based and any user from any part of the world can perform positioning. But in some places, such as tunnels or crowded places in the city, where it is not possible to send a signal, other methods are used. Also, in order to reduce errors, we can use the inertial navigation system...
Herschel-Bulkley rheological parameters of lightweight colloidal gas aphron (CGA) based fluids
, Article Chemical Engineering Research and Design ; Volume 93 , 2015 , Pages 21-29 ; 02638762 (ISSN) ; Arabloo, M ; Ghazanfari, M. H ; Rashtchian, D ; Sharif University of Technology
Institution of Chemical Engineers
2015
Abstract
The proper understanding of rheological characteristics of CGA based fluids is of crucial importance in determining the performance of the fluid, in order to maintain the most effective fluid properties for safe, efficient, and economical drilling operation. This paper presents a concise investigation on the effect of concentration of the three main components of a novel environmentally friendly lightweight CGA based drilling fluid, i.e., xanthan gum biopolymer, starch, and biosurfactant, to the Herschel-Bulkley rheological model parameters. The three parameters of Herschel-Bulkley model, i.e., yield stress, fluid consistency, and fluid flow index were calculated by fitting the experimental...
Experimental Study of Nanoparticles Application to Enhance Properties of Water-baseddrilling Fluid
, M.Sc. Thesis Sharif University of Technology ; Rashtchian, Davood (Supervisor) ; Hazanfari, Mohammad Hossein (Supervisor)
Abstract
One of the most well-established methods of increasing oil production rate from existing fields is infill drilling. However, drilling these depleted reservoirs with conventional high density drilling fluids may cause formationdamage problems and subsequently reduce the expected production rate. To overcome these technical problems, the use of lightweight aphron based fluids isincreasing rapidly in the petroleum industry. Rheological and fluid loss performance of aphron based drilling fluids can be improved in the presence of nanoparticles; however, very limited information is available in this field. Moreover, a thorough knowledge about the hydrodynamic flow behavior of drilling fluids...
Estimation Elasticity of Calorie and Macronutrients with Respect to Income in the Islamic Republic of Iran, 2008-2016
, M.Sc. Thesis Sharif University of Technology ; Vesal, Mohammad (Supervisor)
Abstract
Inadequate nutrition is perhaps the most important problem facing the poor. Being hungry lowers productivity and decreases individuals’ income. All of these factors conspire to help the poor stay poor. Raising the income of the poor is one solution for this problem if the elasticity of calorie and macronutrients with respect to income is greater than zero. This study employs both nonparametric and parametric methods to obtain the elasticity of per capita calorie and macronutrients with respect to household per capita expenditure. The case presented is for urban areas of Islamic republic of Iran, 2008-2016. Under each estimation strategy we employ, we find a strongly significant and positive...
Towards high data-rate diffusive molecular communications: A review on performance enhancement strategies
, Article Digital Signal Processing: A Review Journal ; 2021 ; 10512004 (ISSN) ; Nasiri-Kenari, M ; Mitra, U ; Sharif University of Technology
Elsevier Inc
2021
Abstract
Diffusive molecular communications (DiMC) have recently gained attention as a candidate for nano- to micro- and macro-scale communications due to its simplicity and energy efficiency. As signal propagation is solely enabled by Brownian motion mechanics, DiMC faces severe inter-symbol interference (ISI), which limits reliable and high data-rate communications. Herein, recent literature on DiMC performance enhancement strategies is surveyed; key research directions are identified. Signaling design and associated design constraints are presented. Studies on fundamental information theoretic limits of DiMC channel are reviewed. Classical and novel transceiver designs are discussed with an...
Towards high data-rate diffusive molecular communications: A review on performance enhancement strategies
, Article Digital Signal Processing: A Review Journal ; Volume 124 , 2022 ; 10512004 (ISSN) ; Nasiri Kenari, M ; Mitra, U ; Sharif University of Technology
Elsevier Inc
2022
Abstract
Diffusive molecular communications (DiMC) have recently gained attention as a candidate for nano- to micro- and macro-scale communications due to its simplicity and energy efficiency. As signal propagation is solely enabled by Brownian motion mechanics, DiMC faces severe inter-symbol interference (ISI), which limits reliable and high data-rate communications. Herein, recent literature on DiMC performance enhancement strategies is surveyed; key research directions are identified. Signaling design and associated design constraints are presented. Studies on fundamental information theoretic limits of DiMC channel are reviewed. Classical and novel transceiver designs are discussed with an...
Effect of electrolyte concentration on microstructure and properties of micro arc oxidized hydroxyapatite/titania nanostructured composite
, Article Materials Science and Engineering C ; Volume 33, Issue 5 , 2013 , Pages 2555-2561 ; 09284931 (ISSN) ; Golestani Fard, F ; Mirhosseini, S. M. M ; Ziaee, A ; Mehrjoo, M ; Sharif University of Technology
2013
Abstract
Micro arc oxidation was employed to grow TiO2/hydroxyapatite composite layer on titanium substrate. The correlation between electrolyte concentration, diameter and density of the pores in fabricated layers was investigated. Therefore, the effect of electrolyte concentration on composition and morphology of grown layers was studied using SEM, EDX, XRD and XPS techniques. Samples were coated in electrolytes containing 5, 10 and 15 g/l calcium acetate and 1, 3 and 5 g/l β-glycerophosphate, at optimized voltage for 3 min. Pore size variations obey a similar pattern by the addition of both calcium acetate and β-glycerophosphatein various concentrations based on SEM observations. However,...
MAO-derived hydroxyapatite-TiO 2 nanostructured bio-ceramic films on titanium
, Article Materials Research Bulletin ; Volume 47, Issue 11 , 2012 , Pages 3407-3412 ; 00255408 (ISSN) ; Golestani Fard, F ; Rezaie, H. R ; Mirhosseini, S. M. M ; Ziaee, A ; Sharif University of Technology
2012
Abstract
Micro Arc Oxidation (MAO) process was utilized to fabricate nano bioceramic TiO 2-hydroxyapatite coatings on titanium substrates. Samples were produced in electrolytes contained 1 g/l β-glycerophosphate and 5, 10 and 15 g/l calcium acetate for 3, 6 and 10 min at 350 V. The techniques including XRD, XPS, SEM, FESEM and EDX were employed to study the effect of processing parameters. Hydroxyapatite, anatase, α-tri calcium phosphate and calcium titanate phases as well as 30-60 nm-size crystals were detected in the coating layer. It was also observed that the pore volume would increase by increasing the electrolyte concentration. The growth time was also found to influence the total pore volume....
Diffusion based molecular communication: A simple near optimal receiver
, Article IWCIT 2014 - Iran Workshop on Communication and Information Theory ; 7-8 May , 2014 ; Print ISBN: 9781479948789 ; Arjmandi, H ; Gohari, A ; Kenari, M. N ; Mitra, U ; Sharif University of Technology
2014
Abstract
Nanonetworking indicates new solutions for many applications in biomedical and industrial fields. In this paper, we examine the diffusion-based molecular communication for information transmission in nano-networks. Design of practical decoders for resource-limited nano-networks requires an understanding the fundamental performance limits of memory-limited decoders. While some existing works in the literature do consider decoders with limited memory, to best of our knowledge, the tradeoff between memory and probability of error has not been studied in the literature. In this paper we make a first step by studying this tradeoff for a particular molecular communication channel between two...
Receivers for diffusion-based molecular communication: Exploiting memory and sampling rate
, Article IEEE Journal on Selected Areas in Communications ; Vol. 32, issue. 12 , 2014 , pp. 2368-2380 ; ISSN: 07338716 ; Arjmandi, H ; Gohari, A ; Nasiri-Kenari, M ; Mitra, U ; Sharif University of Technology
2014
Abstract
In this paper, a diffusion-based molecular communication channel between two nano-machines is considered. The effect of the amount of memory on performance is characterized, and a simple memory-limited decoder is proposed; its performance is shown to be close to that of the best possible decoder (without any restrictions on the computational complexity or its functional form), using genie-aided upper bounds. This effect is adapted to the case of Molecular Concentration Shift Keying; it is shown that a four-bit memory achieves nearly the same performance as infinite memory for all of the examples considered. A general class of threshold decoders is considered and shown to be suboptimal for a...
Capacity of LTI-Poisson channel for diffusion based molecular communication
, Article IEEE International Conference on Communications, ICC 2015, 8 June 2015 through 12 June 2015 ; Volume 2015-September , June , 2015 , Pages 1060-1065 ; 15503607 (ISSN) ; 9781467364324 (ISBN) ; Arjmandi, H ; Gohari, A ; Kenari, M. N ; Mitra, U ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2015
Abstract
The LTI-Poisson model is a natural extension of the conventional memoryless Poisson channel to include memory, and can model the ISI effect in diffusion based molecular communication networks. In this paper, we exploit prior art on linear ISI channels to provide a computable finite-letter characterization of the capacity of single-hop LTI-Poisson networks. Then we find more explicit single-letter lower and upper bounds on the capacity in the point to point case. Further, an approach for bounding mutual information in the low SNR regime using the symmetrized KL divergence is introduced and its applicability for Poisson channels is demonstrated. This leads to a non-trivial upper bound on the...
Adaptive molecule transmission rate for diffusion based molecular communication
, Article IEEE International Conference on Communications, ICC 2015, 8 June 2015 through 12 June 2015 ; Volume 2015-September , June , 2015 , Pages 1066-1071 ; 15503607 (ISSN) ; 9781467364324 (ISBN) ; Soleimanifar, M ; Gohari, A ; Kenari, M. N ; Mitra, U ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2015
Abstract
In this paper, a simple memory limited transmitter for molecular communication is proposed, in which information is encoded in the diffusion rate of the molecules. Taking advantage of memory, the proposed transmitter reduces the ISI problem by properly adjusting its diffusion rate. The error probability of the proposed scheme is derived and the result is compared with the lower bound on error probability of the optimum transmitter. It is shown that the performance of introduced transmitter is near optimal (under certain simplifications). Simplicity is the key feature of the presented communication system: the transmitter follows a simple rule, the receiver is a simple threshold decoder and...
Adaptive Transmission Rate with a Fixed Threshold Decoder for Diffusion-Based Molecular Communication
, Article IEEE Transactions on Communications ; Volume 64, Issue 1 , 2016 , Pages 236-248 ; 00906778 (ISSN) ; Soleimanifar, M ; Gohari, A ; Nasiri Kenari, M ; Mitra, U ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2016
Abstract
In this paper, a simple memory limited transmitter for molecular communication is proposed, in which information is encoded in the emission rate of the molecules. Taking advantage of memory, the proposed transmitter reduces the ISI problem by properly adjusting its emission rate, which can be interpreted as water-filling on the expected interference. The error probability of the proposed scheme is derived and the result is compared with the error probability of the optimal transmitter obtained by dynamic programming methods. Furthermore, for the special case of channel with one symbol memory, a tight lower bound on error probability is derived. Numerical results show that the performance of...
The effect of multiwalled carbon nanotubes and activated carbon on the morphology and photocatalytic activity of TiO2/C hybrid materials
, Article Catalysis Science & Technology ; 1 , Jan , 2011 , pp. 279-284 ; Ghasemia, S. (Shahnaz) ; Gholami, M. R. (Mohamad Reza) ; Sharif University of Technology
2011
Abstract
TiO2 nanoparticles supported on activated carbon (AC) and multiwalled carbon nanotubes (MWCNTs) were prepared by the sol–gel method using ultrasonic irradiation. All the prepared samples were calcined at different temperatures and characterized by X-ray diffraction, nitrogen adsorption/desorption isotherms, scanning electron microscopy, transmission electron microscopy and diffuse reflectance spectroscopy. The effects of size and type of carbon on the morphology and photocatalytic activity of the resulting hybrid materials were investigated. The results showed that a decrease in the size of the carbon led to a decrease in size of TiO2 nanoparticles. Both AC and MWCNTs retarded the...