Sharif Digital Repository

In this thesis, first, random lasing in a three dimensional disordered medium has been simulated using FDTD method and some properties of random lasers which were observed by others in the previous experiments have theoretically been shown. Our simulation results show that when the density of particles increases to an upper limit, the intensity of lasing modes is enhanced. Also, the effects of pumping rate and particle size on the number of lasing modes and their intensity are studied. Lasing threshold of laser modes in different disordered systems is calculated and it is shown that by an appropriate selection of the central frequency of gain line-shape, the output power intensity of random... 

In this study, a mixture of nano-encapsulated phase change materials in water has been used as a working fluid in a pulsating heat pipe in order to investigate its thermal performance. The results of the experiments showed that using the nano-encapsulated paraffin dispersed in water as working fluid improves heat transfer and decreases the thermal resistance of the pulsating heat pipe. On the other hand, there is an optimal concentration among tested concentrations for nano-encapsulated paraffin, in which increasing its concentration due to the increased dynamic viscosity of the fluid causes an increase in the thermal resistance of the pulsating heat pipe. Enhancement in the thermal... 

Multimorbidity in an individual is a typical and increasing condition and a major challenge in healthcare. The goal of treatment recommendation for such patients is to decide the most effective combination of treatments. Doctors typically prescribe medication based on their intuition and experience. However, due to knowledge gaps or unintended biases, often times these clinical decisions can be sub-optimal. Broad adoption and usage of electronic health records (EHRs) in the last decade has opened up a great opportunity to leverage healthcare data to improve clinical decisions.In this approach we use EHR and drug-drug interaction (DDI) information to prescribe medications. We use multiple... 

Ontology alignment is a process for selection of a good mapping between entities of two (or more) ontologies. It can be viewed as a two phase process of: 1) Find the similarity of each pair of entities from two ontologies, and 2) Extraction of an optimal or near optimal mapping. Many researches had been down in the first phase, but researches in the second phase are little. Mapping extraction approaches applied in ontology alignment use similarity matrix to extract mapping, and ontologies have not any role in mapping extraction phase. One of the most important components in ontology is its structure which can help us in alignment extraction.
In this thesis, an approach was proposed that... 

In this study, the interaction of tunneling of line 2 of Mashhad metro and existing metro station (Shariati station) in line 1 has been investigated. To produce the stress and displacement which is caused by excavation of station, the process of station excavation has been modeled by method of cut and cover.This method is the common method for station construction at Shallow depth and is used in several cases in line 1 of Mashhad metro. The piled-raft system is used in foundation of central part of the station to reduce the settlements and the effects of interactions between the station and new tunnel. The new tunnel under the station is surrounded by two rows of lateral piles with distance... 

Long Term Evolution (LTE) aims the peak data rates in excess of 300 Mb/s, which may appear to be challenging to achieve due to the existence of some blocks such as the turbo decoder. One efficient approach to achieve this throughput is by parallelizing the Log Maximum a Posteriori (MAP) algorithm in the turbo decoder. In fact, the interleaver is known to be a major challenging part of the turbo decoder due to its need to the parallel interleaved memory access. LTE uses Quadratic Permutation Polynomial (QPP) interleaver, which makes it suitable for the parallel decoding. In this thesis, first, we propose an efficient architecture for the QPP interleaver, called the Add-Compare-Select (ACS)... 

We discuss, in the setting of UMD Banach spaces E, existence, uniqueness and the continuous dependence on the data A, F, G and of mild solutions of semilinear stochastic evolution equations with multiplicative noise of the form dX(t) = [AX(t) + F(t;X(t))]dt + G(t;X(t))dWH(t); t 2 [0; T]; X(0) = ; Where A generates an analytic C0-semigroup on a UMD Banach space E and WH is a cylindrical Brownian motion with values in a Hilbert space H. We can see that if the mappings F : [0; T] E ! E and G : [0; T] E ! L(H;E) satisfy suitable Lipschitz conditions and is F0-measurable and bounded, then this problem has a unique mild solution.And We arw going to review continuous dependence of the solutions... 

Customer loyalty plays one of the most vital roles in business profitability. This concept gives special prominence to attaining new customers, which is by far less costly than attracting new ones. Therefore, investigating the impact of factors affecting customer retention is of precise significance. In the respect, corporate social responsibility, as an imperative factor impacting customer loyalty, gained more attention by various companies in the last decades.Over the past few months, the world has encountered the hazard of the Coronavirus pandemic. Most aspects of daily life in different parts of the globe have been affected by this disease. Companies are no exception. The coronavirus has... 

According to official statistics, family businesses form the majority of businesses around the world. When we talk about businesses, we are more likely to say that those firms face issues related to family businesses.One of the trending topics that has recently been considered by researchers and a lot of research has been done in this regard, is specific issues related to marketing and branding of family businesses.In this study, we tried to examine the family business brand in terms of reputation. Reputation is the perception in the minds of brand stakeholders about the brand and the organization. So we tried to take as fair and accurate a sample as possible, to seek the opinions of...