Sharif Digital Repository

Determining a promotion planning is a critical decision for retail managers. This plan should decide on the amount and duration of promotions for each product in a way that maximizes profit compared to a non-promotion scenario. In this study, the promotion optimization problem in a retail environment is formulated as a non-linear integer programming problem. The objective function is to maximize profit from product sales during the sales period. The problem also includes several business-related constraints that limit the number of promotions. In this study, a reinforcement learning approach, specifically Deep Q-Network, has been used to solve the mathematical model. The implementation... 

Pricing and revenue management are among the most important decisions for any economic enterprise. Several factors can influence decisions in this area and change the company’s pricing strategy, including uncertainties in product demand and customer preferences. This factor becomes particularly significant when the product is newly launched. Therefore, over time, customer preferences and willingness to pay may increase through various advertisements such as customer reviews and word-of-mouth. With rising demand, the seller has the opportunity to raise prices in the next periods. However, price increases can lead to unfair pricing perceptions by customers, hence reducing their purchasing... 

One of the important factors that are effective in the continuation of businesses is their profitability. Pricing, as an important component of the business process, greatly impacts profitability. Therefore, by using a suitable pricing method, retailers and service providers can increase their profits and avoid issues such as inventory congestion, imposed discounts, or lost sales opportunities. In this research, the two-tariff pricing system in internet services is investigated and determined by taking into account the randomness of customer consumption. The problem includes a set of Internet sales plans, each plan has a fixed price for a certain amount of data and a variable price for... 

The growing demand for scalable and cost-effective computing resources has led to the widespread adoption of the Infrastructure as a Service (IaaS) model in cloud computing. One of the pricing models for resources, or virtual machines, in this service is the Spot model, which allows customers to access unused cloud server capacity at significantly lower costs compared to other models. However, despite their affordability, these virtual machines do not come with a Service Level Agreement (SLA) and may experience interruptions during use. Such interruptions increase the time required for customers to complete their tasks. In this study, we utilize discrete-event system simulations to examine... 

Pricing plays an important and essential role in the profit and income of companies. The importance of pricing is not only related to its role in the company's profitability, but it also changes the customer's understanding and loyalty towards the company and can create the company's reputation or destroy it. Determining the right price will increase product sales and increase customer loyalty and create a competitive advantage for the company. One of the most important and influential variables in product pricing is the amount of demand. The main challenge of companies for product pricing is the uncertainty in their demand. In order to deal with this problem, data-driven pricing is used.... 

Coreference resolution is an essential step toward understanding discourses, and it is needed by many NLP tasks such as summarization, machine translation, question answering, etc. Pronoun resolution is a major and challenging subpart of coreference resolution, in which only the resolution of pronouns is considered. The existing coreference resolution approaches can be classified into two broad categories: linguistic and machine learning approaches. Linguistic approaches need a lot of linguistic information for the resolution process. Acquisition of such information is an error- prone and time-consuming process. In contrast, learning approaches need less linguistic information and provide... 

In network science, link prediction is one of the essential tasks that has been neglected. One important application of link prediction in telecommunication networks is analyzing the user's consumption pattern to provide better service. This project aims to predict future links with applications to call data using the users' call history. In previous research, there are two main approaches: 1) heuristic-based approach, and 2) deep-learning-based approach, such as graph neural networks. These methods are mainly used for processing static graphs, and therefore, we cannot generalize them to dynamic graphs. But there are many graphs which are dynamic in nature. For instance, call data records... 

In the upcoming research, with the aim of bone tissue engineering and achieving a new structure, a scaffold based on polyhema (PHEMA) and gelatin (Gel), which are biocompatible polymers for bone tissue, was made and evaluated. Also, in order to improve the bioactivity and mechanical properties, bioactive glass alone (BG45S5) or together with strontium (BG-Sr) was used in the scaffold structure. and chemical by conducting FTIR, XRD, SEM, mechanical strength, bioactivity measurement, contact angle, water absorption and degradation tests. Biological investigations were done using mesenchymal stem cells derived from human bone marrow and with the help of MTT evaluations and SEM photography. The... 

The present thesis investigates the surge phenomenon of high speed centrifugal compressors. Surge is a highly undesired condition and may cause severe damage to the machine and thus the plant. Traditionally, surge is avoided via a surge avoidance scheme wih recycle valve in discharge at the most common approach. A one dimensional technique is developed where the Greitzer lumped parameter model along with the Gravdahl one dimensional model is considered as the basis. Shaft dynamics, volume dynamics, losses, energy transfer and time lag are imbedded in the present model to improve the prediction of the compressor characteristics beyond the stability region. On the other hand, in order to... 

Axial compressor design is a very complex and expensive process. In general, for design and development of a new axial compressor, manufacturing companies usually intend to employ an existing and successful axial compressor as an starting point and modify and upgrade it. In this regard, dimensional scaling is a common method for derivative axial compressors. The goal of dimensional scaling is to get a different capacitywhile minimizing the development time and cost. In this thesis, theNASA eight stage transonic axial flow compressor is chosen as the base model for dimensional scaling to lower and upper size of its original dimension. The scaled compressor is analyzed with a quasi 2-D code.... 

In the present work, the problem of Olympic Games scheduling is investigated. Due to the high number of matches and limited number of resources, scheduling of the Olympic Games is a difficult and time consuming job. Also a balanced distribution of medals on the days of Olympic Games keep each day attractive for the people and prevent sudden changes in the medal ranking of countries. So, in regard to the limitations of the problem and to balance the distribution of medals, the Olympic Games are scheduled. In order to do that, at first, two mathematical models are presented. One of them is for obtaining the feasible and optimum solution in a specified period of time. The other model presents a...