Sharif Digital Repository

Rapid growth in science and technology has created vast diversity in products, services and needs of people and groups. As the Internet and web technologies have progressed, a web-based solution to explore products of either a specific domain or multiple domains is mandatory. One of the main challenges in these systems is learning users’ preferences to recommend items possibly interesting to the user. Social network of the users is one of the sources that can inject additional information about them which can be exploited to improve accuracy of the system. Depending on the method, the performance, accuracy and personalization may differ .One of the most popular methods to extract this... 

One of the electromagnetic methods for partial discharge detection is known as UHF detection. In this method the electromagnetic radiations from PD sources over a wide frequency band of UHF are detected and the related spectrums over the UHF frequency band are captured for diagnostic. The absence of noise in UHF band (300 MHz- 3GHz) is the most important advantage of this method if compared with other electrical PD detection methods. To capture electromagnetic signals and radiations generated by PD sources, application of an electromagnetic sensor, named antenna, is necessary. Therefore one of the goals in this thesis is to select, design, and build a suitable antenna for PD detection.... 

This study aims to solve weekly Flight Frequency Determination and Aircraft Maintenance Routing Problem (AMRP) simultaneously. The objective function here is to maximize the total net profit of an assumptive airline with predetermined airfare and origin-destination market demand. All the needed constraints regarding AMRP is added to the modified version of original model which proposed by Ghafoori in 2011. On the other hand, while this kind of model is based on travelling salesman problem, the occurrence of sub-tours is inevitable. Thus, the model will be, secondly, restricted with more constraints which help eliminate infeasible solutions. The proposed model, then, is tested for three... 

This research investigates what consumers in democratized luxury markets value when purchasing luxury items. Nonetheless, these consumers have a limited budget and can not always buy luxury items, yet they are drawn back to these luxury brands. Thus, we use brand engagement in self-concept (BESC) to explain the relationship between these consumers and luxury brands within democratized luxury markets. A conceptualized model of three luxury value dimensions (experiential, symbolic, and functional) is proposed, and 488 cases were gathered through a phone survey. The data were analyzed using partial least squares structural equation modeling (PLS-SEM). The results show that the most critical... 

For the past few years, increasing the airspace capacity has been one of the most detrimental issues facing air traffic management. Statistically speaking, the demand for aerial transportation has been continuously growing hitting an %8.1 growth in 2017. This growth rate in conjunction with the performance and safety considerations for the ATC systems, clearly indicate the need for a practical and safe solution to the airspace capacity problem. Dynamic Airspace Configuration (DAC), is one of the proposed methods addressing this problem by changing the airspace configuration over time.In this research, we have introduced an intelligent method for airspace configuration given the forecast of... 

In the field of supply chain management, understanding the impact of centralized and decentralized decision-making approaches on overall performance is highly important, especially in environments characterized by uncertainty and complexity. This study introduces an innovative approach by incorporating uncertainty into the NK model framework, a model traditionally used for analyzing interdependencies and adaptability in complex systems. Through this, the research examines the dynamic interactions within supply chains under various levels of uncertainty and complexity, offering a more realistic simulation of real-world conditions. The results show that adding uncertainty to the model... 

The aim of this research is to examine environmentally conscious consumer behavior based on the Theory of Planned Behavior, which includes the antecedents of attitude, behavioral control, norm, moral commitment, and psychological factors in the selection of green products. Additionally, it investigates the extent to which this environmentally conscious behavior influences consumers' green purchase intentions. To further analyze green purchase intentions, the study employs the moderating variable of perceived environmental well-being and the mediating variable of need for cognition based on signaling theory. The integration of the Theory of Planned Behavior and signaling theory is utilized to... 

With the explosive growth of social media platforms, influencers have emerged as important factors in driving consumer decisions, prompting much research into their influence on their audiences. This study examines the relationship between social media influencers and consumer behavior by examining which characteristics of social media influencers influence consumer attitudes toward products and their resulting purchase intentions and increase their endorsement effectiveness. Through an extensive review of existing literature, this research identifies key influencer characteristics, including authenticity, attractiveness, communication, social responsibilities, and product match-up, as key... 

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... 

Previous Research has extensively investigated ambidexterity in organizational and individual level and evaluated their prescedents and outcomes. These studies have led to an agreement on the positive relationship between ambidexterity in different levels and performance, in dynamic business environments. Unlike before, recent studies in the context of ambidexterity have been focused on the prescedents of ambidexterity in the individual level. However very few studies have empirically investigated the direct relationship between ambidexterity in different levels. In this research we have focused on the relationship between the top manager's ambidexterity and the organizational ambidexterity... 

The purpose of this research is to investigate the impact of human capital on the performance of startups in Iran so that its findings can be used to guide the startups and companies, policymakers, and entrepreneurs. According to a study by Aguin andcolleagues. (2009), the establishment of new firms through entrepreneurial activities can increase national economic growth, creativity and productivity at the national level. Joseph, in 1995, stated in an article what has been pointed out by some researchers in the field of entrepreneurship in developing countries, Programs and strategies that succeed in a country will not necessarily succeed in another country, due to cultural and governmental... 

The extant body of literature provides limited coverage regarding the concurrent influence of social responsibility and brand authenticity on both brand expression and adverse consumer behavior. Insufficient attention has been devoted to the correlation between social responsibility and brand forgiveness, as well as mischaracterizations of branding. The interplay of brand and consumer ethnocentrism further serves as a moderating factor in the associations among social responsibility, brand forgiveness, negative discourse, and brand avoidance. Four distinct scenarios, involving the random allocation among distributed companies, were considered: 1. Authentic brand with the presence of social... 

This study investigates whether hotels that implement sustainability practices and obtain environmental certifications charge higher prices compared to other hotels. To answer this question, the hedonic pricing model is used alongside aspect-based sentiment analysis of customer reviews on the Booking.com website. In this regard, structured data on hotel characteristics (such as star rating, location, and amenities) and customer textual reviews were extracted and analyzed using large language models to identify key topics and sentiments. The results showed that having a sustainability certificate does not have a uniform effect on hotel prices and that this effect varies by star rating. In...