Sharif Digital Repository

The use of Spoken Dialogue Systems is growing everyday and these systems will substitute current Iterative Voice Response systems in near future. A Spoken Dialogue System consists of Speech Recognition, Language Understanding, Dialogue Management, Speech Generation and Text to Speech Modules. Among these modules the only one that is specific part of Dialogue Systems is Dialogue Management. The responsibility of this part is to determine system behavior to maximize specific variables such as user goal finding accuracy and speed of finding the goal. There were different approaches to dialogue management in recent years the use of Partially-Observable Markov Decision Processes was very popular... 

WBAN , as one of the most important wireless networks in the near future, has received significant attentions in recent years. The most important designing challenge in these networks is the scarcity of energy resources especially in their sensor nodes. Additionally, special characteristics of these networks have led the other network’s designs, especially the general sensor network protocols to be inefficient for the WBAN. Among others, the existences of recurring patterns in each sensor channel fading and the high correlation among different sensor channels are some of the most important characteristics of WBANs. Considering these characteristics, in this thesis, the MAC sub-layer of... 

Considering energy efficiency ways a key role in designing future wireless networks( 5G mobile networks). Moreover Spectrum efficiency is another critical issues in designing wireless networks. Cognitive radios can improve the spectrum efficiency. On the other hand, radio frequency (RF) energy harvesting has emerged as a promising technique to supply energy for wireless networks and thereby increase their energy efficiency. In this thesis, we propose a new technique for the RF-powered CRNs.To this end,We consider a cognitive radio network comprised of a primary user and a secondary user. The primary user, uses a typical frequency band for transmit data in a time slot basis and both the... 

Computer video games have had a huge growth in recent years, and Dota 2 is one of the most popular video games and e-sports right now. In this research, Dota 2 drafting phase is studied by using stochastic processes and probabilistic models. This phase is modeled as a POMDP (Partially Observable Markov Decision Process) for the first time. Afterwards, the model is solved using data mining methods and machine learning algorithms. A large database of the game's match data is created, and six different machine learning algorithms are used to predict the match outcome based on the drafting stage. The prediction accuracy and power of these algorithms is compared, and finally, a program is... 

Mankind according to his authority (or delusion of authority) always finds himself in a situation which need decision-¬making. Usually, he seeks to make the best possible decision. The basis for measuring the goodness of choices is different in different occasions. This measure could be level of enjoyment, economic profit, probability of reaching a goal, etc. These decisions have consequences such that the situations before and after the decisions are not the same. Most challenging decision¬-making situations are those which the decision¬maker has not the complete authority over the situation and the results of decisions are influenced by out of control factors. A significant part of... 

Recent advancements in wireless communication along with the urgent need for new care systems for the patients, has attracted the attention of many communication researchers to Wireless Body Area Networks (WBANs), which has led to IEEE 802.15.6 and IEEE 802.15.4j standards, accordingly. The main goal of such networks, is to send the vital data of the associate, through the over/in-body-implanted sensors, to one central node. One of the key features of these networks is the limited energy sources of the sensors, transmit the data. Meanwhile, on-time error-free transmission of the data is also of great importance. Therefore, designing a proper algorithm, satisfying the aforementioned... 

Molecular communication (MC) is an emerging communication paradigm, whereas molecules are used as information carriers to establish communication among elements in nano-meter to meter scales. In this thesis, we investigate the problem of detecting and monitoring changes (abnormality) based on molecular communication, using quickest change point detection scheme. We assume the distributions and parameters of the system are known. To this end, we consider a network of multiple sensors, each sensing its surrounding and employing On-Off-keying modulation for data transmission toward a fusion center (FC). An abnormality initiates randomly in time and location, and further propagates in the...