فهرست مطالب محمدعلی نعمت بخش

Typically, when someone wants to buy an online product, he/she reviews the comments and notes written by others about the product. Clearly, it has a profound impact on the person's decision to buy or not to buy the product. Sentiment analysis or opinion mining is one of the hot research topics in computer science. The main purpose of sentiment analysis is to extract opinions of individuals about the characteristics of an entity such as a product. In this research, an unsupervised opinion mining is proposed for Persian products based on implicit feature extraction which is a critical step in sentiment analysis. In most previous studies, statistical information is utilized to create a co-occurrence matrix and determine the implicit features. In this paper, we benefit from syntactic rules and sentiment clustering in conjunction with statistical information to construct an efficient co-occurrence matrix between features and sentiment words. The evaluation results provided on a real-world dataset, extracted from Digikala website, indicates that the proposed method achieves higher recall and precision compared to the previous studies.

Today, the medical tourism industry is considered as one of the most important industries in the world and one of the highest income industries. The growth of information and communication technologies has not affected the growth of the industry over the past few decades and has provided the growth of electronic tourism. Given this position, it is necessary to elaborate a recommendation system template for e-tourism marketing as an issue in the country and to strengthen the strategies and mechanisms for promoting and empowering the industry through the information technology approach. This study aimed to design a recommendation system model for e-tourism marketing in Iran. The research is developmental in scope and is a component of mixed research. The statistical population was in the qualitative part of hospital managers and medical tourism experts who were selected by snowball method. They had an in-depth semi-structured interview. The qualitative results showed that the model of medical tourism has five dimensions including factors related to medical services, factors related to individual characteristics, factors related to internet information, factors related to tourism peripheral attractions, and factors related to travel facilities. In the quantitative section, a questionnaire based on the qualitative model was prepared and distributed among patients who referred to hospitals of Shiraz and Tehran for treatment and use of health services. Content validity and diagnostic validity were used for validity and Cronbach's alpha and composite reliability were used for reliability, respectively. The results of the quantitative section confirmed the model designed in the qualitative section. According to the findings of the study, it is suggested that the model resulting from this research be implemented and proposed by the proposed system, which according to the characteristics of the research, using the hybrid methodology is the most appropriate method for implementing the research model.

Mobile Cloud Computing (MCC) augments capabilities of mobile devices by offloading applications to the cloud. Task allocation is one of the most challenging issues in MCC considering neighboring mobile devices as the service providers. Given an application offloading request, the objective of the task allocation is to select service providers minimizing the completion time of the application offloading as well as consumed energy of all participating mobile devices while satisfying some QoS constraints. This paper models the task allocation problem in MCC as a constrained multi-objective optimization and proposes a two stages approach to solve the problem. In the first stage, a Multi-objective Resource Allocation based on Branch and Bound algorithm (MRABB) is designed to obtain Pareto solution set. In the subsequent stage, using Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method and given user’s preferences, the best compromise solution is determined. Furthermore, a context-aware software for Offloading in Mobile Cloud (OMC) is designed and implemented to collect contextual used in task allocation, and manage the offloading process. The results show the ability of the proposed multi-objective task allocation method to manage the trade-off between time and energy comparing to traditional algorithms.

Semantic web has been one of the most important research areas of computer science in recent years. The concept of ontology as one of the most elements of semantic web is used to formally describe the domain knowledge and to enable the reasoning capability. Semantic web is a distributed system and ontologies may be developed on many different nodes, so centralized reasoning is very hard or even impossible in many cases. On the other hand, since the majority of information in semantic web is uncertain, considering the notion of uncertainty in ontological reasoning is crucial. In this paper a method for distributed reasoning in uncertain ontologies is proposed. For this purpose the distributed description logic (DDL) framework and the certainty theory are considered for distributed reasoning and modeling the uncertainty respectively. To evaluate the functionality and performance of the algorithm, we developed a case study on application of the proposed method in purifying the mappings between ontologies. The results show that our algorithm makes the mappings more precise than other similar methods.

In many applications of wireless sensor networks, certain quality of end-to-end parameters is needed. Due to this requirement, supporting quality of service (QoS) in this kind of networks is of great importance. In recent years, multi-path routing technique is proposed as an effective approach to provide QoS. Utilizing multiple paths between senders and receivers, multi-path routing techniques can improve metrics such as reliability, power consumption, delay, throughput, and bandwidth. In this paper, we review the challenges of supporting QoS in wireless sensor networks. In addition, the benefits of multi-path routing are presented. Main elements of multi-path routing protocols are also introduced. At the end, we investigate the design of some multi-path routing protocols and present an application-based categorization of these protocols.