Sentiment Analysis (SA) of social media contents has become one of the growing areas of research in data mining. SA provides the ability of text mining the public opinions of a subjective manner in real time. This paper proposes a SA model of Arabic Jordanian dialect tweets. Tweets are annotated on three different classes; positive, negative, and neutral. Support Vector Machines (SVM) and Naïve Bayes (NB) are used as supervised machine learning classification tools. Preprocessing of such tweets for SA is done via; cleaning noisy tweets, normalization, tokenization, namely, Entity Recognition, removing stop words, and stemming. The results of the experiments conducted on this model showed encouraging outcomes when Arabic light stemmer/segment is applied on Arabic Jordanian dialect tweets. Also, the results showed that SVM has better performance than NB on such tweets' classifications.

Tor is the low-latency anonymity tool and one of the prevalent used open source anonymity tools for anonymizing TCP traffic on the Internet used by around 500,000 people every day. Tor protects user's privacy against surveillance and censorship by making it extremely difficult for an observer to correlate visited websites in the Internet with the real physical-world identity. Tor accomplished that by ensuring adequate protection of Tor traffic against traffic analysis and feature extraction techniques. Further, Tor ensures antiwebsite fingerprinting by implementing different defences like TLS encryption, padding, and packet relaying. However, in this paper, an analysis has been performed against Tor from a local observer in order to bypass Tor protections; the method consists of a feature extraction from a local network dataset. Analysis shows that it's still possible for a local observer to fingerprint top monitored sites on Alexa and Tor traffic can be classified amongst other HTTPS traffic in the network despite the use of Tor's protections. In the experiment, several supervised machine-learning algorithms have been employed. The attack assumes a local observer sitting on a local network fingerprinting top 100 sites on Alexa; results gave an improvement amongst previous results by achieving an accuracy of 99.64% and 0.01% false positive.

Problem statement: Genetic Algorithms (GAs) have been used as search algorithms to find near-optimal solutions for many NP problems. GAs require effective chromosome representations as well as carefully designed crossover and mutation operators to achieve an efficient search. The Traveling Salesman Problem (TSP), as an NP search problem, involves finding the shortest Hamiltonian Path or Cycle in a graph of N cities. The main objective of this study was to propose a new representation method of chromosomes using upper triangle binary matrices and a new crossover operator to be used as a heuristic method to find near-optimum solutions for the TSP. Approach: A proposed genetic algorithm, that employed these new methods of representation and crossover operator, had been implemented using DELPHI programming language on a personal computer. Also, for the purpose of comparisons, the genetic algorithm of Sneiw had been implemented using the same programming language on the same computer. Results: The outcomes obtained from running the proposed genetic algorithm on several TSP instances taken from the TSPLIB had showed that proposed methods found optimum solution of many TSP benchmark problems and near optimum of the others. Conclusion: Proposed chromosome representation minimized the memory space requirements and proposed genetic crossover operator improved the quality of the solutions in significantly less time in comparison with Sneiw's genetic algorithm.

Data Mining (DM) represents the process of extracting interesting and previously unknown knowledge from data. This study proposes a new algorithm called FD_Discover for discovering Functional Dependencies (FDs) from databases. This algorithm employs some concepts from relational databases design theory specifically the concepts of equivalences and the minimal cover. It has resulted in large improvement in performance in comparison with a recent and similar algorithm called FD_MINE. Key words:Data mining, functional dependencies, equivalent classes, minimal cover INRODUCTIONFDs are relationships (constraints) between the attributes of a database relation; a FD states that the value of some attributes are uniquely determined by the values of some other attributes. Discovering FDs from databases is useful for reverse engineering of legacy systems for which the design information has been lost. Furthermore, discovering FDs can also help a database designer to decompose a relational schema into several relations through the normalization process to get rid or eliminate some of the problems of unsatisfactory database design. The identification of these dependencies that are satisfied by a database instance is an important topic in data mining literature [5] . The problem of generating or discovering FDs from relational databases had been studied in [3,4,7,8,11,12] . A straight forward solution algorithm is shown to require exponential time of all inputs (number of attributes and number of tuples in a relation).In this study, we are proposing a new algorithm for discovering FDs from static databases. This algorithm will use and employ some concepts from relational database theory, such as the theory of equivalencies and minimal cover of FDs. The proposed algorithm aims at minimizing the time requirements of algorithms that discover FDs from databases. We will compare the result of our proposed algorithm with a previous well known algorithm called FD_MINE [12] . Some of the previous studies in discovering FDs from databases presented in [2,4,8] have focused on discovering embedded parallel query execution, optimizing queries, providing some kind of summaries over large data sets or discovering association rules in stream data.Other studies presented in [3,7,9,11,12] have presented various methods for discovering FDs from large databases, these studies have focused on discovering FDs from very large databases and had faced a general problem which is represented by the exponential time requirements that depend on database size (the dimensionality problem in number of tuples and attributes). Definition 1:If A is an attribute or set of attributes in relation R, all the attributes in R that are functionally dependent on A in relation R with respect to F (where F is a set of FDs that holds on R), form the closure of A and it is denoted by A + or Closure(A).Definition 2: The nontrivial closure of attribute A with respect to F that is denoted by Closure→(A), is defined as Closure→(A) = Closure (A)-A.

Dynamic environments pose a challenge for traditional access control models where permissions are granted or revoked merely based on predefined and static access policies making them incapable of dynamically adapting to changing conditions. Risk adaptive access control models have been gaining more attention in the research community as an alternative approach to overcome the limitations of traditional access control models. Radio Frequency Identification (RFID) is an emerging technology widely utilized in both physical and logical access control systems because of its contactless nature, low cost, high read/write speed and long distance operation. Serverless RFID system architecture offers better availability assurance and lower implementation cost, while access rights management is easier in server‐based architecture. In this study, we continue to build on our previous research on the privacy and security of RFID access control systems without a backend database in order to overcome its limitations. We propose a hybrid design for a risk adaptive RFID access control system; that is, dynamically alternating between two access control modes, online (server‐based) and offline (serverless), to adapt to the level of risk depending on rule‐based risk scenarios and current risk value. The proposed design combines features of both serverless and risk adaptive access control systems. Copyright © 2015 John Wiley & Sons, Ltd.