these are notes from introductory survey lectures given at the institute for studies in theoretical physics and mathematics (ipm), teheran, in 2008 and 2010. we present the definition and the fundamental properties of fomin-zelevinsky’s cluster algebras. then, we introduce quiver representations and show how they can be used to construct cluster variables, which are the canonical generators of ...

The SQL Procedure contains many powerful and elegant language features for advanced SQL users. This paper presents SQL topics that will help programmers unlock the many hidden features, options, and other hard-to-find gems found in the SQL universe. Topics include CASE logic; the COALESCE function; SQL statement options _METHOD, _TREE, and other useful options; dictionary tables; automatic macr...

Most interesting real-world optimization problems are very challenging from a computational point of view. In fact, quite often, finding an optimal or even a near-optimal solution to a large-scale optimization problem may require computational resources far beyond what is practically available. There is a substantial body of literature exploring the computational properties of optimization prob...

Most conventional document categorization methods require a large number of documents with labeled categories for training. These methods are hard to be applied in scenarios, such as scientific publications, where training data is expensive to obtain and categories could change over years and across domains. In this work, we propose UNEC, an unsupervised representation learning model that direc...

Developing a standard schema at the abstract syntax tree level for C/C++ to be used by reverse engineering and reengineering tools is a complex and difficult problem. In this paper, we present a catalogue of issues that need to be considered in order to design a solution. Three categories of issues are discussed. Lexical structure is the first category and pertains to characteristics of the sou...

‎in this paper first we define the morphism between geometric spaces in two different types‎. ‎we construct two categories of $uu$ and $l$ from geometric spaces then investigate some properties of the two categories‎, ‎for instance $uu$ is topological‎. ‎the relation between hypergroups and geometric spaces is studied‎. ‎by constructing the category $qh$ of $h_{v}$-groups we answer the question...

The Brazilian government often misclassifies the goods it buys. That makes it hard to audit government expenditures. We cannot know whether the price paid for a ballpoint pen (code #7510) was reasonable if the pen was misclassified as a technical drawing pen (code # 6675) or as any other good. This paper shows how we can use machine learning to reduce misclassification. I trained a support vect...

Aiming at developing a theoretical framework for the formal study of NP-hard optimization problems, which is built on precise mathematical foundations, we have focused on structural properties of optimization problems related to approximative issue. From the observation that, intuitively, there are many connections among categorical concepts and structural complexity notions, in this work we pr...

Data mining plays a vital role in today’s information world wherein it has been widely applied in various business organizations. The current trend in business collaboration demands the need to share data or mined results to gain mutual benefit. However it has also raised a potential threat of revealing sensitive information when releasing data. Data sanitization is the process to conceal the s...

Algorithmic bias is necessary for learning because it allows a learner to generalize rationally. A bias is composed of all assumptions the learner makes outside of the given data set. There exist some approaches to automatically selecting the best algorithm (and therefore bias) for a problem or automatically shifting bias as learning proceeds. In general, these methods are concerned with superv...