Data Mining - Concepts and Techniques.

“Unpaired Image-to-Image Translation using Cycle-Consistent Adversarial Networks”の学習報告

Social Network Analysis

It is shown that, particularly for terrestrial cellular telephony, the interference-suppression feature of CDMA (code division multiple access) can result in a many-fold increase in capacity over analog and even over competing digital techniques. A single-cell system, such as a hubbed satellite network, is addressed, and the basic expression for capacity is developed. The corresponding expressions for a multiple-cell system are derived. and the distribution on the number of users supportable per cell is determined. It is concluded that properly augmented and power-controlled multiple-cell CDMA promises a quantum increase in current cellular capacity. >

On the capacity of a cellular CDMA system

Recommender systems have developed in parallel with the web. They were initially based on demographic, content-based and collaborative filtering. Currently, these systems are incorporating social information. In the future, they will use implicit, local and personal information from the Internet of things. This article provides an overview of recommender systems as well as collaborative filtering methods and algorithms; it also explains their evolution, provides an original classification for these systems, identifies areas of future implementation and develops certain areas selected for past, present or future importance.

http://romisatriawahono.net/lecture/rm/survey/information%20retrieval/Bobadilla%20-%20Recommender%20Systems%20-%202013.pdf

Recommender systems survey

In question-and-answer (QA) systems, various queries need to be processed. In particular, those queries such as temporal information require complex query generation processes. This paper proposes a temporal representation model that can support qualitative and quantitative temporal information on historical ontology by applying the concept of ordinals and sets and introduces operators that allow a QA system to easily handle complex temporal queries. To verify the effectiveness of the proposed model and operators, historical scenarios are presented to show that they can effectively handle complex temporal queries.

Temporal Ontology Representation and Reasoning Using Ordinals and Sets for Historical Events

Well-known media applications of Chromecast such as YouTube, Viki usually use a time slider on the second screen for video navigation. However, the time slider does not offer easy way to access particular contents. Here we propose an aligned thumbnails-based video browsing system with Chromecast using content-based video browsing approach by automatically detecting scenes. It uses hierarchical sliding interface to browse the playing video on TV easily. Through the experimental results, our proposed system helps search specific contents quickly.

Aligned thumbnails-based video browsing system with Chromecast

In this paper, we propose an evolutionary approach to deal with shortcomings on conventional focused crawling systems in semantic web environment. Thereby, meta-evolution strategy for collaboration among multiple crawlers has to be efficiently carried out. It is based on incremental aggregation of partial semantic structures extracted from web resources, which are in advance annotated with local ontologies. To do this, we employ similarity-based matching algorithm, so that fitness function is formulated by summing all possible semantic similarities. As a result, the best mapping condition (i.e., the fitness is maximized) is obtained for efficiently i) reconciling semantic conflicts between multiple crawlers, and ii) evolving semantic structures of web spaces over time.

Meta-evolution strategy to focused crawling on semantic web

A homography matrix is used in computer vision field to solve the correspondence problem between a pair of stereo images. RANSAC algorithm is often used to calculate the homography matrix by randomly selecting a set of features iteratively. CS-RANSAC algorithm in this paper converts RANSAC algorithm into two-layers. The first layer is addressing sampling problem which we can describe our knowledge about degenerate features by mean of Constraint Satisfaction Problems (CSP). By dividing the input image into a N×N grid and making feature points into discrete domains, we can model the image into the CSP model to efficiently filter out degenerate features. By expressing the knowledge about degenerate feature samples using CSP in the first layer, so that computer has knowledge about how to skip computing the homography matrix in the model estimation step for the second layer. The experimental results show that the proposed CS-RANSAC algorithm can outperform the most of variants of RANSAC without sacrificing its execution time.

https://www.aaai.org/ocs/index.php/AAAI/AAAI15/paper/download/9499/9327

RANSAC versus CS-RANSAC

Social network analysis methods have been exploited to support efficient collaborations in virtual organizations. However, a social network within a virtual organization is simply assumed to be homogeneous, i.e., all linkages between actors are contextually identical. For example, in bibliometrics, all linkages on a network are identical to "co- authoring" relationship between the actors. In this paper, we focus on integrating multiple social networks of which relationships between actors are heterogeneous. It makes a new relationship between two actors in different social networks possible to be discovered. In particular, we show how to detect latent community of practice from the multiple networks by measuring semantic centrality of actors. Thereby, we propose a divide-and-conquer approach based on the context matching algorithm, which is capable of separating the multiple social networks, with respect to the contexts of practice. We also take into account the relationships between topological features and the labels by statistical co-occurrence analysis.

Geun-Sik Jo

Papers

Temporal Ontology Representation and Reasoning Using Ordinals and Sets for Historical Events

Aligned thumbnails-based video browsing system with Chromecast

Meta-evolution strategy to focused crawling on semantic web

RANSAC versus CS-RANSAC

A Divide-and-Conquer Approach to Detecting Latent Community of Practice from Virtual Organizations