Search Results

Perceived features and similarity of images: An investigation into their relationships and a test of Tversky's contrast model.

Description: The creation, storage, manipulation, and transmission of images have become less costly and more efficient. Consequently, the numbers of images and their users are growing rapidly. This poses challenges to those who organize and provide access to them. One of these challenges is similarity matching. Most current content-based image retrieval (CBIR) systems which can extract only low-level visual features such as color, shape, and texture, use similarity measures based on geometric models of similarity. However, most human similarity judgment data violate the metric axioms of these models. Tversky's (1977) contrast model, which defines similarity as a feature contrast task and equates the degree of similarity of two stimuli to a linear combination of their common and distinctive features, explains human similarity judgments much better than the geometric models. This study tested the contrast model as a conceptual framework to investigate the nature of the relationships between features and similarity of images as perceived by human judges. Data were collected from 150 participants who performed two tasks: an image description and a similarity judgment task. Qualitative methods (content analysis) and quantitative (correlational) methods were used to seek answers to four research questions related to the relationships between common and distinctive features and similarity judgments of images as well as measures of their common and distinctive features. Structural equation modeling, correlation analysis, and regression analysis confirmed the relationships between perceived features and similarity of objects hypothesized by Tversky (1977). Tversky's (1977) contrast model based upon a combination of two methods for measuring common and distinctive features, and two methods for measuring similarity produced statistically significant structural coefficients between the independent latent variables (common and distinctive features) and the dependent latent variable (similarity). This model fit the data well for a sample of 30 (435 pairs of) images and 150 participants (χ2 =16.97, ...
Date: May 2005
Creator: Rorissa, Abebe
Partner: UNT Libraries

Introduction: International Information Issues and ASIS&T

Description: Article introducing a special section of the Bulletin of the Association for Information Science and Technology (ASIS&T) featuring interviews, discussions of ASIS&T chapters and SIGs roles, networking activities, and past and current organizational initiatives.
Date: Summer 2014
Creator: Alemneh, Daniel Gelaw & Rorissa, Abebe
Item Type: Article
Partner: UNT Libraries

Moodle for Professional Development to Agricultural Extension Professionals in Africa: Workshop

Description: Presentation for the International Association of Agriculture Information Specialists (IAALD) World Congress. The authors discuss the Modular Object-Oriented Dynamic Learning Environment (Moodle) software package and its use for professional development to agriculture extension professionals in Africa.
Date: July 2013
Creator: Assefa, Shimelis; Alemneh, Daniel Gelaw & Rorissa, Abebe
Item Type: Presentation
Partner: UNT Libraries

Partnership for Enhancing Developing Countries' Capacity in Participating in Global Knowledge Production and Use

Description: Poster discussing a partnership for enhancing developing countries' capacity in participating in global knowledge production and use. This poster highlights some of the contributing factors that enhance the capacity of African institutions to play active roles in the current global knowledge economy (in terms of information and knowledge creation, access, use and reuse).
Date: July 2013
Creator: Alemneh, Daniel Gelaw; Assefa, Shimelis & Rorissa, Abebe
Item Type: Poster
Partner: UNT Libraries

Diffusion of Scientific Knowledge in Agriculture: The Case for Africa

Description: Paper discussing the diffusion of scientific knowledge on agriculture for Africa. Using exploratory research method, this paper set out to investigate existing knowledge diffusion models and their limitations, available best practices, and the potential to infuse translational research as a way to augment extension service programs in SSA agricultural practices.
Date: July 2013
Creator: Assefa, Shimelis; Alemneh, Daniel Gelaw & Rorissa, Abebe
Item Type: Paper
Partner: UNT Libraries

Diffusion of Scientific Knowledge in Agriculture: The Case for Africa

Description: Article on the diffusion of scientific knowledge on agriculture for Africa. Using an exploratory research method, this article sets out to investigate existing knowledge diffusion models and their limitations, available best practices, and the potential to infuse translational research as a way to augment extension service programs in SSA agricultural practices.
Date: 2014
Creator: Assefa, Shimelis; Alemneh, Daniel Gelaw & Rorissa, Abebe
Item Type: Article
Partner: UNT Libraries

The Origins of SIG-III and Its 30 Years' Journey: Visions and Reflections

Description: This paper discusses the origins of the Special Interest Group for International Information Issues (SIG-III) of the American Society for Information Science & Technology (ASIS&T) and its early years.
Date: October 2012
Creator: Alemneh, Daniel Gelaw; Carbo, Toni; Caidi, Nadia; Gruzd, Anatoliy & Rorissa, Abebe
Item Type: Paper
Partner: UNT Libraries

Open Access: The Global Scene

Description: Presentation for a panel at the 2014 Association for Information Science and Technology (ASIS&T) Annual Meeting. This panel presentation discusses global open access practices.
Date: November 3, 2014
Creator: Assefa, Shimelis; Rorissa, Abebe; Matusiak, Krystyna; Alemneh, Daniel Gelaw; Helge, Kris & Hastings, Samantha Kelly
Item Type: Presentation
Partner: UNT Libraries