Time filter

Source Type

Columbia, MO, United States

Wang C.,University of Missouri | Jamison B.E.,Grasslands Field Station | Spicci A.A.,Columbia College at Missouri
Remote Sensing of Environment

Tallgrass prairie in North America has been largely converted to croplands and cool season grasslands. In Missouri, only 0.5% of the tallgrass prairie remains in a form of isolated prairie islands. This study sought to delineate prairie-native warm season grass (WSG) from cool season grass (CSG) using five ASTER images acquired on 03/11/2008, 05/12/2007, 07/12/2007, 08/16/2007 and 10/19/2007. Temporal trajectories of the normalized difference vegetation index (NDVI) and the normalized difference moisture index (NDMI) were extracted to examine temporal variation of WSG and CSG grasslands in a growth cycle. It was found that the spring-summer period revealed maximal spectral differences between these two grass types. CSG reached peak NDVI in May while WSG tended to have peak NDMI in July. NDVI was more useful than NDMI in summer-fall. The NDVI trends in this period varied with both phenology and grassland treatments such as haying and grazing, which provided additional information in WSG/CSG delineation. A hierarchical decision tree was developed to delineate WSG and CSG grasslands in a 3-tier process. The WSG lands including those publically conserved prairies were identified in the lower Osage Plain in southwest Missouri. The accuracies were about 80% and could be improved with more frequent satellite observations. The trajectory-based decision tree in this study provides a robust approach of long-term WSG/CSG mapping. © 2009 Elsevier Inc. Source

This study examines the impact of disposition to privacy, perceived reputation of a website, and personal familiarity with the website on a person's privacy concerns about the website. It also analyzes the key attributes of disposition to privacy and its antecedents. Using a survey, the study finds the direct impact of disposition to privacy, website reputation, and personal familiarity on website-specific privacy concerns. The impact of privacy experience on disposition to privacy is also confirmed. The moderating effects of website reputation and personal familiarity on disposition to privacy are not supported, suggesting that the three antecedents exert their impact on privacy concerns independently. The study extends the information privacy literature through the analysis of the roles of contextual factors (reputation and familiarity) in the relationship between disposition to privacy and website-specific privacy concerns. It also moves forward studies on individual disposition to privacy, calling for more attention to this critical concept. © 2013 Elsevier B.V. Source

To study the formation of online consumers' information privacy concern and its effect, scholars from different perspectives applied multiple theories in research. To date, there has yet to be a systematic review and integration of the theories in literature. To fill the gap, this study reviews fifteen established theories in online information privacy research and recognizes the primary contributions and connections of the theories. Based on the review, an integrated framework is developed for further research. The framework highlights two interrelated trade-offs that influence an individual's information disclosure behavior: the privacy calculus (i.e., the trade-off between expected benefits and privacy risks) and the risk calculus (i.e., the trade-off between privacy risks and efficacy of coping mechanisms). These two trade-offs are together called the dual-calculus model. A decision table based on the dual-calculus model is provided to predict an individual's intention to disclose personal information online. Implications of the study for further research and practice are discussed. © 2012 Elsevier B.V. All rights reserved. Source

Li Y.,Columbia College at Missouri
Electronic Commerce Research and Applications

Several types of individual information privacy beliefs have been studied in literature, but their distinctions, relationships, and behavioral impacts have yet been systematically analyzed, causing difficulties in comparing and consolidating results across literature. Based on a review on various types of privacy beliefs, this study develops a multi-level model to strengthen this concept. The model consists of three levels of privacy beliefs, including: disposition to privacy, representing a person's fundamental beliefs and overall propensity to value privacy across contexts; online privacy concern, representing a person's overall perception of privacy risks in the online environment; and website privacy concern, representing a person's perception of privacy risks on a particular website. An empirical test reveals that disposition to privacy has a positive impact on both online privacy concern and website privacy concern, and website privacy concern is the only significant predictor of intentions to disclose information and transact on a website. The study helps to synthesize individual information privacy beliefs and assists in understanding their impacts on online behavior. © 2013 Elsevier B.V. All rights reserved. Source

Li Y.,Columbia College at Missouri
Communications of the Association for Information Systems

In the e-commerce environment, individuals' concerns for online information privacy play critical roles in determining their intention to use the Internet to provide personal information for services and transactions. Understanding this relationship has important implications for e-commerce. Despite much research in this area, an overarching picture of the relationship between information privacy concerns and the antecedent and consequence factors is yet to be drawn. Based on a review on empirical studies in this area, this research summarizes the conceptualizations of privacy concerns and the antecedents and consequences. An integrative framework is developed to illustrate the relationships between the factors. In this framework, a person's concern for information privacy regarding a specific e-commerce website is distinguished from his/her concern for information privacy regarding the general e-commerce environment. These two forms of privacy concerns have distinct impacts on a person's online behavior. Their relationships with multiple antecedent and consequence factors are analyzed. © 2011 by the Association for Information Systems. Source

Discover hidden collaborations