A One-Dimensional Model for Storm Breaching of Barrier Islands

A set of numerical models is developed for simulating the four stages of barrier breaching characterized by one horizontal spatial dimension. The SBEACH model is employed for the first stage of dune/beach erosion. The Lax-Wendroff two-step explicit scheme for Stage II is developed to simulate initiation of ocean flood propagation on initially dry barrier islands and the method of characteristics (MOC), is employed to compute additional boundary data. The development of the Preissmann implicit scheme for water motion and a forward time centered space explicit scheme for sediment motion in Stages III and IV provide a tool to study the volume change and centroid movements of barrier dune during various levels of storm activity. The accuracy and correctness of numerical codes have been verified by conducting a series of standard tests and numerous volume conservation tests. The sensitivity studies show that the most sediments are transported landward by larger peak storm surge difference between ocean and bay with shorter time lag and longer duration, and seaward by smaller peak storm surge difference with longer time lag and shorter storm duration. Finally, the integrated numerical model is found to produce reasonable results from the various sensitivity tests which reveal that the numerical model has properly responded to the changes of each model parameter

Discrepancy between Actual Self and Virtual Self: Theoretical Extensions, Measurement and Relation to Contribution in Virtual Communities

Virtual communities enable one to pretend to be a different person or to possess a different identity at little or no cost. Despite the ubiquity of such communities, there is only limited theoretical and empirical research on how taking on a different identity is associated with one’s contributive behavior in those communities. Drawing on the social psychology literature, we adopt the concept of self-discrepancy rooted in self-identity and derive an index for self-discrepancy by using the differences between actual and virtual identities. Next, we link the self-discrepancy with perceived privacy rights and with quality and quantity of contribution. Analysis of 299 respondents showed that self-discrepancy significantly influenced perceived privacy rights and indirectly reduced quality and quantity of contribution in virtual communities. Furthermore, sub-group analysis revealed that the effects of self-discrepancy varied depending on whether the virtual community was utilitarian or hedonic. The present study aims to show how an individual member’s self-concept is associated with his or her psychological state in a virtual community, thereby offering practical insights for managers of virtual communities by suggesting how multi-identity should be managed therein

Does Virtuality Increase Social Capital within an Organization?

The purpose of this article is to examine the relationship between virtuality and social capital. Does virtuality decrease the strength of individuals’ social ties? Or does virtuality increase social capital by expanding the range of individuals’ social networks? To address these questions, first, we identify the properties of virtuality, whose definition still varies in a variety of research settings and at a variety of units of analysis. Second, we develop a conceptual framework that explores the links between virtuality and social capital. By combining the concept of weak ties from social network research and the notion of virtuality from the IS literature, we suggest a new perspective on virtual work: more virtuality leads to more social capital when the bridging relationships based on weak ties are maximized

A Synthetic DNA Walker for Molecular Transport

Inspired by kinesin movement along a microtubule, we demonstrate a processive bipedal DNA walker. Powered by externally controlled DNA fuel strands, the walker locomotes with a 5 nm stride by advancing the trailing foot to the lead at each step. Real-time monitoring of specific bidirectional walker movement is achieved via multiplexed fluorescence quenching

How People Disclose Themselves Differently According To The Strength Of Relationship In SNS?

Self-disclosure is defined as “act of revealing personal information to others” (Archer, 1980, p.183). It plays a key role in development and maintenance of relationships.Since many companies adopt social networking services for their organizational information sharing platform, it is important to identify the process of creating and maintaining social relationship in virtual spaces for successful adoption of SNS. In this research, we identify a self-disclosure as a driving factor for initiating and maintaining online social relationships.This research assumes that the self-disclose strategy adopted by participants in a communication process would be very similar between a face to face communication and a communication through SNS. In addition, this study explores that how the strength of social relationship does affects participants’ self-discloser strategy in SNS.Self-disclosure on SNS is multidimensional and it consists of five dimensions; intent to disclose, amount, the positive-negative nature, the honesty-accuracy, and general depth-control of disclosure. Our research indicates that strength of relationship affect negatively the amount of disclosure on SNS. SNS users, in other words, less reveal themselves in terms of both frequency and duration to other user in strong tie than in weak tie. We found that strength of social ties significantly influenced dimensions of self-disclosure except for the positive-negative nature of disclosure