Facebook Uses, Boundary Spanning Activities, and Social Capital

The goal of this paper is to examine whether the use of Facebook in the workplace impacts on employees’ boundary spanning activities (BSA) and social capital. Two types of social capital are examined: bonding and bridging. The sample consisted of 399 full-time white-collar workers in Taiwan. A snowball sampling technique was used to recruit participants to complete an online survey. The results indicated that employees who are allowed to use Facebook in the workplace did not have a higher level of overall BSA than the non-user group. In terms of the associations between Facebook use and social capital, the Facebook user group did not have a higher level of bonding social capital than the non-user group, but they did have a higher level of bridging social capital than the non-user group. In terms of the associations between BSA and social capital, the correlation results indicated positive significant relations between BSA and bonding social capital, and between BSA and bridging social capital

A computer implementation of an orthonormal expansion method for digital image noise suppression

Images are usually corrupted by noise which comes from various sources: noise in the recording media (e.g. film grain noise), and noise introduced in the transmission channel. Noise degrades the visual quality of images and obscures the detail information in the images. One of the major sources of noise for images recorded on films is film grain noise. An orthonormal expansion algorithm for digital image noise suppression is implemented. The objective is to preserve as much sharpness and produce as few artifacts in the processed image as possible. The method sections an image into non-overlapping blocks. Each block is treated as a matrix which is decomposed as a sum of outer products of its singular vectors. The coefficient of each outer product is modified by a scaling function and the matrix is reconstructed. The resulting image shows a reduction of noise. The two major problems in the method are: 1. the blocking artifacts due to the sectioned processing, and, 2. the trade-off between the suppression of noise and the loss of sharpness. By separating the image into the low frequency and the high frequency components and processing only the latter component, the method is able to reduce the blocking artifacts to an invisible level. To obtain the optimal trade-off between the suppression of noise and the loss of sharpness, systematic variations of the coefficient scaling function were used to process the image. The best choice of the scaling function is found to be [ 1 - (σi / ai ) 3 ] which is a little different from the least-square-error estimate, [ 1 - (σi / ai ) 2 ]

The Decision to Continue Sharing Knowledge in Virtual Communities: The Moderating Role of Knowledge-Sharing Experience and Knowledge Self-Efficacy

Virtual communities have become increasingly popular in recent years. Despite significant growth in the number of virtual communities, few communities have been successful retaining members and motivating members to continue sharing knowledge. This study focuses on how knowledge-contributor characteristics impact the relationship between individuals’ community-involvement motivation and continued knowledge-sharing intention. According to the study’s online survey of 292 knowledge contributors in two professional virtual communities (PVCs), knowledge-sharing experience and knowledge self-efficacy – two contributor characteristics – moderate the relationship between motivational factors and continued knowledge sharing. Specifically, reputation and enjoyment in helping others had a stronger influence on knowledge contributors with high knowledge self-efficacy, whereas reciprocity had a stronger influence on knowledge contributors with low knowledge selfefficacy. Furthermore, reciprocity and moral obligation had a stronger influence on knowledge contributors with high knowledge-sharing experience. The results of this study provide important implications for research and practice

Supersymmetric Clockwork Axion Model and Axino Dark Matter

Implications of supersymmetrizing the clockwork axions are studied. Supersymmetry ensures that the saxions and axinos have the same pattern of the coupling hierarchy as the clockwork axions. If we assume supersymmetry breaking is universal over the clockwork sites, the coupling structure is preserved, while the mass orderings of the saxions and axinos can differ depending on the supersymmetry breaking scale. While the massive saxions and axions quickly decay, the lightest axino can be stable and thus a dark matter candidate. The relic abundance of the axino dark matter from thermal production is mostly determined by decays of the heavier axinos in the normal mass ordering. This exponentially enhances the thermal yield compared to the conventional axino scenarios. Some cosmological issues are discussed.Comment: 9 pages; v2: added comments about conditions to get the clockwork mixing pattern in page 5, matches the published versio

Social networking friendships: A cross-cultural comparison of network structure between MySpace and Wretch

A cross-cultural comparison of social networking friendship between MySpace (in USA) and Wretch (in Taiwan) was conducted utilizing the high- and low-context framework proposed by Edward T. Hall (1976). Three network indicators were used to describe the network structure of both social network sites: size, density, and heterogeneity. Data were drawn from the forum “Jobs, Work, Careers” on MySpace and “Job-Related” on Wretch over a 2-month period from mid-October to mid-December in 2007. For each of the 2 sites, 6 users (3 men and 3 women) were randomly selected as sources or “seeds” from which to crawl the friendship networks. From the 6 seed users, a snowball sample was constructed by crawling 2 degrees out along the networks. The results indicated that Wretch, although it followed the expected direction predicted by Hall’s model, did not have significantly larger and denser networks than MySpace. Finally, no differences in same-sex and cross-sex friendships were found between the 2 sites either. The overall findings are discussed with implications for future studies

Fundamental Studies on Cassie equation and Cassie-Baxter to Wenzel transition

Department of Chemical EngineeringWetting phenomena have been studied extensively due to their versatile applications such as self-cleaning, microfluidics, and anti-icing. The wettability can be evaluated by measuring contact angle and the contact angle can be predicted by several equations. For molecularly flat and chemically homogeneous surfaces, the Young???s equation is used, and for a molecularly flat, chemically heterogeneous surface, the Cassie equation is used. Moreover, when the surfaces are rough, the Cassie-Baxter equation predicts the contact angle when the liquid droplet cannot penetrate rough pores on the surface, while the Wenzel equation is used for the case when the liquid droplet fully wets the surface. When intrinsic contact angles are lower than 90 degrees, the Wenzel state is thermodynamically favorable over the Cassie-Baxter state resulting in Cassie-Baxter to Wenzel transition over a certain period. The Cassie equation has been successfully used for many decades, but its limitations are still being investigated through various experimental and theoretical studies. Also, fabrication of robust surfaces sustaining the Cassie-Baxter state without transitioning to the Wenzel state for prolonged periods is still a challenging task. Therefore, in this work, we systematically investigated the Cassie equation and Cassie-Baxter to Wenzel transition. In Chapter 2, we measured water contact angles and analyzed droplet shapes to systematically investigate flat and chemically heterogeneous. A wide range of pattern sizes and spacings have been utilized to investigate the static contact angle changes due to chemical heterogeneity. In Chapter 3, we fabricated a concave pillar inspired by the structure of leaf beetle pulvilli, which have hydrophobic concave hairy structures exhibiting self-cleaning property. Photolithography, anisotropic etching of silicon, and the Bosch process were utilized to make a robust hydrophobic surface.clos

Multi-agent hybrid mechanism for financial risk management

Purpose: The goal of this study was to propose the multi-agent mechanism to forecast the corporate financial distress. Design/methodology/approach: This study utilized numerous methods, namely random subspace method, discriminant analysis and decision tree to construct the multi-agent forecasting model. Findings: The study shows a superior forecasting performance. Originality/value: The use of multi-agent model to predict the corporate financial distress.Peer Reviewe

A Deterministic Equivalent for the Analysis of Non-Gaussian Correlated MIMO Multiple Access Channels

Large dimensional random matrix theory (RMT) has provided an efficient analytical tool to understand multiple-input multiple-output (MIMO) channels and to aid the design of MIMO wireless communication systems. However, previous studies based on large dimensional RMT rely on the assumption that the transmit correlation matrix is diagonal or the propagation channel matrix is Gaussian. There is an increasing interest in the channels where the transmit correlation matrices are generally nonnegative definite and the channel entries are non-Gaussian. This class of channel models appears in several applications in MIMO multiple access systems, such as small cell networks (SCNs). To address these problems, we use the generalized Lindeberg principle to show that the Stieltjes transforms of this class of random matrices with Gaussian or non-Gaussian independent entries coincide in the large dimensional regime. This result permits to derive the deterministic equivalents (e.g., the Stieltjes transform and the ergodic mutual information) for non-Gaussian MIMO channels from the known results developed for Gaussian MIMO channels, and is of great importance in characterizing the spectral efficiency of SCNs.Comment: This paper is the revision of the original manuscript titled "A Deterministic Equivalent for the Analysis of Small Cell Networks". We have revised the original manuscript and reworked on the organization to improve the presentation as well as readabilit