Trust-Building Mechanisms and Knowledge Sharing in Virtual Communities

Although trust has received much intention in the virtual communities (VCs) literature, few studies have been conducted to examine how trust develops in VCs. Drawing from prior literature on trust and knowledge sharing, a research model for understanding the antecedents of trust and the role of trust in VCs is presented. Data was collected from 324 members of a technical virtual community to test the model. The results help in identifying how the factors fall into three trust-building mechanisms build trust in the context VCs. The study discusses the theoretical and managerial implications of this study and proposes several future research directions

Empiric antibiotic choices for community-acquired biliary tract infections

SummaryBackgroundThe study was conducted to reveal the most appropriate empiric antibiotics for the treatment of community-acquired biliary tract infections (CA-BTI) at a regional hospital in Taiwan.MethodsThe study was performed between October 1, 2010 and October 31, 2012. All positive bile culture results of presumptive community-acquired origins were collected. The associated etiologic microorganisms and their antimicrobial susceptibilities were analyzed. The appropriateness of empiric therapy (defined as the effectiveness of the antibiotics against the etiologic agents) and the subsequent treatment response were examined through the review of medical records.ResultsA total of 115 patients (cholecystitis, 83 cases, 72.2%; cholangitis, 32 cases, 27.8%) and 189 isolates (136 Gram-negative bacilli, 37 Gram-positive cocci, and 16 anaerobes) were analyzed. The most frequent pathogens were Escherichia coli (n = 69, 36.5%), Klebsiella spp. (n = 37, 19.6%), enterococci (n = 29, 15.3%), and Bacteroides spp. (n = 11, 5.8%). Penicillin resistance (5.4%) was low in Gram-positive cocci, whereas higher resistance (>20%) to cefazolin, cefuroxime, and ampicillin–sulbactam was found in Gram-negative bacilli. Anaerobes also demonstrated high resistance to clindamycin (37.5%) but less to metronidazole (12.5%). Appropriate empiric therapy was found in 92 (80%) cases, and among them, 83 (90.2%) were treated successfully. The treatment success rate (69.6%) was significantly lower among the remaining 23 cases with inappropriate empiric therapy (16 of 23 vs. 83 of 92, p < 0.05). A high treatment success rate (97.2%) was observed among cases empirically treated with ceftriaxone plus metronidazole.ConclusionThe combination of ceftriaxone plus metronidazole appears to be the most appropriate empiric antibiotics for the treatment of CA-BTI at this hospital. Because different hospitals may encounter microorganisms of different antimicrobial susceptibilities, similar approaches may be followed by other hospitals where appropriate empiric therapy has not yet been established for the treatment of CA-BTI

Exploring Online Repeat Purchase Intentions: The Role of Habit

By focusing on online stores, this study investigates the repeat purchase intention of experienced online buyers. Prior research on online behavior continuance models perceived usefulness, trust, satisfaction, and perceived value as the major determinants of continued adoption or loyalty, overlooking the important role of habit. Building on previous work in other disciplines, we define habit in the context of online shopping as the extent to which buyers tend to shop online automatically because of learning. Using recent work on the continued usage of IS (IS continuance) and repeat purchase, we have developed a model suggesting that repeat purchase intention is not only a consequence of trust and switching cost, but also of habit. In particular, in our research model, we propose that online shopping habit moderate the influence of trust such that its importance in determining repeat purchase intention decreases as the online shopping behavior takes on a more habitual nature. Integrating prior research on habit, IS continuance, and repeat purchase further, we suggest how antecedents of repeat purchase intention relate to drivers of habitualization. Data collected from 462 of Yahoo!Kimo shopping center’s customers provide strong support for the research model. Results indicate that higher level of habit deflated trust’s effect on repeat purchase intention. The data also show that satisfaction and familiarity are key to habit formation and thus relevant in the context of online repeat purchase

An anomaly-based IDS framework using centroid-based classification

Botnet is an urgent problem that will reduce the security and availability of the network. When the bot master launches attacks to certain victims, the infected users are awakened, and attacks start according to the commands from the bot master. Via Botnet, DDoS is an attack whose purpose is to paralyze the victim’s service. In all kinds of DDoS, SYN flood is still a problem that reduces security and availability. To enhance the security of the Internet, IDS is proposed to detect attacks and protect the server. In this paper, the concept of centroid-based classification is used to enhance performance of the framework. An anomaly-based IDS framework which combines K-means and KNN is proposed to detect SYN flood. Dimension reduction is designed to achieve visualization, and weights can adjust the occupancy ratio of each sub-feature. Therefore, this framework is also suitable for use on the modern symmetry or asymmetry architecture of information systems. With the detection by the framework proposed in this paper, the detection rate is 96.8 percent, the accuracy rate is 97.3 percent, and the false alarm rate is 1.37 percent

Effects of different ceramic and dentin thicknesses on the temperature rise during photocuring

AbstractBackground/purposeThe aims of this investigation were to describe the effect of different ceramic and remaining dentin thicknesses on substrate temperature during photocuring, and investigate whether the temperature increased by >5.5°C for different dentin/ceramic combinations.Materials and methodsThree groups of dentin thicknesses of 1.0 (D1.0), 1.5 (D1.5), and 2.0 mm (D2.0), and three groups of ceramic thicknesses of 1.5 (C1.5), 2.5 (C2.5), and 3.5 mm (C3.5) were examined. Temperature changes and the maximum temperature were observed under a high-intensity halogen light (QTH-Atralis 10 ECS program at 1200mW/cm2 for 30 seconds, Ivoclar Vivadent AG, Schaan, Liechtenstein). Four groups, D1.0–C1.5 (+11°C), D1.5–C1.5 (+7.2°C), D1.0–C2.5 (+6.7°C), and D2–0C1.5 (+5.8°C), demonstrated temperature changes of >5.5°C.Results and ConclusionsA statistical analysis showed that separate individual thicknesses and combinations of dentin and ceramic had significant effects on temperature changes (P<0.01). It was observed that the ceramic exhibited a smaller temperature shielding effect than dentin. Clinically, it would be optimal to preserve the dentin to avoid damaging pulp tissues. Where there is insufficient overall thickness (≤3.5mm), continuous high-energy output photocuring should be avoided to protect pulp tissues from thermal injury