Value received from Participating in Virtual Communities and The Impact on Virtual Community Participation

[[abstract]]Wikipidia is a collaborative web site of knowledge sharing platforms. Based on a survey of 202 Wikipedians, this study develop a theoretical framework to examine the relationship between individual value (utilitarian/hedonic) received, group cohesiveness and virtual community participation. Result from structural equation modeling (SEM) analysis reveal that individual motivation has positive effect on virtual community participation. Hence, group cohesiveness moderates participants’ motivations on virtual community participation. Most of the past studies on virtual networks knowledge contribution focused only on the individual level, this study address the literature gap by exploring group level and the mutual relationships between participants in virtual communities.[[incitationindex]]EI[[booktype]]紙本[[booktype]]電子

Object unified identifier method in logistics resource integration

Purpose: The status which many programs for the object identifier are not incompatible with each other has become a bottleneck for integrating logistics resources. Scholars have done some relevant studies in terms of coding and conversion mechanisms, but the problem still has not got a better solution. The purpose of this study is to research how to make the object identifier programs compatible. Design/methodology/approach: Author proposed an object unified identifier (OUID) method based on OID and introduced the standard identification code in it, according to the problems of the object identifier in logistics resource integration. And the paper further designed the acquisition process of the resource basic information and location information, and analyzed the application environment of object unified identifier based on OID. Findings: OUID made up for the lack of location information in conversion mechanism, and avoided to promote new unified identifier standards at the same time. The supplement of the application environment provided an important support to solve the problems of poor communication caused by non-unified object identifier in the process of logistics resource integration. Originality/value: Using this method, each identification system not only can keep its own territory, but also can compatible with other object identifiers.Peer Reviewe

Self-sustainable protonic ceramic electrochemical cells using a triple conducting electrode for hydrogen and power production.

The protonic ceramic electrochemical cell (PCEC) is an emerging and attractive technology that converts energy between power and hydrogen using solid oxide proton conductors at intermediate temperatures. To achieve efficient electrochemical hydrogen and power production with stable operation, highly robust and durable electrodes are urgently desired to facilitate water oxidation and oxygen reduction reactions, which are the critical steps for both electrolysis and fuel cell operation, especially at reduced temperatures. In this study, a triple conducting oxide of PrNi0.5Co0.5O3-δ perovskite is developed as an oxygen electrode, presenting superior electrochemical performance at 400~600 °C. More importantly, the self-sustainable and reversible operation is successfully demonstrated by converting the generated hydrogen in electrolysis mode to electricity without any hydrogen addition. The excellent electrocatalytic activity is attributed to the considerable proton conduction, as confirmed by hydrogen permeation experiment, remarkable hydration behavior and computations

Reduction of gas bubbles and improved critical current density in Bi-2212 round wire by swaging

Bi-2212 round wire is made by the powder-in-tube technique. An unavoidable property of powder-in-tube conductors is that there is about 30% void space in the as-drawn wire. We have recently shown that the gas present in the as-drawn Bi-2212 wire agglomerates into large bubbles and that they are presently the most deleterious current limiting mechanism. By densifying short 2212 wires before reaction through cold isostatic pressing (CIPping), the void space was almost removed and the gas bubble density was reduced significantly, resulting in a doubled engineering critical current density (JE) of 810 A/mm2 at 5 T, 4.2 K. Here we report on densifying Bi-2212 wire by swaging, which increased JE (4.2 K, 5 T) from 486 A/mm2 for as-drawn wire to 808 A/mm2 for swaged wire. This result further confirms that enhancing the filament packing density is of great importance for making major JE improvement in this round-wire magnet conductor.Comment: To be published in IEEE Transactions on Applied Superconductivity, 23, xxxxxx (2013

Up-regulation of CNDP2 facilitates the proliferation of colon cancer

BACKGROUND: Cytosolic nonspecific dipetidase (CN2) belongs to the family of M20 metallopeptidases. It was stated in previous articles that higher expression levels of CN2 were observed in renal cell carcinoma and breast cancer. Our study explored the correlation between CN2 and colon carcinogenesis. METHODS: We analysed the relationship between 183 patients clinicopathological characteristics and its CN2 expression. To detect the levels of CN2 in colon cancer cell lines and colon cancer tissues by western blot. To verify cell proliferation in colon cancer cells with knockdown of CNDP2 and explore the causes of these phenomena. RESULTS: The expression levels of CN2 in clinical colon tumors and colon cancer cell lines were significantly higher than that in normal colon mucosa and colon cell lines. The difference in CN2 levels was associated with tumor location (right- and left-sided colon cancer), but there was no significant association with age, gender, tumor size, tumor grade, tumor stage or serum carcinoembryonic antigen (CEA). Knockdown of CNDP2 inhibited cell proliferation, blocked cell cycle progression and retarded carcinogenesis in an animal model. The signaling pathway through which knockdown of CNDP2 inhibited cell proliferation and tumorigenesis involved in EGFR, cyclin B1 and cyclin E. CONCLUSIONS: Knockdown of CNDP2 can inhibit the proliferation of colon cancer in vitro and retarded carcinogenesis in vivo

A Platinum Nanowire Network as a Highly Effective Current Collector for Intermediate Temperature Solid Oxide Fuel Cells

We report the fabrication and evaluation of a platinum nanowire network as a highly efficient current collector for solid oxide fuel cells (SOFCs). The ink of carbon-black supported platinum nanoparticles was sprayed onto the cathode. After firing, the carbon black was oxidized and disappeared as carbon dioxide gas while the platinum nanoparticles connect with one another, forming a tree-branch-like nanowire network. The diameters of the nanowires range from 100 nm to 400 nm. Compared to a conventional platinum paste current collector, the polarization resistance of the PrBaCo2O5+δ (PBCO) cathode with a nanowire current collector was reduced by 44% at 650 °C (from 0.18 Ω cm2 to 0.1 Ω cm2). The peak power density of the button cells was improved at different degrees of 31.8–59.6% under temperatures 650–550 °C for typical cathode materials of PBCO, La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCF), and Ba0.5Sr0.5Co0.8Fe0.2O3−δ(BSCF). The nanowire network did not show obvious changes after long term testing (400 h)

Safe Reinforcement Learning with Contrastive Risk Prediction

As safety violations can lead to severe consequences in real-world robotic applications, the increasing deployment of Reinforcement Learning (RL) in robotic domains has propelled the study of safe exploration for reinforcement learning (safe RL). In this work, we propose a risk preventive training method for safe RL, which learns a statistical contrastive classifier to predict the probability of a state-action pair leading to unsafe states. Based on the predicted risk probabilities, we can collect risk preventive trajectories and reshape the reward function with risk penalties to induce safe RL policies. We conduct experiments in robotic simulation environments. The results show the proposed approach has comparable performance with the state-of-the-art model-based methods and outperforms conventional model-free safe RL approaches