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11.
As the number of messages and social relationships embedded in social networking sites (SNS) increases, the amount of social information demanding a reaction from individuals increases as well. We observe that, as a consequence, SNS users feel they are giving too much social support to other SNS users. Drawing on social support theory (SST), we call this negative association with SNS usage ‘social overload’ and develop a latent variable to measure it. We then identify the theoretical antecedents and consequences of social overload and evaluate the social overload model empirically using interviews with 12 and a survey of 571 Facebook users. The results show that extent of usage, number of friends, subjective social support norms, and type of relationship (online-only vs offline friends) are factors that directly contribute to social overload while age has only an indirect effect. The psychological and behavioral consequences of social overload include feelings of SNS exhaustion by users, low levels of user satisfaction, and a high intention to reduce or even stop using SNS. The resulting theoretical implications for SST and SNS acceptance research are discussed and practical implications for organizations, SNS providers, and SNS users are drawn. 相似文献
12.
This study aims to address the paradigms of consumers’ adoption behavior for mobile government, posits the factors which pursue citizens’ intention to adopt mobile government services, and reveals the impact of cultural dimensions in perceiving driving factors of mobile government adoption. The mobile government adoption model was developed and tested among users of three different countries, namely Bangladesh, Canada, and Germany. The finding suggests the rationale that cross-cultural differences impact consumers’ perception of mobile government adoption behavior. 相似文献
13.
Leyla Dogruel Sven Joeckel Nicholas D. Bowman 《Behaviour & Information Technology》2015,34(11):1052-1063
Research on elderly people's ICT acceptance and use often relies on the technology acceptance model (TAM) framework, but has been mostly limited to task-oriented uses. This article expands approaches in technology acceptance and use by developing a model to explain entertainment-related uses of new media technology by elderly people. On a theoretical level, we expand the TAM perspective by adding concepts that act as barriers and/or facilitators of technology acceptance, namely technophobia, self-efficacy and previous experience and expertise with technology. We develop an expanded TAM by testing the role of these concepts in two studies on entertainment media technology. In Study 1, we investigate behavioural intention to use 3D cinema among N?=?125 German elderly media users (Age 50+). In Study 2, we focus the actual use of a computer game simulation by N?=?115 German and US elderly media users (Age 50+). Findings in both studies point towards the central role of perceived usefulness, here modelled as enjoyment, as the reason for elderly people's use and acceptance of entertainment media technology. Perceived ease of use is seen as a precondition for enjoyment, particularly for interactive media. 相似文献
14.
The high-conductance state of cortical networks 总被引:3,自引:0,他引:3
We studied the dynamics of large networks of spiking neurons with conductance-based (nonlinear) synapses and compared them to networks with current-based (linear) synapses. For systems with sparse and inhibition-dominated recurrent connectivity, weak external inputs induced asynchronous irregular firing at low rates. Membrane potentials fluctuated a few millivolts below threshold, and membrane conductances were increased by a factor 2 to 5 with respect to the resting state. This combination of parameters characterizes the ongoing spiking activity typically recorded in the cortex in vivo. Many aspects of the asynchronous irregular state in conductance-based networks could be sufficiently well characterized with a simple numerical mean field approach. In particular, it correctly predicted an intriguing property of conductance-based networks that does not appear to be shared by current-based models: they exhibit states of low-rate asynchronous irregular activity that persist for some period of time even in the absence of external inputs and without cortical pacemakers. Simulations of larger networks (up to 350,000 neurons) demonstrated that the survival time of self-sustained activity increases exponentially with network size. 相似文献
15.
Darcy T. Haluzan David M. Klymyshyn Martin Börner Sven Achenbach Garth Wells Timo Mappes Jürgen Mohr 《Microsystem Technologies》2008,14(9-11):1709-1714
High aspect ratio variable capacitors have been fabricated using deep X-ray lithography and electroplating. Stiction phenomena applicable to high aspect ratio devices are presented, including the conditions for stiction to occur and the critical dimensions of structures. Actuation tests at 3 GHz are also presented and show a maximum capacitance of 0.86 pF with no actuation voltage and a minimum capacitance of 0.70 pF with an actuation voltage of 20 V just before pull-in, which gives a tuning range of 1.23:1. Corresponding Q-factor values are 49.3 and 70.8 respectively. After pull-in, the measured capacitance is 0.61 pF, corresponding to a tuning range of 1.41:1, with a maximum Q-factor of 102.9. 相似文献
16.
Groppe Sven Groppe Jingua Muller Dirk 《Knowledge and Data Engineering, IEEE Transactions on》2009,21(9):1328-1342
Caching stores the results of previously answered queries in order to answer succeeding queries faster by reusing these results. We propose two different approaches for using caches of XSLT transformed XML data in order to answer queries. The first approach checks whether or not a current query Q can be directly answered from the result of a previously answered query Qi stored in the cache. The new query is otherwise submitted to the source over the network, the answer of the query is determined, transmitted back to the client, and stored in the cache. The second approach determines only the intersection Q−Qi and integrates the result of Q−-Qi into the previous results in the cache, which requires applying a numbering scheme for the output of the XSLT stylesheet. We show by experimental results that the second approach can significantly speed up the answering time in comparison to the first approach, but is not significantly slower in few worst cases than the second approach. 相似文献
17.
John Strassner Sven van der Meer Declan O’Sullivan Simon Dobson 《Journal of Network and Systems Management》2009,17(3):255-284
The purpose of autonomic networking is to manage the business and technical complexity of networked components and systems.
However, existing network management data has no link to business concepts. This makes it very difficult to ensure that services
offered by the network are meeting business objectives. This paper describes a novel context-aware policy model that uses
a combination of modeled and ontological data to determine the current context, which policies are applicable to that context,
and what services and resources should be offered to which users and applications.
John Strassner is the director of autonomic research in the Telecommunications Systems & Software Group in Waterford Institute of Technology, and a Visiting Professor at POSTECH. His research interests are in autonomic systems, policy based management, machine learning, and semantic reasoning. He is the Chairman of the Autonomic Communications Forum, and the past chair of the TMF’s NGOSS SID, metamodel and policy working groups. He has authored two books, written chapters for five other books, and co-edited five journals on network and service management and autonomics. John is the recipient of the Daniel A. Stokesbury memorial award for excellence in network management, and has authored 211 refereed journal papers and publications. Sven van der Meer received his M.Sc in computer science and his Dr.-Ing. from Technical University Berlin (TUB), Germany, in 1996 and 2002. Since November 2002, Sven has been a research fellow at the Telecommunications Software & Systems Group at the Waterford Institute of Technology. Since October 2004 he is Senior Investigator of the Competence Centre for Communication Infrastructure Management at TSSG, involved in the Architecture and Information Modelling teams in the TMF, and has served as editor for Technological Neutral Architecture and Contracts specifications within the TM Forum. Declan O’Sullivan is the director of the Knowledge and Data Engineering (KDEG) research group in Trinity College Dublin (TCD). His research interests are in the use of semantic-driven approaches for network and service management, in particular to enable semantic interoperability. He is currently a Principal Investigator in the SFI funded research project investigating Federated Autonomic Management Environments (FAME). O’Sullivan has a Ph.D. and a M.Sc in computer science from TCD. Simon Dobson is a co-founder of the Systems Research Group at UCD Dublin. His research centers around adaptive pervasive computing and novel programming techniques. He is on the editorial boards of the Journal of Network and Systems Management and the International Journal of Autonomous and Adaptive Communications Systems, and participates in a number of EU strategic workshops and working groups. He is National Director and vice-president of the European Research Consortium for Informatics and Mathematics, a board member of the Autonomic Communication Forum, and a member of the IBEC/ICT Ireland standing committee on academic/industrial research and development. He holds a BSc and DPhil in computer science, is a Chartered Fellow of the British Computer Society, a Chartered Engineer, and member of the IEEE and ACM. 相似文献
Simon DobsonEmail: |
John Strassner is the director of autonomic research in the Telecommunications Systems & Software Group in Waterford Institute of Technology, and a Visiting Professor at POSTECH. His research interests are in autonomic systems, policy based management, machine learning, and semantic reasoning. He is the Chairman of the Autonomic Communications Forum, and the past chair of the TMF’s NGOSS SID, metamodel and policy working groups. He has authored two books, written chapters for five other books, and co-edited five journals on network and service management and autonomics. John is the recipient of the Daniel A. Stokesbury memorial award for excellence in network management, and has authored 211 refereed journal papers and publications. Sven van der Meer received his M.Sc in computer science and his Dr.-Ing. from Technical University Berlin (TUB), Germany, in 1996 and 2002. Since November 2002, Sven has been a research fellow at the Telecommunications Software & Systems Group at the Waterford Institute of Technology. Since October 2004 he is Senior Investigator of the Competence Centre for Communication Infrastructure Management at TSSG, involved in the Architecture and Information Modelling teams in the TMF, and has served as editor for Technological Neutral Architecture and Contracts specifications within the TM Forum. Declan O’Sullivan is the director of the Knowledge and Data Engineering (KDEG) research group in Trinity College Dublin (TCD). His research interests are in the use of semantic-driven approaches for network and service management, in particular to enable semantic interoperability. He is currently a Principal Investigator in the SFI funded research project investigating Federated Autonomic Management Environments (FAME). O’Sullivan has a Ph.D. and a M.Sc in computer science from TCD. Simon Dobson is a co-founder of the Systems Research Group at UCD Dublin. His research centers around adaptive pervasive computing and novel programming techniques. He is on the editorial boards of the Journal of Network and Systems Management and the International Journal of Autonomous and Adaptive Communications Systems, and participates in a number of EU strategic workshops and working groups. He is National Director and vice-president of the European Research Consortium for Informatics and Mathematics, a board member of the Autonomic Communication Forum, and a member of the IBEC/ICT Ireland standing committee on academic/industrial research and development. He holds a BSc and DPhil in computer science, is a Chartered Fellow of the British Computer Society, a Chartered Engineer, and member of the IEEE and ACM. 相似文献
18.
Sven Lautenbach Neil Graf Ralf Seppelt Michael Matthies 《Environmental Modelling & Software》2009,24(1):26-43
We developed a decision support system (DSS) for sustainable river basin management in the German Elbe catchment (~100,000 km2), called Elbe-DSS. The system integrates georeferenced simulation models and related data sets with a user friendly interface and includes a library function. Design and content of the DSS have been developed in close cooperation with end users and stakeholders. The user can evaluate effectiveness of management actions like reforestation, improvement of treatment plant technology or the application of buffer strips under the influence of external constraints on climate, demographic and agro-economic changes to meet water management objectives such as water quality standards and discharge control. The paper (i) describes the conceptual design of the Elbe-DSS, (ii) demonstrates the applicability of the integrated catchment model by running three different management options for phosphate discharge reduction (reforestation, erosion control and ecological-farming) under the assumption of regional climate change based on IPCC scenarios, (iii) evaluates the effectiveness of the management options, and (iv) provides some lessons for the DSS-development in similar settings. The georeferenced approach allows the identification of local inputs in sub-catchments and their impact on the overall water quality, which helps the user to prioritize his management actions in terms of spatial distribution and effectiveness. 相似文献
19.
Simple, CAD compatible small‐signal scalable circuit model for the thin film parallel‐plate ferroelectric varactors is reported. It is based on the measured permittivity and loss tangent of the ferroelectric films along with the fundamental theoretical relationships of ferroelectrics in paraelectric phase. The model makes use of the measured DC field (voltage) at the inflection point of the C‐V curve where the nonlinearity (dC/dV) and the tunability are maximum. Both the capacitance and the equivalent loss resistance (dielectric losses) in the ferroelectric film take into account the low permittivity layers at the boundaries of the nano‐columns of the film. The frequency dependent losses in the top and bottom plates of the varactors and the parasitic inductance of the plates are also taken into account. The model is valid for ferroelectric films having columnar structure. It is useful in wide temperature, DC field, and frequency ranges. © 2008 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2009. 相似文献
20.
Quantitative mass spectrometry to investigate epidermal growth factor receptor phosphorylation dynamics 总被引:1,自引:0,他引:1
Identifying proteins of signaling networks has received much attention, because an array of biological processes are entirely dependent on protein cross-talk and protein-protein interactions. Protein posttranslational modifications (PTM) add an additional layer of complexity, resulting in complex signaling networks. Of particular interest to our working group are the signaling networks of epidermal growth factor (EGF) receptor, a transmembrane receptor tyrosine kinase involved in various cellular processes, including cell proliferation, differentiation, and survival. Ligand binding to the N-terminal residue of the extracellular domain of EGF receptor induces conformational changes, dimerization, and (auto)-phosphorylation of intracellular tyrosine residues. In addition, activated EGF receptor may positively affect survival pathways, and thus determines the pathways for tumor growth and progression. Notably, in many human malignancies exaggerated EGF receptor activities are commonly observed. An understanding of the mechanism that results in aberrant phosphorylation of EGF receptor tyrosine residues and derived signaling cascades is crucial for an understanding of molecular mechanisms in cancer development. Here, we summarize recent labeling methods and discuss the difficulties in quantitative MS-based phosphorylation assays to probe for receptor tyrosine kinase (RTK) activity. We also review recent advances in sample preparation to investigate membrane-bound RTKs, MS-based detection of phosphopeptides, and the diligent use of different quantitative methods for protein labeling. 相似文献