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排序方式: 共有1141条查询结果,搜索用时 78 毫秒
31.
Sonja Grabner-Kruter Ewald A. Kaluscha 《International journal of human-computer studies》2003,58(6):783
Lack of trust is one of the most frequently cited reasons for consumers not purchasing from Internet vendors. During the last four years a number of empirical studies have investigated the role of trust in the specific context of e-commerce, focusing on different aspects of this multi-dimensional construct. However, empirical research in this area is beset by conflicting conceptualizations of the trust construct, inadequate understanding of the relationships between trust, its antecedents and consequents, and the frequent use of trust scales that are neither theoretically derived nor rigorously validated. The major objective of this paper is to provide an integrative review of the empirical literature on trust in e-commerce in order to allow cumulative analysis of results. The interpretation and comparison of different empirical studies on on-line trust first requires conceptual clarification. A set of trust constructs is proposed that reflects both institutional phenomena (system trust) and personal and interpersonal forms of trust (dispositional trust, trusting beliefs, trusting intentions and trust-related behaviours), thus facilitating a multi-level and multi-dimensional analysis of research problems related to trust in e-commerce. 相似文献
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Dominik Soller Thomas Jaumann Gerd Kilian Jörg Robert Albert Heuberger 《Journal of Signal Processing Systems》2017,89(1):181-190
Development of modern Software Defined Radio (SDR) based communication systems can be accelerated significantly by the use of processing frameworks. The evolution of SDR and the involved departure from digital representations of classical radio architecture towards more abstract software systems raises new requirements of increased flexibility and versatility. The proposed Data Flow Control for C++ (DFC++) processing framework concept addresses those requirements by employing modern programming techniques and flow control mechanisms to allow for variable data rates, dynamic paths, and flexible component designs. Another important trend is the integration of various embedded platforms in the software radio domain. The rapidly increasing performance and efficiency of embedded processors enables the deployment of SDR systems in more space and power constrained environments. Therefore covering a heterogeneous hardware selection becomes increasingly important for processing frameworks. By relying exclusively on C++ and minimizing external dependencies, DFC++ is specifically aiming for excellent portability and adaptability to support a wide range of current and future software radio projects while maintaining high performance and ease of use. This paper introduces the key aspects of the DFC++ concept and implementation with focus on the reference pointer based data transport mechanisms responsible for the propagation of user data between different processing components. 相似文献
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Gabriel Rinnerthaler Hubert Hackl Simon Peter Gampenrieder Frank Hamacher Clemens Hufnagl Cornelia Hauser-Kronberger Franz Zehentmayr Gerd Fastner Felix Sedlmayer Brigitte Mlineritsch Richard Greil 《International journal of molecular sciences》2016,17(2)
For quantitative microRNA analyses in formalin-fixed paraffin-embedded (FFPE) tissue, expression levels have to be normalized to endogenous controls. To investigate the most stably-expressed microRNAs in breast cancer and its surrounding tissue, we used tumor samples from primary tumors and from metastatic sites. MiRNA profiling using TaqMan® Array Human MicroRNA Cards, enabling quantification of 754 unique human miRNAs, was performed in FFPE specimens from 58 patients with metastatic breast cancer. Forty-two (72%) samples were collected from primary tumors and 16 (28%) from metastases. In a cross-platform analysis of a validation cohort of 32 FFPE samples from patients with early breast cancer genome-wide microRNA expression analysis using SurePrintG3 miRNA (8 × 60 K)® microarrays from Agilent® was performed. Eleven microRNAs could be detected in all samples analyzed. Based on NormFinder and geNorm stability values and the high correlation (rho ≥ 0.8) with the median of all measured microRNAs, miR-16-5p, miR-29a-3p, miR-126-3p, and miR-222-3p are suitable single gene housekeeper candidates. In the cross-platform validation, 29 human microRNAs were strongly expressed (mean log2-intensity > 10) and 21 of these microRNAs including miR-16-5p and miR-29a-3p were also stably expressed (CV < 5%). Thus, miR-16-5p and miR-29a-3p are both strong housekeeper candidates. Their Normfinder stability values calculated across the primary tumor and metastases subgroup indicate that miR-29a-3p can be considered as the strongest housekeeper in a cohort with mainly samples from primary tumors, whereas miR-16-5p might perform better in a metastatic sample enriched cohort. 相似文献
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Venkatesh Ramakrishnan Tobias Veerkamp Gerd Ascheid Marc Adrat Markus Antweiler 《Journal of Signal Processing Systems》2012,69(1):41-53
Matrix decomposition of the channel matrix in the form of QR decomposition (QRD) is needed for advanced multiple input and multiple output (MIMO) demapping algorithms like sphere decoder. Due to the computation-intensive nature of the QRD, its implementation has to be highly efficient. Flexibility in several forms, e.g. support for different algorithms, reusability of wireless implementations, portability, etc. is highly sought in wireless devices. The contradictory nature of flexibility and efficiency requires tradeoffs to be made between them in system development. In this paper, we have analyzed such tradeoffs by implementing two minimum mean squared error-sorted QRD algorithms. The algorithms have been implemented in four different methods with varying degree of reusability and in five different forms of portability. The performance of the implementations is evaluated by using the real-time constraints from the LTE standard. For all the implementations, modular equations for accurately estimating the execution time are derived. 相似文献
40.
Monitoring kidney and renal cyst volumes applying MR approaches on a rapamycin treated mouse model of ADPKD 总被引:1,自引:1,他引:0
Wilfried Reichardt Daniel Romaker Anne Becker Martin Buechert Gerd Walz Dominik von Elverfeldt 《Magma (New York, N.Y.)》2009,22(3):143-149
Object The aim of our study was to determine total cystic volume in a mouse model of PKD using MR imaging to monitor therapeutic
effects in vivo.
Materials and methods We imaged eight female pcy-mice in two groups: four belonged to an untreated control group and four were treated with the anticystic agent rapamycin,
which has proven to be effective in reducing cystogenesis in animal models. The mice were imaged using a 9.4 Tesla animal
scanner. MRI measurements were taken at six time points during the therapy. Total renal volumes and total cyst volumes were
calculated using a thresholding approach.
Results During the course of the treatment, the total cyst volume increased significantly faster than the total renal volume in the
untreated group, indicating that growth of the total renal volume in the untreated group was primarily due to the growth of
the cysts, rather than the parenchyma. The measured total renal volume in the control (placebo) group was significantly higher
than the volume in the treated group.
Conclusion Using MRI, we were able to monitor the cystic volume in a mouse model of PKD to assess the therapeutic effect of anticystic
treatment. 相似文献