1,237 research outputs found
Providing Long-Term Participation Incentive in Participatory Sensing
Providing an adequate long-term participation incentive is important for a
participatory sensing system to maintain enough number of active users
(sensors), so as to collect a sufficient number of data samples and support a
desired level of service quality. In this work, we consider the sensor
selection problem in a general time-dependent and location-aware participatory
sensing system, taking the long-term user participation incentive into explicit
consideration. We study the problem systematically under different information
scenarios, regarding both future information and current information
(realization). In particular, we propose a Lyapunov-based VCG auction policy
for the on-line sensor selection, which converges asymptotically to the optimal
off-line benchmark performance, even with no future information and under
(current) information asymmetry. Extensive numerical results show that our
proposed policy outperforms the state-of-art policies in the literature, in
terms of both user participation (e.g., reducing the user dropping probability
by 25% to 90%) and social performance (e.g., increasing the social welfare by
15% to 80%).Comment: This manuscript serves as the online technical report of the article
published in IEEE International Conference on Computer Communications
(INFOCOM), 201
The Integration of Interpretive Teaching and Assessment: Instructed by Portfolio Assessment
Portfolio assessment focuses on the learning process, which combines comprehensively both the process and outcome. By means of test, questionnaire and interview, this study employs both qualitative and quantitative methods to explore the impacts on the learnersā interpretive ability and learning autonomy instructed by portfolio assessment, finally resulting in the integration of interpretive teaching and assessment. The results show that the post-test scores of the Experimental group are higher than the Control group, particularly in terms of listening and analysis, plus translation, and also significantly higher than the pre-test scores of the Experimental group. In addition, the questionnaire and interview reveal that the testees not only increase their activeness in interpretive training but also develop their strong autonomy in learning, thus enhancing their meta cognitive ability in the interpretive training
Context-dependent functions of specific microRNAs in neuronal development
MicroRNAs (miRNAs) are small noncoding RNAs that regulate multiple developmental processes at the post-transcriptional level. Recent rapid progresses have demonstrated critical roles for a number of miRNAs in neuronal development and function. In particular, miR-9 and miR-124 are specifically expressed in the mammalian nervous system, and their respective nucleotide sequences are 100% identical among many species. Yet, their expression patterns and mRNA targets are less conserved throughout evolution. As a consequence, these miRNAs exhibit diverse context-dependent functions in different aspects of neuronal development, ranging from early neurogenesis and neuronal differentiation to dendritic morphogenesis and synaptic plasticity. Some other neuronal miRNAs also exhibit context-dependent functions in development. Thus, post-transcriptional regulation of spatial and temporal expression levels of protein-coding genes by miRNAs contributes uniquely to the proper development and evolution of the complex nervous system
Dense-Coding Attack on Three-Party Quantum Key Distribution Protocols
Cryptanalysis is an important branch in the study of cryptography, including
both the classical cryptography and the quantum one. In this paper we analyze
the security of two three-party quantum key distribution protocols (QKDPs)
proposed recently, and point out that they are susceptible to a simple and
effective attack, i.e. the dense-coding attack. It is shown that the
eavesdropper Eve can totally obtain the session key by sending entangled qubits
as the fake signal to Alice and performing collective measurements after
Alice's encoding. The attack process is just like a dense-coding communication
between Eve and Alice, where a special measurement basis is employed.
Furthermore, this attack does not introduce any errors to the transmitted
information and consequently will not be discovered by Alice and Bob. The
attack strategy is described in detail and a proof for its correctness is
given. At last, the root of this insecurity and a possible way to improve these
protocols are discussed.Comment: 6 pages, 3 figure
Cause or Effect: Misregulation of microRNA Pathways in Neurodegeneration
During normal aging or neurodegenerative diseases, neuronal survival and function depend on protein homeostasis, which is regulated by multiple mechanisms, including the microRNA (miRNA) pathway. In different cells types, the absence of Dicer, a key miRNA processing enzyme, leads to neurodegeneration through cell-autonomous and non-cell-autonomous mechanisms. Loss of certain miRNAs also causes neurodegeneration in some model organisms. On the other hand, miRNA expression is misregulated in patients with different neurodegenerative diseases. Thus, the miRNA pathway appears to be essential in the pathogenesis of several age-dependent neurodegenerative conditions; however, our understanding of the underlying mechanism remains rudimentary. The precise causal relationships between specific miRNAs and neurodegeneration in humans need to be further investigated
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