14,204 research outputs found
Towards a Semantic Gas Source Localization under Uncertainty
Towards a Semantic Gas Source Localization under Uncertainty.Communications in Computer and Information Science book series (CCIS, volume 855), doi:10.1007/978-3-319-91479-4_42This work addresses the problem of efficiently and coherently
locating a gas source in a domestic environment with a mobile
robot, meaning efficiently the coverage of the shortest distance as possible
and coherently the consideration of different gas sources explaining
the gas presence. The main contribution is the exploitation, for the
first time, of semantic relationships between the gases detected and the
objects present in the environment to face this challenging issue. Our
proposal also takes into account both the uncertainty inherent in the
gas classification and object recognition processes. These uncertainties
are combined through a probabilistic Bayesian framework to provide a
priority-ordered list of (previously observed) objects to check. Moreover
the proximity of the different candidates to the current robot location
is also considered by a cost function, which output is used for planning
the robot inspection path. We have conducted an initial demonstration
of the suitability of our gas source localization approach by simulating
this task within domestic environments for a variable number of objects,
and comparing it with an greedy approach.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Users' perceptions of domestic windows in Hong Kong: Challenging daylighting-based design regulations
The authors suspected that the contemporary quantified daylight control on window design is insufficient to satisfy the user expectation in Hong Kong. A survey was carried out from December 2007 to June 2008 to study the human-window interactions in high-rise residential buildings in Hong Kong. The result indicated that daylighting is not the dominant factor for domestic window design because of Hong Kong's sociocultural context; other factors such as dining habit, toilet hygiene, views from living room and privacy for bedroom proved to be more important in the users perception. This suggested that the current statutory control may not fulfill or match user expectations. Thus, the window design framework should be a qualitative approach with the understanding of space function and user behavior in the sociocultural context in order to provide for a better living environment. © 2010 Macmillan Publishers Ltd.postprin
Managerial incentives, CEO characteristics and corporate innovation in China's private sector
We use a unique World Bank survey of 1088 private manufacturing firms from 18 Chinese cities over the period 2000-2002 to empirically examine the roles of managerial incentives and CEO characteristics in a firm's innovation activities. We look at both innovation effort (R&D intensity) and innovation performance measures such as new product sales. We obtain the following main results: (1) the presence of CEO incentive schemes increases both corporate innovation effort and innovation performance; (2) sales-based performance measures in the incentive scheme, as compared with profit-based performance measure, are more conducive to firm innovation; and (3) CEO education level, professional background and political connection are positively associated with firm's innovation efforts. The main results are robust to endogeneity tests with instrumental variables. We also discuss some important policy implications. © 2010 Association for Comparative Economic Studies.postprin
D'yakonov-Perel' spin relaxation in InSb/AlInSb quantum wells
We investigate theoretically the D'yakonov-Perel' spin relaxation time by
solving the eight-band Kane model and Poisson equation self-consistently. Our
results show distinct behavior with the single-band model due to the anomalous
spin-orbit interactions in narrow band-gap semiconductors, and agree well with
the experiment values reported in recent experiment (K. L. Litvinenko, et al.,
New J. Phys. \textbf{8}, 49 (2006)). We find a strong resonant enhancement of
the spin relaxation time appears for spin align along [] at a
certain electron density at 4 K. This resonant peak is smeared out with
increasing the temperature.Comment: 4 pages, 4 figure
TGFβR2 is a major target of miR-93 in nasopharyngeal carcinoma aggressiveness.
BACKGROUND: MiR-17-92 cluster and its paralogues have emerged as crucial regulators of many oncogenes and tumor suppressors. Transforming growth factor-β receptor II (TGFβR2), as an important tumor suppressor, is involved in various cancer types. However, it is in cancer that only two miRNAs of this cluster and its paralogues have been reported so far to regulate TGFβR2. MiR-93 is oncogenic, but its targetome in cancer has not been fully defined. The role of miR-93 in nasopharyngeal carcinoma (NPC) still remains largely unknown. METHODS: We firstly evaluated the clinical signature of TGFβR2 down-regulation in clinical samples, and next used a miRNA expression profiling analysis followed by multi-validations, including Luciferase reporter assay, to identify miRNAs targeting TGFβR2 in NPC. In vitro and in vivo studies were performed to further investigate the effects of miRNA-mediated TGFβR2 down-regulation on NPC aggressiveness. Finally, mechanism studies were conducted to explore the associated pathway and genes influenced by this miRNA-mediated TGFβR2 down-regulation. RESULTS: TGFβR2 was down-regulated in more than 50% of NPC patients. It is an unfavorable prognosis factor contributing to clinical NPC aggressiveness. A cluster set of 4 TGFβR2-associated miRNAs was identified; they are all from miR-17-92 cluster and its paralogues, of which miR-93 was one of the most significant miRNAs, directly targeting TGFβR2, promoting cell proliferation, invasion and metastasis in vitro and in vivo. Moreover, miR-93 resulted in the attenuation of Smad-dependent TGF-β signaling and the activation of PI3K/Akt pathway by suppressing TGFβR2, further promoting NPC cell uncontrolled growth, invasion, metastasis and EMT-like process. Impressively, the knockdown of TGFβR2 by siRNA displayed a consentaneous phenocopy with the effect of miR-93 in NPC cells, supporting TGFβR2 is a major target of miR-93. Our findings were also substantiated by investigation of the clinical signatures of miR-93 and TGFβR2 in NPC. CONCLUSION: The present study reports an involvement of miR-93-mediated TGFβR2 down-regulation in NPC aggressiveness, thus giving extended insights into molecular mechanisms underlying cancer aggressiveness. Approaches aimed at blocking miR-93 may serve as a promising therapeutic strategy for treating NPC patients
Casimir forces on a silicon micromechanical chip
Quantum fluctuations give rise to van der Waals and Casimir forces that
dominate the interaction between electrically neutral objects at sub-micron
separations. Under the trend of miniaturization, such quantum electrodynamical
effects are expected to play an important role in micro- and nano-mechanical
devices. Nevertheless, utilization of Casimir forces on the chip level remains
a major challenge because all experiments so far require an external object to
be manually positioned close to the mechanical element. Here, by integrating a
force-sensing micromechanical beam and an electrostatic actuator on a single
chip, we demonstrate the Casimir effect between two micromachined silicon
components on the same substrate. A high degree of parallelism between the two
near-planar interacting surfaces can be achieved because they are defined in a
single lithographic step. Apart from providing a compact platform for Casimir
force measurements, this scheme also opens the possibility of tailoring the
Casimir force using lithographically defined components of non-conventional
shapes
Clinical-pathological study on β-APP, IL-1β, GFAP, NFL, Spectrin II, 8OHdG, TUNEL, miR-21, miR-16, miR-92 expressions to verify DAI-diagnosis, grade and prognosis
Traumatic brain injury (TBI) is one of the most important death and disability cause, involving substantial costs, also in economic terms, when considering the young age of the involved subject. Aim of this paper is to report a series of patients treated at our institutions, to verify neurological results at six months or survival; in fatal cases we searched for βAPP, GFAP, IL-1β, NFL, Spectrin II, TUNEL and miR-21, miR-16, and miR-92 expressions in brain samples, to verify DAI diagnosis and grade as strong predictor of survival and inflammatory response. Concentrations of 8OHdG as measurement of oxidative stress was performed. Immunoreaction of β-APP, IL-1β, GFAP, NFL, Spectrin II and 8OHdG were significantly increased in the TBI group with respect to control group subjects. Cell apoptosis, measured by TUNEL assay, were significantly higher in the study group than control cases. Results indicated that miR-21, miR-92 and miR-16 have a high predictive power in discriminating trauma brain cases from controls and could represent promising biomarkers as strong predictor of survival, and for the diagnosis of postmortem traumatic brain injury
Reversible Data Perturbation Techniques for Multi-level Privacy-preserving Data Publication
The amount of digital data generated in the Big Data age is increasingly rapidly. Privacy-preserving data publishing techniques based on differential privacy through data perturbation provide a safe release of datasets such that sensitive information present in the dataset cannot be inferred from the published data. Existing privacy-preserving data publishing solutions have focused on publishing a single snapshot of the data with the assumption that all users of the data share the same level of privilege and access the data with a fixed privacy level. Thus, such schemes do not directly support data release in cases when data users have different levels of access on the published data. While a straight-forward approach of releasing a separate snapshot of the data for each possible data access level can allow multi-level access, it can result in a higher storage cost requiring separate storage space for each instance of the published data. In this paper, we develop a set of reversible data perturbation techniques for large bipartite association graphs that use perturbation keys to control the sequential generation of multiple snapshots of the data to offer multi-level access based on privacy levels. The proposed schemes enable multi-level data privacy, allowing selective de-perturbation of the published data when suitable access credentials are provided. We evaluate the techniques through extensive experiments on a large real-world association graph dataset and our experiments show that the proposed techniques are efficient, scalable and effectively support multi-level data privacy on the published data
Phonon-assisted radiofrequency absorption by gold nanoparticles resulting in hyperthermia
It is suggested that in gold nanoparticles (GNPs) of about 5 nm sizes used in
the radiofrequency (RF) hyperthermia, an absorption of the RF photon by the
Fermi electron occurs with involvement of the longitudinal acoustic vibrational
mode (LAVM), the dominating one in the distribution of vibrational density of
states (VDOS). This physical mechanism helps to explain two observed phenomena:
the size dependence of the heating rate (HR) in GNPs and reduced heat
production in aggregated GNPs. The argumentation proceeds within the
one-electron approximation, taking into account the discretenesses of energies
and momenta of both electrons and LAVMs. The heating of GNPs is thought to
consist of two consecutive processes: first, the Fermi electron absorbs
simultaneously the RF photon and the LAVM available in the GNP; hereafter the
excited electron gets relaxed within the GNP's boundary, exciting a LAVM with
the energy higher than that of the previously absorbed LAVM. GNPs containing
the Ta and/or Fe impurities are proposed for the RF hyperthermia as promising
heaters with enhanced HRs, and GNPs with rare-earth impurity atoms are also
brought into consideration. It is shown why the maximum HR values should be
expected in GNPs with about 5-7 nm size.Comment: proceedings at the NATO Advanced Research workshop FANEM-2015 (Minsk,
May 25-27, 2015). To be published in the final form in: "Fundamental and
Applied NanoElectroMagnetics" (Springer Science + Business Media B.V.
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