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An agent-based DDM for high level architecture
The Data Distribution Management (DDM) service is one of the six services provided in the Runtime Infrastructure (RTI) of High Level Architecture (HLA). Its purpose is to perform data filtering and reduce irrelevant data communicated between federates. The two DDM schemes proposed for RTI, region based and grid based DDM, are oriented to send as little irrelevant data to subscribers as possible, but only manage to filter part of this information and some irrelevant data is still being communicated. Previously (G. Tan et al., 2000), we employed intelligent agents to perform data filtering in HLA, implemented an agent based DDM in RTI (ARTI) and compared it with the other two filtering mechanisms. The paper reports on additional experiments, results and analysis using two scenarios: the AWACS sensing aircraft simulation and the air traffic control simulation scenario. Experimental results show that compared with other mechanisms, the agent based approach communicates only relevant data and minimizes network communication, and is also comparable in terms of time efficiency. Some guidelines on when the agent based scheme can be used are also give
Pathological element-based active device models and their application to symbolic analysis
This paper proposes new pathological element-based active device models which can be used in analysis tasks of linear(ized) analog circuits. Nullators and norators along with the voltage mirror-current mirror (VM-CM) pair (collectively known as pathological elements) are used to model the behavior of active devices in voltage-, current-, and mixed-mode, also considering parasitic elements. Since analog circuits are transformed to nullor-based equivalent circuits or VM-CM pairs or as a combination of both, standard nodal analysis can be used to formulate the admittance matrix. We present a formulation method in order to build the nodal admittance (NA) matrix of nullor-equivalent circuits, where the order of the matrix is given by the number of nodes minus the number of nullors. Since pathological elements are used to model the behavior of active devices, we introduce a more efficient formulation method in order to compute small-signal characteristics of pathological element-based equivalent circuits, where the order of the NA matrix is given by the number of nodes minus the number of pathological elements. Examples are discussed in order to illustrate the potential of the proposed pathological element-based active device models and the new formulation method in performing symbolic analysis of analog circuits. The improved formulation method is compared with traditional formulation methods, showing that the NA matrix is more compact and the generation of nonzero coefficients is reduced. As a consequence, the proposed formulation method is the most efficient one reported so far, since the CPU time and memory consumption is reduced when recursive determinant-expansion techniques are used to solve the NA matrix.Promep-Mexico UATLX-PTC-088Junta de Andalucía TIC-2532Ministerio de Educación y Ciencia TEC2007-67247, TEC2010-14825UC-MEXUS-CONACyT CN-09-31
Sampled-data sliding mode observer for robust fault reconstruction: A time-delay approach
A sliding mode observer in the presence of sampled output information and its application to robust fault reconstruction is studied. The observer is designed by using the delayed continuous-time representation of the sampled-data system, for which sufficient conditions are given in the form of linear matrix inequalities (LMIs) to guarantee the ultimate boundedness of the error dynamics. Though an ideal sliding motion cannot be achieved in the observer when the outputs are sampled, ultimately bounded solutions can be obtained provided the sampling frequency is fast enough. The bound on the solution is proportional to the sampling interval and the magnitude of the switching gain. The proposed observer design is applied to the problem of fault reconstruction under sampled outputs and system uncertainties. It is shown that actuator or sensor faults can be reconstructed reliably from the output error dynamics. An example of observer design for an inverted pendulum system is used to demonstrate the merit of the proposed methodology compared to existing sliding mode observer design approaches
High performance photonic microwave filters based on a 50GHz optical soliton crystal Kerr micro-comb
We demonstrate a photonic radio frequency (RF) transversal filter based on an
integrated optical micro-comb source featuring a record low free spectral range
of 49 GHz yielding 80 micro-comb lines across the C-band. This record-high
number of taps, or wavelengths for the transversal filter results in
significantly increased performance including a QRF factor more than four times
higher than previous results. Further, by employing both positive and negative
taps, an improved out-of-band rejection of up to 48.9 dB is demonstrated using
Gaussian apodization, together with a tunable centre frequency covering the RF
spectra range, with a widely tunable 3-dB bandwidth and versatile dynamically
adjustable filter shapes. Our experimental results match well with theory,
showing that our transversal filter is a competitive solution to implement
advanced adaptive RF filters with broad operational bandwidths, high frequency
selectivity, high reconfigurability, and potentially reduced cost and
footprint. This approach is promising for applications in modern radar and
communications systems.Comment: 19 pages, 12 figures, 107 reference
Effects of ac-field amplitude on the dielectric susceptibility of relaxors
The thermally activated flips of the local spontaneous polarization in
relaxors were simulated to investigate the effects of the applied-ac-field
amplitude on the dielectric susceptibility. It was observed that the
susceptibility increases with increasing the amplitude at low temperatures. At
high temperatures, the susceptibility experiences a plateau and then drops. The
maximum in the temperature dependence of susceptibility shifts to lower
temperatures when the amplitude increases. A similarity was found between the
effects of the amplitude and frequency on the susceptibility.Comment: 8 pages, 7 figures, Phys. Rev. B (in July 1st
Study on the Formation Processes of Wormlike Micelles Derived from Peptide Amphiphiles
制度:新 ; 報告番号:甲3567号 ; 学位の種類:博士(工学) ; 授与年月日:2012/3/15 ; 早大学位記番号:新590
Content-Adaptive Sketch Portrait Generation by Decompositional Representation Learning
Sketch portrait generation benefits a wide range of applications such as
digital entertainment and law enforcement. Although plenty of efforts have been
dedicated to this task, several issues still remain unsolved for generating
vivid and detail-preserving personal sketch portraits. For example, quite a few
artifacts may exist in synthesizing hairpins and glasses, and textural details
may be lost in the regions of hair or mustache. Moreover, the generalization
ability of current systems is somewhat limited since they usually require
elaborately collecting a dictionary of examples or carefully tuning
features/components. In this paper, we present a novel representation learning
framework that generates an end-to-end photo-sketch mapping through structure
and texture decomposition. In the training stage, we first decompose the input
face photo into different components according to their representational
contents (i.e., structural and textural parts) by using a pre-trained
Convolutional Neural Network (CNN). Then, we utilize a Branched Fully
Convolutional Neural Network (BFCN) for learning structural and textural
representations, respectively. In addition, we design a Sorted Matching Mean
Square Error (SM-MSE) metric to measure texture patterns in the loss function.
In the stage of sketch rendering, our approach automatically generates
structural and textural representations for the input photo and produces the
final result via a probabilistic fusion scheme. Extensive experiments on
several challenging benchmarks suggest that our approach outperforms
example-based synthesis algorithms in terms of both perceptual and objective
metrics. In addition, the proposed method also has better generalization
ability across dataset without additional training.Comment: Published in TIP 201
Holographic Bosonic Technicolor
We consider a technicolor model in which the expectation value of an
additional, possibly composite, scalar field is responsible for the generation
of fermion masses. We define the dynamics of the strongly coupled sector by
constructing its holographic dual. Using the AdS/CFT correspondence, we study
the S parameter and the phenomenology of the light technihadrons. We find that
the S parameter is small over a significant region of the model's parameter
space. The particle spectrum is distinctive and includes a nonstandard Higgs
boson as well as heavier hadronic resonances. Technihadron masses and decay
rates are calculated holographically, as a function of the model's parameters.Comment: 20 Pages, 4 eps figures, REVTex. Minor corrections and comments adde
Mechanical self-confinement to enhance energy storage density of antiferroelectric capacitors
The energy storage density of electrical capacitors utilizing antiferroelectric compositions Pb0.99Nb0.02[(Zr0.57Sn0.43)1−yTiy]0.98O3 as dielectrics is measured at a series of temperatures in a series of dielectric compositions with and without self-confinement. Under the applied electric field of 70 kV/cm, a maximum energy density of 1.3 J/cm3 is achieved. The mechanical self-confinement was introduced by partially electroding the central portion of thedielectric ceramic disk. A phase-field model was developed and it confirms the presence of compressive stresses ∼30 MPa in the electroded portion of the dielectric disk and the contribution to the increased energy density from the mechanical confinement
Scientific Basis for the Potential Use of Melatonin in Bone Diseases: Osteoporosis and Adolescent Idiopathic Scoliosis
The objective of this paper was to analyze the data supporting the possible role of melatonin on bone metabolism and its repercussion in the etiology and treatment of bone pathologies such as the osteoporosis and the adolescent idiopathic scoliosis (AIS). Melatonin may prevent bone degradation and promote bone formation through mechanisms involving both melatonin receptor-mediated and receptor-independent actions. The three principal mechanisms of melatonin effects on bone function could be: (a) the promotion of the osteoblast differentiation and activity; (b) an increase in the osteoprotegerin expression by osteoblasts, thereby preventing the differentiation of osteoclasts; (c) scavenging of free radicals generated by osteoclast activity and responsible for bone resorption. A variety of in vitro and in vivo experimental studies, although with some controversial results, point toward a possible role of melatonin deficits in the etiology of osteoporosis and AIS and open a new field related to the possible therapeutic use of melatonin in these bone diseases
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