Search results for "Signal"
showing 10 items of 6924 documents
Twitter sentiment as a weak signal in venture capital financing
2021
Abstract How do venture capitalists (VCs) incorporate weak and strong signals in the valuation of technology-based startups? Based on a sociocognitive perspective of signaling theory, we introduce Twitter sentiment as a novel and weak signal, which we juxtapose with patents as a traditional, strong signal. While we find a positive association between both signals and VCs' venture valuations, our results reveal that Twitter sentiment does not correlate with actual long-term investment success, whereas patents do. Additionally, we identify and test novelty and experience characteristics (i.e., startup age and VC firm experience) as boundary conditions for our proposed signal-valuation relatio…
DEPFET Active Pixel Detectors for a Future Linear e(+)e(-) Collider
2013
arXiv:1212.2160v1.-- et al.
Efficient Dense Disparity Map Reconstruction using Sparse Measurements
2018
International audience; In this paper, we propose a new stereo matching algorithm able to reconstruct efficiently a dense disparity maps from few sparse disparity measurements. The algorithm is initialized by sampling the reference image using the Simple Linear Iterative Clustering (SLIC) superpixel method. Then, a sparse disparity map is generated only for the obtained boundary pixels. The reconstruction of the entire disparity map is obtained through the scanline propagation method. Outliers were effectively removed using an adaptive vertical median filter. Experimental results were conducted on the standard and the new Middlebury datasets show that the proposed method produces high-quali…
The PAPIA system
1991
In 1983 an Italian research program was begun for the design, simulation and construction of a multiprocessor image processing system. After a first phase devoted to the comparison of suggested and existing systems and to the definition of a set of benchmarks, a new system was defined. The structure of this new system is introduced here: it is based on a fine-grained pyramid of processors built up by means of a pyramidal cell implemented on a VLSI multiprocessor chip. The peculiarities and the capabilities of the processing element are highlighted. The complete hardware and software system has been fully designed and is described. A first working prototype has been built and is now operatio…
A VLSI for deskewing and fault tolerance in LVDS links
2005
The device presented at this work is a switch implemented in a 0.35 mum CMOS process for compensating the skew which affects parallel data signal transmissions and for providing fault tolerance in large scale scalable systems, for instance used in trigger farms for high energy physics experiments. The SWIFT chip (SWItch for Fault Tolerance) is part of a cluster built around commercially components which has been inspired by the LHCb experiment. The skew is extremely important because it directly affects the sample window available to the receiver logic and either forces to use quality and expensive cables in order to minimize its effects or reduces the maximum signal transmission range or d…
Visual spike-based convolution processing with a Cellular Automata architecture
2010
this paper presents a first approach for implementations which fuse the Address-Event-Representation (AER) processing with the Cellular Automata using FPGA and AER-tools. This new strategy applies spike-based convolution filters inspired by Cellular Automata for AER vision processing. Spike-based systems are neuro-inspired circuits implementations traditionally used for sensory systems or sensor signal processing. AER is a neuromorphic communication protocol for transferring asynchronous events between VLSI spike-based chips. These neuro-inspired implementations allow developing complex, multilayer, multichip neuromorphic systems and have been used to design sensor chips, such as retinas an…
Optimized FPGA-implementation of quadrature DDS
2003
This paper presents the optimized implementation of high performance quadrature direct digital synthesizers (DDS). Although VLSI designs and optimizations have already been discussed in the literature they may not be successfully translated into an FPGA-based technology. This work examines each phase-to-amplitude mapping technique, such as ROM compression and partitioning techniques and the CORDIC algorithm, and it proposes the most suitable structure for Virtex FPGAs in order to obtain the most efficient implementation in terms of area and throughput.
AER Filtering Using GLIDER: VHDL Cellular Automata Description
2008
Cellular Automata (CA) is a bio-inspired processing model for problem solving, initially proposed by Von Neumann. This approach modularizes the processing by dividing the solution into synchronous cells that change their states at the same time in order to get the solution. The communication between them is crucial to achieve the correct solution. On the other hand, the Address-Event-Representation (AER) is a neuromorphic communication protocol for transferring asynchronous events between VLSI chips. These neuro-inspired implementations have been used to design sensor chips (retina, cochleas), processing chips (convolutions, filters) and learning chips, which makes it possible to develop co…
A Computational Approach to Vibration Control of Vehicle Engine-Body Systems
2012
In recent years, the noise and vibration of cars have become increasingly important [20, 23, 29, 30, 35]. A major comfort aspect is the transmission of engine-induced vibrations through powertrain mounts into the chassis (see Figure 1). Engine and powertrain mounts are usually designed according to criteria that incorporate a trade-off between the isolation of the engine from the chassis and the restriction of engine movements. The engine mount is an efficient passive means to isolate the car chassis structure from the engine vibration. However, the passive means for isolation is efficient only in the high frequency range. However the vibration disturbance generated by the engine occurs mai…
A convex optimization approach for vibration control of base isolated structures with limited wireless communication capacity
2010
The problem of H ∞ control design for vibration reduction of a base isolated structure with limited wireless communication capacity is studied in this paper. The network under consideration is subjected to measurement quantization, signal transmission delay, and data packet dropout, which appear typically in a network environment. Based on Lyapunov-Krasovskii functional (LKF) theory, some delay-range-dependent conditions are established for the existence of desired controllers such that the resulting closed-loop system is asymptotically stable and its performance is kept within a prescribed level. Finally, some simulation results are given to illustrate the effectiveness of our method.