Search results for "asynchronous"
showing 10 items of 82 documents
Asynchronous Occlusion Culling on Heterogeneous PC Clusters for Distributed 3D Scenes
2012
We present a parallel rendering system for heterogeneous PC clusters to visualize massive models. One single, powerful visualization node is supported by a group of backend nodes with weak graphics performance. While the visualization node renders the visible objects, the backend nodes asynchronously perform visibility tests and supply the front end with visible scene objects. The visualization node stores only currently visible objects in its memory, while the scene is distributed among the backend nodes’ memory without redundancy. To efficiently compute the occlusion tests in spite of that each backend node stores only a fraction of the original geometry, we complete the scene by adding h…
MALTA: an asynchronous readout CMOS monolithic pixel detector for the ATLAS High-Luminosity upgrade
2019
The ATLAS collaboration is currently investigating CMOS monolithic pixel sensors for the outermost layer of the upgrade of its Inner Tracker (ITk). For this application, two large scale prototypes featuring small collection electrode have been produced in a radiation-hard process modification of a standard 0.18 μm CMOS imaging technology: the MALTA, with a novel asynchronous readout, and the TJ MONOPIX, based on the well established "column-drain" architecture. The MALTA chip is the first full-scale prototype suitable for the development of a monolithic module for the ITk. It features a fast and low-power front-end, an architecture designed to cope with an hit-rate up to 2 MHz/mm2 without c…
On the Advantages of Asynchronous Pixel Reading and Processing for High-Speed Motion Estimation
2008
Biological visual systems are becoming an interesting source for the improvement of artificial visual systems. A biologically inspired read-out and pixel processing strategy is presented. This read-out mechanism is based on Selective pixel Change-Driven (SCD) processing. Pixels are individually processed and read-out instead of the classical approach where the read-out and processing is based on complete frames. Changing pixels are read-out and processed at short time intervals. The simulated experiments show that the response delay using this strategy is several orders of magnitude lower than current cameras while still keeping the same, or even tighter, bandwidth requirements.
A fast PC-interface for synchronized sampling of digital data
1994
We describe a high-speed interface unit for a PC-like microcomputer used for pulsar observations at the Northern Cross radiotelescope. The unit allows sampling synchronized to a master UTC clock and asynchronous output to a storage device with a peak data rate of about 2.5 MB/sec.
Low-cost motion control solution for industrial manufacturing systems
2011
This paperwork deals with a low-cost actuation solution, based upon induction motors, which was seldom used in the motion control systems, especially for the machine tools feed drives. A simulation approach, based upon a mathematical model of the induction motor, for tuning the controllers of the systems is presented. Experimental researches developed upon a two axes motion control system, both axes being driven by alternating current asynchronous motors were also performed in order to test the proposed strategies. The asynchronous motors, used as actuation devices were equipped with incremental rotary encoders and controlled by vector frequency inverters and DSP motion control cards were u…
Positioning system for assembly and manufacturing tasks
2019
The paper presents a two-axis positioning system using asynchronous motors as actuation devices. Theuse of asynchronous motors reduces the overall cost of the system, while providing actuating torques superior to the ones provided by stepping motors. The system is controlled by mean of a programmable logic controller (PLC) and two voltage-frequency inverters fitted with motion control cards. In contrasts to a stepping motor system, which works in open loop mode, the proposed system uses closed loop control on each axis. The motion loop is closed by means of an incremental encoder.
Analyzing the Contextual Nature of Collaborative Activity
2010
This chapter discusses a methodology designed to explore the contextual nature of collaborative activity. The methods that can be generally considered to be based on ‘socio-cultural’ discourse analysis are discussed as a means to explore how different aspects of a situation mediate students’ shared meaning-making. First, an analysis is demonstrated, illustrating how different immediate and mediated contexts are embedded in students’ discourse as they are engaged in face-to-face collaborative activity in a computer-mediated context. Second, a multidimensional coding scheme is presented for analyzing the contextualized process of collaborative knowledge construction in an asynchronous web-ba…
A Cognitive-based scheme for user reliability and expertise assessment in Q&A social networks
2011
Q&A social media has gained a great deal of attention during recent years. People rely on these sites to obtain information due to the number of advantages they offer as compared to conventional sources of knowledge (e.g., asynchronous and convenient access). However, for the same question one may find highly contradictory answers, causing ambiguity with respect to the correct information. This can be attributed to the presence of unreliable and/or non-expert users. In this work, we propose a novel approach for estimating the reliability and expertise of a user based on human cognitive traits. Every user can individually estimate these values based on local pairwise interactions. We examine…
The use of sea waves for generation of electrical energy: a linear tubular asynchronous electrical generator
2007
A linear tubular asynchronous generator to be used as generator driven by seawave is presented. The design criteria of a TLIM with hollowed iron induced part as well as the technological processes to be adopted and the materials utilized in the various parts are described. The methodologies for mechanical assembling and electric wiring are considered too. Finally, the prototype with bimetallic induced part that has been designed and built is presented and some experimental results on electrical and mechanical variables are shown.
A Web-Based Coordination Infrastructure for Grid Collective Services
2004
Virtual Organizations (VO) consisting of heterogeneous institutions and individuals that share resources dynamically and in a coordinated way to support collaborative problem-solving are emerging in many fields. Consequently, new types of distributed infrastructures known as Grids have been proposed to cope with these new sharing requirements. Grids offer sets of collective services to support collaborative tasks which are distributed in nature and need asynchronous communication. Existing approaches to this problem lack of flexibility, adaptability and are tightly bound to the collective service that is provided. We present here a generic event model to build collective services that requi…