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Hardware Architecture (hardware + architecture)

Distribution by Scientific Domains

Engineering	62%
Medical Sciences	25%

Selected Abstracts

Hardware architecture for a visualization classroom: VizClass

COMPUTER APPLICATIONS IN ENGINEERING EDUCATION, Issue 4 2004
Tara C. Hutchinson
Abstract Interactive learning, critical thinking, creative problem-solving, and problem-based learning are all critical elements for enhancing engineering education. Visualization can provide the much needed computer-assisted design and analysis environment to foster problem-based learning, while virtual reality (VR) can provide the environment for hands-on manipulation, stimulating interactive learning in the engineering classroom. To provide such a space, at the University of California, Irvine a new interactive, spatially balanced learning environment, termed VizClass, has been developed. VizClass incorporates a specially designed lecture room and laboratory integrating both 2- and 3-dimensional spatial learning by coupling a series of interactive projection display boards (touch sensitive whiteboards) and a semi-immersive 3D wall display. Control of devices integrated with VizClass is supported via a centrally located, easy to activate, touch-sensitive display. Digital material, including slides, web content, video clips, sound files, numerical simulations, or animations may be loaded and presented by instructors using either 2D or 3D modalities. This environment has already been integrated into both undergraduate and graduate level courses, providing a balanced spatial learning environment for students. This article describes the unique hardware architecture developed to support this new environment and presents the first course activities conducted within the space. © 2004 Wiley Periodicals, Inc. Comput Appl Eng Educ 12: 232,241, 2004; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20024 [source]

Fast Inverse Reflector Design (FIRD)

COMPUTER GRAPHICS FORUM, Issue 8 2009
A. Mas
I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism; I.3.5 [Computer Graphics]: Computational Geometry and Object Modeling , Physically based modeling; I.3.1 [Hardware architecture]: Graphics processors Abstract This paper presents a new inverse reflector design method using a GPU-based computation of outgoing light distribution from reflectors. We propose a fast method to obtain the outgoing light distribution of a parametrized reflector, and then compare it with the desired illumination. The new method works completely in the GPU. We trace millions of rays using a hierarchical height-field representation of the reflector. Multiple reflections are taken into account. The parameters that define the reflector shape are optimized in an iterative procedure in order for the resulting light distribution to be as close as possible to the desired, user-provided one. We show that our method can calculate reflector lighting at least one order of magnitude faster than previous methods, even with millions of rays, complex geometries and light sources. [source]

Hardware architecture for a visualization classroom: VizClass

Experimental validation and field performance metrics of a hybrid mobile robot mechanism

JOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 3 2010
Pinhas Ben-Tzvi
This paper presents the experimental validation and field testing of a novel hybrid mobile robot (HMR) system using a complete physical prototype. The mobile robot system consists of a hybrid mechanism whereby the locomotion platform and manipulator arm are designed as one entity to support both locomotion and manipulation symbiotically and interchangeably. The mechanical design is briefly described along with the related control hardware architecture based on an embedded onboard wireless communication network between the robot's subsystems, including distributed onboard power using Li-ion batteries. The paper focuses on demonstrating through extensive experimental results the qualitative and quantitative field performance improvements of the mechanical design and how it significantly enhances mobile robot functionality in terms of the new operative locomotion and manipulation capabilities that it provides. In terms of traversing challenging obstacles, the robot was able to surmount cylindrical obstacles up to 0.6-m diameter; cross ditches with at least 0.635-m width; climb and descend step obstacles up to 0.7-m height; and climb and descend stairs of different materials (wood, metal, concrete, plastic plaster, etc.), different stair riser and run sizes, and inclinations up to 60 deg. The robot also demonstrated the ability to manipulate objects up to 61 kg before and after flipping over, including pushing capacity of up to 61 kg when lifting objects from underneath. The above-mentioned functions are critical in various challenging applications, such as search and rescue missions, military and police operations, and hazardous site inspections. © 2010 Wiley Periodicals, Inc. [source]

Robust computer-controlled system for intracytoplasmic sperm injection and subsequent cell electro-activation

THE INTERNATIONAL JOURNAL OF MEDICAL ROBOTICS AND COMPUTER ASSISTED SURGERY, Issue 1 2009
K. K. Tan
Abstract Introduction Intracytoplasmic sperm injection (ICSI) and the subsequent cell electro-activation process is a relatively new enhanced procedure to address male factor infertility. The current method involves the engagement of experienced embryologists for such a purpose. More advanced methodologies, which use high precision instrumentation tools, will speed up the whole procedure. Methods In this paper, the development of a computer-controlled system for ICSI and the subsequent cell electro-activation process is presented. The system is integrated to a microinjection workstation and piezo-actuator to perform the ICSI procedure, with vision capability to automatically position the components precisely. A micro-pump assembly is utilized for automatic medium refreshment and a heater plate assembly provides temperature control during the cell electro-activation process. The overall system is comprehensive, comprising modular functional components integrated within a hardware architecture. Results Experimental results on mice oocytes verified the effectiveness of the developed system over the current method. Conclusions Further improvements on the instrumentation tools will improve the robustness and overall performance of the developed system. Copyright © 2009 John Wiley & Sons, Ltd. [source]

A Power Efficient Electronic Implant for a Visual Cortical Neuroprosthesis

ARTIFICIAL ORGANS, Issue 3 2005
Jonathan Coulombe
Abstract:, An integrated microstimulator designed for a cortical visual prosthesis is presented, along with a pixel reordering algorithm, together minimizing the peak total current and voltage required for stimulation of large numbers of electrodes at a high rate. In order to maximize the available voltage for stimulation at a given supply voltage for generating biphasic pulses, the device uses monopolar stimulation, where the return electrode voltage is dynamically varied. Thus, the voltage available for stimulation is maximized, as opposed to the conventional fixed return voltage monopolar approach, and impedance is significantly lower than can be achieved using bipolar stimulation with microelectrodes. This enables the use of a low voltage power supply, minimizing power consumption of the device. An important constraint resulting from this stimulation strategy, however, is that current generation needs to be simultaneous and in-phase for all active parallel channels, imposing heavy stress on the wireless power recovery and regulation circuitry in large electrode count systems such as a visual prosthesis. An ordering algorithm to be implemented in the external controller of the prosthesis is then proposed. Based on the data for each frame of the video signal to be transmitted to the implant, the algorithm minimizes the total generated current standard deviation between time multiplexed stimulations by determining the most appropriate combination of parallel stimulation channels to be activated simultaneously. A stimulator prototype has been implemented in CMOS technology and successfully tested. Execution of the external controller reordering algorithm on an application specific hardware architecture has been verified using a System-On-Chip development platform. A near 75% decrease in the total stimulation current standard deviation was observed with a one-pass algorithm, whereas a recursive variation of the algorithm resulted in a greater than 95% decrease of the same variable. [source]

Multimedia satellite communications experiments to the international space station

INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING, Issue 5 2002
Carlo Matarasso
Abstract In the present concept of the International Space Station ISS, it is planned to provide the communication services between the European Columbus module of the ISS and the ground equipment via the TDRS (tracking and data relay satellite) network provided by the American NASA (National Aeronautics and Space Agency). Especially because of its low uplink data rate, an unacceptable limitation of the communication services with Columbus is to be expected. In order to investigate possible improvements to this situation, the MEDIS proposal studies the feasibility of a 150 Mbps full duplex communication system to the Columbus Module on via two MEO satellites. A mixed topology with optical inter satellite links and Ka-band up/down-links shall be employed. Also possible liaisons with the Artemis mission will be considered. The MEDIS project is a collaboration of Astrium GmbH, which is project manager, Bosch SatCom, GMD-Fokus and the German Aerospace Center (DLR). The preparation phase of the project will investigate the concept of the communications infrastructure and the experiments that could be realized when the MEOs are launched. This stage has been completed in February 2001. An additional study phase followed, which will be completed with a presentation in July 2002. Briefly the following aspects have been studied by DLR in the preparation phase: the overall concept of experimental communication services for Columbus, the system requirements and network topology, the relevant protocol and hardware architectures, useful satellite constellations and link scenarios. Two phases could follow the preparation phase, in phase one the satellite will be launched and the link will be tested. In phase two the satellites will be connected to the ISS. Copyright © 2002 John Wiley & Sons, Ltd. [source]

Embryonic systems implementation with FPGA-based artificial cell network hardware architectures

ASIAN JOURNAL OF CONTROL, Issue 2 2010
Csaba Szász
Abstract The cell-based structure, which makes up the majority of biological organisms, offers the ability to grow with fault-tolerance abilities and self-repair. By adapting these mechanisms and capabilities to nature, scientific approaches have promoted research for understanding related phenomena and associated principles to engine complex novel digital systems and improve their capability. Founded by these observations, the paper is focused on computer-aided modeling, simulation and experimental research of embryonic systems, with the purpose to implement very large scale integrated hardware structures which are able to imitate cells or artificial organism operation mode, with similar robustness and fault-tolerance properties like their biological equivalents from nature. Field Programmable Gate Array (FPGA)-based artificial cell model configuration provided with strongly network communication capabilities is proposed and developed. The presented theoretical and simulation approaches were tested on a laboratory prototype embryonic system (embryonic machine), for study and implementation of basic abilities of living organisms. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society [source]