83 research outputs found
Opportunistic power reassignment between processor and memory in 3D stacks
The pin count largely determines the cost of a chip package, which is often comparable to the cost of a die. In 3D processor-memory designs, power and ground (P/G) pins can account for the majority of the pins. This is because packages include separate pins for the disjoint processor and memory power delivery networks (PDNs). Supporting separate PDNs and P/G pins for processor and memory is inefficient, as each set has to be provisioned for the worst-case power delivery requirements.
In this thesis, we propose to reduce the number of P/G pins of both processor and memory in a 3D design, and dynamically and opportunistically divert some power between the two PDNs on demand. To perform the power transfer, we use a small bidirectional on-chip voltage regulator that connects the two PDNs. Our concept, called Snatch, is effective. It allows the computer to execute code sections with high processor or memory power requirements without having to throttle performance. We evaluate Snatch with simulations of an 8-core multicore stacked with two memory dies. In a set of compute-intensive codes, the processor snatches memory power for 30% of the time on average, speeding-up the codes by up to 23% over advanced turbo-boosting; in memory-intensive codes, the memory snatches processor power. Alternatively, Snatch can reduce the package cost by about 30%
Dam Performance And Safety In Tropical Climates – Recent Developments On Field Monitoring And Computational Analysis
Earth dams are massive water-retaining structures that are used widely in the world for irrigation, water supply and hydroelectric energy generation. Many such dams are built every year and the International Committee on Large Dams (ICOLD) has gathered together experts from the world to work on preparing guidelines for design, construction and monitoring of such massive infrastructure. A potential failure of a large dam may potentially have significant effects on a huge area downstream, as the sudden release of the large volume of retained water can travel for large distances and destroy entire cities and even result in unfortunate fatalities. It is therefore important to recognise the potential causes of failure of such dams and provide timely and effective measures to prevent any degradation or loss of stability. The main threats for dams are seismic activity, internal erosion, faulting and seasonal climate variations. The latter factor, i.e. climate changes, has not been studied widely and therefore there is a need for further understanding of the problem. In arid and tropical climates, e.g. the Mediterranean, Middle East, south Asia, large changes in the temperature and rainfall cause significant variations in the upstream reservoir level. This results in the dam rockfill undergoing cycles of wetting and drying which further causes permanent displacements and potentially cracking. Such structural response needs to be closely monitored, so that any potential leakage (and therefore erosion) is prevented.This keynote paper presents an experimental study to investigate the effects of seasonal climate variations on the deformations of earth dams. A well-instrumented dam in Cyprus, the Kouris earth dam, which is the largest dam in the country is used as a case study. Long-term monitoring data from three-independent and different instrumentation sets are collected, processed and analysed. A periodic variation in the crest settlements is identified and thus relevant statistical analysis is performed to identify the dominant frequencies of fluctuations and to examine any relation between the dam crest settlements and the reservoir level changes. Subsequently, a nonlinear coupled hydro-mechanical finite element analysis is performed which models the entire stress history of the dam, i.e. layered construction, reservoir impoundment, consolidation and reservoir level changes. The latter finite element analysis attempts to identify the relative effects of soil consolidation and reservoir level changes on the induced dam displacements.<br/
Concurrent Hypofractionated Radiotherapy and 5-Fluorouracil for Advanced Sarcomas of the Bone
Purpose. 5-Fluorouracil (5-FU) has shown radiosensitizing properties in vitro. This paper reports the effects of radiotherapy and concomitant intravenous 5-FU radiosensitization in the treatment of advanced bone sarcomas
impact of dehazing on underwater marker detection for augmented reality
Underwater augmented reality is a very challenging task and amongst several issues, one of the most crucial aspects involves real-time tracking. Particles present in water combined with the uneven absorption of light decrease the visibility in the underwater environment. Dehazing methods are used in many areas to improve the quality of digital image data that is degraded by the influence of the environment. This paper describes the visibility conditions affecting underwater scenes and shows existing dehazing techniques that successfully improve the quality of underwater images. Four underwater dehazing methods are selected for evaluation of their capability of improving the success of square marker detection in underwater videos. Two reviewed methods represent approaches of image restoration: Multi-Scale Fusion, and Bright Channel Prior. Another two methods evaluated, the Automatic Color Enhancement and the Screened Poisson Equation, are methods of image enhancement. The evaluation uses diverse test data set to evaluate different environmental conditions. Results of the evaluation show an increased number of successful marker detections in videos pre-processed by dehazing algorithms and evaluate the performance of each compared method. The Screened Poisson method performs slightly better to other methods across various tested environments, while Bright Channel Prior and Automatic Color Enhancement shows similarly positive results
Development and integration of digital technologies addressed to raise awareness and access to European underwater cultural heritage. An overview of the H2020 i-MARECULTURE project
The Underwater Cultural Heritage (UCH)
represents a vast historical and scientific resource that, often, is
not accessible to the general public due the environment and depth
where it is located. Digital technologies (Virtual Museums, Virtual
Guides and Virtual Reconstruction of Cultural Heritage) provide
a unique opportunity for digital accessibility to both scholars and
general public, interested in having a better grasp of underwater
sites and maritime archaeology. This paper presents the
architecture and the first results of the Horizon 2020 iMARECULTURE
(Advanced VR, iMmersive Serious Games and
Augmented REality as Tools to Raise Awareness and Access to
European Underwater CULTURal heritage) project that aims to
develop and integrate digital technologies for supporting the wide
public in acquiring knowledge about UCH. A Virtual Reality (VR)
system will be developed to allow users to visit the underwater sites
through the use of Head Mounted Displays (HMDs) or digital
holographic screens. Two serious games will be implemented for
supporting the understanding of the ancient Mediterranean
seafaring and the underwater archaeological excavations. An
Augmented Reality (AR) system based on an underwater tablet
will be developed to serve as virtual guide for divers that visit the
underwater archaeological sites
GEOMATICS AND CIVIL ENGINEERING INNOVATIVE RESEARCH ON HERITAGE: INTRODUCING THE “ENGINEER” PROJECT
This paper aims to introduce the concept and objectives of a recently supported European project entitled “Geomatics and Civil
Engineering Innovative Research on Heritage”, in short ENGINEER. The ENGINEER project visions to enhance and extend inter-
departmental multidisciplinary research activities of the Department of Civil Engineering & Geomatics of the Cyprus University of
Technology through coordination and support actions as well as through targeted research activities with the support of European
leading institutions. Project tasks aim to fill research multidisciplinary gaps, push, and extend knowledge into new and innovative
fields dealing with the monitoring, digitization, visualization, and preservation of ancient monuments and cultural heritage sites,
assisting their protection, promotion, and safeguarding
Needs and gaps in optical underwater technologies and methods for the investigation of marine animal forest 3D-structural complexity
Marine animal forests are benthic communities dominated by sessile suspension feeders (such as sponges, corals, and bivalves) able to generate three-dimensional (3D) frameworks with high structural complexity. The biodiversity and functioning of marine animal forests are strictly related to their 3D complexity. The present paper aims at providing new perspectives in underwater optical surveys. Starting from the current gaps in data collection and analysis that critically limit the study and conservation of marine animal forests, we discuss the main technological and methodological needs for the investigation of their 3D structural complexity at different spatial and temporal scales. Despite recent technological advances, it seems that several issues in data acquisition and processing need to be solved, to properly map the different benthic habitats in which marine animal forests are present, their health status and to measure structural complexity. Proper precision and accuracy should be chosen and assured in relation to the biological and ecological processes investigated. Besides, standardized methods and protocols are strictly necessary to meet the FAIR (findability, accessibility, interoperability, and reusability) data principles for the stewardship of habitat mapping and biodiversity, biomass, and growth data
Image matching towards maturity
Presented at 19th International Congress for Photogrammetry and Remote Sensing, Amsterdam, Netherlands, 16-23 July, 2000This paper deals with the least squares matching algorithm, focused on stereo pairs, without the use of epipolar geometry. The least squares matching algorithm although widely used has still some shortcomings, which in certain cases keep it away from commercial production. The shortcomings are the low reliability of the "successful" matches and the automation/adaptation of the algorithm, which has numerous parameters. These problems will be addressed in this paper by introducing a new algorithm for dynamic adaptation of the template size and two new algorithms to enhance accuracy and reliability. Discussion and examples will be presented along with proposals for further work, based on the combination of the three algorithms and the use of epipolar geometry
Orthophotograph production in urban areas
This paper investigates possible solutions to the problem of urban orthophotography. Extensive work has been carried out to attain the best possible results, using all the existing software in the Department of Geomatic Engineering, University College London. Two of the most promising methods, which yield the best results, are analysed further. New routines were written in C language, as additions to the existing software, to allow for the special problems that arise in urban areas. The final results overcome the problem of double mapping (or occlusions) and will potentially enable even greater success to be achieved. A simple accuracy assessment of the results has been made. Difficulties and current limitations are analysed and presented
Geomatic Sensors for Heritage Documentation: A Meta-Analysis of the Scientific Literature
This review paper aims to provide a meta-analysis of the scientific literature for heritage documentation and monitoring using geo-information sensors. The study initially introduces the main types of geomatic sensors that are currently widely used for heritage studies. Although the list provided here is indicative rather than exhaustive, it provides a general overview of the variety of sensors used for different observation scales. The study next focuses on the existing literature, based on published documents. Targeted queries were implemented to the Scopus database to extract the relevant information. Filtering was then applied to the results so as to limit the analysis on the specific thematic sub-domains that is applied for heritage documentation and monitoring. These domains include, among other close-range and underwater photogrammetry, Terrestrial Laser Scanner, Unmanned Aerial Vehicles platforms, and satellite observations. In total, more than 12,000 documents were further elaborated. The overall findings are summarized and presented here, providing further insights into the current status of the domain
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