Comparison of Image-Based and Time-of-Flight-Based Technologies for 3D Reconstruction of Infrastructure

Image-based (i.e., photo/videogrammetry) and time-of-flight-based (i.e., laser scanning) technologies are typically used to collect spatial data of infrastructure. In order to help architecture, engineering, and construction (AEC) industries make cost-effective decisions in selecting between these two technologies with respect to their settings, this paper makes an attempt to measure the accuracy, quality, time efficiency, and cost of applying image-based and time-of-flight-based technologies to conduct as-built 3D reconstruction of infrastructure. In this paper, a novel comparison method is proposed, and preliminary experiments are conducted. The results reveal that if the accuracy and quality level desired for a particular application is not high (i.e., error < 10 cm, and completeness rate > 80%), image-based technologies constitute a good alternative for time-of-flight-based technologies and significantly reduce the time and cost needed for collecting the data on site.

Comparison of Image-Based and Time-of-Flight-Based Technologies for Three-Dimensional Reconstruction of Infrastructure

Image-based (i.e., photo/videogrammetry) and time-of-flight-based (i.e., laser scanning) technologies are typically used to collect spatial data of infrastructure. In order to help architecture, engineering, and construction (AEC) industries make cost-effective decisions in selecting between these two technologies with respect to their settings, this paper makes an attempt to measure the accuracy, quality, time efficiency, and cost of applying image-based and time-of-flight-based technologies to conduct as-built 3D reconstruction of infrastructure. In this paper, a novel comparison method is proposed, and preliminary experiments are conducted. The results reveal that if the accuracy and quality level desired for a particular application is not high (i.e., error < 10 cm, and completeness rate > 80%), image-based technologies constitute a good alternative for time-of-flight-based technologies and significantly reduce the time and cost needed for collecting the data on site.

Real time analysis of atmospheric single particles in urban environments using aerosol time of flight mass spectrometry

In order to determine the size-resolved chemical composition of single particles in real-time an ATOFMS was deployed at urban background sites in Paris and Barcelona during the MEGAPOLI and SAPUSS monitoring campaigns respectively. The particle types detected during MEGAPOLI included several carbonaceous species, metal-containing types and sea-salt. Elemental carbon particle types were highly abundant, with 86% due to fossil fuel combustion and 14% attributed to biomass burning. Furthermore, 79% of the EC was apportioned to local emissions and 21% to continental transport. The carbonaceous particle types were compared with quantitative measurements from other instruments, and while direct correlations using particle counts were poor, scaling of the ATOFMS counts greatly improved the relationship. During SAPUSS carbonaceous species, sea-salt, dust, vegetative debris and various metal-containing particle types were identified. Throughout the campaign the site was influenced by air masses altering the composition of particles detected. During North African air masses the city was heavily influenced by Saharan dust. A regional stagnation was also observed leading to a large increase in carbonaceous particle counts. While the ATOFMS provides a list of particle types present during the measurement campaigns, the data presented is not directly quantitative. The quantitative response of the ATOFMS to metals was examined by comparing the ion signals within particle mass spectra and to hourly mass concentrations of; Na, K, Ca, Ti, V, Cr, Mn, Fe, Zn and Pb. The ATOFMS was found to have varying correlations with these metals depending on sampling issues such as matrix effects. The strongest correlations were observed for Al, Fe, Zn, Mn and Pb. Overall the results of this work highlight the excellent ability of the ATOFMS in providing composition and mixing state information on atmospheric particles at high time resolution. However they also show its limitations in delivering quantitative information directly.

Time of flight mass spectrometry for quantitative data analysis in fast transient studies using a Temporal Analysis of Products (TAP) reactor

A Time of flight (ToF) mass spectrometer suitable in terms of sensitivity, detector response and time resolution, for application in fast transient Temporal Analysis of Products (TAP) kinetic catalyst characterization is reported. Technical difficulties associated with such application as well as the solutions implemented in terms of adaptations of the ToF apparatus are discussed. The performance of the ToF was validated and the full linearity of the specific detector over the full dynamic range was explored in order to ensure its applicability for the TAP application. The reported TAP-ToF setup is the first system that achieves the high level of sensitivity allowing monitoring of the full 0-200 AMU range simultaneously with sub-millisecond time resolution. In this new setup, the high sensitivity allows the use of low intensity pulses ensuring that transport through the reactor occurs in the Knudsen diffusion regime and that the data can, therefore, be fully analysed using the reported theoretical TAP models and data processing.

Calibration of time of flight detectors using laser-driven neutron source

Calibration of three scintillators (EJ232Q, BC422Q, and EJ410) in a time-of-flight arrangement using a laser drive-neutron source is presented. The three plastic scintillator detectors were calibrated with gamma insensitive bubble detector spectrometers, which were absolutely calibrated over a wide range of neutron energies ranging from sub-MeV to 20 MeV. A typical set of data obtained simultaneously by the detectors is shown, measuring the neutron spectrum emitted from a petawatt laser irradiated thin foil.

A frontal view gait recognition based on 3D imaging using a time of flight camera

Studies have been carried out to recognize individuals from a frontal view using their gait patterns. In previous work, gait sequences were captured using either single or stereo RGB camera systems or the Kinect 1.0 camera system. In this research, we used a new frontal view gait recognition method using a laser based Time of Flight (ToF) camera. In addition to the new gait data set, other contributions include enhancement of the silhouette segmentation, gait cycle estimation and gait image representations. We propose four new gait image representations namely Gait Depth Energy Image (GDE), Partial GDE (PGDE), Discrete Cosine Transform GDE (DGDE) and Partial DGDE (PDGDE). The experimental results show that all the proposed gait image representations produce better accuracy than the previous methods. In addition, we have also developed Fusion GDEs (FGDEs) which achieve better overall accuracy and outperform the previous methods.

A methodology to estimate the residence time of estuaries

The residence time has long been used as a classification parameter for estuaries and other semi- enclosed water bodies. It aims to quantify the time water remains inside the estuary, being used as an indicator both for pollution assessment and for ecological processes. Estuaries with a short residence time will export nutrients from upstream sources more rapidly then estuaries with longer residence time. On the other hand the residence time determines if micro-algae can stay long enough to generate a bloom. As a consequence, estuaries with very short residence time are expected to have much lower algae blooms, then estuaries with longer residence time. In addition, estuaries with residence times shorter than the doubling time of algae cells will inhibit formation of algae blooms (EPA, 2001). The residence time is also an important issue for processes taking place in the sediment. The fluxes of particulate matter and associated adsorbed species from the water column to the sediment depends of the particle’s vertical velocity, water depth and residence time. This is particularly important for the fine fractions with lower sinking velocities. The question is how to compute the residence time and how does it depend on the computation method adopted.

A question of tomorrow: Blanchot, surrealism and the time of the fragment

This article offers a close critical reading of Blanchot's essay on Surrealism, 'Tomorrow at Stake', raising a series of questions concerning the time of 'Surrealist experience' and its relation to those temporal structures inscribed within the concepts of modernity, the avant-garde, and (art) history itself. It is argued, through a posited connection to Romantic conceptions of the fragment, that those 'reflexes of the future' which for Surrealism determine the value of the present, may be understood, philosophically, in relation to diverse conceptions of the 'openness' of the question, in turn suggesting a more complex understanding of Surrealism's 'avant-garde' character.

How health organizations can apply scenario based planning and analytic technologies to make strategic consequential decisions in a time of uncertainty

The magnitude of the cervical cancer problem, coupled with the potential for prevention with recent technological advances, made it imperative to step back and reassess strategic options for dealing with cervical cancer screening in Kenya. The purpose of this qualitative study was: 1) to explore the extent to which the Participatory Action Research (PAR) methodology and the Scenario Based Planning (SBP) method, with the application of analytics, could enable strategic, consequential, informed decision making, and 2) to determine how influential Kenyan decision makers could apply SBP with analytic tools and techniques to make strategic, consequential decisions regarding the implementation of a Cervical Self Sampling Program (CSSP) in both urban and rural settings. The theoretical paradigm for this study was action research; it was experiential, practical, and action oriented, and resulted in co-created knowledge that influenced study participants’ decision making. Action Africa Help International (AAHI) and Brock University collaborated with Local Decision Influencing Participants (LDIP’s) to develop innovative strategies on how to implement the CSSP. SBP tools, along with traditional approaches to data collection and analysis, were applied to collect, visualize and analyze predominately qualitative data. Outputs from the study included: a) a generic implementation scenario for a CSSP (along with scenarios unique to urban and rural settings), and b) 10 strategic directions and 22 supporting implementation strategies that address the variables of: 1) technical viability, 2) political support, 3) affordability, 4) logistical feasibility, 5) social acceptability, and 6) transformation/sustainability. In addition, study participants’ capacity to effectively engage in predictive/prescriptive strategic decision making was strengthened.

The Rebirth of a Communications Network: Europe at the Time of the Carolingians.

Rapport de recherche

The English novel in the time of Shakespeare

The rise of the English novel needs rethinking after it has been confined to the "formal realism" of Defoe, Richardson, and Fielding (Watt, 1957), to "antecedents, forerunners" (Schlauch, 1968; Klein, 1970) or to mere "prose fiction" (McKillop, 1951; Davis, Richetti, 1969; Fish, 1971; Salzman, 1985; Kroll, 1998). My paper updates a book by Jusserand under the same title (1890) by proving that the social and moral history of the long prose genre admits no strict separation of "novel" and "romance", as both concepts are intertwined in most fiction (Cuddon, Preston, 1999; Mayer, 2000). The rise of the novel, seen in its European context, mainly in France and Spain (Kirsch, 1986), and equally in England, was due to the melting of the nobility and high bourgeoisie into a "meritocracy", or to its failure, to become the new bearer of the national culture, around 1600. (Brink, 1998). My paper will concentrate on Euphues (1578), a negative romance, Euphues and His England (1580), a novel of manners, both by Lyly; Arcadia (1590-93) by Sidney, a political roman à clef in the disguise of a Greek pastoral romance; The Unfortunate Traveller (1594) by Nashe, the first English picaresque novel, and on Jack of Newbury (1596-97) by Deloney, the first English bourgeois novel. My analysis of the central values in these novels will prove a transition from the aristocratic cardinal virtues of WISDOM, JUSTICE, COURAGE, and HONOUR to the bourgeois values of CLEVERNESS, FAIR PLAY, INDUSTRY, and VIRGINITY. A similar change took place from the Christian virtues of LOVE, FAITH, HOPE to business values like SERVICE, TRUST, and OPTIMISM. Thus, the legacy of history proves that the main concepts of the novel of manners, of political romance, of picaresque and middle-class fiction were all developed in the time of Shakespeare.

Insurgency in a time of terrorism

Is it possible to separate terrorism from armed insurgency? Are all armed manifestations terrorism? Is terrorism a method of action or a logic for action? This article purports to analyze insurgency in the midst of the anti-terrorist era of the new century. By using Vietnam as an example, the author points out how armed insurgency has as of lately been called “terrorist”, yet stresses that this concept should be carefully and strategically looked through in order to better understand the violent nature of two very different phenomena: transactional and trans-national insurgencies-----¿Se puede escindir el terrorismo de la insurgencia armada? ¿Toda expresión armada es terrorismo? ¿El territorio es un método de acción o una lógica de acción? Este artículo presenta un análisis de la insurgencia a la luz de la era antiterrorista del nuevo siglo. Con la utilización del ejemplo de Vietnam el autor señala cómo la insurgencia armada ha sido señalada de “terrorista”; sin embargo, debe revisarse detenidamente de manera estratégica este concepto para entender mejor la naturaleza de la violencia de dos fenómenos diferentes: la insurgencia transnacional y el terrorismo transnacional.