2,874 research outputs found
From TLS survey to 3d solid modeling for documentation of built heritage: The case study of porta savonarola in Padua
It is a matter of fact that 3D visualisation and proper documentation of cultural objects helps to preserve the history and memories of historic buildings, archaeological sites and cultural landscapes, and supports economic growth by stimulating cultural tourism. Preservation, visualisation and recreation of valuable historical and architectural objects and places has always been a serious challenge for specialists in the field. Today, the rapid developments in the fields of close-range photogrammetry, terrestrial laser scanning (TLS) and computer vision (CV) enable to carry out highly accurate 3D models so as to be extremely effective and intuitive for users who have stringent requirements and high expectations. In this note we present the results of the survey and 3D modeling of an ancient gate, Porta Savonarola, located within the remains of the medieval town walls surrounding the historical city center of Padua, Italy. The work has been undertaken within the framework of the project \u201cWalls Multimedia Museum\u201d (WMM) promoted by the local private association \u201cPadua Walls Committee\u201d. The goal of the project was to develop a prototype of an \u201cextended\u201d virtual museum, spreaded along most interesting locations of the town walls. The survey of the ancient gate was performed with a Leica C10 and P20 terrestrial laser scanners. Once the acquired scans were properly merged together, a solid model was generated from the global point cloud, and plans and elevations were extracted from it for restoration purposes. A short multimedia video was also created for the \u201cWalls Multimedia Museum\u201d, showing both the outer and inner part of the gate. In the paper we will discuss all the steps and challenges addressed to provide the 3D solid model of Porta Savonarola from the TLS data
COMPARISON OF LOW COST PHOTOGRAMMETRIC SURVEY WITH TLS AND LEICA PEGASUS BACKPACK 3D MODELS
This paper considers Leica backpack and photogrammetric surveys of a mediaeval bastion in Padua, Italy. Furhtermore, terrestrial
laser scanning (TLS) survey is considered in order to provide a state of the art reconstruction of the bastion. Despite control points
are typically used to avoid deformations in photogrammetric surveys and ensure correct scaling of the reconstruction, in this paper
a different approach is considered: this work is part of a project aiming at the development of a system exploiting ultra-wide band
(UWB) devices to provide correct scaling of the reconstruction. In particular, low cost Pozyx UWB devices are used to estimate
camera positions during image acquisitions. Then, in order to obtain a metric reconstruction, scale factor in the photogrammetric
survey is estimated by comparing camera positions obtained from UWB measurements with those obtained from photogrammetric
reconstruction. Compared with the TLS survey, the considered photogrammetric model of the bastion results in a RMSE of 21.9cm, average error 13.4cm, and standard deviation 13.5cm. Excluding the final part of the bastion left wing, where the presence of several poles make reconstruction more difficult, (RMSE) fitting error is 17.3cm, average error 11.5cm, and standard deviation 9.5cm. Instead, comparison of Leica backpack and TLS surveys leads to an average error of 4.7cm and standard deviation 0.6cm (4.2 cm and 0.3 cm, respectively, by excluding the final part of the left wing)
The optical light curve of GRB 970228 refined
We present the R and V light curves of the optical counterpart of GRB 970228.
A critical analysis of all the available data is made in light of the results
achieved in the recent GRB Symposium held in Huntsville and by considering the
latest information from the HST images on the underlying nebulosity.Comment: 3 pages, 2 .ps figures, Nuclear Physics style file espcrc2.sty
included. To appear in the proceedings of the conference "The Active X-Ray
Sky: Results from BeppoSAX and Rossi-XTE", Rome, Italy, 21-24 October, 1997.
L. Scarsi, H. Bradt, P. Giommi and F. Fiore editors, Nuc. Phys. B Proc. Supp
From survey to fem analysis for documentation of built heritage: The case study of villa revedin-bolasco
In the last decade advances in the fields of close-range photogrammetry, terrestrial laser scanning (TLS) and Computer Vision (CV) have enabled to collect different kind of information about a Cultural Heritage objects and to carry out highly accurate 3D models. Additionally, the integration between laser scanning technology and Finite Element Analysis (FEA) is gaining particular interest in recent years for structural analysis of built heritage, since the increasing computational capabilities allow to manipulate large datasets. In this note we illustrate the approach adopted for surveying, 3D modeling and structural analysis of Villa Revedin-Bolasco, a magnificent historical building located in the small walled town of Castelfranco Veneto, in northern Italy. In 2012 CIRGEO was charged by the University of Padova to carry out a survey of the Villa and Park, as preliminary step for subsequent restoration works.
The inner geometry of the Villa was captured with two Leica Disto D3a BT hand-held laser meters, while the outer walls of the
building were surveyed with a Leica C10 and a Faro Focus 3D 120 terrestrial laser scanners. Ancillary GNSS measurements were
also collected for 3D laser model georeferencing. A solid model was then generated from the laser global point cloud in Rhinoceros software, and portion of it was used for simulation in a Finite Element Analysis (FEA). In the paper we discuss in detail all the steps and challenges addressed and solutions adopted concerning the survey, solid modeling and FEA from laser scanning data of the historical complex of Villa Revedin-Bolasco
Electric Waterborne Public Transportation in Venice: a Case Study
The paper reports the results of a study for moving the present diesel-based watercraft propulsion technology used for public transportation in Venice city and lagoon to a more efficient and smart electric propulsion technology, in view of its adopted in a near future. Energy generation and storage systems, electrical machines and drives, as well as economic, environmental and social issues are presented and discussed. Some alternative solutions based on hybrid diesel engine and electric and full electric powertrains are compared in terms of weights, costs and payback times. Previews researches on ship propulsion and electric energy storage developed by the University of Padua and preliminary experiences on electric boats carried out in Venice lagoon by the municipal transportation company ACTV and other stakeholders are the starting point for this study. Results can be transferred to other waterborne mobility systems
Transient increases in intracellular calcium and reactive oxygen species levels in TCam-2 cells exposed to microgravity
The effects of microgravity on functions of the human body are well described, including alterations in the male and female reproductive systems. In the present study, TCam-2 cells, which are considered a good model of mitotically active male germ cells, were used to investigate intracellular signalling and cell metabolism during exposure to simulated microgravity, a condition that affects cell shape and cytoskeletal architecture. After a 24 hour exposure to simulated microgravity, TCam-2 cells showed 1) a decreased proliferation rate and a delay in cell cycle progression, 2) increased anaerobic metabolism accompanied by increased levels of intracellular Ca(2+), reactive oxygen species and superoxide anion and modifications in mitochondrial morphology. Interestingly, all these events were transient and were no longer evident after 48 hours of exposure. The presence of antioxidants prevented not only the effects described above but also the modifications in cytoskeletal architecture and the activation of the autophagy process induced by simulated microgravity. In conclusion, in the TCam-2 cell model, simulated microgravity activated the oxidative machinery, triggering transient macroscopic cell events, such as a reduction in the proliferation rate, changes in cytoskeleton-driven shape and autophagy activation
GRBs with optical afterglow and known redshift: a statistical study
We present a correlation between two intrinsic parameters of GRB optical
afterglows. These are the isotropic luminosity at the maximum of the light
curve (Lpeak) and the time-integrated isotropic energy (Eiso) radiated after
the observed maximum. We test the correlation between the logarithms of (Eiso)
and (Lpeak) and finally we value the effect of the different samples of GRBs in
according with the first optical observation reduced to proper time.Comment: To be published in the proceedings of the conference "SWIFT and GRBs:
Unveiling the Relativistic Universe", Venice, June 5-9, 200
Interrelationships among attachment style, personality traits, interpersonal competency, and Facebook use
Online social media has become a popular way to communicate and develop interpersonal relationships. Facebook use in particular has become an important topic for researchers and clinicians, as young adults are increasingly integrating this use into their daily lives and social behavior. As empirical work on the personality traits and interpersonal competency associated with use and the potential consequences of use on social behavior is still emerging, the present study sought to investigate the interrelationships among constructs relevant to the developmental tasks associated with emerging adulthood, including adult attachment style, Five Factor Model personality traits, interpersonal competency, and Facebook use. Using data collected from 617 emerging adults in college, we utilized structural equation modeling to develop a model explaining the interrelationships among the constructs under study in order to further the research in this area. Results yielded a well-fitting model that explained the interrelationships among these latent constructs in the data, which suggested that insecure attachment had direct and positive effects on neuroticism, direct and negative effects on extraversion, direct and negative effects on interpersonal competency, and indirect effects on Facebook use. In addition, only extraversion and not neuroticism was related to interpersonal competency and Facebook use, when first accounting for attachment style. Interestingly, interpersonal competency did not seem to play a prominent mediating role between these personality traits and Facebook use. These results highlight the role of attachment style, and its importance in both developing personality traits, interpersonal skills, and online social behavior, which aligns well with the attachment theory framework. Lastly, we discussed future directions for research, as well as theoretical and practice implications for psychologists
GRB 970228 Revisited: Evidence for a Supernova in the Light Curve and La te Spectral Energy Distribution of the Afterglow
At the time of its discovery, the optical and X-ray afterglow of GRB 970228
appeared to be a ringing endorsement of the previously untried relativistic
fireball model of gamma-ray burst (GRB) afterglows, but now that nearly a dozen
optical afterglows to GRBs have been observed, the wavering light curve and
reddening spectrum of this afterglow make it perhaps the most difficult of the
observed afterglows to reconcile with the fireball model. In this Letter, we
argue that this afterglow's unusual temporal and spectral properties can be
attributed to a supernova that overtook the light curve nearly two weeks after
the GRB. This is the strongest case yet for a GRB/supernova connection. It
strengthens the case that a supernova also dominated the late afterglow of GRB
980326, and the case that GRB 980425 is related to SN 1998bw.Comment: Accepted to The Astrophysical Journal (Letters), 14 pages, LaTe
ASSESSMENT OF A PORTABLE TOF CAMERA AND COMPARISON WITH SMARTPHONE STEREO VISION
Abstract. Nowadays time-of-flight (ToF) cameras and multiple RGB cameras are being embedded in an increasing number of high-end smartphones: despite their integration in mobile devices is mostly motivated by photographic applications, their availability can be exploited to enable 3D reconstructions directly on smartphones. Furthermore, even when a ToF camera is not embedded in a smartphone, low cost solutions are available on the market in order to easily provide standard mobile devices with a lightweight and extremely portable ToF camera. This work deals with the assessment of a low cost ToF camera, namely Pico Zense DCAM710, which perfectly fits with the above description. According to the results obtained in the considered tests, the ranging error (precision) of the DCAM710 camera increases linearly approximately up to the nominal maximum range in the considered working mode, up to approximately 1 cm. Despite the device allows to acquire measurements also at larger ranges, the measurement quality significantly worsen. After assessing the main characteristics of such ToF camera, this paper aims at comparing its 3D reconstruction ability with that of a smartphone stereo vision system. In particular, the comparison of a 3D reconstruction obtained with stereo vision from images acquired with an LG G6 shows that the stereo reconstruction leads to a much larger point cloud. However, points generated by the ToF camera are more homogeneously distributed, and they seem to slightly better describe the real geometry of the reconstructed object. The combination of such two technologies, which will be investigated in our future work, can potentially lead to a denser cloud with respect to the ToF camera, while preserving a reasonable accuracy
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