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Sensors, Volume 8, Issue 9 (September 2008), Pages 5229-6124

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Open AccessArticle Spectral-Based Blind Image Restoration Method for Thin TOMBO Imagers
Sensors 2008, 8(9), 6108-6124; https://doi.org/10.3390/s8096108
Received: 1 July 2008 / Revised: 7 September 2008 / Accepted: 8 September 2008 / Published: 26 September 2008
Cited by 12 | PDF Full-text (733 KB) | HTML Full-text | XML Full-text
Abstract
With the recent advances in microelectronic fabrication technology, it becomes now possible to fabricate thin imagers, less than half a millimeter thick. Dubbed TOMBO (an acronym for thin observation module by bound optics), a thin camera-on-a-chip integrates micro-optics and photo-sensing elements, together with
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With the recent advances in microelectronic fabrication technology, it becomes now possible to fabricate thin imagers, less than half a millimeter thick. Dubbed TOMBO (an acronym for thin observation module by bound optics), a thin camera-on-a-chip integrates micro-optics and photo-sensing elements, together with advanced processing circuitry, all on a single silicon chip. Modeled after the compound-eye found in insects and many other arthropods, the TOMBO imager captures simultaneously a mosaic of low resolution images. In this paper, we describe and analyze a novel spectral-based blind algorithm that enables the restoration of a high resolution image from the captured low resolution images.The proposed blind restoration method does not require prior information about the imaging system nor the original scene. Furthermore, it alleviates the need for conventional de-shading and rearrangement processing techniques. Experimental results demonstrate that the proposed method can restore images for SNER lower than 3dB. Full article
(This article belongs to the Special Issue Integrated High-performance Imagers)
Open AccessReview BioMEMS –Advancing the Frontiers of Medicine
Sensors 2008, 8(9), 6077-6107; https://doi.org/10.3390/s8096077
Received: 28 August 2008 / Revised: 16 September 2008 / Accepted: 24 September 2008 / Published: 26 September 2008
Cited by 33 | PDF Full-text (549 KB) | HTML Full-text | XML Full-text
Abstract
Biological and medical application of micro-electro-mechanical-systems (MEMS) is currently seen as an area of high potential impact. Integration of biology and microtechnology has resulted in the development of a number of platforms for improving biomedical and pharmaceutical technologies. This review provides a general
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Biological and medical application of micro-electro-mechanical-systems (MEMS) is currently seen as an area of high potential impact. Integration of biology and microtechnology has resulted in the development of a number of platforms for improving biomedical and pharmaceutical technologies. This review provides a general overview of the applications and the opportunities presented by MEMS in medicine by classifying these platforms according to their applications in the medical field. Full article
(This article belongs to the Special Issue BioMEMS)
Open AccessArticle An Evaluation of Radarsat-1 and ASTER Data for Mapping Veredas (Palm Swamps)
Sensors 2008, 8(9), 6055-6076; https://doi.org/10.3390/s8096055
Received: 6 August 2008 / Revised: 10 September 2008 / Accepted: 22 September 2008 / Published: 26 September 2008
Cited by 11 | PDF Full-text (913 KB) | HTML Full-text | XML Full-text
Abstract
Veredas (palm swamps) are wetland complexes associated with the Brazilian savanna (cerrado) that often represent the only available source of water for the ecosystem during the dry months. Their extent and condition are mainly unknown and their cartography is an essential
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Veredas (palm swamps) are wetland complexes associated with the Brazilian savanna (cerrado) that often represent the only available source of water for the ecosystem during the dry months. Their extent and condition are mainly unknown and their cartography is an essential issue for their protection. This research article evaluates some of the fine resolution satellite data both in the radar (Radarsat-1) and optical domain (ASTER) for the delineation and characterization of veredas. Two separate approaches are evaluated. First, given the known potential of Radarsat-1 images for wetland inventories, the automatic delineation of veredas is tested using only Radarsat-1 data and a Markov random fields region-based segmentation. In this case, to increase performance, processing is limited to a buffer zone around the river network. Then, characterization of their type is attempted using traditional classification methods of ASTER optical data combined with Radarsat-1 data. The automatic classification of Radarsat data yielded results with an overall accuracy between 62 and 69%, that proved reliable enough for delineating wide and very humid veredas. Scenes from the wet season and with a smaller angle of incidence systematically yielded better results. For the classification of the main vegetation types, better results (overall success of 78.8%) were obtained by using only the visible and near infrared (VNIR) bands of the ASTER image. Radarsat data did not bring any improvement to these classification results. In fact, when using solely the Radarsat data from two different angle of incidence and two different dates, the classification results were low (50.8%) but remained powerful for delineating the permanently moist riparian forest portion of the veredas with an accuracy better than 75% in most cases. These results are considered good given the width of some types often less than 50 m wide compared with the resolution of the images (12.5 - 15 m). Comparing the classification results with the Radarsat-generated delineation allows an understanding of the relation between synthetic aperture radar (SAR) backscattering and vegetation types of the veredas. Full article
(This article belongs to the Special Issue Synthetic Aperture Radar (SAR))
Open AccessReview Sensors and Biosensors for the Determination of Small Molecule Biological Toxins
Sensors 2008, 8(9), 6045-6054; https://doi.org/10.3390/s8096045
Received: 19 July 2008 / Revised: 3 September 2008 / Accepted: 5 September 2008 / Published: 26 September 2008
Cited by 36 | PDF Full-text (76 KB) | HTML Full-text | XML Full-text
Abstract
The following review of sensors and biosensors focuses on the determination of commonly studied small molecule biological toxins, including mycotoxins and small molecule neurotoxins. Because of the high toxicity of small molecule toxins, an effective analysis technique for determining their toxicity is indispensable.
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The following review of sensors and biosensors focuses on the determination of commonly studied small molecule biological toxins, including mycotoxins and small molecule neurotoxins. Because of the high toxicity of small molecule toxins, an effective analysis technique for determining their toxicity is indispensable. Sensors and biosensors have emerged as sensitive and rapid techniques for toxicity analysis in the past decade. Several different sensors for the determination of mycotoxins and other small molecule neurotoxins have been reported in the literature, and many of these sensors such as tissue biosensors, enzyme sensors, optical immunosensors, electrochemical sensors, quartz crystal sensors, and surface plasmon resonance biosensors are reviewed in this paper. Sensors are a practical and convenient monitoring tool in the area of routine analysis, and their specificity, sensitivity, reproducibility and analysis stability should all be improved in future work. In addition, accuracy field portable sensing devices and multiplexing analysis devices will be important requirement for the future. Full article
(This article belongs to the Special Issue Toxin Sensors)
Open AccessArticle Surface Heat Balance Analysis of Tainan City on March 6, 2001 Using ASTER and Formosat-2 Data
Sensors 2008, 8(9), 6026-6044; https://doi.org/10.3390/s8096026
Received: 1 September 2008 / Revised: 18 September 2008 / Accepted: 24 September 2008 / Published: 26 September 2008
Cited by 19 | PDF Full-text (2862 KB) | HTML Full-text | XML Full-text
Abstract
The urban heat island phenomenon occurs as a mixed result of anthropogenic heat discharge, decreased vegetation, and increased artificial impervious surfaces. To clarify the contribution of each factor to the urban heat island, it is necessary to evaluate the surface heat balance. Satellite
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The urban heat island phenomenon occurs as a mixed result of anthropogenic heat discharge, decreased vegetation, and increased artificial impervious surfaces. To clarify the contribution of each factor to the urban heat island, it is necessary to evaluate the surface heat balance. Satellite remote sensing data of Tainan City, Taiwan, obtained from Terra ASTER and Formosat-2 were used to estimate surface heat balance in this study. ASTER data is suitable for analyzing heat balance because of the wide spectral range. We used Formosat-2 multispectral data to classify the land surface, which was used to interpolate some surface parameters for estimating heat fluxes. Because of the high spatial resolution of the Formosat-2 image, more roads, open spaces and small vegetation areas could be distinguished from buildings in urban areas; however, misclassifications of land cover in such areas using ASTER data would overestimate the sensible heat flux. On the other hand, the small vegetated areas detected from the Formosat-2 image slightly increased the estimation of latent heat flux. As a result, the storage heat flux derived from Formosat-2 is higher than that derived from ASTER data in most areas. From these results, we can conclude that the higher resolution land coverage map increases accuracy of the heat balance analysis. Storage heat flux occupies about 60 to 80% of the net radiation in most of the artificial surface areas in spite of their usages. Because of the homogeneity of the building roof materials, there is no contrast between the storage heat flux in business and residential areas. In sparsely vegetated urban areas, more heat is stored and latent heat is smaller than that in the forested suburbs. This result implies that density of vegetation has a significant influence in decreasing temperatures. Full article
(This article belongs to the Special Issue Sensors for Urban Environmental Monitoring)
Open AccessArticle Fabrication of a Novel Conductometric Biosensor for Detecting Mycobacterium avium subsp. paratuberculosis Antibodies
Sensors 2008, 8(9), 6015-6025; https://doi.org/10.3390/s8096015
Received: 2 September 2008 / Revised: 18 September 2008 / Accepted: 22 September 2008 / Published: 26 September 2008
Cited by 13 | PDF Full-text (89 KB) | HTML Full-text | XML Full-text
Abstract
Johne’s disease (JD) is one of the most costly bacterial diseases in cattle. In the U.S., economic losses from the disease have been estimated to exceed $1,500,000,000 per year, mainly from the effects of reduced milk production. Current diagnostic tests for JD are
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Johne’s disease (JD) is one of the most costly bacterial diseases in cattle. In the U.S., economic losses from the disease have been estimated to exceed $1,500,000,000 per year, mainly from the effects of reduced milk production. Current diagnostic tests for JD are laboratory based and many of those tests require specialized equipment and training. Development of rapid and inexpensive diagnostic assays, which are adapted for point-ofcare applications, would aid in the control of JD. In this study, a polyaniline (Pani)-based conductometric biosensor, in an immunomigration format, was fabricated for the detection of serum antibody (IgG) against the causal organism of JD, Mycobacterium avium subsp. paratuberculosis (MAP). Immobilized Mycobacterium avium purified proteins in the capture membrane were used to detect MAP IgG, previously bound with Pani/anti-bovine IgG* conjugate in the conjugate membrane. After detection, the Pani in the sandwiched captured complex bridges an electrical circuit between the silver electrodes, flanking the capture membrane. The electrical conductance, caused by Pani, was measured as drop in electrical resistance. Testing of the biosensor with known JD positive and negative serum samples demonstrated a significant difference in the mean resistance observed between the groups. This proof-of-concept study demonstrated that a conductometric biosensor could detect MAP IgG in 2 minutes. The biosensor’s speed of detection and the equipment involved would, among other things, support its application towards the various point-ofcare opportunities aimed at JD management and control. Full article
(This article belongs to the Special Issue Biosensors for Point-of-Care Applications)
Open AccessArticle Programming an Artificial Neural Network Tool for Spatial Interpolation in GIS - A Case Study for Indoor Radio Wave Propagation of WLAN
Sensors 2008, 8(9), 5996-6014; https://doi.org/10.3390/s8095996
Received: 31 July 2008 / Revised: 3 September 2008 / Accepted: 11 September 2008 / Published: 25 September 2008
Cited by 8 | PDF Full-text (536 KB) | HTML Full-text | XML Full-text
Abstract
Wireless communication networks offer subscribers the possibilities of free mobility and access to information anywhere at any time. Therefore, electromagnetic coverage calculations are important for wireless mobile communication systems, especially in Wireless Local Area Networks (WLANs). Before any propagation computation is performed, modeling
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Wireless communication networks offer subscribers the possibilities of free mobility and access to information anywhere at any time. Therefore, electromagnetic coverage calculations are important for wireless mobile communication systems, especially in Wireless Local Area Networks (WLANs). Before any propagation computation is performed, modeling of indoor radio wave propagation needs accurate geographical information in order to avoid the interruption of data transmissions. Geographic Information Systems (GIS) and spatial interpolation techniques are very efficient for performing indoor radio wave propagation modeling. This paper describes the spatial interpolation of electromagnetic field measurements using a feed-forward back-propagation neural network programmed as a tool in GIS. The accuracy of Artificial Neural Networks (ANN) and geostatistical Kriging were compared by adjusting procedures. The feedforward back-propagation ANN provides adequate accuracy for spatial interpolation, but the predictions of Kriging interpolation are more accurate than the selected ANN. The proposed GIS ensures indoor radio wave propagation model and electromagnetic coverage, the number, position and transmitter power of access points and electromagnetic radiation level. Pollution analysis in a given propagation environment was done and it was demonstrated that WLAN (2.4 GHz) electromagnetic coverage does not lead to any electromagnetic pollution due to the low power levels used. Example interpolated electromagnetic field values for WLAN system in a building of Yildiz Technical University, Turkey, were generated using the selected network architectures to illustrate the results with an ANN. Full article
Open AccessArticle Electrochemical Assay of Human Islet Amyloid Polypeptide and Its Aggregation
Sensors 2008, 8(9), 5987-5995; https://doi.org/10.3390/s8095987
Received: 14 August 2008 / Revised: 11 September 2008 / Accepted: 22 September 2008 / Published: 25 September 2008
Cited by 9 | PDF Full-text (120 KB) | HTML Full-text | XML Full-text
Abstract
Square wave voltammetry is used in this work to detect human islet amyloid polypeptide (hIAPP) by using the oxidized signal of the tyrosine residue in hIAPP. A detection limit of 1×10-6 M for hIAPP has been obtained. A kinetic study of the
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Square wave voltammetry is used in this work to detect human islet amyloid polypeptide (hIAPP) by using the oxidized signal of the tyrosine residue in hIAPP. A detection limit of 1×10-6 M for hIAPP has been obtained. A kinetic study of the aggregation process has been carried out according to the relationship between the anodic peak current in the square wave voltammograms of hIAPP and the incubation period. The results show that the nucleation starts in the first hour of incubation and then, during the next two hours, aggregation may occur rapidly. hIAPP can therefore be monitored with a label-free electrochemical method with low detection limit and high sensitivity. This electrochemical method can be also utilized to study the kinetics of hIAPP aggregation, and it may be also employed to study the conformational changes of the polypeptide. Full article
Open AccessArticle Integrated Evaluation of Urban Development Suitability Based on Remote Sensing and GIS Techniques – A Case Study in Jingjinji Area, China
Sensors 2008, 8(9), 5975-5986; https://doi.org/10.3390/s8095975
Received: 27 July 2008 / Revised: 15 September 2008 / Accepted: 20 September 2008 / Published: 25 September 2008
Cited by 32 | PDF Full-text (220 KB) | HTML Full-text | XML Full-text | Correction | Supplementary Files
Abstract
Jingjinji area (namely Beijing, Tianjin and He Bei Province) is one of the three largest regional economic communities in China. Urban expansion has sped up in the past 20 years in this area due to the rapid economic and population growth. Evaluating the
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Jingjinji area (namely Beijing, Tianjin and He Bei Province) is one of the three largest regional economic communities in China. Urban expansion has sped up in the past 20 years in this area due to the rapid economic and population growth. Evaluating the landuse suitability for urban growth on a regional scale is an urgent need, because the most suitable areas and the most suitable scale of urban growth can thus be determined accordingly. In order to meet this requirement, remote sensing and geographic information system (GIS) techniques were adopted, and an integrated evaluating model was developed supported by AHP method. The integrated urban development suitability index (UDSI) was calculated using this model. According to the UDSI result, the spatial distribution of urban development suitability and its driving forces were analyzed. Urban boundaries in 1995, 2000 and 2005, which were derived from Landsat TM/ETM+ satellite data, were overlaid on the UDSI map, and the suitable urban develop tendency in this area were discussed. The result of this study indicated that integrated evaluation of urban development could be conducted in an operational way using remote sensing data, GIS spatial analysis technique and AHP modeling method. Full article
(This article belongs to the Special Issue Sensors for Urban Environmental Monitoring)
Open AccessArticle Color Changes of UHT Milk During Storage
Sensors 2008, 8(9), 5961-5974; https://doi.org/10.3390/s8095961
Received: 17 July 2008 / Revised: 19 September 2008 / Accepted: 20 September 2008 / Published: 25 September 2008
Cited by 12 | PDF Full-text (440 KB) | HTML Full-text | XML Full-text
Abstract
In this study measurements of color parameters of UHT milk were performed, by using a MOM-color 100 photoelectric tristimulus colorimeter. Colors of UHT milk samples containing 3.2% and 1.6% milk fat, processed under industrial conditions, packed in polyethylene terephtalate (PET) based packages, and
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In this study measurements of color parameters of UHT milk were performed, by using a MOM-color 100 photoelectric tristimulus colorimeter. Colors of UHT milk samples containing 3.2% and 1.6% milk fat, processed under industrial conditions, packed in polyethylene terephtalate (PET) based packages, and stored for 0, 15, 30, 45, 60 and 90 days at ambient temperature (20±5°C) were examined. Results are shown in four different systems that define measurement of color parameters expressed in: CIE, CIE L*a*b*, Hünter and ANLAB – Adams Nickerson systems. Average value of mean reflectance of UHT milk determined in CIE system statistically is highly significantly changed, (p < 0.01) depending on duration of storaging, percentage of milk fat, as well as on the interaction of the mentioned factors. For the UHT milk with 1.6% milk fat statistically significant (p < 0.05) decrease of psychometric chroma b* occurs after 60 days, and for milk with 3.2% milk fat established on 45th day of storage. Full article
Open AccessReview Developments and Applications of Electrogenerated Chemiluminescence Sensors Based on Micro- and Nanomaterials
Sensors 2008, 8(9), 5942-5960; https://doi.org/10.3390/s8095942
Received: 11 August 2008 / Revised: 22 September 2008 / Accepted: 23 September 2008 / Published: 25 September 2008
Cited by 19 | PDF Full-text (197 KB) | HTML Full-text | XML Full-text
Abstract
A variety of recent developments and applications of electrogenerated chemiluminescence (ECL) for sensors are described. While tris(2,2′-bipyridyl)-ruthenium(II) and luminol have dominated and continue to pervade the field of ECL-based sensors, recent work has focused on use of these lumophores with micro- and nanomaterials.
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A variety of recent developments and applications of electrogenerated chemiluminescence (ECL) for sensors are described. While tris(2,2′-bipyridyl)-ruthenium(II) and luminol have dominated and continue to pervade the field of ECL-based sensors, recent work has focused on use of these lumophores with micro- and nanomaterials. It has also extended to inherently luminescent nanomaterials, such as quantum dots. Sensor configurations including microelectrode arrays and microfluidics are reviewed and, with the recent trend toward increased use of nanomaterials, special attention has been given to sensors which include thin films, nanoparticles and nanotubes. Applications of ECL labels and examples of label-free sensing that incorporate nanomaterials are also discussed. Full article
Open AccessArticle Influence of Fluid Cell Design on the Frequency Response of AFM Microcantilevers in Liquid Media
Sensors 2008, 8(9), 5927-5941; https://doi.org/10.3390/s8095927
Received: 5 August 2008 / Revised: 10 September 2008 / Accepted: 12 September 2008 / Published: 25 September 2008
Cited by 10 | PDF Full-text (328 KB) | HTML Full-text | XML Full-text
Abstract
A study of the frequency response of AFM microcantilevers in liquid media contained in a commercial fluid cell is presented. Such systems exhibit complicated dynamics which are often not well described by available theories. Their dynamic behavior has a direct effect on the
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A study of the frequency response of AFM microcantilevers in liquid media contained in a commercial fluid cell is presented. Such systems exhibit complicated dynamics which are often not well described by available theories. Their dynamic behavior has a direct effect on the use of the AFM in dynamic mode while imaging in liquid or while extracting the rheological properties of the fluid. We explore the issues related to the design of the cantilever holder/fluid cell and propose an approach for evaluating, minimizing and recognizing the ultimate limitations of commercial cantilever holders. A technique for estimating the frequency response spectrum of the fluid cell itself from experimental data is presented. This spectrum can then be used to evaluate whether or not the fluid cell is suited for the desired purpose. Full article
Open AccessArticle Structural Simulation of a Bone-Prosthesis System of the Knee Joint
Sensors 2008, 8(9), 5897-5926; https://doi.org/10.3390/s8095897
Received: 14 July 2008 / Revised: 19 September 2008 / Accepted: 22 September 2008 / Published: 24 September 2008
Cited by 3 | PDF Full-text (2362 KB) | HTML Full-text | XML Full-text
Abstract
In surgical knee replacement, the damaged knee joint is replaced with artificial prostheses. An accurate clinical evaluation must be carried out before applying knee prostheses to ensure optimal outcome from surgical operations and to reduce the probability of having long-term problems. Useful
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In surgical knee replacement, the damaged knee joint is replaced with artificial prostheses. An accurate clinical evaluation must be carried out before applying knee prostheses to ensure optimal outcome from surgical operations and to reduce the probability of having long-term problems. Useful information can be inferred from estimates of the stress acting onto the bone-prosthesis system of the knee joint. This information can be exploited to tailor the prosthesis to the patient’s anatomy. We present a compound system for pre-operative surgical planning based on structural simulation of the bone-prosthesis system, exploiting patient-specific data. Full article
(This article belongs to the Special Issue Medical Images Processing)
Open AccessArticle Tomographic Imaging of a Forested Area By Airborne Multi-Baseline P-Band SAR
Sensors 2008, 8(9), 5884-5896; https://doi.org/10.3390/s8095884
Received: 30 May 2008 / Revised: 29 August 2008 / Accepted: 18 September 2008 / Published: 24 September 2008
Cited by 26 | PDF Full-text (9604 KB) | HTML Full-text | XML Full-text
Abstract
In recent years, various attempts have been undertaken to obtain information about the structure of forested areas from multi-baseline synthetic aperture radar data. Tomographic processing of such data has been demonstrated for airborne L-band data but the quality of the focused tomographic images
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In recent years, various attempts have been undertaken to obtain information about the structure of forested areas from multi-baseline synthetic aperture radar data. Tomographic processing of such data has been demonstrated for airborne L-band data but the quality of the focused tomographic images is limited by several factors. In particular, the common Fourierbased focusing methods are susceptible to irregular and sparse sampling, two problems, that are unavoidable in case of multi-pass, multi-baseline SAR data acquired by an airborne system. In this paper, a tomographic focusing method based on the time-domain back-projection algorithm is proposed, which maintains the geometric relationship between the original sensor positions and the imaged target and is therefore able to cope with irregular sampling without introducing any approximations with respect to the geometry. The tomographic focusing quality is assessed by analysing the impulse response of simulated point targets and an in-scene corner reflector. And, in particular, several tomographic slices of a volume representing a forested area are given. The respective P-band tomographic data set consisting of eleven flight tracks has been acquired by the airborne E-SAR sensor of the German Aerospace Center (DLR). Full article
(This article belongs to the Special Issue Synthetic Aperture Radar (SAR))
Open AccessArticle A New Approach for Structural Monitoring of Large Dams with a Three-Dimensional Laser Scanner
Sensors 2008, 8(9), 5866-5883; https://doi.org/10.3390/s8095866
Received: 29 August 2008 / Revised: 19 September 2008 / Accepted: 23 September 2008 / Published: 24 September 2008
Cited by 64 | PDF Full-text (674 KB) | HTML Full-text | XML Full-text
Abstract
Driven by progress in sensor technology, computer methods and data processing capabilities, 3D laser scanning has found a wide range of new application fields in recent years. Particularly, monitoring the static and dynamic behaviour of large dams has always been a topic of
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Driven by progress in sensor technology, computer methods and data processing capabilities, 3D laser scanning has found a wide range of new application fields in recent years. Particularly, monitoring the static and dynamic behaviour of large dams has always been a topic of great importance, due to the impact these structures have on the whole landscape where they are built. The main goal of this paper is to show the relevance and novelty of the laserscanning methodology developed, which incorporates different statistical and modelling approaches not considered until now. As a result, the methods proposed in this paper have provided the measurement and monitoring of the large “Las Cogotas” dam (Avila, Spain). Full article
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