scholarly journals Quality Assessment of Milling Pavement Surface Using 3D Line Laser Technology

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Bing Hui ◽  
Mu Guo ◽  
Xiaofang Liu
Keyword(s):  
Laser Scanning ◽  
Three Dimensional ◽  
Poor Quality ◽  
Surface Model ◽  
Premature Failure ◽  
Quality Work ◽  
Milled Surface ◽  
Surface Assessment

To ensure that a regular milled surface texture provides good bonding without residual distress, a new specification of milling surface assessment has been established for quantitatively evaluating the milled surface quality. This research explores the possibility of using three-dimensional (3D) laser scanning technology to develop an algorithm to obtain a milled surface model that can measure evaluating indicators, milling depth and texture depth, and identify poorly milled areas. A case study was conducted by using a laser scanning vehicular system to collect 3D continuous pavement transverse profiles data in a 500 m long segment of Highway S107. The results show that the proposed method is very promising and can measure the milling depth and texture depth to effectively and quantitatively differentiate between good- (milling depth between 47 mm and 53 mm and texture depth exceeding 2 mm) and poor-quality work. Moreover, the poorly milled areas such as those with residual distress and unmilled areas that will lead to premature failure can also be identified using the proposed method. The proposed method can effectively support remilling work and ensure the quality of the overlay pavement.

scholarly journals HISTORICAL PHOTOGRAMMETRY AND TERRESTRIAL LASER SCANNING FOR THE 3D VIRTUAL RECONSTRUCTION OF DESTROYED STRUCTURES: A CASE STUDY IN ITALY

2017 ◽  
Vol XLII-5/W1 ◽  
pp. 113-119 ◽  
Author(s):  
G. Bitelli ◽  
M. Dellapasqua ◽  
V. A. Girelli ◽  
S. Sbaraglia ◽  
M. A. Tinia
Keyword(s):  
Laser Scanning ◽  
Laser Scanner ◽  
Poor Quality ◽  
Armed Conflicts ◽  
Archaeological Sites ◽  
Geometric Information ◽  
Virtual Reconstruction ◽  
The City

The current dramatic episodes of destruction of archaeological sites have again highlighted the problem of the safeguarding the threatened heritage and, if possible, recovering those damaged by all the armed conflicts of the past.<br><br> The historical photogrammetry offers the possibility to recover a posteriori the geometrical and material properties of destroyed structures, reconstructing their 3D model to document, study and maintain their memory, until to support their real anastylosis.<br><br> The presented work is about the 3D reconstruction of the civic tower of the little town of Sant’Alberto, near the city of Ravenna, Italy. The tower, as a symbol of resistance and pride of the town's population, was destroyed in December 1944 by German troops in retaliation, when they were forced to leave the area.<br><br> A city committee has subsequently collected all the historical evidence concerning the tower, including a series of photographic images that can be used for the photogrammetric reconstruction; the images calibration and orientation have been solved using the geometric information derived by a terrestrial laser scanner survey realized in the area where the tower was originally located.<br><br> Despite the scarcity and very poor quality of the available images, the conducted photogrammetric procedure has allowed a complete and qualitatively satisfying object reconstruction, also thanks to the use of geometric constraint tools offered by the chosen software.<br><br> The integration between the obtained model of the old tower and the 3D TLS survey of the square made it possible to reconstruct the ancient situation of the area.

scholarly journals Testing as-Built Quality of Free-Form Panels: Lessons Learned from a Case Study and Mock-up Panel Tests

2021 ◽  
Vol 11 (4) ◽  
pp. 1439
Author(s):  
Jong-Ho Ock
Keyword(s):  
Laser Scanning ◽  
Three Dimensional ◽  
Lessons Learned ◽  
Fiber Reinforced Concrete ◽  
Free Form ◽  
Geometric Difference ◽  
Curved Panel ◽  
Curved Panels

Constructing free-form buildings is very complex due to the difficulty in fabricating the curved façade. To install the façade, the complex geometric shapes of the façade need to be divided into panels. The panels developed are classified into three categories in terms of their curvatures, i.e., planar, single-curved, double-curved panels. The quality of the curved façade is determined by the geometric difference between as-built and as-designed panel shapes. Among the three types of curved panels, the double-curved panel is very difficult to form, showing greater quality discrepancy than the other two panel types. Ensuring the as-built quality of the curved façade is for contractors. The main objective of this study is to enhance small/mid-size contractors’ capacity of managing the as-built quality of the double-curved panel. To meet the study objectives, a case study of a small free-form building and empirical mock-up tests of curved panels were performed and beneficial lessons for the contractors were identified through the tests. Among diverse materials, aluminum and glass-fiber-reinforced concrete (GFRC) were utilized for the mock-up tests. Three-dimensional laser scanning technology was employed to foster the as-built data of the case study project and the mocked-up double-curved panels. The data superimposition method was used to measure the deviation between the as-designed and the as-built data of the case study.

scholarly journals Mind the Gap: Why the Landscape Planning System in Sardinia Does Not Work

2021 ◽  
Vol 13 (13) ◽  
pp. 7300
Author(s):  
Anna Maria Colavitti ◽  
Alessio Floris ◽  
Sergio Serra
Keyword(s):  
Landscape Planning ◽  
Comparative Method ◽  
Poor Quality ◽  
Planning System ◽  
Local Planning ◽  
The Common ◽  
Regional Landscape ◽  
Landscape Protection

In Italy, after the introduction of the Code of Cultural Heritage and Landscape in 2004, the Regional Landscape Plan (RLP) has acquired a coordination role in the urban planning system, for the implementation of policies for landscape protection and valorisation. The case study of the RLP of Sardinia is a paradigmatic application to the coastal area of the island, which is considered most vulnerable and subject to settlement pressure. The objectives of preservation and valorisation of the territorial resources should be transferred into local planning instruments by adopting strategies aimed at the preservation of the consolidated urban fabric, at the requalification and completion of the existing built-up areas according to the principles of land take limitation and increase in urban quality. The paper investigates the state of implementation and the level of integration of landscape contents in the local plans that have been adapted to the RLP, using a qualitative comparative method. In addition, the results of the plan coherence checks, elaborated by the regional monitoring bodies after the adaptation process, have been analysed to identify the common criticalities and weaknesses. The results highlight the lack of effectiveness of the RLP, after more than a decade since its approval, considering the limited number of adequate local plans and the poor quality of their analytical and regulative contents in terms of landscape protection and valorisation. Conclusions suggest some possible ways to revise the RLP, focusing on the participation of local communities and the development of a new landscape culture.

scholarly journals Kontribusi Muhasabah dalam Mengembangkan Resiliensi Pada Orang Tua Anak Berkebutuhan Khusus

2021 ◽  
Vol 6 (2) ◽  
pp. 244-262
Author(s):  
Fatma Laili Khoirun Nida
Keyword(s):  
Special Needs ◽  
Poor Quality ◽  
Children With Special Needs ◽  
Case Study Approach ◽  
Study Approach ◽  
Study Results ◽  
Resilience Factors ◽  
Depth Interviews

The phenomenon of the poor quality of parental care for children with disabilities makes resilience one of the psychological capital that contributes to improving the quality of care. This study describes how through a muhasabah intervention in Blimbingrejo Village, Nalumsari District, Jepara Regency. The purpose of this study was to provide information for parents of children with special needs about muhasabah interventions in developing the resilience abilities of parents when carrying out their care. The urgency of this research is to reduce parenting stress experienced by parents because of the developmental barriers of their children. This research is qualitative with a case study approach through in-depth interviews and observation techniques. The study results explain that the condition of children with special needs is often a stressor for their parents. However, parents can live with complete steadfastness as a form of their resilience. The pattern of resilience formed is supported mainly by thinking about what they are trying to do. There are indications of the meaning of resilience factors in the practice of muhasabah in the form of the ability to regulate emotions, develop optimism and empathy, control impulses and causal analysis, good self-efficacy and take wisdom as an indication of aspects of the reaching out process. The results of this study are helpful information in developing the concept and practice of caring for children with special needs.

scholarly journals ACCURACY ASSESSMENT IN STRUCTURE FROM MOTION 3D RECONSTRUCTION FROM UAV-BORN IMAGES: THE INFLUENCE OF THE DATA PROCESSING METHODS

2015 ◽  
Vol XL-1/W4 ◽  
pp. 103-109 ◽  
Author(s):  
G. Caroti ◽  
I. Martínez-Espejo Zaragoza ◽  
A. Piemonte
Keyword(s):  
Data Processing ◽  
Structure From Motion ◽  
Laser Scanning ◽  
Accuracy Assessment ◽  
Three Dimensional ◽  
Evolution Of Structure ◽  
Textured Models ◽  
The Church ◽  
Data Processing Methods

The evolution of Structure from Motion (SfM) techniques and their integration with the established procedures of classic stereoscopic photogrammetric survey have provided a very effective tool for the production of three-dimensional textured models. Such models are not only aesthetically pleasing but can also contain metric information, the quality of which depends on both survey type and applied processing methodologies. An open research topic in this area refers to checking attainable accuracy levels. The knowledge of such accuracy is essential, especially in the integration of models obtained through SfM with other models derived from different sensors or methods (laser scanning, classic photogrammetry ...). Accuracy checks may be conducted by either comparing SfM models against a reference one or measuring the deviation of control points identified on models and measured with classic topographic instrumentation and methodologies. This paper presents an analysis of attainable accuracy levels, according to different approaches of survey and data processing. For this purpose, a survey of the Church of San Miniato in Marcianella (Pisa, Italy), has been used. The dataset is an integration of laser scanning with terrestrial and UAV-borne photogrammetric surveys; in addition, a high precision topographic network was established for the specific purpose. In particular, laser scanning has been used for the interior and the exterior of the church, with the exclusion of the roof, while UAVs have been used for the photogrammetric survey of both roof, with horizontal strips, and façade, with vertical strips.

Planted Roofs Over Buildings

2022 ◽  
pp. 338-349
Author(s):  
Theodoros Galanis ◽  
Ploutarhos Kerpelis
Keyword(s):  
Decision Making ◽  
Poor Quality ◽  
School Building ◽  
Human Beings ◽  
Original Design ◽  
Advantages And Disadvantages ◽  
The Poor ◽  
Financial Benefits

Humans in addition with other factors have increased the environmental pollution of the planet. Many highly populated cities like Athens have problems with air quality due to the poor quality of construction, high temperatures in summer, noise, no existence of city plans, etc. The scope of this study is the investigation of urban towns' benefits using planted roofs. All types of planted roofs have many environmental, constructional, social, and financial benefits. The research suggests a method from the design, the study until the construction, using decision making, informing the citizens, and taking into account their opinion. The original design of buildings must have adopted an integrated energy strategy such as the solution of planted roofs so as to maximize the benefits to the environment and human beings. The research is specialized using a case study about a planted roof of an existing school building in Athens. The advantages and disadvantages of the usage are shown focusing on environmental, social, and construction aspects.

DECONSTRUCTING THE ARGUMENT FOR FREE TRADE: A CASE STUDY OF THE ROLE OF ECONOMISTS IN POLICY DEBATES

2012 ◽  
Vol 28 (1) ◽  
pp. 1-30 ◽  
Author(s):  
Robert Driskill
Keyword(s):  
Trade Liberalization ◽  
Free Trade ◽  
Poor Quality ◽  
Standard Argument ◽  
Policy Debates ◽  
The World ◽  
Value Judgements

This paper argues that, in light of the apparent settled nature of economists’ judgement on the issue of trade liberalization, the profession has stopped thinking critically about the question and, as a consequence, makes poor-quality arguments justifying their consensus. To develop support for this claim, the paper first recounts what economic analysis can say about trade liberalization. Then it analyses the quality of the arguments that economists make in support of free trade. The paper argues that the standard argument made by economists in favour of free trade is either incoherent or implicitly imposes philosophical value judgements about what is good for a nation or society, or it makes leaps of empirical faith about how the world works. The paper concludes with suggestions for better arguments.

“The Last Laugh?” A Multimodal Analysis of Captions in Photojournalism

Pólemos ◽  
2017 ◽  
Vol 11 (1) ◽  
Author(s):  
Mara Logaldo
Keyword(s):  
Poor Quality ◽  
Pop Art ◽  
Point Of View ◽  
Multimodal Analysis ◽  
Multimodal Discourse ◽  
Low Culture ◽  
Verbal Discourse ◽  
Selective Process

Abstract It is generally agreed that in photojournalism pictures come first. However, also the short verbal texts that accompany them play a crucial role, as they lead readers among the different signifieds of the image. A multimodal discourse analysis of captions will aptly consider both the linguistic elements that appear within the verbal discourse and the image-text relation. The interconnectedness of captions and pictures has lately been defined as a “loop,” a view which blurs the traditional distinction between anchoring and relaying processes theorized by Barthes. The association of the relaying function with comics, however, seems to establish an interesting point of contact between photojournalism and pop art. Captions actually show the tension between “high” and “low” culture, the former being traditionally identified with the word and the latter with the image. While in the heyday of photojournalism captions were made necessary by the poor quality of the photographs, they soon began to provide an abstractive summary of the story told by the picture. This selective process involves interpretation. For this reason, captions can be ethically misleading and even legally controversial forms of discourse, for instance when they are used instrumentally to convey a specific point of view. In photojournalism dealing with crime cases, in particular, captions may display a sensationalist and populist view of justice, thus articulating the thoughts of public opinion supported by the newspaper’s stand. My case study focuses on the caption that accompanied the photo portraying Perry Smith and Richard Hickock while leaving the courtroom on March 29, 1960. The two murderers – who have become famous after the publication of the documentary novel

scholarly journals Three-dimensional Modeling of Carbon Fiber Cloth Surface from Dense and Scattered Points Cloud

2015 ◽  
Vol 9 (1) ◽  
pp. 152-157
Author(s):  
Cheng Jie ◽  
Chen Li
Keyword(s):  
Carbon Fiber ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Reconstruction Algorithm ◽  
Quality Analysis ◽  
Surface Model ◽  
Scanning System ◽  
Three Dimensional Modeling ◽  
Dimensional Modeling ◽  
Fabric Surface

Fabric surface analysis, as part of fabric analysis, is very important for the textile manufacturing process and is traditionally based on human-labor or image processing which is a conventional automatic method. However, image quality is influenced by ambient light, background light and optical properties of the surface. In this paper, we present a three dimensional modeling techniques for the reconstruction of carbon-fiber fabric surface. Firstly, a dense and scattered points cloud is collected using 3D laser scanning system after necessary data quality analysis. Secondly, the original points cloud is preprocessed according to classification. Finally, three-dimensional fabric surface model is reconstructed using screened Poisson reconstruction algorithm. The experimental results show that the reconstructed model is acceptable.

scholarly journals A flash-based thermal simulation of scanning paths in LPBF additive manufacturing

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kamel Ettaieb ◽  
Sylvain Lavernhe ◽  
Christophe Tournier
Keyword(s):  
High Performance ◽  
Laser Scanning ◽  
Thermal Field ◽  
Computational Cost ◽  
Three Dimensional ◽  
Three Dimensional Model ◽  
Content Type ◽  
Proposed Model ◽  
Scanning Path

Purpose This paper aims to propose an analytical thermal three-dimensional model that allows an efficient evaluation of the thermal effect of the laser-scanning path. During manufacturing by laser powder bed fusion (LPBF), the laser-scanning path influences the thermo-mechanical behavior of parts. Therefore, it is necessary to validate the path generation considering the thermal behavior induced by this process to improve the quality of parts. Design/methodology/approach The proposed model, based on the effect of successive thermal flashes along the scanning path, is calibrated and validated by comparison with thermal results obtained by FEM software and experimental measurements. A numerical investigation is performed to compare different scanning path strategies on the Ti6Al4V material with different stimulation parameters. Findings The simulation results confirm the effectiveness of the approach to simulate the thermal field to validate the scanning strategy. It suggests a change in the scale of simulation thanks to high-performance computing resources. Originality/value The flash-based approach is designed to ensure the quality of the simulated thermal field while minimizing the computational cost.

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