期刊文献+
共找到20篇文章
< 1 >
每页显示 20 50 100
An ArcGIS Geo-Morphological Approach for Snow Avalanche Zoning and Risk Estimation in the Province of Bergamo
1
作者 Barbara Marana 《Journal of Geographic Information System》 2017年第2期83-97,共15页
This paper describes the results of a study developed, with a GIS approach, at the University of Bergamo, about snow avalanche zoning and risk assessment in the Province of Bergamo. The adoption of a simplified estima... This paper describes the results of a study developed, with a GIS approach, at the University of Bergamo, about snow avalanche zoning and risk assessment in the Province of Bergamo. The adoption of a simplified estimation model, presented here, nonetheless allowed achieving results in good accordance with those provided by previous, more rigorous studies at the Province of Bergamo. A following analysis has also been performed to estimate ski lifts, urban areas, power lines, highways, railroads and roads at possible risk. This is a work in progress, since further development has already been taken into account to enrich the risk model with more parameters describing land morphology and meteorology. These results will then be used to simulate accidents and to estimate the shortest routes for rescuers. Finally, the development of a geo-app for mobile devices could become a very useful and fast tool for avalanche risk areas information. 展开更多
关键词 AVALANCHE ZONING AVALANCHE RISK ANALYSIS in the PROVINCE of Bergamo GIS ANALYSIS Higher RISK ZONES Identification
下载PDF
A Green GIS Solution against Air Pollution in the Province of Bergamo: The Paulownia Tree
2
作者 Barbara Marana 《Journal of Geographic Information System》 2018年第2期193-218,共26页
The paper describes a GIS approach to identify the most suitable areas for growing the Paulownia tree in the Province of Bergamo;this work will become the subject of a dissertation thesis at the School of Engineering ... The paper describes a GIS approach to identify the most suitable areas for growing the Paulownia tree in the Province of Bergamo;this work will become the subject of a dissertation thesis at the School of Engineering of the University of Bergamo. Paulownia is quite an ancient tree, well known especially in the far east countries, for its wonderful flowers and the quality of the wood which is a source of certain profit. The paper is focused on the employment of the Paulownia tree against air pollution, since its big leaves absorb high amounts of CO2 in the atmosphere and can capture the small particles of pollutants in the air ten times more than any other tree species. First, the analysis identifies the most favourable areas for its growth in the Province of Bergamo. Secondly, among the latter, the analysis detects the strategic areas for its growth near the most polluted zones. Finally, a quantitative evaluation is carried out about the trees contribution against pollutants in the atmosphere. 展开更多
关键词 AIR POLLUTION PROVINCE of Bergamo PAULOWNIA TREE Selection of the Best Growth Areas Analysis of the Most Polluted Areas Quantitative Contribution of the TREE AGAINST AIR POLLUTION
下载PDF
A Simplified ArcGIS Approach for Landslides Risk Assessment in the Province of Bergamo
3
作者 Barbara Marana 《Journal of Geographic Information System》 2017年第6期699-716,共18页
The paper describes a simplified GIS approach, for landslides risk assessment in the Province of Bergamo, developed for a GIS degree thesis at the faculty of Engineering of the University of Bergamo. The subject has b... The paper describes a simplified GIS approach, for landslides risk assessment in the Province of Bergamo, developed for a GIS degree thesis at the faculty of Engineering of the University of Bergamo. The subject has been and still is largely studied by many researchers with the aid of rigorous mathematical/statistical analysis tools. This work follows some procedures carried out by other studies, but at the end it has been decided to adopt a simple, fast and not rigorous way to find a solution. A following analysis, on the higher risk areas identified, has also been performed to test their reliability, allowing achieving satisfactory results. It has been planned to study the risk model more thoroughly, by taking into account other triggering causes for landslide susceptibility and to try also a rigorous approach, so as to get a better idea of the results achieved so far and how to improve them. 展开更多
关键词 LANDSLIDES PROVINCE of Bergamo TRIGGERING Factors RISK Assessment Evaluation GIS Analysis HIGHER RISK ZONES Identification and Test
下载PDF
Stages of Emotional Experience of Parents of Children with Cochlear Implantation (CI)
4
作者 Iuliia Khomiakova 《Open Journal of Medical Psychology》 2023年第4期231-238,共8页
Rehabilitation is a set of measures aimed at compensating or fully restoring the functions of the patient impaired by the disease. In the rehabilitation of children with a cochlear implant, a comprehensive, systematic... Rehabilitation is a set of measures aimed at compensating or fully restoring the functions of the patient impaired by the disease. In the rehabilitation of children with a cochlear implant, a comprehensive, systematic approach is essential in the work of doctors, teachers, sign language teachers, psychologists, and families. Rehabilitation and social adaptation of children with a cochlear implant depend not only on specialists but also on the ability of parents to help the child organize educational activities in an optimistic mood and the ability to provide emotional support. This means that the role of parents in the way to successful rehabilitation is high, and therefore this topic is especially relevant today. . 展开更多
关键词 Emotions during the Rehabilitation Children with a Cochlear Implantation Rehabilitation Process Parents of Children with Cochlear Implantation (CI)
下载PDF
p-Multilevel Preconditioners for HHO Discretizations of the Stokes Equations with Static Condensation
5
作者 Lorenzo Botti Daniele A.Di Pietro 《Communications on Applied Mathematics and Computation》 2022年第3期783-822,共40页
We propose a p-multilevel preconditioner for hybrid high-order(HHO)discretizations of the Stokes equation,numerically assess its performance on two variants of the method,and compare with a classical discontinuous Gal... We propose a p-multilevel preconditioner for hybrid high-order(HHO)discretizations of the Stokes equation,numerically assess its performance on two variants of the method,and compare with a classical discontinuous Galerkin scheme.An efficient implementa-tion is proposed where coarse level operators are inherited using L2-orthogonal projec-tions defined over mesh faces and the restriction of the fine grid operators is performed recursively and matrix-free.Both h-and k-dependency are investigated tackling two-and three-dimensional problems on standard meshes and graded meshes.For the two HHO for-mulations,featuring discontinuous or hybrid pressure,we study how the combination of p-coarsening and static condensation influences the V-cycle iteration.In particular,two dif-ferent static condensation procedures are considered for the discontinuous pressure HHO variant,resulting in global linear systems with a different number of unknowns and matrix non-zero entries.Interestingly,we show that the efficiency of the solution strategy might be impacted by static condensation options in the case of graded meshes. 展开更多
关键词 Stokes equations Divergence free constraint Hybrid high-order Discontinuous Galerkin P-MULTIGRID Static condensation
下载PDF
GIS Analyses and Maps Creation of a Naturalistic Area: The Carengione Oasis
6
作者 Barbara Marana 《Journal of Geographic Information System》 2019年第4期457-479,共23页
This paper describes the experience carried out with the aim to provide a technical and geo-referenced contribution to a project, submitted to the Common of Peschiera Borromeo in the Province of Milan in Lombardy. The... This paper describes the experience carried out with the aim to provide a technical and geo-referenced contribution to a project, submitted to the Common of Peschiera Borromeo in the Province of Milan in Lombardy. The promoter is a group of local associations;the aim is the valorisation and fruition of a green area, named Carengione Oasis. At first a GIS pre-analysis of the area has been performed to achieve a thorough knowledge of the area object of study. Then, a handheld GSP navigator has been employed to collect the data to be processed in a GIS software. This device choice has pros (a fast and very easy survey has been carried out) and cons (the acquired data have a precision of 3 to 5 meters). These data have been processed with the aid of the GIS software ArcMap release 10.4.1 by Esri. Also some free aerial images have been employed to edit features inaccessible on site. The achieved results are some thematic, metric and georeferenced maps and also a 3D virtual tour for a realistic visit of this area. They fulfil the project requirements. Anyway, due to their low precision, they have not been uploaded to enrich the official Lombardy cartography (DBTR);for this reason, part of them has been donated to the free data interchange OpenStreetMap. This work could be considered as a first step for future more precise surveys which would allow adding the acquired results to the DBTR;it has also been planned to create a story map describing the experience illustrated in this paper. 展开更多
关键词 Carengione OASIS Valorisation Topographic Survey GIS ANALYSES THEMATIC Geometric Georeferenced MAPS OpenStreetMap 3D Virtual Tour
下载PDF
An Application of the ABS Algorithm for Modeling Multiple Regression on Massive Data, Predicting the Most Influencing Factors
7
作者 Soniya Lalwani M. Krishna Mohan +3 位作者 Pooran Singh Solanki Sorabh Singhal Sandeep Mathur Emilio Spedicato 《Applied Mathematics》 2013年第6期907-913,共7页
Linear Least Square (LLS) is an approach for modeling regression analysis, applied for prediction and quantification of the strength of relationship between dependent and independent variables. There are a number of m... Linear Least Square (LLS) is an approach for modeling regression analysis, applied for prediction and quantification of the strength of relationship between dependent and independent variables. There are a number of methods for solving the LLS problem but as soon as the data size increases and system becomes ill conditioned, the classical methods become complex at time and space with decreasing level of accuracy. Proposed work is based on prediction and quantification of the strength of relationship between sugar fasting and Post-Prandial (PP) sugar with 73 factors that affect diabetes. Due to the large number of independent variables, presented problem of diabetes prediction also presented similar complexities. ABS method is an approach proven better than other classical approaches for LLS problems. ABS algorithm has been applied for solving LLS problem. Hence, separate regression equations were obtained for sugar fasting and PP severity. 展开更多
关键词 ABS ALGORITHM Linear Least SQUARE Regression DIABETES HUANG ALGORITHM
下载PDF
Proportioning Criteria for Traditional and Innovative Extrados Techniques for the Strengthening of Barrel Vaulted Structures Subjected to Rocking of the Abutments
8
作者 Luca Ferrario Alessandra Marini +1 位作者 Paolo Riva Ezio Giuriani 《Journal of Civil Engineering and Architecture》 2010年第5期1-14,共14页
关键词 拱形结构 加固技术 传统技法 摇摆 创新 配比 非线性数值分析 易损性评估
下载PDF
Aerodynamic Simulation of a 2017 F1 Car with Open-Source CFD Code
9
作者 Umberto Ravelli Marco Savini 《Journal of Traffic and Transportation Engineering》 2018年第4期155-163,共9页
Open-wheeled race car aerodynamics is unquestionably challenging insofar as it involves many physical phenomena,such as slender and blunt body aerodynamics,ground effect,vortex management and interaction between diffe... Open-wheeled race car aerodynamics is unquestionably challenging insofar as it involves many physical phenomena,such as slender and blunt body aerodynamics,ground effect,vortex management and interaction between different sophisticated aero devices.In the current work,a 2017 F1 car aerodynamics has been investigated from a numerical point of view by using an open-source code.The vehicle project was developed by PERRINN(Copyright.2011—Present PERRINN),an engineering community founded by Nicolas Perrin in 2011.The racing car performance is quantitatively evaluated in terms of drag,downforce,efficiency and front balance.The goals of the present CFD(computational fluid dynamics)-based research are the following:analyzing the capabilities of the open-source software OpenFOAM in dealing with complex meshes and external aerodynamics calculation,and developing a reliable workflow from CAD(computer aided design)model to the post-processing of the results,in order to meet production demands. 展开更多
关键词 External AERODYNAMICS OPEN-SOURCE CFD 2017 F1 CAR drag downforce efficiency FRONT balance
下载PDF
Design of Torque Balancing Mechanisms
10
作者 Bruno Zappa Vittorio Lorenzi +1 位作者 Paolo Righettini Roberto Strada 《Journal of Mechanics Engineering and Automation》 2017年第6期312-320,共9页
机器经常受到周期的精液,与收费载重的特征或到为运动产生使用的运动学的链相关,例如连接或摄象机追随者机制。负担变化能引起几不方便到机器的合适的工作,象摇力量和时刻一样,颤动,严重速度变化。通常,速度变化从那时起是担心的... 机器经常受到周期的精液,与收费载重的特征或到为运动产生使用的运动学的链相关,例如连接或摄象机追随者机制。负担变化能引起几不方便到机器的合适的工作,象摇力量和时刻一样,颤动,严重速度变化。通常,速度变化从那时起是担心的主要来源考虑到从理想的行为的经常的主要的柄速度和离开变得更坏,机制设计和优化被执行增加的机器速度。过去常减轻这个事实的更简单的途径在采用一个大飞轮或一台巨大的马达在于,甚至到开车小负担。更复杂的过程把适当 balancer 机制加到机器。这份报纸,从可得到的文学的评论开始,介绍一个理论框架给平衡的输入转矩的问题并且为平衡机制的合成定义方法论。 展开更多
关键词 转矩平衡 飞轮 周期的运动
下载PDF
An Experimental Investigation on the Dynamic Behavior of Step Motor Drives
11
作者 Paolo Righettini Roberto Strada Alberto Oldani Andrea Ginammi 《Journal of Mechanics Engineering and Automation》 2012年第7期431-440,共10页
关键词 步进电机驱动器 实验测试 动态特性 运行条件 数学模型 特性测量 驱动系统 定子磁场
下载PDF
Protection of steel hooks embedded in glass-fiber-reinforced concrete against macrocell corrosion
12
作者 Husnu Gerengi Muhammed Maraşlı +2 位作者 Marziya Rizvi Beni Kohen Ismail Taşkıran 《Petroleum Research》 EI 2024年第2期317-326,共10页
This study evaluated the corrosion behavior of steel hooks embedded in GFRC,which were protected by a zinc-rich(96%Zn)galvanizing coating.The coating provided the hooks with active cathodic protection and a passive ph... This study evaluated the corrosion behavior of steel hooks embedded in GFRC,which were protected by a zinc-rich(96%Zn)galvanizing coating.The coating provided the hooks with active cathodic protection and a passive physical shield.Macrocell corrosion may form when the anode is smaller than the total steel surface.Thus,the steel hooks at the embedment juncture were additionally sealed against water ingress and air exchange using a construction sealant.The study was conducted in three phases in a salt-spray chamber.First,the electrogalvanized steel hooks embedded in GFRC were allowed to freely corrode for 7 days.In the second phase,the electrogalvanized steel hooks were painted with the zinc-rich coating and observed over 7 days.In the third phase,the steel hooks were protected by the zinc-rich coating together with a primer and construction sealant,and observed over 7 days.To evaluate the electrogalvanized hooks and the corrosion products formed,the thickness of the material was measured.Corrosion on the metal surface was inferred by studying the surface morphology of the hooks at various points of contact and after different periods of time. 展开更多
关键词 Steel rebars Concrete corrosion GFRC Galvanization SEALANT
原文传递
WJSC 6^(th) Anniversary Special Issues(2):Mesenchymal stem cells Mesenchymal stem cells help pancreatic islet transplantation to control type 1 diabetes 被引量:10
13
作者 Marina Figliuzzi Barbara Bonandrini +1 位作者 Sara Silvani Andrea Remuzzi 《World Journal of Stem Cells》 SCIE CAS 2014年第2期163-172,共10页
Islet cell transplantation has therapeutic potential to treat type 1 diabetes,which is characterized by autoimmune destruction of insulin-producing pancreatic isletβcells.It represents a minimal invasive approach for... Islet cell transplantation has therapeutic potential to treat type 1 diabetes,which is characterized by autoimmune destruction of insulin-producing pancreatic isletβcells.It represents a minimal invasive approach forβcell replacement,but long-term blood control is still largely unachievable.This phenomenon can be attributed to the lack of islet vasculature and hypoxic environment in the immediate post-transplantation period that contributes to the acute loss of islets by ischemia.Moreover,graft failures continue to occur because of immunological rejection,despite the use of potent immunosuppressive agents.Mesenchymal stem cells(MSCs)have the potential to enhance islet transplantation by suppressing inflammatory damage and immune mediated rejection.In this review we discuss the impact of MSCs on islet transplantation and focus on the potential role of MSCs in protecting islet grafts from early graft failure and from autoimmune attack. 展开更多
关键词 MESENCHYMAL stem cell ISLET TRANSPLANTATION Type 1 diabetes VASCULARIZATION Immune modulation
下载PDF
A refined Frequency Domain Decomposition tool for structural modal monitoring in earthquake engineering 被引量:2
14
作者 Fabio Pioldi Egidio Rizzi 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2017年第3期627-648,共22页
Output-only structural identification is developed by a refined Frequency Domain Decomposition(rFDD) approach, towards assessing current modal properties of heavy-damped buildings(in terms of identification challe... Output-only structural identification is developed by a refined Frequency Domain Decomposition(rFDD) approach, towards assessing current modal properties of heavy-damped buildings(in terms of identification challenge), under strong ground motions. Structural responses from earthquake excitations are taken as input signals for the identification algorithm. A new dedicated computational procedure, based on coupled Chebyshev Type Ⅱ bandpass filters, is outlined for the effective estimation of natural frequencies, mode shapes and modal damping ratios. The identification technique is also coupled with a Gabor Wavelet Transform, resulting in an effective and self-contained time-frequency analysis framework. Simulated response signals generated by shear-type frames(with variable structural features) are used as a necessary validation condition. In this context use is made of a complete set of seismic records taken from the FEMA P695 database, i.e. all 44 "Far-Field"(22 NS, 22 WE) earthquake signals. The modal estimates are statistically compared to their target values, proving the accuracy of the developed algorithm in providing prompt and accurate estimates of all current strong ground motion modal parameters. At this stage, such analysis tool may be employed for convenient application in the realm of Earthquake Engineering, towards potential Structural Health Monitoring and damage detection purposes. 展开更多
关键词 Operational Modal Analysis (OMA) modal dynamic identification refined Frequency Domain Decomposition(rFDD) FEMA P695 seismic database earthquake response identification input
下载PDF
Machine Learning Based Psychotic Behaviors Prediction from Facebook Status Updates 被引量:1
15
作者 Mubashir Ali Anees Baqir +3 位作者 Hafiz Husnain Raza Sherazi Asad Hussain Asma Hassan Alshehri Muhammad Ali Imran 《Computers, Materials & Continua》 SCIE EI 2022年第8期2411-2427,共17页
With the advent of technological advancements and the widespread Internet connectivity during the last couple of decades,social media platforms(such as Facebook,Twitter,and Instagram)have consumed a large proportion o... With the advent of technological advancements and the widespread Internet connectivity during the last couple of decades,social media platforms(such as Facebook,Twitter,and Instagram)have consumed a large proportion of time in our daily lives.People tend to stay alive on their social media with recent updates,as it has become the primary source of interactionwithin social circles.Although social media platforms offer several remarkable features but are simultaneously prone to various critical vulnerabilities.Recent studies have revealed a strong correlation between the usage of social media and associated mental health issues consequently leading to depression,anxiety,suicide commitment,and mental disorder,particularly in the young adults who have excessively spent time on socialmedia which necessitates a thorough psychological analysis of all these platforms.This study aims to exploit machine learning techniques for the classification of psychotic issues based on Facebook status updates.In this paper,we start with depression detection in the first instance and then expand on analyzing six other psychotic issues(e.g.,depression,anxiety,psychopathic deviate,hypochondria,unrealistic,and hypomania)commonly found in adults due to extreme use of social media networks.To classify the psychotic issues with the user’s mental state,we have employed different Machine Learning(ML)classifiers i.e.,Random Forest(RF),Support Vector Machine(SVM),Naïve Bayes(NB),and K-Nearest Neighbor(KNN).The used ML models are trained and tested by using different combinations of features selection techniques.To observe themost suitable classifiers for psychotic issue classification,a cost-benefit function(sometimes termed as‘Suitability’)has been used which combines the accuracy of the model with its execution time.The experimental evidence argues that RF outperforms its competitor classifiers with the unigram feature set. 展开更多
关键词 Psychotic behaviors mental health socialmedia machine learning
下载PDF
A GIS Pre and Post Processing Contribution to a Multi Techniques Test Survey for an Ancient Railway Restoration in the Brembana Valley
16
作者 Barbara Marana 《Journal of Geographic Information System》 2018年第5期573-602,共30页
Stemming from the renewed desire to requalify the former Brembana Valley railway route (inside one of the valleys of the Province of Bergamo and close to the important city of Milan), from Bergamo to Villa d’Almè... Stemming from the renewed desire to requalify the former Brembana Valley railway route (inside one of the valleys of the Province of Bergamo and close to the important city of Milan), from Bergamo to Villa d’Almè, in 2017, the Bergamo Transport Company and other partners have signed a memorandum of understanding. They have also entrusted a project company to develop a technical and economic viability study, which would be an update of a preliminary one presented in 2009. A private proposal for the realization of a test survey, useful for the required engineering project, has been submitted to the project company and accepted. For this reason, a team, comprising different companies, and among them also the Geomatics group at the University of Bergamo, was formed so as to perform this task and develop it in a degree thesis. The aim of the test survey is to evaluate a joint use of the new available technologies, so as to possibly get faster, more economic and thorough results, by performing a 3D metric analysis over two sub-areas selected along the route. The paper describes this experience and the achieved results. In particular, the areas of interest in the test project have been analyzed first thing with a GIS software and then surveyed with a multi-sensor approach, i.e. terrestrial laser scanner, GNSS techniques and UAV. The final integrated results allowed providing a metric model of the morphological and urban aspect for the territorial layout, useful also for further advanced GIS analyses. The analysis of the reached precisions has provided satisfactory results which agree with the metric requirements of the project. Further meaningful considerations can be derived from this test survey: the implementation of different techniques has helped to overcome problems due to hidden parts in complex objects, it has allowed to provide a faster survey and to test different technologies and software packages. The results have been quite satisfactory. 展开更多
关键词 Brembana VALLEY RAILWAY RESTORATION TEST SURVEY MULTI Sensor Acquisition Integrated Results GIS Analyses
下载PDF
Women, Business, and Finance in 19th Century Milan
17
作者 Stefania Licini 《Journal of Modern Accounting and Auditing》 2020年第3期117-129,共13页
This paper contributes to the growing body of literature on the relations between women and the economy market by adding a backward and Mediterranean country on the chart of female engagement in the world of business.... This paper contributes to the growing body of literature on the relations between women and the economy market by adding a backward and Mediterranean country on the chart of female engagement in the world of business.With regard to Anglophone settings,scholars found women managing small and medium business,entering trade,purchasing shares and“consols”,supporting firms,lending money,and investing capitals for profit.As for Italy,women’s involvement in economic activities is almost completely unknown because of the paucity of studies on the theme.The way the country industrialized played a role in that,as it drove scholars’attention mainly if not exclusively to corporate and large enterprises,where men were obviously ad lead.As privileged sources of business and economic historians,such as trade directories,narrative tales,family,and company papers often undervalue if not hiding the female participation in the“public”sphere of the economy,this work draws on fiscal sources,tax rolls,and estate returns in particular.Notwithstanding robust limitations of such documents due to the high rate of evasion and elusion in Italy,their examination unveils the relevance of women’s role not only in family business,but also in“petty”trade and informal finance,all activities that were crucial to the catching up process of a“late joiner”like Italy. 展开更多
关键词 female ENTREPRENEURSHIP 19th CENTURY ITALY FISCAL sources
下载PDF
A Clustering Algorithm for Planning the Integration Process of a Large Number of Conceptual Schemas 被引量:1
18
作者 Carlo Batini: Paola Bonizzoni +3 位作者 Marco Comerio Riccardo Dondi Yuri Pirola Prancesco Salandra 《Journal of Computer Science & Technology》 SCIE EI CSCD 2015年第1期214-224,共11页
When tens and even hundreds of schemas are involved in the integration process, criteria are needed for choosing clusters of schemas to be integrated, so as to deal with the integration problem through an efficient it... When tens and even hundreds of schemas are involved in the integration process, criteria are needed for choosing clusters of schemas to be integrated, so as to deal with the integration problem through an efficient iterative process. Schemas in clusters should be chosen according to cohesion and coupling criteria that are based on similarities and dissimilarities among schemas. In this paper, we propose an algorithm for a novel variant of the correlation clustering approach that addresses the problem of assisting a designer in integrating a large number of conceptual schemas. The novel variant introduces upper and lower bounds to the number of schemas in each cluster, in order to avoid too complex and too simple integration contexts respectively. We give a heuristic for solving the problem, being an NP hard combinatorial problem. An experimental activity demonstrates an appreciable increment in the effectiveness of the schema integration process when clusters are computed by means of the proposed algorithm w.r.t, the ones manually defined by an expert. 展开更多
关键词 conceptual schema schema integration CLUSTERING
原文传递
A cross-analysis framework formulti-source volunteered, crowdsourced, and authoritative geographic information: The case study of volunteered personal traces analysis against transport network data
19
作者 Gloria Bordogna Steven Capelli +1 位作者 Daniele E.Ciriello Giuseppe Psaila 《Geo-Spatial Information Science》 SCIE CSCD 2018年第3期257-271,共15页
The paper discusses the need of a high-level query language to allow analysts,geographers and,in general,non-programmers to easily cross-analyze multi-source VGI created by means of apps,crowd-sourced data from social... The paper discusses the need of a high-level query language to allow analysts,geographers and,in general,non-programmers to easily cross-analyze multi-source VGI created by means of apps,crowd-sourced data from social networks and authoritative geo-referenced data,usually represented as JSON data sets(nowadays,the de facto standard for data exported by social networks).Since an easy to use high-level language for querying and manipulating collections of possibly geo-tagged JSON objects is still unavailable,we propose a truly declarative language,named J-CO-QL,that is based on a well-defined execution model.A plug-in for a GIS permits to visualize geo-tagged data sets stored in a NoSQL database such as MongoDB;furthermore,the same plug-in can be used to write and execute J-CO-QL queries on those databases.The paper introduces the language by exemplifying its operators within a real study case,the aim of which is to understand the mobility of people in the neighborhood of Bergamo city.Cross-analysis of data about transportation networks and VGI from travelers is performed,by means of J-CO-QL language,capable to manipulate and transform,combine and join possibly geo-tagged JSON objects,in order to produce new possibly geo-tagged JSON objects satisfying users’needs. 展开更多
关键词 Cross-analysis framework comparing VGI crowd-sourced and authoritative geographical data JSON data-sets declarative query language heterogeneous data-sets
原文传递
萘系和聚羧酸高效减水剂与几种不同水泥品种间的相容性问题(长期结果)(英文) 被引量:11
20
作者 COPPOLA L BUOSO A LORENZI S 《硅酸盐学报》 EI CAS CSCD 北大核心 2010年第9期1631-1637,共7页
研究了水泥与减水剂的相容性。采用萘系(naphthalene,NSF)和聚羧酸(polycarboxylate-based,PCE)系两类高效减水剂,5批次的6种广泛分布于意大利不同区域的水泥为原料。通过改变高效减水剂的掺入量使拌和后的砂浆和混凝土具有恒定的工作性... 研究了水泥与减水剂的相容性。采用萘系(naphthalene,NSF)和聚羧酸(polycarboxylate-based,PCE)系两类高效减水剂,5批次的6种广泛分布于意大利不同区域的水泥为原料。通过改变高效减水剂的掺入量使拌和后的砂浆和混凝土具有恒定的工作性;通过测定拌合后1h内的流动度保持度以表征每种减水剂的工作性经时损失。还测定了砂浆和混凝土1,7d和28d的抗压强度。结果表明:与萘系高效减水剂相比,聚羧酸高效减水剂的减水效果和流动度保持性较好;萘系高效减水剂的作用几乎与水泥的品种及批次无关。混凝土的流变性能和力学性能与其砂浆的测试结果一致。 展开更多
关键词 萘系高效减水剂 聚羧酸高效减水剂 水泥–高效减水剂相容性 性能多变性 高效减水剂
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部