Unbonded concrete overlay(UBCO) is the most used pavement rehabilitation technique across United States with an overall usage of 47% amongst all the rehabilitation methods.It is aimed to improve the performance of any...Unbonded concrete overlay(UBCO) is the most used pavement rehabilitation technique across United States with an overall usage of 47% amongst all the rehabilitation methods.It is aimed to improve the performance of any deteriorated/cracked jointed plain concrete pavement(JPCP).Unbonded JPCP overlay involves placement of a separation layer of hot mix asphalt(HMA),which acts as a stress relief layer between the existing concrete pavement and the overlay.There are numerous factors that affect the design and performance of UBCOs and out of these,existing pavement condition or the severity of damage of existing pavement is a prime factor.The severity of damage is described by the distressed elastic modulus thus,accurate determination of the distressed elastic modulus of the existing concrete pavement is essential for predicting the accurate performance of the unbonded overlay.This study focuses on analyzing the impact of distressed modulus by conducting simulations in the AASHTOWare pavement ME design software version 2.3 and evaluating the predicted performance of JPCP overlay for two different climatic regions.The results indicated that the distressed modulus of existing concrete pavement affects the performance of the overlay with regards to transverse cracking,joint faulting and pavement roughness.Transverse cracking is the most affected performance parameter with a change of 0.27% 2.31% with a unit change in distressed modulus.The impact of climatic conditions on the performance of unbonded overlay was also observed.The adverse effects of distressed modulus can be minimized by reducing the joint spacing or increasing the overlay slab thickness.展开更多
In this paper, a study and evaluation of the combination of GPS/GNSS techniques and advanced image processing algorithms for distressed human detection, positioning and tracking, from a fully autonomous Unmanned Aeria...In this paper, a study and evaluation of the combination of GPS/GNSS techniques and advanced image processing algorithms for distressed human detection, positioning and tracking, from a fully autonomous Unmanned Aerial Vehicle (UAV)-based rescue support system, </span><span style="font-family:Verdana;">are</span><span style="font-family:Verdana;"> presented. In particular, the issue of human detection both on terrestrial and marine environment under several illumination and background conditions, as the human silhouette in water differs significantly from a terrestrial one</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> is addressed. A robust approach, including an adaptive distressed human detection algorithm running every N input image frames combined with a much faster tracking algorithm, is proposed. Real time or near-real-time distressed human detection rates achieved, using a single, low cost day/night NIR camera mounted onboard a fully autonomous UAV for Search and Rescue (SAR) operations. Moreover, the generation of our own dataset, for the image processing algorithms training is also presented. Details about both hardware and software configuration as well as the assessment of the proposed approach performance are fully discussed. Last, a comparison of the proposed approach to other human detection methods used in the literature is presented.展开更多
The purpose of this paper is to feed the debate regarding investor’s reaction to relevant financial information releases as yearly earnings announcements(EAs)with a specific focus on financial distressed firms.Using ...The purpose of this paper is to feed the debate regarding investor’s reaction to relevant financial information releases as yearly earnings announcements(EAs)with a specific focus on financial distressed firms.Using the event study methodology and adopting two well-known tests in the literature,we analyzed Italian listed companies in the period of 2008-2016,to detect whether there is a market reaction to EAs releases for firms in financial distress,adopting as a measure of financial distress the presence in the audit report of a going concern opinion(GCO).In the Italian legislation,the GCO must be communicated immediately to the market and this can be done before,simultaneously or after EAs.The achieved results shed light on the negative impact of EAs of distressed firms receiving a GCO.On the other hand,the possibility that negative abnormal returns are mainly due to the GCO release cannot be neglected.Hence,through additional tests,we found that effects of EAs are more persistent and significant than GCOs,in accordance with the prevailing literature,which sees,on average,EAs predominant information for investors.Our study is pioneering in disentangling possible effects of confounding events for the Italian stock market.The EAs superior effect confirms the dynamics characterizing weak and small equity markets as Italy where,before GCOs releases,some relevant and more precise information(such as earnings magnitude)is often held by shareholders because of the high percentage of family firms and/or concentrated ownership,demonstrating also the weakness of auditor profession if compared with other developed countries.展开更多
文摘Unbonded concrete overlay(UBCO) is the most used pavement rehabilitation technique across United States with an overall usage of 47% amongst all the rehabilitation methods.It is aimed to improve the performance of any deteriorated/cracked jointed plain concrete pavement(JPCP).Unbonded JPCP overlay involves placement of a separation layer of hot mix asphalt(HMA),which acts as a stress relief layer between the existing concrete pavement and the overlay.There are numerous factors that affect the design and performance of UBCOs and out of these,existing pavement condition or the severity of damage of existing pavement is a prime factor.The severity of damage is described by the distressed elastic modulus thus,accurate determination of the distressed elastic modulus of the existing concrete pavement is essential for predicting the accurate performance of the unbonded overlay.This study focuses on analyzing the impact of distressed modulus by conducting simulations in the AASHTOWare pavement ME design software version 2.3 and evaluating the predicted performance of JPCP overlay for two different climatic regions.The results indicated that the distressed modulus of existing concrete pavement affects the performance of the overlay with regards to transverse cracking,joint faulting and pavement roughness.Transverse cracking is the most affected performance parameter with a change of 0.27% 2.31% with a unit change in distressed modulus.The impact of climatic conditions on the performance of unbonded overlay was also observed.The adverse effects of distressed modulus can be minimized by reducing the joint spacing or increasing the overlay slab thickness.
文摘In this paper, a study and evaluation of the combination of GPS/GNSS techniques and advanced image processing algorithms for distressed human detection, positioning and tracking, from a fully autonomous Unmanned Aerial Vehicle (UAV)-based rescue support system, </span><span style="font-family:Verdana;">are</span><span style="font-family:Verdana;"> presented. In particular, the issue of human detection both on terrestrial and marine environment under several illumination and background conditions, as the human silhouette in water differs significantly from a terrestrial one</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> is addressed. A robust approach, including an adaptive distressed human detection algorithm running every N input image frames combined with a much faster tracking algorithm, is proposed. Real time or near-real-time distressed human detection rates achieved, using a single, low cost day/night NIR camera mounted onboard a fully autonomous UAV for Search and Rescue (SAR) operations. Moreover, the generation of our own dataset, for the image processing algorithms training is also presented. Details about both hardware and software configuration as well as the assessment of the proposed approach performance are fully discussed. Last, a comparison of the proposed approach to other human detection methods used in the literature is presented.
文摘The purpose of this paper is to feed the debate regarding investor’s reaction to relevant financial information releases as yearly earnings announcements(EAs)with a specific focus on financial distressed firms.Using the event study methodology and adopting two well-known tests in the literature,we analyzed Italian listed companies in the period of 2008-2016,to detect whether there is a market reaction to EAs releases for firms in financial distress,adopting as a measure of financial distress the presence in the audit report of a going concern opinion(GCO).In the Italian legislation,the GCO must be communicated immediately to the market and this can be done before,simultaneously or after EAs.The achieved results shed light on the negative impact of EAs of distressed firms receiving a GCO.On the other hand,the possibility that negative abnormal returns are mainly due to the GCO release cannot be neglected.Hence,through additional tests,we found that effects of EAs are more persistent and significant than GCOs,in accordance with the prevailing literature,which sees,on average,EAs predominant information for investors.Our study is pioneering in disentangling possible effects of confounding events for the Italian stock market.The EAs superior effect confirms the dynamics characterizing weak and small equity markets as Italy where,before GCOs releases,some relevant and more precise information(such as earnings magnitude)is often held by shareholders because of the high percentage of family firms and/or concentrated ownership,demonstrating also the weakness of auditor profession if compared with other developed countries.
