COVID-19 (Coronavirus disease of 2019) is caused by SARS-CoV2(Severe Acute Respiratory Syndrome Coronavirus 2) and it was first diagnosedin December 2019 in China. As of 25th Aug 2021, there are 165 million con-firmed...COVID-19 (Coronavirus disease of 2019) is caused by SARS-CoV2(Severe Acute Respiratory Syndrome Coronavirus 2) and it was first diagnosedin December 2019 in China. As of 25th Aug 2021, there are 165 million con-firmed COVID-19 positive cases and 4.4 million deaths globally. As of today,though there are approved COVID-19 vaccine candidates only 4 billion doseshave been administered. Until 100% of the population is safe, no one is safe. Eventhough these vaccines can provide protection against getting seriously ill anddying from the disease, it does not provide 100% protection from getting infectedand passing it on to others. The more the virus spreads;it has more opportunity tomutate. So, it is mandatory to follow all precautions like maintaining social distance, wearing mask, washing hands frequently irrespective of whether a person isvaccinated or not. To prevent spread of the virus, contact tracing based on socialdistance also becomes equally important. The work proposes a solution that canhelp with contact tracing/identification, knowing the infected persons recent travelhistory (even within the city) for few days before being assessed positive. Whilethe person would be able to give the known contacts with whom he/she has interacted with, he/she will not be aware of who all were in proximity if he/she hadbeen in public places. The proposed solution is to get the CCTV (Closed-CircuitTelevision) video clips from those public places for the specific date and time andidentify the people who were in proximity—i.e., not followed the safe distance tothe infected person. The approach uses YOLO V3 (You Only Look Once) whichuses darknet framework for people detection. Once the infected person is locatedfrom the video frames, the distance from that person to the other people in theframe is found, to check if there is a violation of social distance guideline. If thereis, then the people violating the distance are extracted and identified using Facialdetection and recognition algorithms. Two different solutions for Face detectionand Recognition are implemented and results compared—Dlib based modelsand OpenCV (Open Source Computer Vision Library) based models. The solutions were studied for two different CCTV footages and the results for Dlib basedmodels were better than OpenCV based models for the studied videos.展开更多
The recent unprecedented threat from COVID-19 and past epidemics,such as SARS,AIDS,and Ebola,has affected millions of people in multiple countries.Countries have shut their borders,and their nationals have been advise...The recent unprecedented threat from COVID-19 and past epidemics,such as SARS,AIDS,and Ebola,has affected millions of people in multiple countries.Countries have shut their borders,and their nationals have been advised to self-quarantine.The variety of responses to the pandemic has given rise to data privacy concerns.Infection prevention and control strategies as well as disease control measures,especially real-time contact tracing for COVID-19,require the identification of people exposed to COVID-19.Such tracing frameworks use mobile apps and geolocations to trace individuals.However,while the motive may be well intended,the limitations and security issues associated with using such a technology are a serious cause of concern.There are growing concerns regarding the privacy of an individual’s location and personal identifiable information(PII)being shared with governments and/or health agencies.This study presents a real-time,trust-based contact-tracing framework that operateswithout the use of an individual’sPII,location sensing,or gathering GPS logs.The focus of the proposed contact tracing framework is to ensure real-time privacy using the Bluetooth range of individuals to determine others within the range.The research validates the trust-based framework using Bluetooth as practical and privacy-aware.Using our proposed methodology,personal information,health logs,and location data will be secure and not abused.This research analyzes 100,000 tracing dataset records from 150 mobile devices to identify infected users and active users.展开更多
Tuberculosis (TB) is a chronic disease that has impacted negatively on human history. The biology of the mycobacterium tuberculosis is complicated and has affected the control as well as elimination of the disease. Ni...Tuberculosis (TB) is a chronic disease that has impacted negatively on human history. The biology of the mycobacterium tuberculosis is complicated and has affected the control as well as elimination of the disease. Nigeria is one of the countries with high incidence and prevalence of TB. The late and low case detection has been a major problem with National TB control program, caused by passive case finding strategy practiced by the country. A shift from the passive and active case search has been recommended for detection of missing cases of TB and improved program performance. The proximity of TB contact is a major determinant of disease transmission. However, maximizing early case detection and prompt treatment of notified cases is very useful in (TB) control especially in high burden countries. The tracking of TB contacts provides a good platform for early diagnosis, educating the household on TB disease and infection control as well as breaking the chain of transmission. The objective of the study is to ascertain effectiveness of contact tracing on Tuberculosis case detection. The study is a retrospective quasi experimental with quantitative arm. The study was conducted in Abia State, one of the South Eastern States of Nigeria. A pre-tested questionnaire was used for data collection and analyzed with SPSS. A total of 168 and 162 index cases of TB were recruited for both intervention and control facilities. The 168 index TB cases yielded 301 TB contacts. The result revealed 55% contact/index ratio, presumptive TB yield of 130 (43.2%) and TB yield of 68 (22.6%). The cases registered in the State increased from 336 to 417 and p value = 0.001, while presumptive TB and BCG vaccination were major predictors. The study shows that tracing contact of index TB cases is an effective and complementary method of finding undetected cases of TB.展开更多
The wheel-rail contact problems, such as the number, location and the track of contact patches, are very important for optimizing the spatial structure of the rails and lowering the vehicle-turnout system dynamics. Ho...The wheel-rail contact problems, such as the number, location and the track of contact patches, are very important for optimizing the spatial structure of the rails and lowering the vehicle-turnout system dynamics. However, the above problems are not well solved currently because of having the difficulties in how to determine the multi-contact, to preciously present the changeable profiles of the rails and to establish an accurate spatial turnout system dynamics model. Based on a high-speed vehicle-turnout coupled model in which the track is modeled as flexible with rails and sleepers represented by beams, the line tracing extreme point method is introduced to investigate the wheel-rail multiple contact conditions and the key sections of the blade rail, longer nose rail, shorter rail in the switch and nose rail area are discretized to represent the varying profiles of rails in the turnout. The dynamic interaction between the vehicle and turnout is simulated for cases of the vehicle divergently passing the turnout and the multi-point contact is obtained. The tracks of the contact patches on the top of the rails are presented and the wheel-rail impact forces are offered in comparison with the contact patches transference on the rails. The numerical simulation results indicate that the length of two-point contact occurrence of a worn wheel profile and rails is longer than that of the new wheel profile and rails; The two-point contact definitely occurs in the switch and crossing area. Generally, three-point contact doesn’t occur for the new rail profile, which is testified by the wheel-rails interpolation distance and the first order derivative function of the tracing line extreme points. The presented research is not only helpful to optimize the structure of the turnout, but also useful to lower the dynamics of the high speed vehicle-turnout system.展开更多
文摘COVID-19 (Coronavirus disease of 2019) is caused by SARS-CoV2(Severe Acute Respiratory Syndrome Coronavirus 2) and it was first diagnosedin December 2019 in China. As of 25th Aug 2021, there are 165 million con-firmed COVID-19 positive cases and 4.4 million deaths globally. As of today,though there are approved COVID-19 vaccine candidates only 4 billion doseshave been administered. Until 100% of the population is safe, no one is safe. Eventhough these vaccines can provide protection against getting seriously ill anddying from the disease, it does not provide 100% protection from getting infectedand passing it on to others. The more the virus spreads;it has more opportunity tomutate. So, it is mandatory to follow all precautions like maintaining social distance, wearing mask, washing hands frequently irrespective of whether a person isvaccinated or not. To prevent spread of the virus, contact tracing based on socialdistance also becomes equally important. The work proposes a solution that canhelp with contact tracing/identification, knowing the infected persons recent travelhistory (even within the city) for few days before being assessed positive. Whilethe person would be able to give the known contacts with whom he/she has interacted with, he/she will not be aware of who all were in proximity if he/she hadbeen in public places. The proposed solution is to get the CCTV (Closed-CircuitTelevision) video clips from those public places for the specific date and time andidentify the people who were in proximity—i.e., not followed the safe distance tothe infected person. The approach uses YOLO V3 (You Only Look Once) whichuses darknet framework for people detection. Once the infected person is locatedfrom the video frames, the distance from that person to the other people in theframe is found, to check if there is a violation of social distance guideline. If thereis, then the people violating the distance are extracted and identified using Facialdetection and recognition algorithms. Two different solutions for Face detectionand Recognition are implemented and results compared—Dlib based modelsand OpenCV (Open Source Computer Vision Library) based models. The solutions were studied for two different CCTV footages and the results for Dlib basedmodels were better than OpenCV based models for the studied videos.
基金The author would like to thank the Deanship of Scientific Research at Majmaah University for supporting this work under Project No.R-2021-131.
文摘The recent unprecedented threat from COVID-19 and past epidemics,such as SARS,AIDS,and Ebola,has affected millions of people in multiple countries.Countries have shut their borders,and their nationals have been advised to self-quarantine.The variety of responses to the pandemic has given rise to data privacy concerns.Infection prevention and control strategies as well as disease control measures,especially real-time contact tracing for COVID-19,require the identification of people exposed to COVID-19.Such tracing frameworks use mobile apps and geolocations to trace individuals.However,while the motive may be well intended,the limitations and security issues associated with using such a technology are a serious cause of concern.There are growing concerns regarding the privacy of an individual’s location and personal identifiable information(PII)being shared with governments and/or health agencies.This study presents a real-time,trust-based contact-tracing framework that operateswithout the use of an individual’sPII,location sensing,or gathering GPS logs.The focus of the proposed contact tracing framework is to ensure real-time privacy using the Bluetooth range of individuals to determine others within the range.The research validates the trust-based framework using Bluetooth as practical and privacy-aware.Using our proposed methodology,personal information,health logs,and location data will be secure and not abused.This research analyzes 100,000 tracing dataset records from 150 mobile devices to identify infected users and active users.
文摘Tuberculosis (TB) is a chronic disease that has impacted negatively on human history. The biology of the mycobacterium tuberculosis is complicated and has affected the control as well as elimination of the disease. Nigeria is one of the countries with high incidence and prevalence of TB. The late and low case detection has been a major problem with National TB control program, caused by passive case finding strategy practiced by the country. A shift from the passive and active case search has been recommended for detection of missing cases of TB and improved program performance. The proximity of TB contact is a major determinant of disease transmission. However, maximizing early case detection and prompt treatment of notified cases is very useful in (TB) control especially in high burden countries. The tracking of TB contacts provides a good platform for early diagnosis, educating the household on TB disease and infection control as well as breaking the chain of transmission. The objective of the study is to ascertain effectiveness of contact tracing on Tuberculosis case detection. The study is a retrospective quasi experimental with quantitative arm. The study was conducted in Abia State, one of the South Eastern States of Nigeria. A pre-tested questionnaire was used for data collection and analyzed with SPSS. A total of 168 and 162 index cases of TB were recruited for both intervention and control facilities. The 168 index TB cases yielded 301 TB contacts. The result revealed 55% contact/index ratio, presumptive TB yield of 130 (43.2%) and TB yield of 68 (22.6%). The cases registered in the State increased from 336 to 417 and p value = 0.001, while presumptive TB and BCG vaccination were major predictors. The study shows that tracing contact of index TB cases is an effective and complementary method of finding undetected cases of TB.
基金supported by National Natural Science Foundation of China (Grant Nos. 51175032, U1134201)National Basic Research Program of China (973 Program, Grant No. 2011CD711104)
文摘The wheel-rail contact problems, such as the number, location and the track of contact patches, are very important for optimizing the spatial structure of the rails and lowering the vehicle-turnout system dynamics. However, the above problems are not well solved currently because of having the difficulties in how to determine the multi-contact, to preciously present the changeable profiles of the rails and to establish an accurate spatial turnout system dynamics model. Based on a high-speed vehicle-turnout coupled model in which the track is modeled as flexible with rails and sleepers represented by beams, the line tracing extreme point method is introduced to investigate the wheel-rail multiple contact conditions and the key sections of the blade rail, longer nose rail, shorter rail in the switch and nose rail area are discretized to represent the varying profiles of rails in the turnout. The dynamic interaction between the vehicle and turnout is simulated for cases of the vehicle divergently passing the turnout and the multi-point contact is obtained. The tracks of the contact patches on the top of the rails are presented and the wheel-rail impact forces are offered in comparison with the contact patches transference on the rails. The numerical simulation results indicate that the length of two-point contact occurrence of a worn wheel profile and rails is longer than that of the new wheel profile and rails; The two-point contact definitely occurs in the switch and crossing area. Generally, three-point contact doesn’t occur for the new rail profile, which is testified by the wheel-rails interpolation distance and the first order derivative function of the tracing line extreme points. The presented research is not only helpful to optimize the structure of the turnout, but also useful to lower the dynamics of the high speed vehicle-turnout system.
