AIM:To evaluate whether an endoscopy position detecting unit(UPD-3) can improve cecal intubation rates, cecal intubation times and visual analog scale(VAS) pain scores, regardless of the colonoscopist's level of e...AIM:To evaluate whether an endoscopy position detecting unit(UPD-3) can improve cecal intubation rates, cecal intubation times and visual analog scale(VAS) pain scores, regardless of the colonoscopist's level of experience.METHODS:A total of 260 patients(170 men and 90women)who underwent a colonoscopy were divided into the UPD-3-guided group or the conventional group(no UPD-3 guidance).Colonoscopies were performed by experts(experience of more than 1000colonoscopies)or trainees(experience of less than 100colonoscopies).Cecal intubation rates,cecal intubation times,insertion methods(straight insertion:shortening the colonic fold through the bending technique;roping insertion:right turn shortening technique)and patient discomfort were assessed.Patient discomfort during the endoscope insertion was scored by the VAS that was divided into 6 degrees of pain.RESULTS:The cecum intubation rates,cecal intubation times,number of cecal intubations that were performed in<15 min and insertion methods were not significantly different between the conventional group and the UPD-3-guided group.The number of patients who experienced pain during the insertion was markedly less in the UPD-3-guided group than in the conventional group.Univariate and multivariate analysis showed that the following factors were associated with lower VAS pain scores during endoscope insertion:insertion method(straight insertion)and UPD-3guidance in the trainee group.For the experts group,univariate analysis showed that only the insertion method(straight insertion)was associated with lower VAS pain scores.CONCLUSION:Although UPD-3 guidance did not shorten intubation times,it resulted in less patient painduring endoscope insertion compared with conventional endoscopy for the procedures performed by trainees.展开更多
An indoor positioning system( IPS) is designed to realize positioning and tracking of mobile targets,by taking advantages of both the visible light communication( VLC) and inertial measurement unit( IMU). The platform...An indoor positioning system( IPS) is designed to realize positioning and tracking of mobile targets,by taking advantages of both the visible light communication( VLC) and inertial measurement unit( IMU). The platform of the IPS is designed,which consists of the light-emitting diode( LED)based transmitter,the receiver and the positioning server. To reduce the impact caused by measurement errors,both inertial sensing data and the received signal strength( RSS) from the VLC are calibrated. Then,a practical propagation model is established to obtain the distance between the transmitter and the receiver from the RSS measurements. Furthermore,a hybrid positioning algorithm is proposed by using the adaptive Kalman filter( AKF) and the weighted least squares( WLS)trilateration to estimate the positions of the mobile targets.Experimental results show that the developed IPS using the proposed hybrid positioning algorithm can extend the localization area of VLC,mitigate the IMU drifts and improve the positioning accuracy of mobile targets.展开更多
Based on the unit quaternion decomposition of rotation matrix, this paper puts forward an algorithm to estimate motion parameters from the space position vectors of 3D feature points. Rotation matrix’s representation...Based on the unit quaternion decomposition of rotation matrix, this paper puts forward an algorithm to estimate motion parameters from the space position vectors of 3D feature points. Rotation matrix’s representation with the unit quaternion has no singular points, so the unit quaternion-based estimation method is of more practical importance, and the algorithm in this paper does not need iteration computation compared to those unit quaternion-based methods proposed by Horn(1987) and Su, et al.(1989). Solution’s uniqueness analysis of the algorithm and simulation experiment results are also presented, it can be seen that performance of our method is satisfactory.展开更多
Considering the need of target positioning,a remote positioning system is designed based on global positioning system(GPS)and general packet radio service(GPRS);The data collection terminal is based on microcontroller...Considering the need of target positioning,a remote positioning system is designed based on global positioning system(GPS)and general packet radio service(GPRS);The data collection terminal is based on microcontroller unit(MCU)PIC24FV301.It uses GPRS network to create wireless link and transmits GPS source information which is collected by LEA-5H board to monitor center on the Internet.The monitor center obtains the target information through processing and analysis of the calculated data.Actual operation results indicate that the designed system has excellent performance and achieves the goal of the remote location.展开更多
The robot' s eyes through the background difference method were used to find broke into the visual range of a moving object and track and monitor the moving object. On the basis of geometry and according to the dista...The robot' s eyes through the background difference method were used to find broke into the visual range of a moving object and track and monitor the moving object. On the basis of geometry and according to the distance and deflection angle of the robot eyes positioning, the objects were captured and tracked by robots eyes. Geometry method precision was low, but simple calculation processing was quick. Thus, it can effectively meet the robot eyes preliminary positioning of the fast moving target.展开更多
With the continued increase in the number of people that are food insecure globally, which could be increasing because of the ongoing Ukraine-Russia war, leading to reduction in international agribusinesses, coupled w...With the continued increase in the number of people that are food insecure globally, which could be increasing because of the ongoing Ukraine-Russia war, leading to reduction in international agribusinesses, coupled with drastic climate change exacerbating the problem of food insecurity, there is a constant need to come up with innovative approaches to solve this global issue. In this article, we articulated how precision agriculture can be a tool for ensuring food security in the United States. This study aims to reiterate the significance of precision agriculture in solving global food insecurity.展开更多
We classify all positive solutions for the following integral system:{ui(x)=∫Rn1/│x-y│^n-α fi(u(y))dy,x∈R^n,i=1,…,m,0〈α〈n,and u(x)=(u1(x),u2(x)…,um(x)).Here fi(u), 1 ≤ i ≤m, monotone non...We classify all positive solutions for the following integral system:{ui(x)=∫Rn1/│x-y│^n-α fi(u(y))dy,x∈R^n,i=1,…,m,0〈α〈n,and u(x)=(u1(x),u2(x)…,um(x)).Here fi(u), 1 ≤ i ≤m, monotone nondecreasing are real-valued functions of homogeneous degree n+α/n-α and are monotone nondecreasing with respect to all the independent variables U1, u2, ..., urn.In the special case n ≥ 3 and α = 2. we show that the above system is equivalent to thefollowing elliptic PDE system:This system is closely related to the stationary SchrSdinger system with critical exponents for Bose-Einstein condensate展开更多
In this paper, by using the method of moving planes, we are concerned with the symmetry and monotonicity of positive solutions for the fractional Hartree equation.
In this paper, we consider the semilinear equation involving the fractional Laplacian in the Euclidian space R^n:(-△)^α/2u(x) : f(xn)u^p(x), x ∈R^n(0.1)in the subcritical case with 1〈 p〈n+a/n-a.Inste...In this paper, we consider the semilinear equation involving the fractional Laplacian in the Euclidian space R^n:(-△)^α/2u(x) : f(xn)u^p(x), x ∈R^n(0.1)in the subcritical case with 1〈 p〈n+a/n-a.Instead of carrying out direct investigations on pseudo-differential equation (0.1), we first seek its equivalent form in an integral equation as below:u(x)=∫R^nG∞(x, y) f(yn) u^p(y)dy,where G∞(x, y) is the Green's function associated with the fractional Laplacian in R^n. Employing the method of moving planes in integral forms, we are able to derive the nonexistence of positive solutions for (0.2) in the subcritical case. Thanks to the equivalence, same con- clusion is true for (0.1).展开更多
To realize the goal of harvesting energy from pavement vibration on a large scale, a new type of piezoelectric harvesting units as the energy transducer has been proposed. The piezoelectric harvesting units are paved ...To realize the goal of harvesting energy from pavement vibration on a large scale, a new type of piezoelectric harvesting units as the energy transducer has been proposed. The piezoelectric harvesting units are paved 40 mm below the asphalt, which is the same as thickness of the top layer of typical asphalt pavement in China. The spacing distance is 2200 mm, which is the same as the one between two tires of a normal vehicle. A mathematical model of the unit is deduced on Meda empirical formula and Hamilton principle and piezoelectric equations. Effects of the external vehicle load on its harvesting energy properties and pavement deformation and stress are analyzed with the finite element method. The results show that the excited voltage is linearly variation with contact pressure while the harvested electrical energy exponential varies with contact pressure. The more the contact pressure is, the larger the harvested electrical energy and the deformation and stress are. The harvested electrical energy also increases with the load frequency. At least 100 mJ of electrical energy can be collected with the proposed piezoelectric harvesting unit. It shows that the technology application of the piezoelectric harvesting energy from pavement is promising.展开更多
Objective:To investigate the effect of the first prone position on arterial blood gas analysis and respiratory parameters of acute respiratory distress syndrome(ARDS)patients with and without COVID.Methods:This study ...Objective:To investigate the effect of the first prone position on arterial blood gas analysis and respiratory parameters of acute respiratory distress syndrome(ARDS)patients with and without COVID.Methods:This study was conducted retrospectively with 22 COVID-ARDS and 22 non-COVID ARDS patients,who were placed in a prone position for at least 16 hours on the first day at the intensive care unit admission,and arterial blood gas analysis was taken in the pre-prone,prone and post-prone periods.Results:PaO2 were significantly increased in the pre-prone vs.prone comparison in both groups,but the increase in the PaO2/FiO2 ratio was not significant.In comparing the pre-prone vs.post-prone PaO2/FiO2 ratios,there was a significant difference only in the non-COVID ARDS group.Conclusions:The improved oxygenation provided by prone positioning is more permanent with the“post-prone effect”in non-COVID ARDS patients.This can be attributed to the differences in the pathogenesis of the two ARDS types.展开更多
Based on a questionnaire survey,the paper made a comparative study on the changes of traditional library positions within the context of the emerging professional positions and functional units at some large academic ...Based on a questionnaire survey,the paper made a comparative study on the changes of traditional library positions within the context of the emerging professional positions and functional units at some large academic libraries in China and in the United States from 1998 to 2007.It describes how some of the library professional positions and functional units have gone through a time period of intensified and proactive position allocation realignment in terms of their rise,decline,fission and/or fusion within the administrative context of their library's evolving changes in missions,objectives and service delivery structure under the impact of the rapid development of information technologies.Such changes are graphically demonstrated in several charts in this paper to highlight the evolutionary development of academic librarianship in general and the waves of changes for library position reallocations in specific in the ten-year period under study.It is believed that such a study can be useful for discerning the overall developing trend of academic librarianship,especially in the area of the rising professional and social status of academic librarianship during this period.The movement of library position allocation realignment was a corresponding response at the time to the influx of applicable information technologies to the library scene.It not only made the library operation to become'leaner and meaner,' but also gave added impetus to the rise of the professional and social status of their practitioners in the society due to the latter's enhanced service delivery innovations and capabilities for meeting their constituencies' timely information needs more satisfactorily.展开更多
The novel coronavirus,which was declared a pandemic by the World Health Organization in early 2020 has brought with itself major morbidity and mortality.It has increased hospital occupancy,heralded economic turmoil,an...The novel coronavirus,which was declared a pandemic by the World Health Organization in early 2020 has brought with itself major morbidity and mortality.It has increased hospital occupancy,heralded economic turmoil,and the rapid transmission and community spread have added to the burden of the virus.Most of the patients are admitted to the intensive care unit(ICU)for acute hypoxic respiratory failure often secondary to acute respiratory distress syndrome(ARDS).Based on the limited data available,there have been different opinions about the respiratory mechanics of the ARDS caused by coronavirus disease 2019(COVID-19).Our article provides an insight into COVID-19 pathophysiology and how it differs from typical ARDS.Based on these differences,our article explains the different approach to ventilation in COVID-19 ARDS compared to typical ARDS.We critically analyze the role of positive end-expiratory pressure(PEEP)and proning in the ICU patients.Through the limited data and clinical experience are available,we believe that early proning in COVID-19 patients improves oxygenation and optimal PEEP should be titrated based on individual lung compliance.展开更多
The development of spatio-temporal database systems is primarily motivated by applications which track and present mobile objects. In this paper, solutions for establishing the moving object database based on GPS/GIS ...The development of spatio-temporal database systems is primarily motivated by applications which track and present mobile objects. In this paper, solutions for establishing the moving object database based on GPS/GIS environment are presented, and a data modeling of moving object is given by using Temporal logical to extent the query language, finally the application model in cargo delivery system is shown.展开更多
时差定位(Time Difference of Arrival,TDOA)是一种广泛应用的被动定位技术,具有定位精度高、组网能力强、系统鲁棒性强等特点。针对运动目标定位计算复杂、精度收敛较慢等问题,在给出视距(Line of Sight,LOS)环境下定位模型的基础上,...时差定位(Time Difference of Arrival,TDOA)是一种广泛应用的被动定位技术,具有定位精度高、组网能力强、系统鲁棒性强等特点。针对运动目标定位计算复杂、精度收敛较慢等问题,在给出视距(Line of Sight,LOS)环境下定位模型的基础上,提出了定位适用于多站时差定位系统的定位方法,该方法将组群时差定位关系方程合理地线性化为统计估计问题,利用在线迭代实时求解目标位置。给出了针对目标不同运动特性条件下的多平台协同定位算法及其仿真结果,仿真结果表明所述方法可以实现对目标的精确定位,并且分析了运动形式对于定位精度的影响,仿真结果对于系统的工程设计具有指导作用。展开更多
文摘AIM:To evaluate whether an endoscopy position detecting unit(UPD-3) can improve cecal intubation rates, cecal intubation times and visual analog scale(VAS) pain scores, regardless of the colonoscopist's level of experience.METHODS:A total of 260 patients(170 men and 90women)who underwent a colonoscopy were divided into the UPD-3-guided group or the conventional group(no UPD-3 guidance).Colonoscopies were performed by experts(experience of more than 1000colonoscopies)or trainees(experience of less than 100colonoscopies).Cecal intubation rates,cecal intubation times,insertion methods(straight insertion:shortening the colonic fold through the bending technique;roping insertion:right turn shortening technique)and patient discomfort were assessed.Patient discomfort during the endoscope insertion was scored by the VAS that was divided into 6 degrees of pain.RESULTS:The cecum intubation rates,cecal intubation times,number of cecal intubations that were performed in<15 min and insertion methods were not significantly different between the conventional group and the UPD-3-guided group.The number of patients who experienced pain during the insertion was markedly less in the UPD-3-guided group than in the conventional group.Univariate and multivariate analysis showed that the following factors were associated with lower VAS pain scores during endoscope insertion:insertion method(straight insertion)and UPD-3guidance in the trainee group.For the experts group,univariate analysis showed that only the insertion method(straight insertion)was associated with lower VAS pain scores.CONCLUSION:Although UPD-3 guidance did not shorten intubation times,it resulted in less patient painduring endoscope insertion compared with conventional endoscopy for the procedures performed by trainees.
基金The National Natural Science Foundation of China(No.61741102,61471164,61601122)the Fundamental Research Funds for the Central Universities(No.SJLX_160040)
文摘An indoor positioning system( IPS) is designed to realize positioning and tracking of mobile targets,by taking advantages of both the visible light communication( VLC) and inertial measurement unit( IMU). The platform of the IPS is designed,which consists of the light-emitting diode( LED)based transmitter,the receiver and the positioning server. To reduce the impact caused by measurement errors,both inertial sensing data and the received signal strength( RSS) from the VLC are calibrated. Then,a practical propagation model is established to obtain the distance between the transmitter and the receiver from the RSS measurements. Furthermore,a hybrid positioning algorithm is proposed by using the adaptive Kalman filter( AKF) and the weighted least squares( WLS)trilateration to estimate the positions of the mobile targets.Experimental results show that the developed IPS using the proposed hybrid positioning algorithm can extend the localization area of VLC,mitigate the IMU drifts and improve the positioning accuracy of mobile targets.
基金"863"High Technology Research and Development Program of China under Grant 863-306-03-01
文摘Based on the unit quaternion decomposition of rotation matrix, this paper puts forward an algorithm to estimate motion parameters from the space position vectors of 3D feature points. Rotation matrix’s representation with the unit quaternion has no singular points, so the unit quaternion-based estimation method is of more practical importance, and the algorithm in this paper does not need iteration computation compared to those unit quaternion-based methods proposed by Horn(1987) and Su, et al.(1989). Solution’s uniqueness analysis of the algorithm and simulation experiment results are also presented, it can be seen that performance of our method is satisfactory.
文摘Considering the need of target positioning,a remote positioning system is designed based on global positioning system(GPS)and general packet radio service(GPRS);The data collection terminal is based on microcontroller unit(MCU)PIC24FV301.It uses GPRS network to create wireless link and transmits GPS source information which is collected by LEA-5H board to monitor center on the Internet.The monitor center obtains the target information through processing and analysis of the calculated data.Actual operation results indicate that the designed system has excellent performance and achieves the goal of the remote location.
文摘The robot' s eyes through the background difference method were used to find broke into the visual range of a moving object and track and monitor the moving object. On the basis of geometry and according to the distance and deflection angle of the robot eyes positioning, the objects were captured and tracked by robots eyes. Geometry method precision was low, but simple calculation processing was quick. Thus, it can effectively meet the robot eyes preliminary positioning of the fast moving target.
文摘With the continued increase in the number of people that are food insecure globally, which could be increasing because of the ongoing Ukraine-Russia war, leading to reduction in international agribusinesses, coupled with drastic climate change exacerbating the problem of food insecurity, there is a constant need to come up with innovative approaches to solve this global issue. In this article, we articulated how precision agriculture can be a tool for ensuring food security in the United States. This study aims to reiterate the significance of precision agriculture in solving global food insecurity.
基金supported by NSF Grant DMS-0604638Li partially supported by NSF Grant DMS-0401174
文摘We classify all positive solutions for the following integral system:{ui(x)=∫Rn1/│x-y│^n-α fi(u(y))dy,x∈R^n,i=1,…,m,0〈α〈n,and u(x)=(u1(x),u2(x)…,um(x)).Here fi(u), 1 ≤ i ≤m, monotone nondecreasing are real-valued functions of homogeneous degree n+α/n-α and are monotone nondecreasing with respect to all the independent variables U1, u2, ..., urn.In the special case n ≥ 3 and α = 2. we show that the above system is equivalent to thefollowing elliptic PDE system:This system is closely related to the stationary SchrSdinger system with critical exponents for Bose-Einstein condensate
基金supported by NSFC(11761082)Yunnan Province,Young Academic and Technical Leaders Program(2015HB028)
文摘In this paper, by using the method of moving planes, we are concerned with the symmetry and monotonicity of positive solutions for the fractional Hartree equation.
文摘In this paper, we consider the semilinear equation involving the fractional Laplacian in the Euclidian space R^n:(-△)^α/2u(x) : f(xn)u^p(x), x ∈R^n(0.1)in the subcritical case with 1〈 p〈n+a/n-a.Instead of carrying out direct investigations on pseudo-differential equation (0.1), we first seek its equivalent form in an integral equation as below:u(x)=∫R^nG∞(x, y) f(yn) u^p(y)dy,where G∞(x, y) is the Green's function associated with the fractional Laplacian in R^n. Employing the method of moving planes in integral forms, we are able to derive the nonexistence of positive solutions for (0.2) in the subcritical case. Thanks to the equivalence, same con- clusion is true for (0.1).
文摘To realize the goal of harvesting energy from pavement vibration on a large scale, a new type of piezoelectric harvesting units as the energy transducer has been proposed. The piezoelectric harvesting units are paved 40 mm below the asphalt, which is the same as thickness of the top layer of typical asphalt pavement in China. The spacing distance is 2200 mm, which is the same as the one between two tires of a normal vehicle. A mathematical model of the unit is deduced on Meda empirical formula and Hamilton principle and piezoelectric equations. Effects of the external vehicle load on its harvesting energy properties and pavement deformation and stress are analyzed with the finite element method. The results show that the excited voltage is linearly variation with contact pressure while the harvested electrical energy exponential varies with contact pressure. The more the contact pressure is, the larger the harvested electrical energy and the deformation and stress are. The harvested electrical energy also increases with the load frequency. At least 100 mJ of electrical energy can be collected with the proposed piezoelectric harvesting unit. It shows that the technology application of the piezoelectric harvesting energy from pavement is promising.
文摘Objective:To investigate the effect of the first prone position on arterial blood gas analysis and respiratory parameters of acute respiratory distress syndrome(ARDS)patients with and without COVID.Methods:This study was conducted retrospectively with 22 COVID-ARDS and 22 non-COVID ARDS patients,who were placed in a prone position for at least 16 hours on the first day at the intensive care unit admission,and arterial blood gas analysis was taken in the pre-prone,prone and post-prone periods.Results:PaO2 were significantly increased in the pre-prone vs.prone comparison in both groups,but the increase in the PaO2/FiO2 ratio was not significant.In comparing the pre-prone vs.post-prone PaO2/FiO2 ratios,there was a significant difference only in the non-COVID ARDS group.Conclusions:The improved oxygenation provided by prone positioning is more permanent with the“post-prone effect”in non-COVID ARDS patients.This can be attributed to the differences in the pathogenesis of the two ARDS types.
文摘Based on a questionnaire survey,the paper made a comparative study on the changes of traditional library positions within the context of the emerging professional positions and functional units at some large academic libraries in China and in the United States from 1998 to 2007.It describes how some of the library professional positions and functional units have gone through a time period of intensified and proactive position allocation realignment in terms of their rise,decline,fission and/or fusion within the administrative context of their library's evolving changes in missions,objectives and service delivery structure under the impact of the rapid development of information technologies.Such changes are graphically demonstrated in several charts in this paper to highlight the evolutionary development of academic librarianship in general and the waves of changes for library position reallocations in specific in the ten-year period under study.It is believed that such a study can be useful for discerning the overall developing trend of academic librarianship,especially in the area of the rising professional and social status of academic librarianship during this period.The movement of library position allocation realignment was a corresponding response at the time to the influx of applicable information technologies to the library scene.It not only made the library operation to become'leaner and meaner,' but also gave added impetus to the rise of the professional and social status of their practitioners in the society due to the latter's enhanced service delivery innovations and capabilities for meeting their constituencies' timely information needs more satisfactorily.
文摘The novel coronavirus,which was declared a pandemic by the World Health Organization in early 2020 has brought with itself major morbidity and mortality.It has increased hospital occupancy,heralded economic turmoil,and the rapid transmission and community spread have added to the burden of the virus.Most of the patients are admitted to the intensive care unit(ICU)for acute hypoxic respiratory failure often secondary to acute respiratory distress syndrome(ARDS).Based on the limited data available,there have been different opinions about the respiratory mechanics of the ARDS caused by coronavirus disease 2019(COVID-19).Our article provides an insight into COVID-19 pathophysiology and how it differs from typical ARDS.Based on these differences,our article explains the different approach to ventilation in COVID-19 ARDS compared to typical ARDS.We critically analyze the role of positive end-expiratory pressure(PEEP)and proning in the ICU patients.Through the limited data and clinical experience are available,we believe that early proning in COVID-19 patients improves oxygenation and optimal PEEP should be titrated based on individual lung compliance.
基金Supported by the National Science Research Project (No.2001BA205A18)
文摘The development of spatio-temporal database systems is primarily motivated by applications which track and present mobile objects. In this paper, solutions for establishing the moving object database based on GPS/GIS environment are presented, and a data modeling of moving object is given by using Temporal logical to extent the query language, finally the application model in cargo delivery system is shown.
文摘时差定位(Time Difference of Arrival,TDOA)是一种广泛应用的被动定位技术,具有定位精度高、组网能力强、系统鲁棒性强等特点。针对运动目标定位计算复杂、精度收敛较慢等问题,在给出视距(Line of Sight,LOS)环境下定位模型的基础上,提出了定位适用于多站时差定位系统的定位方法,该方法将组群时差定位关系方程合理地线性化为统计估计问题,利用在线迭代实时求解目标位置。给出了针对目标不同运动特性条件下的多平台协同定位算法及其仿真结果,仿真结果表明所述方法可以实现对目标的精确定位,并且分析了运动形式对于定位精度的影响,仿真结果对于系统的工程设计具有指导作用。