ZTE Corporation announced on July 14, 2010 that it has been positioned in the leaders quadrant in Gartner＇s Magic Quadrant for Softswitch Architecture Report.
Polygonal coil systems are designed for increasing and more kinds of sensors and electromagnetic systems.This paper presents a method for calculating mutual inductance between polygonal coils including irregular polyg...Polygonal coil systems are designed for increasing and more kinds of sensors and electromagnetic systems.This paper presents a method for calculating mutual inductance between polygonal coils including irregular polygons.Based on the Biot-Savart law,the method calculates mutual inductance by dividing a polygonal coil into finite wires,and expresses the magnetic induction intensity generated by the excitation coil as a function of the spatial position of each vertex of the coil.The calculation method of the feasible region of the objective function is updated and the calculation process is simplified,so the calculation accuracy is improved.For octagon coils arbitrarily positioned in space,the accuracy of the algorithm is verified by the simulation and experiment.展开更多
In this paper,we consider the maximal positive definite solution of the nonlinear matrix equation.By using the idea of Algorithm 2.1 in ZHANG(2013),a new inversion-free method with a stepsize parameter is proposed to ...In this paper,we consider the maximal positive definite solution of the nonlinear matrix equation.By using the idea of Algorithm 2.1 in ZHANG(2013),a new inversion-free method with a stepsize parameter is proposed to obtain the maximal positive definite solution of nonlinear matrix equation X+A^(*)X|^(-α)A=Q with the case 0<α≤1.Based on this method,a new iterative algorithm is developed,and its convergence proof is given.Finally,two numerical examples are provided to show the effectiveness of the proposed method.展开更多
BACKGROUND The imbalance of hormone levels in the body is closely related to the occurrence and progression of schizophrenia,especially thyroid hormones.AIM To study the relationship between triiodothyronine(T3),thyro...BACKGROUND The imbalance of hormone levels in the body is closely related to the occurrence and progression of schizophrenia,especially thyroid hormones.AIM To study the relationship between triiodothyronine(T3),thyroxine(T4),free T3(FT3),free T4(FT4),thyroid stimulating hormone(TSH)and schizophrenia.METHODS In this study,100 schizophrenia patients were selected from our hospital between April 2022 and April 2024.Their clinical data were analyzed retrospectively.Based on the Positive and Negative Syndrome Scale(PANSS)score,patients were divided into mild(1-3 points,n=39),moderate(4 points,n=45),and severe groups(5-7 points,n=16).Additionally,55 healthy individuals served as a control group.Venous blood samples were collected to measure T3,T4,FT3,FT4,TSH,and cortisol concentrations,analyzing their relationship with PANSS scores.RESULTS The serum levels of T3,FT3,FT4,TSH and cortisol in the schizophrenia group were lower than those in the control group(P<0.05).With the increase of the severity of the disease,the concentrations of T3 and T4 decreased,while the con-centrations of TSH and cortisol increased(P<0.05).The concentrations of TSH and cortisol were positively correlated with the PANSS score,while T3 and T4 were negatively correlated with the PANSS score(P<0.05).The receiver ope-rating characteristic curve results showed that T3,T4,TSH,and cortisol had good efficacy in the diagnosis of schizophrenia.Logistic results showed that decreased T3 level,decreased T4 level,decreased TSH level and increased cortisol level may be independent risk factors for schizophrenia.CONCLUSION Thyroid hormone levels are associated with the severity of schizophrenia symptoms,which can provide new solutions for the diagnosis and treatment of schizophrenia.展开更多
BACKGROUND:Tracheal intubation(TI)is a fundamental procedure for securing the airway or assisting ventilation in emergency medicine.Tracheal intubation in the lateral position(TILP)has been utilized in clinical practi...BACKGROUND:Tracheal intubation(TI)is a fundamental procedure for securing the airway or assisting ventilation in emergency medicine.Tracheal intubation in the lateral position(TILP)has been utilized in clinical practice,demonstrating potential advantages in specific scenarios,including emergency settings.However,there is a lack of comprehensive reviews and practical protocols on TILP application.To address this gap,we performed a narrative review,and provided evidence-based recommendations to formulate a practice protocol,to assist clinicians to effectively apply TILP.METHODS:We conducted a narrative review of TILP applications and developed recommendations based on clinical research evidence and clinical experience.Delphi method was used among the TILP consortium to grade the strength of the recommendations and to help reach consensus.The practice protocols were formulated as warranted by advancements in medical knowledge,technology,and practice.RESULTS:This narrative review summarized the current evidence on TILP application,highlighting its safety,efficacy,challenges,and potential complications.In total,24 recommendations and a clinical protocol for TILP application in emergency patients were established.CONCLUSION:TILP is a valuable technique in emergency medicine.We reviewed its application in emergency settings and formulated recommendations along with a clinical practice protocol.Future studies are needed to evaluate the safety and efficacy of TILP,broaden its scope of application,and explore effective training protocols.展开更多
Initial success has been achieved in Hong Kong in controlling primary air pollutants,but ambient ozone levels kept increasing during the past three decades.Volatile organic compounds(VOCs)are important for mitigating ...Initial success has been achieved in Hong Kong in controlling primary air pollutants,but ambient ozone levels kept increasing during the past three decades.Volatile organic compounds(VOCs)are important for mitigating ozone pollution as its major precursors.This study analyzed VOC characteristics of roadside,suburban,and rural sites in Hong Kong to investigate their compositions,concentrations,and source contributions.Herewe showthat the TVOC concentrations were 23.05±13.24,12.68±15.36,and 5.16±5.48 ppbv for roadside,suburban,and rural sites between May 2015 to June 2019,respectively.By using Positive Matrix Factorization(PMF)model,six sources were identified at the roadside site over five years:Liquefied petroleum gas(LPG)usage(33%–46%),gasoline evaporation(8%–31%),aged air mass(11%–28%),gasoline exhaust(5%–16%),diesel exhaust(2%–16%)and fuel filling(75–9%).Similarly,six sources were distinguished at the suburban site,including LPG usage(30%–33%),solvent usage(20%–26%),diesel exhaust(14%–26%),gasoline evaporation(8%–16%),aged air mass(4%–11%),and biogenic emissions(2%–5%).At the rural site,four sources were identified,including aged airmass(33%–51%),solvent usage(25%–30%),vehicular emissions(11%–28%),and biogenic emissions(6%–12%).The analysis further revealed that fuel filling and LPG usage were the primary contributors to OFP and OH reactivity at the roadside site,while solvent usage and biogenic emissions accounted for almost half of OFP and OH reactivity at the suburban and rural sites,respectively.These findings highlight the importance of identifying and characterizing VOC sources at different sites to help policymakers develop targeted measures for pollution mitigation in specific areas.展开更多
Currently,the BeiDou⁃3(BDS⁃3)precise point positioning(PPP)service(PPP⁃B2b)mostly employs the ionosphere⁃free(IF)combination model for precise timing,which tends to amplify the noise in observation values.To address t...Currently,the BeiDou⁃3(BDS⁃3)precise point positioning(PPP)service(PPP⁃B2b)mostly employs the ionosphere⁃free(IF)combination model for precise timing,which tends to amplify the noise in observation values.To address this issue,this paper proposes a real⁃time BDS⁃3 precise unidirectional timing model based on uncombined(UC)observations using the BDS⁃3 PPP⁃B2b service.This model resolves the challenge of the amplified observation noise inherent in the IF combination model.The experiment involved selecting eight global navigation satellite system(GNSS)observation stations within China and collecting continuous observation data for 15 d.A comparative analy⁃sis with the traditional dual⁃frequency IF combination PPP timing model showed that the BDS⁃3 UC PPP timing based on the BDS⁃3 PPP⁃B2b service can achieve a timing preci⁃sion of 0.5 ns.In addition,it was found that due to global positioning system(GPS)satellite clock products in the BDS⁃3 PPP⁃B2b service not being unified to the standard time,the GPS IF PPP timing method based on the BDS⁃3 PPP⁃B2b service is not recommended for precise timing.In summary,the BDS⁃3 UC PPP timing model proposed in this paper is suitable for precise timing,providing observa⁃tion values with smaller noise,and its timing accuracy is comparable to that of the BDS⁃3 IF PPP,with slightly better frequency stability.展开更多
Objectives:This systematic review and meta-analysis aimed to identify and synthesize the factors correlated with posttraumatic growth(PTG)in patients with colorectal cancer(CRC).Methods:PubMed,Web of Science,Embase,Ps...Objectives:This systematic review and meta-analysis aimed to identify and synthesize the factors correlated with posttraumatic growth(PTG)in patients with colorectal cancer(CRC).Methods:PubMed,Web of Science,Embase,PsycINFO,CINAHL,Cochrane Library,China National Knowledge Infrastructure(CNKI),Wanfang database,China Science and Technology Journal Database(VIP)and SinoMed were searched for studies that reported data on the correlated factors associated with PTG in patients with CRC from inception to September 3,2024.The methodological quality of the included studies was assessed via the Agency for Healthcare Research and Quality(AHRQ)methodology checklist and the Newcastle-Ottawa Scale(NOS).Pearson correlation coefficient(r)was utilized to indicate effect size.Meta-analysis was conducted in R Studio.Results:Thirty-one eligible studies encompassing 6,400 participants were included in this review.Correlated factors were identified to be significantly associated with PTG in patients with CRC including demographic factors:residential area(r=0.13),marital status(r=0.10),employment status(r=0.18),education level(r=0.19),income level(r=0.16);disease-related factors:time since surgery(r=0.17),stoma-related complications(r=0.14),health-promoting behavior(r=0.46),and sexual function(r=0.17);psychosocial factors:confrontation coping(r=0.68),avoidance coping(r=-0.65),deliberate rumination(r=0.56),social support(r=0.47),family function(r=0.50),resilience(r=0.53),selfefficacy(r=0.91),self-compassion(r=-0.32),psychosocial adjustment(r=0.39),gratitude(r=0.45),stigma(r=-0.65),self-perceived burden(r=-0.31),fear of cancer recurrence(r=-0.45);and quality of life(r=0.32).Conclusions:This meta-analysis identified 23 factors associated with PTG in CRC patients.Medical workers can combine those relevant factors from the perspective of positive psychology,further explore the occurrence and development mechanism of PTG,and establish targeted interventions to promote PTG.展开更多
In GNSS denied environments,pseudolites have to rely on prior information,such as ground anchoring points,terrain matching or other multi-source means for positioning.This paper proposes a method of dynamic networking...In GNSS denied environments,pseudolites have to rely on prior information,such as ground anchoring points,terrain matching or other multi-source means for positioning.This paper proposes a method of dynamic networking of UAVs pseudolites for accurate navigation with only inertial navigation during GNSS denied area,which can provide accurate positioning services without prior information like anchor points.On this basis,this paper proposes a mathematical model of UAV pseudolite networking to describe the relationship of UAV flight altitude,network service coverage and anti-jamming capabilities.This model demonstrates excellent anti-interference ability,which can achieve a maximum power enhancement of up to 54.58 dB.And it can also offer another operating mode with a maximum coverage range of up to 2675.47 km^(2),while still ensuring a power enhancement of 37.57dB.This method can effectively solve the problem of providing continuous positioning services as an alternative GNSS,and is also a powerful support solution for resilient Positioning,Navigation,and Timing(PNT)^([1]).展开更多
Mountainous areas are the priority for forest restoration in semiarid regions,with hillslopes serving as the basic units of mountains.Precipitation is the only water source in these regions,and the uneven distribution...Mountainous areas are the priority for forest restoration in semiarid regions,with hillslopes serving as the basic units of mountains.Precipitation is the only water source in these regions,and the uneven distribution of hillslope soil moisture replenishment after precipitation determines vegetation survival and growth.Therefore,in this study experiments were performed on a hillslope in the Liupan Mountains,Ningxia Hui Autonomous Region,China,to quantify the unevenness of soil moisture replenishment.Soil water content(SWC)in the 0–60 cm layer and precipitation were monitored throughout the growing season in 2020 and 2021.The results showed that(1)Annual soil moisture replenishment was the highest at the mid-slope position,with an average of 309.9 mm,especially under moderate and heavy rain grade conditions,reaching 38.7% and 30.8% of the total replenishment,respectively;(2)Vertical replenishment played a dominant role in the total replenishment,accounting for 82.8%;lateral replenishment played an important but lesser role,accounting for up to 17.2% of the total replenishment;(3)Based on a soil moisture replenishment model established in this study,the maximal replenishment occurred at 90 m from the top of the slope;(4)The dominant factors contributing to the soil moisture replenishment were rainfall amount and saturated hydraulic conductivity(Ks).These findings suggest that attention should be given to both vertical and lateral soil moisture replenishment,and the mid-slope position could be preferred for site selection to achieve precise and integrated forest-water management on hillslopes in semi-arid mountainous regions.展开更多
Aiming at the problem that the existing algorithms for vehicle detection in smart factories are difficult to detect partial occlusion of vehicles,vulnerable to background interference,lack of global vision,and excessi...Aiming at the problem that the existing algorithms for vehicle detection in smart factories are difficult to detect partial occlusion of vehicles,vulnerable to background interference,lack of global vision,and excessive suppression of real targets,which ultimately cause accuracy degradation.At the same time,to facilitate the subsequent positioning of vehicles in the factory,this paper proposes an improved YOLOv8 algorithm.Firstly,the RFCAConv module is combined to improve the original YOLOv8 backbone.Pay attention to the different features in the receptive field,and give priority to the spatial features of the receptive field to capture more vehicle feature information and solve the problem that the vehicle is partially occluded and difficult to detect.Secondly,the SFE module is added to the neck of v8,which improves the saliency of the target in the reasoning process and reduces the influence of background interference on vehicle detection.Finally,the head of the RT-DETR algorithm is used to replace the head in the original YOLOv8 algorithm,which avoids the excessive suppression of the real target while combining the context information.The experimental results show that compared with the original YOLOv8 algorithm,the detection accuracy of the improved YOLOv8 algorithm is improved by 4.6%on the self-made smart factory data set,and the detection speed also meets the real-time requirements of smart factory vehicle detection and subsequent vehicle positioning.展开更多
For multi-vehicle networks,Cooperative Positioning(CP)technique has become a promising way to enhance vehicle positioning accuracy.Especially,the CP performance could be further improved by introducing Sensor-Rich Veh...For multi-vehicle networks,Cooperative Positioning(CP)technique has become a promising way to enhance vehicle positioning accuracy.Especially,the CP performance could be further improved by introducing Sensor-Rich Vehicles(SRVs)into CP networks,which is called SRV-aided CP.However,the CP system may split into several sub-clusters that cannot be connected with each other in dense urban environments,in which the sub-clusters with few SRVs will suffer from degradation of CP performance.Since Unmanned Aerial Vehicles(UAVs)have been widely used to aid vehicular communications,we intend to utilize UAVs to assist sub-clusters in CP.In this paper,a UAV-aided CP network is constructed to fully utilize information from SRVs.First,the inter-node connection structure among the UAV and vehicles is designed to share available information from SRVs.After that,the clustering optimization strategy is proposed,in which the UAV cooperates with the high-precision sub-cluster to obtain available information from SRVs,and then broadcasts this positioning-related information to other low-precision sub-clusters.Finally,the Locally-Centralized Factor Graph Optimization(LC-FGO)algorithm is designed to fuse positioning information from cooperators.Simulation results indicate that the positioning accuracy of the CP system could be improved by fully utilizing positioning-related information from SRVs.展开更多
A rock-drilling jumbo is the main piece of tunneling equipment used in the energy and infrastructure industries in various countries.The positioning accuracy of its drilling boom greatly affects tunneling efficiency a...A rock-drilling jumbo is the main piece of tunneling equipment used in the energy and infrastructure industries in various countries.The positioning accuracy of its drilling boom greatly affects tunneling efficiency and section-forming quality of mine roadways and engineering tunnels.In order to improve the drilling-positioning accuracy of a three-boom drilling jumbo,we established a kinematics model of the multi-degree-of-freedom(multi-DOF)multi-boom system,using the improved Denavit-Hartenberg(D-H)method,and obtained the mapping relationship between the end position and the amount of motion of each joint.The error of the inverse kinematics calculation for the drilling boom is estimated by an analytical method and a global search algorithm based on particle swarm optimization(PSO)for a straight blasting hole and an inclined blasting hole.On this basis,we propose a back-propagation(BP)neural network optimized by an improved sparrow search algorithm(ISSA)to predict the positioning error of the drilling booms of a three-boom drilling jumbo.In order to verify the accuracy of the proposed error compensation model,we built an automatic-control test platform for the boom,and carried out a positioning error compensation test on the boom.The results show that the average drilling-positioning error was reduced from 9.79 to 5.92 cm,and the error was reduced by 39.5%.Therefore,the proposed method effectively reduces the positioning error of the drilling boom,and improves the accuracy and efficiency of rock drilling.展开更多
Zenith Tropospheric Delay(ZTD)is an important factor that restricts the high-precision positioning of global navigation satellite system(GNSS),and it is of great significance in establishing a real-time and highprecis...Zenith Tropospheric Delay(ZTD)is an important factor that restricts the high-precision positioning of global navigation satellite system(GNSS),and it is of great significance in establishing a real-time and highprecision ZTD model.However,existing ZTD models only consider the impact of linear terms on ZTD estimation,whereas the nonlinear factors have rarely been investigated before and thus become the focus of this study.A real-time and high-precision ZTD model for large height difference area is proposed by considering the linear and nonlinear characteristics of ZTD spatiotemporal variations and is called the realtime linear and nonlinearity ZTD(RLNZ)model.This model uses the ZTD estimated from the Global Pressure and Temperature 3(GPT3)model as the initial value.The linear impacts of periodic term and height on the estimation of ZTD difference between GNSS and GPT3 model are first considered.In addition,nonlinear factors such as geographical location and time are further used to fit the remaining nonlinear ZTD residuals using the general regression neural network method.Finally,the RLNZ-derived ZTD is obtained at an arbitrary location.The western United States,with height difference ranging from-500 to 4000 m,is selected,and the hourly ZTD of 484 GNSS stations provided by the Nevada Geodetic Laboratory(NGL)and the data of 9 radiosonde(RS)stations in the year 2021 are used.Experiment results show that a better performance of ZTD estimation can be retrieved from the proposed RLNZ model when compared with the GPT3 model.Statistical results show the averaged root mean square(RMS),Bias,and mean absolute error(MAE)of ZTD from GPT3 and RLNZ models are 33.7/0.8/25.7 mm and 22.6/0.1/17.4 mm,respectively.The average improvement rate of the RLNZ model is 33% when compared to the GPT3 model.Finally,the application of the proposed RLNZ model in simulated real-time Precise Point Positioning(PPP)indicates that the accuracy of PPP in N,E and U components is improved by 8%,2%,and 6% when compared with that from the GPT3-based PPP.Meanwhile,the convergence time in N and U components is improved by 23% and 7%,respectively.Such results verify the superiority of the proposed RLNZ model in retrieving realtime ZTD maps for GNSS positioning and navigation applications.展开更多
The centroid coordinate serves as a critical control parameter in motion systems,including aircraft,missiles,rockets,and drones,directly influencing their motion dynamics and control performance.Traditional methods fo...The centroid coordinate serves as a critical control parameter in motion systems,including aircraft,missiles,rockets,and drones,directly influencing their motion dynamics and control performance.Traditional methods for centroid measurement often necessitate custom equipment and specialized positioning devices,leading to high costs and limited accuracy.Here,we present a centroid measurement method that integrates 3D scanning technology,enabling accurate measurement of centroid across various types of objects without the need for specialized positioning fixtures.A theoretical framework for centroid measurement was established,which combined the principle of the multi-point weighing method with 3D scanning technology.The measurement accuracy was evaluated using a designed standard component.Experimental results demonstrate that the discrepancies between the theoretical and the measured centroid of a standard component with various materials and complex shapes in the X,Y,and Z directions are 0.003 mm,0.009 mm,and 0.105 mm,respectively,yielding a spatial deviation of 0.106 mm.Qualitative verification was conducted through experimental validation of three distinct types.They confirmed the reliability of the proposed method,which allowed for accurate centroid measurements of various products without requiring positioning fixtures.This advancement significantly broadened the applicability and scope of centroid measurement devices,offering new theoretical insights and methodologies for the measurement of complex parts and systems.展开更多
Lung cancer, the leading cause of cancer deaths worldwide and in China, has a 19.7% five-year survival rate due to terminal-stage diagnosis^([1-3]).Although low-dose computed tomography(CT) screening can reduce mortal...Lung cancer, the leading cause of cancer deaths worldwide and in China, has a 19.7% five-year survival rate due to terminal-stage diagnosis^([1-3]).Although low-dose computed tomography(CT) screening can reduce mortality, high false positive rates can create economic and psychological burdens.展开更多
Despite advancements in neuroimaging,false positive diagnoses of intracranial aneurysms remain a significant concern.This article examines the causes,prevalence,and implications of such false-positive diagnoses.We dis...Despite advancements in neuroimaging,false positive diagnoses of intracranial aneurysms remain a significant concern.This article examines the causes,prevalence,and implications of such false-positive diagnoses.We discuss how conditions like arterial occlusion with vascular stump formation and infundibular widening can mimic aneurysms,particularly in the anterior circulation.The article compares various imaging modalities,including computer tomography angiogram,magnetic resonance imaging/angiography,and digital subtraction angiogram,highlighting their strengths and limitations.We emphasize the im-portance of accurate differentiation to avoid unnecessary surgical interventions.The potential of emerging technologies,such as high-resolution vessel wall ima-ging and deep neural networks for automated detection,is explored as promising avenues for improving diagnostic accuracy.This manuscript underscores the need for continued research and clinical vigilance in the diagnosis of intracranial aneurysms.展开更多
A general metal-free photochemcial oxidation of benzylic C—H bonds has been successfully accomplished via a hydrogen atom transfer(HAT)process.A range of high value-added aromatic ketones were facilely synthesized wi...A general metal-free photochemcial oxidation of benzylic C—H bonds has been successfully accomplished via a hydrogen atom transfer(HAT)process.A range of high value-added aromatic ketones were facilely synthesized with high chemoselectivity under mild conditions.Moreover,the mild conditions by using air as the oxidant render the developed proto-col more ecofriendly and environmentally sustainable.展开更多
The accuracy of spot centroid positioning has a significant impact on the tracking accuracy of the system and the stability of the laser link construction.In satellite laser communication systems,the use of short-wave...The accuracy of spot centroid positioning has a significant impact on the tracking accuracy of the system and the stability of the laser link construction.In satellite laser communication systems,the use of short-wave infrared wavelengths as beacon light can reduce atmospheric absorption and signal attenuation.However,there are strong non-uniformity and blind pixels in the short-wave infrared image,which makes the image distorted and leads to the decrease of spot centroid positioning accuracy.Therefore,the high-precision localization of the spot centroid of the short-wave infrared images is of great research significance.A high-precision spot centroid positioning model for short-wave infrared is proposed to correct for non-uniformity and blind pixels in short-wave infrared images and quantify the localization errors caused by the two,further model-based localization error simulations are performed,and a novel spot centroid positioning payload for satellite laser communications has been designed using the latest 640×512 planar array InGaAs shortwave infrared detector.The experimental results show that the non-uniformity of the corrected image is reduced from 7%to 0.6%,the blind pixels rejection rate reaches 100%,the frame rate can be up to 2000 Hz,and the spot centroid localization accuracy is as high as 0.1 pixel point,which realizes high-precision spot centroid localization of high-frame-frequency short-wave infrared images.展开更多
In this paper,we study the Bowen entropy of stable sets in positive entropy G-system of amenable group actions.The lower bound of the Bowen entropy of these sets are estimated.
文摘ZTE Corporation announced on July 14, 2010 that it has been positioned in the leaders quadrant in Gartner＇s Magic Quadrant for Softswitch Architecture Report.
文摘Polygonal coil systems are designed for increasing and more kinds of sensors and electromagnetic systems.This paper presents a method for calculating mutual inductance between polygonal coils including irregular polygons.Based on the Biot-Savart law,the method calculates mutual inductance by dividing a polygonal coil into finite wires,and expresses the magnetic induction intensity generated by the excitation coil as a function of the spatial position of each vertex of the coil.The calculation method of the feasible region of the objective function is updated and the calculation process is simplified,so the calculation accuracy is improved.For octagon coils arbitrarily positioned in space,the accuracy of the algorithm is verified by the simulation and experiment.
基金Supported in part by Natural Science Foundation of Guangxi(2023GXNSFAA026246)in part by the Central Government's Guide to Local Science and Technology Development Fund(GuikeZY23055044)in part by the National Natural Science Foundation of China(62363003)。
文摘In this paper,we consider the maximal positive definite solution of the nonlinear matrix equation.By using the idea of Algorithm 2.1 in ZHANG(2013),a new inversion-free method with a stepsize parameter is proposed to obtain the maximal positive definite solution of nonlinear matrix equation X+A^(*)X|^(-α)A=Q with the case 0<α≤1.Based on this method,a new iterative algorithm is developed,and its convergence proof is given.Finally,two numerical examples are provided to show the effectiveness of the proposed method.
文摘BACKGROUND The imbalance of hormone levels in the body is closely related to the occurrence and progression of schizophrenia,especially thyroid hormones.AIM To study the relationship between triiodothyronine(T3),thyroxine(T4),free T3(FT3),free T4(FT4),thyroid stimulating hormone(TSH)and schizophrenia.METHODS In this study,100 schizophrenia patients were selected from our hospital between April 2022 and April 2024.Their clinical data were analyzed retrospectively.Based on the Positive and Negative Syndrome Scale(PANSS)score,patients were divided into mild(1-3 points,n=39),moderate(4 points,n=45),and severe groups(5-7 points,n=16).Additionally,55 healthy individuals served as a control group.Venous blood samples were collected to measure T3,T4,FT3,FT4,TSH,and cortisol concentrations,analyzing their relationship with PANSS scores.RESULTS The serum levels of T3,FT3,FT4,TSH and cortisol in the schizophrenia group were lower than those in the control group(P<0.05).With the increase of the severity of the disease,the concentrations of T3 and T4 decreased,while the con-centrations of TSH and cortisol increased(P<0.05).The concentrations of TSH and cortisol were positively correlated with the PANSS score,while T3 and T4 were negatively correlated with the PANSS score(P<0.05).The receiver ope-rating characteristic curve results showed that T3,T4,TSH,and cortisol had good efficacy in the diagnosis of schizophrenia.Logistic results showed that decreased T3 level,decreased T4 level,decreased TSH level and increased cortisol level may be independent risk factors for schizophrenia.CONCLUSION Thyroid hormone levels are associated with the severity of schizophrenia symptoms,which can provide new solutions for the diagnosis and treatment of schizophrenia.
基金National Natural Science Foundation of China(U24A20714 to XMF and 82102238 to PC)。
文摘BACKGROUND:Tracheal intubation(TI)is a fundamental procedure for securing the airway or assisting ventilation in emergency medicine.Tracheal intubation in the lateral position(TILP)has been utilized in clinical practice,demonstrating potential advantages in specific scenarios,including emergency settings.However,there is a lack of comprehensive reviews and practical protocols on TILP application.To address this gap,we performed a narrative review,and provided evidence-based recommendations to formulate a practice protocol,to assist clinicians to effectively apply TILP.METHODS:We conducted a narrative review of TILP applications and developed recommendations based on clinical research evidence and clinical experience.Delphi method was used among the TILP consortium to grade the strength of the recommendations and to help reach consensus.The practice protocols were formulated as warranted by advancements in medical knowledge,technology,and practice.RESULTS:This narrative review summarized the current evidence on TILP application,highlighting its safety,efficacy,challenges,and potential complications.In total,24 recommendations and a clinical protocol for TILP application in emergency patients were established.CONCLUSION:TILP is a valuable technique in emergency medicine.We reviewed its application in emergency settings and formulated recommendations along with a clinical practice protocol.Future studies are needed to evaluate the safety and efficacy of TILP,broaden its scope of application,and explore effective training protocols.
基金supported by Hong Kong Environment Protection Department(Quotation Ref.18-06532)Hong Kong Innovation and Technology Fund(ITS/193/20FP)Hong Kong Research Grants Council(No.26304921).
文摘Initial success has been achieved in Hong Kong in controlling primary air pollutants,but ambient ozone levels kept increasing during the past three decades.Volatile organic compounds(VOCs)are important for mitigating ozone pollution as its major precursors.This study analyzed VOC characteristics of roadside,suburban,and rural sites in Hong Kong to investigate their compositions,concentrations,and source contributions.Herewe showthat the TVOC concentrations were 23.05±13.24,12.68±15.36,and 5.16±5.48 ppbv for roadside,suburban,and rural sites between May 2015 to June 2019,respectively.By using Positive Matrix Factorization(PMF)model,six sources were identified at the roadside site over five years:Liquefied petroleum gas(LPG)usage(33%–46%),gasoline evaporation(8%–31%),aged air mass(11%–28%),gasoline exhaust(5%–16%),diesel exhaust(2%–16%)and fuel filling(75–9%).Similarly,six sources were distinguished at the suburban site,including LPG usage(30%–33%),solvent usage(20%–26%),diesel exhaust(14%–26%),gasoline evaporation(8%–16%),aged air mass(4%–11%),and biogenic emissions(2%–5%).At the rural site,four sources were identified,including aged airmass(33%–51%),solvent usage(25%–30%),vehicular emissions(11%–28%),and biogenic emissions(6%–12%).The analysis further revealed that fuel filling and LPG usage were the primary contributors to OFP and OH reactivity at the roadside site,while solvent usage and biogenic emissions accounted for almost half of OFP and OH reactivity at the suburban and rural sites,respectively.These findings highlight the importance of identifying and characterizing VOC sources at different sites to help policymakers develop targeted measures for pollution mitigation in specific areas.
基金The Basic Science Center Project of the National Natural Science Foundation of China(No.42388102)the Jiangsu Province Natural Resources Science and Technology Project(No.JSZRKJ202404).
文摘Currently,the BeiDou⁃3(BDS⁃3)precise point positioning(PPP)service(PPP⁃B2b)mostly employs the ionosphere⁃free(IF)combination model for precise timing,which tends to amplify the noise in observation values.To address this issue,this paper proposes a real⁃time BDS⁃3 precise unidirectional timing model based on uncombined(UC)observations using the BDS⁃3 PPP⁃B2b service.This model resolves the challenge of the amplified observation noise inherent in the IF combination model.The experiment involved selecting eight global navigation satellite system(GNSS)observation stations within China and collecting continuous observation data for 15 d.A comparative analy⁃sis with the traditional dual⁃frequency IF combination PPP timing model showed that the BDS⁃3 UC PPP timing based on the BDS⁃3 PPP⁃B2b service can achieve a timing preci⁃sion of 0.5 ns.In addition,it was found that due to global positioning system(GPS)satellite clock products in the BDS⁃3 PPP⁃B2b service not being unified to the standard time,the GPS IF PPP timing method based on the BDS⁃3 PPP⁃B2b service is not recommended for precise timing.In summary,the BDS⁃3 UC PPP timing model proposed in this paper is suitable for precise timing,providing observa⁃tion values with smaller noise,and its timing accuracy is comparable to that of the BDS⁃3 IF PPP,with slightly better frequency stability.
基金supported by the‘Double First-Class’Construction Specialized Discipline Project at Zhejiang University(No HL2024012).
文摘Objectives:This systematic review and meta-analysis aimed to identify and synthesize the factors correlated with posttraumatic growth(PTG)in patients with colorectal cancer(CRC).Methods:PubMed,Web of Science,Embase,PsycINFO,CINAHL,Cochrane Library,China National Knowledge Infrastructure(CNKI),Wanfang database,China Science and Technology Journal Database(VIP)and SinoMed were searched for studies that reported data on the correlated factors associated with PTG in patients with CRC from inception to September 3,2024.The methodological quality of the included studies was assessed via the Agency for Healthcare Research and Quality(AHRQ)methodology checklist and the Newcastle-Ottawa Scale(NOS).Pearson correlation coefficient(r)was utilized to indicate effect size.Meta-analysis was conducted in R Studio.Results:Thirty-one eligible studies encompassing 6,400 participants were included in this review.Correlated factors were identified to be significantly associated with PTG in patients with CRC including demographic factors:residential area(r=0.13),marital status(r=0.10),employment status(r=0.18),education level(r=0.19),income level(r=0.16);disease-related factors:time since surgery(r=0.17),stoma-related complications(r=0.14),health-promoting behavior(r=0.46),and sexual function(r=0.17);psychosocial factors:confrontation coping(r=0.68),avoidance coping(r=-0.65),deliberate rumination(r=0.56),social support(r=0.47),family function(r=0.50),resilience(r=0.53),selfefficacy(r=0.91),self-compassion(r=-0.32),psychosocial adjustment(r=0.39),gratitude(r=0.45),stigma(r=-0.65),self-perceived burden(r=-0.31),fear of cancer recurrence(r=-0.45);and quality of life(r=0.32).Conclusions:This meta-analysis identified 23 factors associated with PTG in CRC patients.Medical workers can combine those relevant factors from the perspective of positive psychology,further explore the occurrence and development mechanism of PTG,and establish targeted interventions to promote PTG.
基金National Social Science Fund of China(No.2023-SKJJ-B-069).
文摘In GNSS denied environments,pseudolites have to rely on prior information,such as ground anchoring points,terrain matching or other multi-source means for positioning.This paper proposes a method of dynamic networking of UAVs pseudolites for accurate navigation with only inertial navigation during GNSS denied area,which can provide accurate positioning services without prior information like anchor points.On this basis,this paper proposes a mathematical model of UAV pseudolite networking to describe the relationship of UAV flight altitude,network service coverage and anti-jamming capabilities.This model demonstrates excellent anti-interference ability,which can achieve a maximum power enhancement of up to 54.58 dB.And it can also offer another operating mode with a maximum coverage range of up to 2675.47 km^(2),while still ensuring a power enhancement of 37.57dB.This method can effectively solve the problem of providing continuous positioning services as an alternative GNSS,and is also a powerful support solution for resilient Positioning,Navigation,and Timing(PNT)^([1]).
基金financially supported by the Central Public-Interest Scientific Institution Basal Research Fund of Chinese Academy of Forestry(CAFYBB2021ZW002)the National Key Research and Development Program of China(2022YFF1300404)the National Natural Science Foundation of China(U21A2005)。
文摘Mountainous areas are the priority for forest restoration in semiarid regions,with hillslopes serving as the basic units of mountains.Precipitation is the only water source in these regions,and the uneven distribution of hillslope soil moisture replenishment after precipitation determines vegetation survival and growth.Therefore,in this study experiments were performed on a hillslope in the Liupan Mountains,Ningxia Hui Autonomous Region,China,to quantify the unevenness of soil moisture replenishment.Soil water content(SWC)in the 0–60 cm layer and precipitation were monitored throughout the growing season in 2020 and 2021.The results showed that(1)Annual soil moisture replenishment was the highest at the mid-slope position,with an average of 309.9 mm,especially under moderate and heavy rain grade conditions,reaching 38.7% and 30.8% of the total replenishment,respectively;(2)Vertical replenishment played a dominant role in the total replenishment,accounting for 82.8%;lateral replenishment played an important but lesser role,accounting for up to 17.2% of the total replenishment;(3)Based on a soil moisture replenishment model established in this study,the maximal replenishment occurred at 90 m from the top of the slope;(4)The dominant factors contributing to the soil moisture replenishment were rainfall amount and saturated hydraulic conductivity(Ks).These findings suggest that attention should be given to both vertical and lateral soil moisture replenishment,and the mid-slope position could be preferred for site selection to achieve precise and integrated forest-water management on hillslopes in semi-arid mountainous regions.
基金funded by Changzhou Science and Technology Project(No.CZ20230025)Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.XSJCX23_36).
文摘Aiming at the problem that the existing algorithms for vehicle detection in smart factories are difficult to detect partial occlusion of vehicles,vulnerable to background interference,lack of global vision,and excessive suppression of real targets,which ultimately cause accuracy degradation.At the same time,to facilitate the subsequent positioning of vehicles in the factory,this paper proposes an improved YOLOv8 algorithm.Firstly,the RFCAConv module is combined to improve the original YOLOv8 backbone.Pay attention to the different features in the receptive field,and give priority to the spatial features of the receptive field to capture more vehicle feature information and solve the problem that the vehicle is partially occluded and difficult to detect.Secondly,the SFE module is added to the neck of v8,which improves the saliency of the target in the reasoning process and reduces the influence of background interference on vehicle detection.Finally,the head of the RT-DETR algorithm is used to replace the head in the original YOLOv8 algorithm,which avoids the excessive suppression of the real target while combining the context information.The experimental results show that compared with the original YOLOv8 algorithm,the detection accuracy of the improved YOLOv8 algorithm is improved by 4.6%on the self-made smart factory data set,and the detection speed also meets the real-time requirements of smart factory vehicle detection and subsequent vehicle positioning.
基金supported by the National Natural Science Foundation of China(No.62271399)the National Key Research and Development Program of China(No.2022YFB1807102)。
文摘For multi-vehicle networks,Cooperative Positioning(CP)technique has become a promising way to enhance vehicle positioning accuracy.Especially,the CP performance could be further improved by introducing Sensor-Rich Vehicles(SRVs)into CP networks,which is called SRV-aided CP.However,the CP system may split into several sub-clusters that cannot be connected with each other in dense urban environments,in which the sub-clusters with few SRVs will suffer from degradation of CP performance.Since Unmanned Aerial Vehicles(UAVs)have been widely used to aid vehicular communications,we intend to utilize UAVs to assist sub-clusters in CP.In this paper,a UAV-aided CP network is constructed to fully utilize information from SRVs.First,the inter-node connection structure among the UAV and vehicles is designed to share available information from SRVs.After that,the clustering optimization strategy is proposed,in which the UAV cooperates with the high-precision sub-cluster to obtain available information from SRVs,and then broadcasts this positioning-related information to other low-precision sub-clusters.Finally,the Locally-Centralized Factor Graph Optimization(LC-FGO)algorithm is designed to fuse positioning information from cooperators.Simulation results indicate that the positioning accuracy of the CP system could be improved by fully utilizing positioning-related information from SRVs.
基金National Natural Science Foundation of China(No.12472038)Natural Science Foundation of Jiangsu Province(No.BK20230688)+2 种基金Natural Science Foundation of the Jiangsu Higher Education Institutions of China(No.22KJB440004)Key Research and Development Program of Xuzhou(No.KC22404)Research Fund for Doctoral Degree Teachers of Jiangsu Normal University of China(No.22XFRS011).
文摘A rock-drilling jumbo is the main piece of tunneling equipment used in the energy and infrastructure industries in various countries.The positioning accuracy of its drilling boom greatly affects tunneling efficiency and section-forming quality of mine roadways and engineering tunnels.In order to improve the drilling-positioning accuracy of a three-boom drilling jumbo,we established a kinematics model of the multi-degree-of-freedom(multi-DOF)multi-boom system,using the improved Denavit-Hartenberg(D-H)method,and obtained the mapping relationship between the end position and the amount of motion of each joint.The error of the inverse kinematics calculation for the drilling boom is estimated by an analytical method and a global search algorithm based on particle swarm optimization(PSO)for a straight blasting hole and an inclined blasting hole.On this basis,we propose a back-propagation(BP)neural network optimized by an improved sparrow search algorithm(ISSA)to predict the positioning error of the drilling booms of a three-boom drilling jumbo.In order to verify the accuracy of the proposed error compensation model,we built an automatic-control test platform for the boom,and carried out a positioning error compensation test on the boom.The results show that the average drilling-positioning error was reduced from 9.79 to 5.92 cm,and the error was reduced by 39.5%.Therefore,the proposed method effectively reduces the positioning error of the drilling boom,and improves the accuracy and efficiency of rock drilling.
基金supported by the National Natural Science Foundation of China(42274039)Shaanxi Provincial Innovation Capacity Support Plan Project(2023KJXX-050)+2 种基金The Open Grants of the State Key Laboratory of Severe Weather(2023LASW-B18)Scientific and technological research projects for major issues in military medicine and aviation medicine(2022ZZXM012)Local special scientific research plan project of Shaanxi Provincial Department of Education(22JE012)。
文摘Zenith Tropospheric Delay(ZTD)is an important factor that restricts the high-precision positioning of global navigation satellite system(GNSS),and it is of great significance in establishing a real-time and highprecision ZTD model.However,existing ZTD models only consider the impact of linear terms on ZTD estimation,whereas the nonlinear factors have rarely been investigated before and thus become the focus of this study.A real-time and high-precision ZTD model for large height difference area is proposed by considering the linear and nonlinear characteristics of ZTD spatiotemporal variations and is called the realtime linear and nonlinearity ZTD(RLNZ)model.This model uses the ZTD estimated from the Global Pressure and Temperature 3(GPT3)model as the initial value.The linear impacts of periodic term and height on the estimation of ZTD difference between GNSS and GPT3 model are first considered.In addition,nonlinear factors such as geographical location and time are further used to fit the remaining nonlinear ZTD residuals using the general regression neural network method.Finally,the RLNZ-derived ZTD is obtained at an arbitrary location.The western United States,with height difference ranging from-500 to 4000 m,is selected,and the hourly ZTD of 484 GNSS stations provided by the Nevada Geodetic Laboratory(NGL)and the data of 9 radiosonde(RS)stations in the year 2021 are used.Experiment results show that a better performance of ZTD estimation can be retrieved from the proposed RLNZ model when compared with the GPT3 model.Statistical results show the averaged root mean square(RMS),Bias,and mean absolute error(MAE)of ZTD from GPT3 and RLNZ models are 33.7/0.8/25.7 mm and 22.6/0.1/17.4 mm,respectively.The average improvement rate of the RLNZ model is 33% when compared to the GPT3 model.Finally,the application of the proposed RLNZ model in simulated real-time Precise Point Positioning(PPP)indicates that the accuracy of PPP in N,E and U components is improved by 8%,2%,and 6% when compared with that from the GPT3-based PPP.Meanwhile,the convergence time in N and U components is improved by 23% and 7%,respectively.Such results verify the superiority of the proposed RLNZ model in retrieving realtime ZTD maps for GNSS positioning and navigation applications.
基金supported by National Natural Science Foundation of China(No.52176122).
文摘The centroid coordinate serves as a critical control parameter in motion systems,including aircraft,missiles,rockets,and drones,directly influencing their motion dynamics and control performance.Traditional methods for centroid measurement often necessitate custom equipment and specialized positioning devices,leading to high costs and limited accuracy.Here,we present a centroid measurement method that integrates 3D scanning technology,enabling accurate measurement of centroid across various types of objects without the need for specialized positioning fixtures.A theoretical framework for centroid measurement was established,which combined the principle of the multi-point weighing method with 3D scanning technology.The measurement accuracy was evaluated using a designed standard component.Experimental results demonstrate that the discrepancies between the theoretical and the measured centroid of a standard component with various materials and complex shapes in the X,Y,and Z directions are 0.003 mm,0.009 mm,and 0.105 mm,respectively,yielding a spatial deviation of 0.106 mm.Qualitative verification was conducted through experimental validation of three distinct types.They confirmed the reliability of the proposed method,which allowed for accurate centroid measurements of various products without requiring positioning fixtures.This advancement significantly broadened the applicability and scope of centroid measurement devices,offering new theoretical insights and methodologies for the measurement of complex parts and systems.
基金supported by the National Natural Science Foundation of China(grant numbers 82204127 and 72204172)。
文摘Lung cancer, the leading cause of cancer deaths worldwide and in China, has a 19.7% five-year survival rate due to terminal-stage diagnosis^([1-3]).Although low-dose computed tomography(CT) screening can reduce mortality, high false positive rates can create economic and psychological burdens.
文摘Despite advancements in neuroimaging,false positive diagnoses of intracranial aneurysms remain a significant concern.This article examines the causes,prevalence,and implications of such false-positive diagnoses.We discuss how conditions like arterial occlusion with vascular stump formation and infundibular widening can mimic aneurysms,particularly in the anterior circulation.The article compares various imaging modalities,including computer tomography angiogram,magnetic resonance imaging/angiography,and digital subtraction angiogram,highlighting their strengths and limitations.We emphasize the im-portance of accurate differentiation to avoid unnecessary surgical interventions.The potential of emerging technologies,such as high-resolution vessel wall ima-ging and deep neural networks for automated detection,is explored as promising avenues for improving diagnostic accuracy.This manuscript underscores the need for continued research and clinical vigilance in the diagnosis of intracranial aneurysms.
文摘A general metal-free photochemcial oxidation of benzylic C—H bonds has been successfully accomplished via a hydrogen atom transfer(HAT)process.A range of high value-added aromatic ketones were facilely synthesized with high chemoselectivity under mild conditions.Moreover,the mild conditions by using air as the oxidant render the developed proto-col more ecofriendly and environmentally sustainable.
基金Supported by the Short-wave Infrared Camera Systems(B025F40622024)。
文摘The accuracy of spot centroid positioning has a significant impact on the tracking accuracy of the system and the stability of the laser link construction.In satellite laser communication systems,the use of short-wave infrared wavelengths as beacon light can reduce atmospheric absorption and signal attenuation.However,there are strong non-uniformity and blind pixels in the short-wave infrared image,which makes the image distorted and leads to the decrease of spot centroid positioning accuracy.Therefore,the high-precision localization of the spot centroid of the short-wave infrared images is of great research significance.A high-precision spot centroid positioning model for short-wave infrared is proposed to correct for non-uniformity and blind pixels in short-wave infrared images and quantify the localization errors caused by the two,further model-based localization error simulations are performed,and a novel spot centroid positioning payload for satellite laser communications has been designed using the latest 640×512 planar array InGaAs shortwave infrared detector.The experimental results show that the non-uniformity of the corrected image is reduced from 7%to 0.6%,the blind pixels rejection rate reaches 100%,the frame rate can be up to 2000 Hz,and the spot centroid localization accuracy is as high as 0.1 pixel point,which realizes high-precision spot centroid localization of high-frame-frequency short-wave infrared images.
基金Supported by NSFC(No.11861010),also supported by NSFC(No.12171175),also supported by NSFC(No.12261006)NSF of Guangxi Province(No.2018GXNSFFA281008)Project of Guangxi First Class Disciplines of Statistics(No.GJKY-2022-01)。
文摘In this paper,we study the Bowen entropy of stable sets in positive entropy G-system of amenable group actions.The lower bound of the Bowen entropy of these sets are estimated.
