Background:Esophageal cancer(EC)remains a global health challenge due to its poor prognosis.China and the United States of America(USA)represent two distinct epicenters of EC burden.Understanding the EC disparities in...Background:Esophageal cancer(EC)remains a global health challenge due to its poor prognosis.China and the United States of America(USA)represent two distinct epicenters of EC burden.Understanding the EC disparities in these two countries is vital for tailoring prevention strategies,optimizing treatment,and enhancing outcomes in both countries.Yet,there lacks a comprehensive comparison of EC characteristics between the two countries.Methods:In this multicenter,retrospective hospital-based study,we enrolled primary EC patients who received their initial treatment at one of 23 hospitals in China during 2016-2017.Using electronic medical records and cancer registration records,information on demographics,lifestyle,and clinicopathological characteristics(in-cluding tumor site,pathology,stage,metastases,differentiation,and treatment)were collected.Additionally,we compared these data with the clinicopathological information of invasive EC patients diagnosed in 2016-2017 from the Surveillance,Epidemiology,and End Results(SEER)database in the USA.Results:A total of 6,658 EC patients in China and 8,555 EC patients in the USA were included finally.85.5%(n=5,694)of EC were esophageal squamous cell carcinoma(ESCC)in China,while esophageal adenocarcinoma(EAC)was prominent in the USA(58.9%,n=5,041).Among EC patients with known staging,the proportion of early stage was higher in China compared to the USA(48.3%vs.30.5%).Among ESCC patients,early-stage cases were higher in China than in the USA(49.8%vs.31.8%),while among EAC patients,late-stage cases were higher in China than in the USA(77.3%vs.68.5%)(all P<0.001).In China,EC mainly occurred in the middle third(60.2%)of the esophagus,whereas in the USA,it was more common in the lower third(59.9%)of the organ.Compared with EC patients with known metastatic status in the USA,China had fewer cases of lymph node metastases(51.4%vs.57.7%)and distant metastases(7.9%vs.33.8%).Regarding treatment,China had more surgical therapy(53.7%vs.22.6%),less radiotherapy(35.6%vs.53.3%),and less chemotherapy(46.7%vs.59.7%)compared to the USA.Conclusions:This study reveals notable disparities in EC between China and the USA,encompassing epidemi-ological,clinicopathological,and treatment dimensions.These findings provide insight for tailored strategies addressing regional variations in clinicopathological and therapeutic characteristics.展开更多
Both acceleration and pseudo-acceleration response spectra play important roles in structural seismic design.However,only one of them is generally provided in most seismic codes.Therefore,many studies have attempted t...Both acceleration and pseudo-acceleration response spectra play important roles in structural seismic design.However,only one of them is generally provided in most seismic codes.Therefore,many studies have attempted to develop conversion models between the acceleration response spectrum(SA)and the pseudo-acceleration response spectrum(PSA).Our previous studies found that the relationship between SA and PSA is affected by magnitude,distance,and site class.Subsequently,we developed an SA/PSA model incorporating these effects.However,this model is suitable for cases with small and moderate magnitudes and its accuracy is not good enough for cases with large magnitudes.This paper aims to develop an efficient SA/PSA model by considering influences of magnitude,distance,and site class,which can be applied to cases not only with small or moderate magnitudes but also with large ones.For this purpose,regression analyses were conducted using 16,660 horizontal seismic records with a wider range of magnitude.The magnitude of these seismic records varies from 4 to 9 and the distances vary from 10 to 200 km.These ground motions were recorded at 338 stations covering four site classes.By comparing them with existing models,it was found that the proposed model shows better accuracy for cases with any magnitudes,distances,and site classes considered in this study.展开更多
BACKGROUND Orthodontic treatment for open bite and crossbite cases is always challenging.In this paper,we demonstrate a skeletal class III patient with anterior open bite and crossbite whose problem was successfully c...BACKGROUND Orthodontic treatment for open bite and crossbite cases is always challenging.In this paper,we demonstrate a skeletal class III patient with anterior open bite and crossbite whose problem was successfully corrected with improved super-elastic Ti-Ni alloy wire(ISW).CASE SUMMARY A 19 years old male came to our clinic with a chief complaint of anterior open bite and crossbite and not able to chew food well.Clinical examination revealed an angle class III malocclusion with anterior open bite,crossbite and spaced arch.Ra-diographic and clinical examination showed a skeletal class III pattern.We used ISW to level the upper and lower arch and to correct the anterior open bite and crossbite.Intermaxillary elastics were also used to achieve a better interdigitation.Finally,adequate overbite,overjet and a desirable occlusion were achieved.The active treatment time took 2 years and 2 months.CONCLUSION In a case of class III angular malocclusion with open bite and crossbite in the ante-rior teeth,ideal results were achieved using the ISW technique and the patient was satisfied with the outcome.展开更多
This study compared HPV testing and liquid-based cytology (LCT) as performance indicators for cervical cancer screening in a hospital-based study. A total of 61,193 outpatients were screened initially by LCT. Sample...This study compared HPV testing and liquid-based cytology (LCT) as performance indicators for cervical cancer screening in a hospital-based study. A total of 61,193 outpatients were screened initially by LCT. Samples with screening results showing atypical squamous cells of undetermined significance (ASC-US) or worse were referred for colposcopy, and some samples were tested for high-risk HPV types with the Hybrid Capture II system (HC II). Data on LCT (n=61,193) and HC II (n=1056) results were analysed. Overall test positivity for LCT was 2.53% using an ASC-US threshold, 3.11% using a low-grade squamous intraepithelial lesion (LSIL) threshold, and 0.67% using a high-grade squamous intraepithelial lesion (HSIL) threshold. A total of 1839 women (84% of the 3893 patients with abnormal cytology) underwent colposcopy-directed biopsy. HPV was positive in 80.3% of women with cervical intraepithelial neoplasia 1 (CIN1), 88.3% of those with CIN2, 79.2% of women with CIN3 and 50% (2 of 4) of women with invasive cancer. There was a significant increase in the detection of CIN2 or worse with adjunct HPV testing of women with ASC-US and LSIL However, there were detection of CIN2+ cases no differences in the with adjunct HPV testing of women with HSlI.. The results indicate that HPV testing for HSlL triage should not be recommended in cervical cancer screening.展开更多
Hospital-based health technology assessment(HB-HTA)is highly valuable in the application of hospital medical technology,cost control,improvement of medical quality,and protection of medical safety,and its use is incre...Hospital-based health technology assessment(HB-HTA)is highly valuable in the application of hospital medical technology,cost control,improvement of medical quality,and protection of medical safety,and its use is increasing daily globally.However,in China,HB-HTA is still in its infancy,and it is yet to be adopted in traditional Chinese medicine(TCM).Therefore,this article introduces the application and development of HB-HTA,as well as discusses the current situation of TCM and related future development strategies to provide ideas and references for the development of HB-HTA in TCM.We conclude and recommend that all major stakeholders,including the state,health departments,and hospital leaders,support and promote the exploration and development of HB-HTA in TCM hospitals and integrative medicine hospitals.We also suggest the utilization of existing talents and introduction of other necessary talents to promote better and faster organizational development,as well as suggest the formation of a national and internationally recognized HB-HTA guidance manual and toolkit for TCM hospitals based on both the national HTA guidelines and the evaluation of TCM hospitals pilot projects.Moreover,we recommend that HB-HTA pilot study should be executed with Chinese patent medicine as the starting point to form the implementation process and framework in the TCM arena.展开更多
BACKGROUND The relation between orthodontic treatment and temporomandibular disorders(TMDs)is under debate;the management of TMD during orthodontic treatment has always been a challenge.If TMD symptoms occur during or...BACKGROUND The relation between orthodontic treatment and temporomandibular disorders(TMDs)is under debate;the management of TMD during orthodontic treatment has always been a challenge.If TMD symptoms occur during orthodontic treatment,an immediate pause of orthodontic adjustments is recommended;the treatment can resume when the symptoms are managed and stabilized.CASE SUMMARY This case report presents a patient(26-year-old,female)with angle class I,skeletal class II and TMDs.The treatment was a hybrid of clear aligners,fixed appliances and temporary anchorage devices(TADs).After 3 mo resting and treatment on her TMD,the patient’s TMD symptom alleviated,but her anterior occlusion displayed deep overbite.Therefore,the fixed appliances with TAD were used to correct the anterior deep-bite and level maxillary and mandibular deep curves.After the levelling,the patient showed dual bite with centric relation and maximum intercuspation discrepancy on her occlusion.After careful examination of temporomandibular joints(TMJ)position,the stable bite splint and Invisible Mandibular Advancement appliance were used to reconstruct her occlusion.Eventually,the improved facial appearance and relatively stable occlusion were achieved.The 1-year follow-up records showed there was no obvious change in TMJ morphology,and her occlusion was stable.CONCLUSION TMD screening and monitoring is of great clinical importance in the TMD susceptible patients.Hybrid treatment with clear aligners and fixed appliances and TADs is an effective treatment modality for the complex cases.展开更多
The study of machine learning has revealed that it can unleash new applications in a variety of disciplines.Many limitations limit their expressiveness,and researchers are working to overcome them to fully exploit the...The study of machine learning has revealed that it can unleash new applications in a variety of disciplines.Many limitations limit their expressiveness,and researchers are working to overcome them to fully exploit the power of data-driven machine learning(ML)and deep learning(DL)techniques.The data imbalance presents major hurdles for classification and prediction problems in machine learning,restricting data analytics and acquiring relevant insights in practically all real-world research domains.In visual learning,network information security,failure prediction,digital marketing,healthcare,and a variety of other domains,raw data suffers from a biased data distribution of one class over the other.This article aims to present a taxonomy of the approaches for handling imbalanced data problems and their comparative study on the classification metrics and their application areas.We have explored very recent trends of techniques employed for solutions to class imbalance problems in datasets and have also discussed their limitations.This article has also identified open challenges for further research in the direction of class data imbalance.展开更多
The popularity of the Internet of Things(IoT)has enabled a large number of vulnerable devices to connect to the Internet,bringing huge security risks.As a network-level security authentication method,device fingerprin...The popularity of the Internet of Things(IoT)has enabled a large number of vulnerable devices to connect to the Internet,bringing huge security risks.As a network-level security authentication method,device fingerprint based on machine learning has attracted considerable attention because it can detect vulnerable devices in complex and heterogeneous access phases.However,flexible and diversified IoT devices with limited resources increase dif-ficulty of the device fingerprint authentication method executed in IoT,because it needs to retrain the model network to deal with incremental features or types.To address this problem,a device fingerprinting mechanism based on a Broad Learning System(BLS)is proposed in this paper.The mechanism firstly characterizes IoT devices by traffic analysis based on the identifiable differences of the traffic data of IoT devices,and extracts feature parameters of the traffic packets.A hierarchical hybrid sampling method is designed at the preprocessing phase to improve the imbalanced data distribution and reconstruct the fingerprint dataset.The complexity of the dataset is reduced using Principal Component Analysis(PCA)and the device type is identified by training weights using BLS.The experimental results show that the proposed method can achieve state-of-the-art accuracy and spend less training time than other existing methods.展开更多
Extensive numerical simulations and scaling analysis are performed to investigate competitive growth between the linear and nonlinear stochastic dynamic growth systems, which belong to the Edwards–Wilkinson(EW) and K...Extensive numerical simulations and scaling analysis are performed to investigate competitive growth between the linear and nonlinear stochastic dynamic growth systems, which belong to the Edwards–Wilkinson(EW) and Kardar–Parisi–Zhang(KPZ) universality classes, respectively. The linear growth systems include the EW equation and the model of random deposition with surface relaxation(RDSR), the nonlinear growth systems involve the KPZ equation and typical discrete models including ballistic deposition(BD), etching, and restricted solid on solid(RSOS). The scaling exponents are obtained in both the(1 + 1)-and(2 + 1)-dimensional competitive growth with the nonlinear growth probability p and the linear proportion 1-p. Our results show that, when p changes from 0 to 1, there exist non-trivial crossover effects from EW to KPZ universality classes based on different competitive growth rules. Furthermore, the growth rate and the porosity are also estimated within various linear and nonlinear growths of cooperation and competition.展开更多
This study analyzed the difference between using a downward breaststroke kick and a horizontal breaststroke kick in a sample of world class elite swimmers.We compared average muscle activity of the gluteus maximus,qua...This study analyzed the difference between using a downward breaststroke kick and a horizontal breaststroke kick in a sample of world class elite swimmers.We compared average muscle activity of the gluteus maximus,quadriceps femoris(vastus medialis and rectus femoris),hamstring/long head of the biceps femoris,gastrocnemius medialis,rectus abdominal,and erector spinae when using the downward breaststroke kick technique.We find that when this sample of swimmers utilized the downward breaststroke kick,max speed and velocity per stroke increased,measured by 12,788 EMG samples,where the results are highly correlated to duration of the aerodynamic buoyant force in breaststroke kick technique.The increases in performance observed from measuring the world class elite swimmers is highly correlated to the duration of the kick aerodynamic buoyant force.Among this sample of elite swimmers,the longer a swimmer demonstrates a buoyant force breaststroke kick,the lower the time in a 100 breaststroke.展开更多
BACKGROUND Severe skeletal class II malocclusion is the indication for combined orthodontic and orthognathic treatment.CASE SUMMARY A woman with a chief complaint of a protruding chin and an inability to close her lip...BACKGROUND Severe skeletal class II malocclusion is the indication for combined orthodontic and orthognathic treatment.CASE SUMMARY A woman with a chief complaint of a protruding chin and an inability to close her lips requested orthodontic camouflage.The treatment plan consisted of extracting the right upper third molar,right lower third molar,left lower second molar,and left upper third molar and moving the maxillary dentition distally using a convenient method involving microimplant nail anchors,push springs,long arm traction hooks,and elastic traction chains.After 52 months of treatment,her overbite and overjet were normal,and her facial profile was favorable.CONCLUSION This method can be used for distal movement of the maxillary dentition and to correct severe skeletal class II malocclusion in adults.展开更多
As an online course-teaching mode,Massive Open Online Course(MOOC)has drawn great attention from both teachers and students.It is necessary to give full play to the advantages of MOOC resources and to enhance teachers...As an online course-teaching mode,Massive Open Online Course(MOOC)has drawn great attention from both teachers and students.It is necessary to give full play to the advantages of MOOC resources and to enhance teachers’consciousness of“identity remodeling”in the process of Integrated Business English flipping classroom teaching.Combining the advantages of MOOC and flipped classroom teaching during before-,during-,and after-class will greatly help promote the overall quality of business English teaching in universities.展开更多
This paper discusses the feasibility of thin-shell wormholes in spacetimes of embedding class one admitting a one-parameter group of conformal motions. It is shown that the surface energy density σis positive, while ...This paper discusses the feasibility of thin-shell wormholes in spacetimes of embedding class one admitting a one-parameter group of conformal motions. It is shown that the surface energy density σis positive, while the surface pressure is negative, resulting in , thereby signaling a violation of the null energy condition, a necessary condition for holding a wormhole open. For a Morris-Thorne wormhole, matter that violates the null energy condition is referred to as “exotic”. For the thin-shell wormholes in this paper, however, the violation has a physical explanation since it is a direct consequence of the embedding theory in conjunction with the assumption of conformal symmetry. These properties avoid the need to hypothesize the existence of the highly problematical exotic matter.展开更多
The professional and moral education of high school mathematics teachers will make classroom management work better,but their work pressure will also lead to classroom management problems.To do a good job in high scho...The professional and moral education of high school mathematics teachers will make classroom management work better,but their work pressure will also lead to classroom management problems.To do a good job in high school class teacher management and organically integrate it with mathematics teaching,we need to start from two aspects:mathematics teaching class teachers and class teacher work teaching,and penetrate mathematical thinking into daily classroom management,moral education,and classroom culture construction.Based on the attributes of the subject,we guide high school students to reflect after class to stimulate their self-management initiative through the cultivation of qualified class representatives.In addition,it is necessary to skillfully resolve classroom generative problems,change the roles of teachers and students,and integrate classroom management with mathematics teaching.展开更多
Based on the characteristics of College English teaching in minority classes,this paper analyzes the ideological and political teaching cases of College English courses in ethnic minority classes from four aspects:bef...Based on the characteristics of College English teaching in minority classes,this paper analyzes the ideological and political teaching cases of College English courses in ethnic minority classes from four aspects:before-class,in-class(flipped classroom teaching),after-class,and teaching design feedback(feedback on students’learning situation,teaching content and methods),starts from the three aspects of knowledge impartation,ability improvement,and value guidance,and integrates the course ideology and politics into the theme,language,and reality,so as to form a“one point and three sides”course ideological and political teaching model.展开更多
基金supported by the National Key R&D Program of China(grant number:2022YFC3600805,2016YFC1302502).
文摘Background:Esophageal cancer(EC)remains a global health challenge due to its poor prognosis.China and the United States of America(USA)represent two distinct epicenters of EC burden.Understanding the EC disparities in these two countries is vital for tailoring prevention strategies,optimizing treatment,and enhancing outcomes in both countries.Yet,there lacks a comprehensive comparison of EC characteristics between the two countries.Methods:In this multicenter,retrospective hospital-based study,we enrolled primary EC patients who received their initial treatment at one of 23 hospitals in China during 2016-2017.Using electronic medical records and cancer registration records,information on demographics,lifestyle,and clinicopathological characteristics(in-cluding tumor site,pathology,stage,metastases,differentiation,and treatment)were collected.Additionally,we compared these data with the clinicopathological information of invasive EC patients diagnosed in 2016-2017 from the Surveillance,Epidemiology,and End Results(SEER)database in the USA.Results:A total of 6,658 EC patients in China and 8,555 EC patients in the USA were included finally.85.5%(n=5,694)of EC were esophageal squamous cell carcinoma(ESCC)in China,while esophageal adenocarcinoma(EAC)was prominent in the USA(58.9%,n=5,041).Among EC patients with known staging,the proportion of early stage was higher in China compared to the USA(48.3%vs.30.5%).Among ESCC patients,early-stage cases were higher in China than in the USA(49.8%vs.31.8%),while among EAC patients,late-stage cases were higher in China than in the USA(77.3%vs.68.5%)(all P<0.001).In China,EC mainly occurred in the middle third(60.2%)of the esophagus,whereas in the USA,it was more common in the lower third(59.9%)of the organ.Compared with EC patients with known metastatic status in the USA,China had fewer cases of lymph node metastases(51.4%vs.57.7%)and distant metastases(7.9%vs.33.8%).Regarding treatment,China had more surgical therapy(53.7%vs.22.6%),less radiotherapy(35.6%vs.53.3%),and less chemotherapy(46.7%vs.59.7%)compared to the USA.Conclusions:This study reveals notable disparities in EC between China and the USA,encompassing epidemi-ological,clinicopathological,and treatment dimensions.These findings provide insight for tailored strategies addressing regional variations in clinicopathological and therapeutic characteristics.
基金National Natural Science Foundation of China under Grant No.52278135。
文摘Both acceleration and pseudo-acceleration response spectra play important roles in structural seismic design.However,only one of them is generally provided in most seismic codes.Therefore,many studies have attempted to develop conversion models between the acceleration response spectrum(SA)and the pseudo-acceleration response spectrum(PSA).Our previous studies found that the relationship between SA and PSA is affected by magnitude,distance,and site class.Subsequently,we developed an SA/PSA model incorporating these effects.However,this model is suitable for cases with small and moderate magnitudes and its accuracy is not good enough for cases with large magnitudes.This paper aims to develop an efficient SA/PSA model by considering influences of magnitude,distance,and site class,which can be applied to cases not only with small or moderate magnitudes but also with large ones.For this purpose,regression analyses were conducted using 16,660 horizontal seismic records with a wider range of magnitude.The magnitude of these seismic records varies from 4 to 9 and the distances vary from 10 to 200 km.These ground motions were recorded at 338 stations covering four site classes.By comparing them with existing models,it was found that the proposed model shows better accuracy for cases with any magnitudes,distances,and site classes considered in this study.
文摘BACKGROUND Orthodontic treatment for open bite and crossbite cases is always challenging.In this paper,we demonstrate a skeletal class III patient with anterior open bite and crossbite whose problem was successfully corrected with improved super-elastic Ti-Ni alloy wire(ISW).CASE SUMMARY A 19 years old male came to our clinic with a chief complaint of anterior open bite and crossbite and not able to chew food well.Clinical examination revealed an angle class III malocclusion with anterior open bite,crossbite and spaced arch.Ra-diographic and clinical examination showed a skeletal class III pattern.We used ISW to level the upper and lower arch and to correct the anterior open bite and crossbite.Intermaxillary elastics were also used to achieve a better interdigitation.Finally,adequate overbite,overjet and a desirable occlusion were achieved.The active treatment time took 2 years and 2 months.CONCLUSION In a case of class III angular malocclusion with open bite and crossbite in the ante-rior teeth,ideal results were achieved using the ISW technique and the patient was satisfied with the outcome.
基金funded by Beijing Municipal Science & Technology Commission(No.Y0905001000091)
文摘This study compared HPV testing and liquid-based cytology (LCT) as performance indicators for cervical cancer screening in a hospital-based study. A total of 61,193 outpatients were screened initially by LCT. Samples with screening results showing atypical squamous cells of undetermined significance (ASC-US) or worse were referred for colposcopy, and some samples were tested for high-risk HPV types with the Hybrid Capture II system (HC II). Data on LCT (n=61,193) and HC II (n=1056) results were analysed. Overall test positivity for LCT was 2.53% using an ASC-US threshold, 3.11% using a low-grade squamous intraepithelial lesion (LSIL) threshold, and 0.67% using a high-grade squamous intraepithelial lesion (HSIL) threshold. A total of 1839 women (84% of the 3893 patients with abnormal cytology) underwent colposcopy-directed biopsy. HPV was positive in 80.3% of women with cervical intraepithelial neoplasia 1 (CIN1), 88.3% of those with CIN2, 79.2% of women with CIN3 and 50% (2 of 4) of women with invasive cancer. There was a significant increase in the detection of CIN2 or worse with adjunct HPV testing of women with ASC-US and LSIL However, there were detection of CIN2+ cases no differences in the with adjunct HPV testing of women with HSlI.. The results indicate that HPV testing for HSlL triage should not be recommended in cervical cancer screening.
基金This study was supported by China Center for Evidence Based Traditional Chinese Medicine,CCEBTCM(2020YJSZX-2).
文摘Hospital-based health technology assessment(HB-HTA)is highly valuable in the application of hospital medical technology,cost control,improvement of medical quality,and protection of medical safety,and its use is increasing daily globally.However,in China,HB-HTA is still in its infancy,and it is yet to be adopted in traditional Chinese medicine(TCM).Therefore,this article introduces the application and development of HB-HTA,as well as discusses the current situation of TCM and related future development strategies to provide ideas and references for the development of HB-HTA in TCM.We conclude and recommend that all major stakeholders,including the state,health departments,and hospital leaders,support and promote the exploration and development of HB-HTA in TCM hospitals and integrative medicine hospitals.We also suggest the utilization of existing talents and introduction of other necessary talents to promote better and faster organizational development,as well as suggest the formation of a national and internationally recognized HB-HTA guidance manual and toolkit for TCM hospitals based on both the national HTA guidelines and the evaluation of TCM hospitals pilot projects.Moreover,we recommend that HB-HTA pilot study should be executed with Chinese patent medicine as the starting point to form the implementation process and framework in the TCM arena.
基金Natural Science Foundation of Jiangsu Province, No. SBK2021021787the Major Project of the Health Commission ofJiangsu Province, No. ZD2022025and the Key Project of the Nanjing Health Commission, No. ZKX20048.
文摘BACKGROUND The relation between orthodontic treatment and temporomandibular disorders(TMDs)is under debate;the management of TMD during orthodontic treatment has always been a challenge.If TMD symptoms occur during orthodontic treatment,an immediate pause of orthodontic adjustments is recommended;the treatment can resume when the symptoms are managed and stabilized.CASE SUMMARY This case report presents a patient(26-year-old,female)with angle class I,skeletal class II and TMDs.The treatment was a hybrid of clear aligners,fixed appliances and temporary anchorage devices(TADs).After 3 mo resting and treatment on her TMD,the patient’s TMD symptom alleviated,but her anterior occlusion displayed deep overbite.Therefore,the fixed appliances with TAD were used to correct the anterior deep-bite and level maxillary and mandibular deep curves.After the levelling,the patient showed dual bite with centric relation and maximum intercuspation discrepancy on her occlusion.After careful examination of temporomandibular joints(TMJ)position,the stable bite splint and Invisible Mandibular Advancement appliance were used to reconstruct her occlusion.Eventually,the improved facial appearance and relatively stable occlusion were achieved.The 1-year follow-up records showed there was no obvious change in TMJ morphology,and her occlusion was stable.CONCLUSION TMD screening and monitoring is of great clinical importance in the TMD susceptible patients.Hybrid treatment with clear aligners and fixed appliances and TADs is an effective treatment modality for the complex cases.
文摘The study of machine learning has revealed that it can unleash new applications in a variety of disciplines.Many limitations limit their expressiveness,and researchers are working to overcome them to fully exploit the power of data-driven machine learning(ML)and deep learning(DL)techniques.The data imbalance presents major hurdles for classification and prediction problems in machine learning,restricting data analytics and acquiring relevant insights in practically all real-world research domains.In visual learning,network information security,failure prediction,digital marketing,healthcare,and a variety of other domains,raw data suffers from a biased data distribution of one class over the other.This article aims to present a taxonomy of the approaches for handling imbalanced data problems and their comparative study on the classification metrics and their application areas.We have explored very recent trends of techniques employed for solutions to class imbalance problems in datasets and have also discussed their limitations.This article has also identified open challenges for further research in the direction of class data imbalance.
基金supported by National Key R&D Program of China(2019YFB2102303)National Natural Science Foundation of China(NSFC61971014,NSFC11675199)Young Backbone Teacher Training Program of Henan Colleges and Universities(2021GGJS170).
文摘The popularity of the Internet of Things(IoT)has enabled a large number of vulnerable devices to connect to the Internet,bringing huge security risks.As a network-level security authentication method,device fingerprint based on machine learning has attracted considerable attention because it can detect vulnerable devices in complex and heterogeneous access phases.However,flexible and diversified IoT devices with limited resources increase dif-ficulty of the device fingerprint authentication method executed in IoT,because it needs to retrain the model network to deal with incremental features or types.To address this problem,a device fingerprinting mechanism based on a Broad Learning System(BLS)is proposed in this paper.The mechanism firstly characterizes IoT devices by traffic analysis based on the identifiable differences of the traffic data of IoT devices,and extracts feature parameters of the traffic packets.A hierarchical hybrid sampling method is designed at the preprocessing phase to improve the imbalanced data distribution and reconstruct the fingerprint dataset.The complexity of the dataset is reduced using Principal Component Analysis(PCA)and the device type is identified by training weights using BLS.The experimental results show that the proposed method can achieve state-of-the-art accuracy and spend less training time than other existing methods.
基金supported by Undergraduate Training Program for Innovation and Entrepreneurship of China University of Mining and Technology (CUMT)(Grant No. 202110290059Z)Fundamental Research Funds for the Central Universities of CUMT (Grant No. 2020ZDPYMS33)。
文摘Extensive numerical simulations and scaling analysis are performed to investigate competitive growth between the linear and nonlinear stochastic dynamic growth systems, which belong to the Edwards–Wilkinson(EW) and Kardar–Parisi–Zhang(KPZ) universality classes, respectively. The linear growth systems include the EW equation and the model of random deposition with surface relaxation(RDSR), the nonlinear growth systems involve the KPZ equation and typical discrete models including ballistic deposition(BD), etching, and restricted solid on solid(RSOS). The scaling exponents are obtained in both the(1 + 1)-and(2 + 1)-dimensional competitive growth with the nonlinear growth probability p and the linear proportion 1-p. Our results show that, when p changes from 0 to 1, there exist non-trivial crossover effects from EW to KPZ universality classes based on different competitive growth rules. Furthermore, the growth rate and the porosity are also estimated within various linear and nonlinear growths of cooperation and competition.
文摘This study analyzed the difference between using a downward breaststroke kick and a horizontal breaststroke kick in a sample of world class elite swimmers.We compared average muscle activity of the gluteus maximus,quadriceps femoris(vastus medialis and rectus femoris),hamstring/long head of the biceps femoris,gastrocnemius medialis,rectus abdominal,and erector spinae when using the downward breaststroke kick technique.We find that when this sample of swimmers utilized the downward breaststroke kick,max speed and velocity per stroke increased,measured by 12,788 EMG samples,where the results are highly correlated to duration of the aerodynamic buoyant force in breaststroke kick technique.The increases in performance observed from measuring the world class elite swimmers is highly correlated to the duration of the kick aerodynamic buoyant force.Among this sample of elite swimmers,the longer a swimmer demonstrates a buoyant force breaststroke kick,the lower the time in a 100 breaststroke.
基金Supported by Medical Science Research Project Plan by Health Commission of the Hebei Province,No.20220063.
文摘BACKGROUND Severe skeletal class II malocclusion is the indication for combined orthodontic and orthognathic treatment.CASE SUMMARY A woman with a chief complaint of a protruding chin and an inability to close her lips requested orthodontic camouflage.The treatment plan consisted of extracting the right upper third molar,right lower third molar,left lower second molar,and left upper third molar and moving the maxillary dentition distally using a convenient method involving microimplant nail anchors,push springs,long arm traction hooks,and elastic traction chains.After 52 months of treatment,her overbite and overjet were normal,and her facial profile was favorable.CONCLUSION This method can be used for distal movement of the maxillary dentition and to correct severe skeletal class II malocclusion in adults.
基金“Provincial Online and Offline Hybrid First-Class Course-Integrated Business English 1-of Zhejiang Province in 2020”.
文摘As an online course-teaching mode,Massive Open Online Course(MOOC)has drawn great attention from both teachers and students.It is necessary to give full play to the advantages of MOOC resources and to enhance teachers’consciousness of“identity remodeling”in the process of Integrated Business English flipping classroom teaching.Combining the advantages of MOOC and flipped classroom teaching during before-,during-,and after-class will greatly help promote the overall quality of business English teaching in universities.
文摘This paper discusses the feasibility of thin-shell wormholes in spacetimes of embedding class one admitting a one-parameter group of conformal motions. It is shown that the surface energy density σis positive, while the surface pressure is negative, resulting in , thereby signaling a violation of the null energy condition, a necessary condition for holding a wormhole open. For a Morris-Thorne wormhole, matter that violates the null energy condition is referred to as “exotic”. For the thin-shell wormholes in this paper, however, the violation has a physical explanation since it is a direct consequence of the embedding theory in conjunction with the assumption of conformal symmetry. These properties avoid the need to hypothesize the existence of the highly problematical exotic matter.
文摘The professional and moral education of high school mathematics teachers will make classroom management work better,but their work pressure will also lead to classroom management problems.To do a good job in high school class teacher management and organically integrate it with mathematics teaching,we need to start from two aspects:mathematics teaching class teachers and class teacher work teaching,and penetrate mathematical thinking into daily classroom management,moral education,and classroom culture construction.Based on the attributes of the subject,we guide high school students to reflect after class to stimulate their self-management initiative through the cultivation of qualified class representatives.In addition,it is necessary to skillfully resolve classroom generative problems,change the roles of teachers and students,and integrate classroom management with mathematics teaching.
基金Research Topic of Higher Education of Heilongjiang Higher Education Society(Research on Innovation of English Teaching Curriculum Construction System for Minority Classes in Colleges and Universities Under Digital Empowerment(Fund No.23GJYBJ022)Reform and Innovation Project of Foreign Language Education in Undergraduate Colleges in Heilongjiang Province(Research on the Construction of Ubiquitous Learning Mode of Integrating College English Humanistic Literacy and Language Skills Under the Background of New Engineering(Fund No.HWX2022004-A)Research on the Construction and Effectiveness of College English 4I Seminar Teaching Mode Under the Background of the General Project of Provincial Higher Education Teaching Reform in 2021“First-Class Undergraduate Course”(Fund No.SJGY20210164).
文摘Based on the characteristics of College English teaching in minority classes,this paper analyzes the ideological and political teaching cases of College English courses in ethnic minority classes from four aspects:before-class,in-class(flipped classroom teaching),after-class,and teaching design feedback(feedback on students’learning situation,teaching content and methods),starts from the three aspects of knowledge impartation,ability improvement,and value guidance,and integrates the course ideology and politics into the theme,language,and reality,so as to form a“one point and three sides”course ideological and political teaching model.