The fast slewing rate and wide band of the VLBI2010 Global Observing System(VGOS) telescopes are beneficial to procure more observations and to obtain VLBI reference points(RPs) of high precisions.Meanwhile, with the ...The fast slewing rate and wide band of the VLBI2010 Global Observing System(VGOS) telescopes are beneficial to procure more observations and to obtain VLBI reference points(RPs) of high precisions.Meanwhile, with the development of synchronous tracking of fixed targets on telescopes during the observing, the RPs also can be determined in near real time based on a frame defined by other techniques. These opportunities provide us a possibility to explore the high geodetic resolution of VGOS telescopes. We design a thermal variation in RP as true values, and schedule a synchronous session of VGOS and target point(TP) series observing. Then VGOS delays and TP series are simulated and solved via piecewise functions. The results show that the accuracy of vertical component of the RP could be determined at an accuracy of 0.5 ± 0.3 mm in an hour using TP series, whereas the vertical components of RP solved by using VGOS delay measurements have a greater uncertainty due to the random error in the simulated atmosphere and bad radio source sky coverage in a shorter time interval. Some details in the data processing and accuracy evaluation are also introduced.展开更多
Ensemble simulations, which use multiple short independent trajectories from dispersive initial conformations, rather than a single long trajectory as used in traditional simulations, are expected to sample complex sy...Ensemble simulations, which use multiple short independent trajectories from dispersive initial conformations, rather than a single long trajectory as used in traditional simulations, are expected to sample complex systems such as biomolecules much more efficiently. The re-weighted ensemble dynamics（RED） is designed to combine these short trajectories to reconstruct the global equilibrium distribution. In the RED, a number of conformational functions, named as basis functions,are applied to relate these trajectories to each other, then a detailed-balance-based linear equation is built, whose solution provides the weights of these trajectories in equilibrium distribution. Thus, the sufficient and efficient selection of basis functions is critical to the practical application of RED. Here, we review and present a few possible ways to generally construct basis functions for applying the RED in complex molecular systems. Especially, for systems with less priori knowledge, we could generally use the root mean squared deviation（RMSD） among conformations to split the whole conformational space into a set of cells, then use the RMSD-based-cell functions as basis functions. We demonstrate the application of the RED in typical systems, including a two-dimensional toy model, the lattice Potts model, and a short peptide system. The results indicate that the RED with the constructions of basis functions not only more efficiently sample the complex systems, but also provide a general way to understand the metastable structure of conformational space.展开更多
The transition points of lattice quantum chromodynamics（QCD） with two degenerate flavors of Wilson quarks at finite temperature T and small imaginary quark chemical potential μ are determined by using the reweighti...The transition points of lattice quantum chromodynamics（QCD） with two degenerate flavors of Wilson quarks at finite temperature T and small imaginary quark chemical potential μ are determined by using the reweighting technique.Under the positive fermion determinant,i.e.,the chemical potential is pure imaginary,the simulations are performed at hopping parameter κ = 0.165.The comparison between the reweighting technique and the conventional point-by-point scanning method is presented.The results prove that the reweighting technique is an effective and efficient method in investigating the critical phenomenon.展开更多
BACKGROUND Persistent postural-perceptual dizziness(PPPD)is a functional disorder,typically preceded by acute vestibular disorders.It is characterized by a shift in processing spatial orientation information,to favor ...BACKGROUND Persistent postural-perceptual dizziness(PPPD)is a functional disorder,typically preceded by acute vestibular disorders.It is characterized by a shift in processing spatial orientation information,to favor visual over vestibular and somatosensory inputs,and a failure of higher cortical mechanisms.To date,no therapies for PPPD have been approved.Kampo medicine hangebyakujutsutemmato(HBT)has been reported to alleviate disturbances of equilibrium.We hypothesized that HBT would be a beneficial treatment for PPPD.AIM To examine the efficacy of HBT for the treatment of PPPD.METHODS Patients with PPPD were enrolled and divided into two groups:The HBT group(n=24)and the non-HBT group(n=14).The participants completed questionnaire surveys[Niigata PPPD questionnaire(NPQ),dizziness handicap inventory,hospital anxiety and depression scale(HADS),orthostatic dysregulation questionnaire,pittsburg sleep quality index(PSQI),and motion sickness scores]before and after HBT treatment.Additionally,to identify HBT responders,multivariate regression analysis was performed using the results of the ques-tionnaire surveys and equilibrium tests;including stabilometry,and caloric,vestibular evoked myogenic response,and head-up tilt tests.RESULTS Thirty-eight outpatients were included in this study,of which 14 patients(3 men,11 women;mean age,63.5±15.9 years)received treatment without HBT,and 24(1 man,23 women;mean age,58.2±18.7 years)received combination treatment with HBT.Following HBT treatment,NPQ scores decreased significantly(baseline 40.1±10.0 vs 2 mo 24.6±17.7,P<0.001).No statistically significant changes were observed in the NPQ scores in the non-HBT group(baseline 38.6±12.2 vs 2 mo 39.4±14.4,P=0.92).Multivariable regression analysis revealed that the results of stabilometry(P=0.02)and the caloric(P=0.03),and head-up tilt tests(P<0.001),HADS(P=0.003),and PSQI(P=0.01)were associated with HBT responsiveness in PPPD patients.CONCLUSION HBT may be an effective adjunct therapy for PPPD.Patients with autonomic dysfunction展开更多
电子病历EMR(Electronic Medical Records)检索是信息检索研究中的一个新领域。医学术语在电子病历检索中占有重要地位,通常用来限定检索条件、表达用户的检索意图。针对这种情况,提出一种基于医学术语权重调整的查询重构方法,以提高电...电子病历EMR(Electronic Medical Records)检索是信息检索研究中的一个新领域。医学术语在电子病历检索中占有重要地位,通常用来限定检索条件、表达用户的检索意图。针对这种情况,提出一种基于医学术语权重调整的查询重构方法,以提高电子病历检索的性能。该方法首先从原始查询语句中筛选出医学术语,然后使用自信息来度量每个医学术语的权重,最后将加权的医学术语与原始查询语句按照一定的权重比例结合,构造出新的查询语句。将该方法在TREC数据集上进行实验,结果表明与原始查询结果相比,重构后的查询结果在MAP、bpref和P10这三项指标上,分别提高了14.2%、10.1%和9.6%,验证了该方法的有效性。展开更多
Reweighting adversarial examples during training plays an essential role in improving the robustness of neural networks,which lies in the fact that examples closer to the decision boundaries are much more vulnerable t...Reweighting adversarial examples during training plays an essential role in improving the robustness of neural networks,which lies in the fact that examples closer to the decision boundaries are much more vulnerable to being attacked and should be given larger weights.The probability margin(PM)method is a promising approach to continuously and path-independently mea-suring such closeness between the example and decision boundary.However,the performance of PM is limited due to the fact that PM fails to effectively distinguish the examples having only one misclassified category and the ones with multiple misclassified categories,where the latter is closer to multi-classification decision boundaries and is supported to be more critical in our observation.To tackle this problem,this paper proposed an improved PM criterion,called confused-label-based PM(CL-PM),to measure the closeness mentioned above and reweight adversarial examples during training.Specifi-cally,a confused label(CL)is defined as the label whose prediction probability is greater than that of the ground truth label given a specific adversarial example.Instead of considering the discrepancy between the probability of the true label and the probability of the most misclassified label as the PM method does,we evaluate the closeness by accumulating the probability differences of all the CLs and ground truth label.CL-PM shares a negative correlation with data vulnerability:data with larger/smaller CL-PM is safer/riskier and should have a smaller/larger weight.Experiments demonstrated that CL-PM is more reliable in indicating the closeness regarding multiple misclassified categories,and reweighting adversarial training based on CL-PM outperformed state-of-the-art counterparts.展开更多
In point cloud registration applications,noise and poor initial conditions lead to many false matches.False matches significantly degrade registration accuracy and speed.A penalty function is adopted in many robust po...In point cloud registration applications,noise and poor initial conditions lead to many false matches.False matches significantly degrade registration accuracy and speed.A penalty function is adopted in many robust point-to-point registration methods to suppress the influence of false matches.However,after applying a penalty function,problems cannot be solved in their analytical forms based on the introduction of nonlinearity.Therefore,most existing methods adopt the descending method.In this paper,a novel iterative-reweighting-based method is proposed to overcome the limitations of existing methods.The proposed method iteratively solves the eigenvectors of a four-dimensional matrix,whereas the calculation of the descending method relies on solving an eight-dimensional matrix.Therefore,the proposed method can achieve increased computational efficiency.The proposed method was validated on simulated noise corruption data,and the results reveal that it obtains higher efficiency and precision than existing methods,particularly under very noisy conditions.Experimental results for the KITTI dataset demonstrate that the proposed method can be used in real-time localization processes with high accuracy and good efficiency.展开更多
基金supported by National Natural Science Foundation of China (1703067)
文摘The fast slewing rate and wide band of the VLBI2010 Global Observing System(VGOS) telescopes are beneficial to procure more observations and to obtain VLBI reference points(RPs) of high precisions.Meanwhile, with the development of synchronous tracking of fixed targets on telescopes during the observing, the RPs also can be determined in near real time based on a frame defined by other techniques. These opportunities provide us a possibility to explore the high geodetic resolution of VGOS telescopes. We design a thermal variation in RP as true values, and schedule a synchronous session of VGOS and target point(TP) series observing. Then VGOS delays and TP series are simulated and solved via piecewise functions. The results show that the accuracy of vertical component of the RP could be determined at an accuracy of 0.5 ± 0.3 mm in an hour using TP series, whereas the vertical components of RP solved by using VGOS delay measurements have a greater uncertainty due to the random error in the simulated atmosphere and bad radio source sky coverage in a shorter time interval. Some details in the data processing and accuracy evaluation are also introduced.
基金Project supported by the National Natural Science Foundation of China(Grant No.11175250)
文摘Ensemble simulations, which use multiple short independent trajectories from dispersive initial conformations, rather than a single long trajectory as used in traditional simulations, are expected to sample complex systems such as biomolecules much more efficiently. The re-weighted ensemble dynamics（RED） is designed to combine these short trajectories to reconstruct the global equilibrium distribution. In the RED, a number of conformational functions, named as basis functions,are applied to relate these trajectories to each other, then a detailed-balance-based linear equation is built, whose solution provides the weights of these trajectories in equilibrium distribution. Thus, the sufficient and efficient selection of basis functions is critical to the practical application of RED. Here, we review and present a few possible ways to generally construct basis functions for applying the RED in complex molecular systems. Especially, for systems with less priori knowledge, we could generally use the root mean squared deviation（RMSD） among conformations to split the whole conformational space into a set of cells, then use the RMSD-based-cell functions as basis functions. We demonstrate the application of the RED in typical systems, including a two-dimensional toy model, the lattice Potts model, and a short peptide system. The results indicate that the RED with the constructions of basis functions not only more efficiently sample the complex systems, but also provide a general way to understand the metastable structure of conformational space.
基金Supported by the National Natural Science Foundation of China (10847137)the Science Foundation of Jiangsu University (1283000345)
文摘The transition points of lattice quantum chromodynamics（QCD） with two degenerate flavors of Wilson quarks at finite temperature T and small imaginary quark chemical potential μ are determined by using the reweighting technique.Under the positive fermion determinant,i.e.,the chemical potential is pure imaginary,the simulations are performed at hopping parameter κ = 0.165.The comparison between the reweighting technique and the conventional point-by-point scanning method is presented.The results prove that the reweighting technique is an effective and efficient method in investigating the critical phenomenon.
文摘BACKGROUND Persistent postural-perceptual dizziness(PPPD)is a functional disorder,typically preceded by acute vestibular disorders.It is characterized by a shift in processing spatial orientation information,to favor visual over vestibular and somatosensory inputs,and a failure of higher cortical mechanisms.To date,no therapies for PPPD have been approved.Kampo medicine hangebyakujutsutemmato(HBT)has been reported to alleviate disturbances of equilibrium.We hypothesized that HBT would be a beneficial treatment for PPPD.AIM To examine the efficacy of HBT for the treatment of PPPD.METHODS Patients with PPPD were enrolled and divided into two groups:The HBT group(n=24)and the non-HBT group(n=14).The participants completed questionnaire surveys[Niigata PPPD questionnaire(NPQ),dizziness handicap inventory,hospital anxiety and depression scale(HADS),orthostatic dysregulation questionnaire,pittsburg sleep quality index(PSQI),and motion sickness scores]before and after HBT treatment.Additionally,to identify HBT responders,multivariate regression analysis was performed using the results of the ques-tionnaire surveys and equilibrium tests;including stabilometry,and caloric,vestibular evoked myogenic response,and head-up tilt tests.RESULTS Thirty-eight outpatients were included in this study,of which 14 patients(3 men,11 women;mean age,63.5±15.9 years)received treatment without HBT,and 24(1 man,23 women;mean age,58.2±18.7 years)received combination treatment with HBT.Following HBT treatment,NPQ scores decreased significantly(baseline 40.1±10.0 vs 2 mo 24.6±17.7,P<0.001).No statistically significant changes were observed in the NPQ scores in the non-HBT group(baseline 38.6±12.2 vs 2 mo 39.4±14.4,P=0.92).Multivariable regression analysis revealed that the results of stabilometry(P=0.02)and the caloric(P=0.03),and head-up tilt tests(P<0.001),HADS(P=0.003),and PSQI(P=0.01)were associated with HBT responsiveness in PPPD patients.CONCLUSION HBT may be an effective adjunct therapy for PPPD.Patients with autonomic dysfunction
文摘电子病历EMR(Electronic Medical Records)检索是信息检索研究中的一个新领域。医学术语在电子病历检索中占有重要地位,通常用来限定检索条件、表达用户的检索意图。针对这种情况,提出一种基于医学术语权重调整的查询重构方法,以提高电子病历检索的性能。该方法首先从原始查询语句中筛选出医学术语,然后使用自信息来度量每个医学术语的权重,最后将加权的医学术语与原始查询语句按照一定的权重比例结合,构造出新的查询语句。将该方法在TREC数据集上进行实验,结果表明与原始查询结果相比,重构后的查询结果在MAP、bpref和P10这三项指标上,分别提高了14.2%、10.1%和9.6%,验证了该方法的有效性。
基金supported by the National Natural Science Foundation of China (No.62072127,No.62002076,No.61906049)Natural Science Foundation of Guangdong Province (No.2023A1515011774,No.2020A1515010423)+3 种基金Project 6142111180404 supported by CNKLSTISS,Science and Technology Program of Guangzhou,China (No.202002030131)Guangdong basic and applied basic research fund joint fund Youth Fund (No.2019A1515110213)Open Fund Project of Fujian Provincial Key Laboratory of Information Processing and Intelligent Control (Minjiang University) (No.MJUKF-IPIC202101)Scientific research project for Guangzhou University (No.RP2022003).
文摘Reweighting adversarial examples during training plays an essential role in improving the robustness of neural networks,which lies in the fact that examples closer to the decision boundaries are much more vulnerable to being attacked and should be given larger weights.The probability margin(PM)method is a promising approach to continuously and path-independently mea-suring such closeness between the example and decision boundary.However,the performance of PM is limited due to the fact that PM fails to effectively distinguish the examples having only one misclassified category and the ones with multiple misclassified categories,where the latter is closer to multi-classification decision boundaries and is supported to be more critical in our observation.To tackle this problem,this paper proposed an improved PM criterion,called confused-label-based PM(CL-PM),to measure the closeness mentioned above and reweight adversarial examples during training.Specifi-cally,a confused label(CL)is defined as the label whose prediction probability is greater than that of the ground truth label given a specific adversarial example.Instead of considering the discrepancy between the probability of the true label and the probability of the most misclassified label as the PM method does,we evaluate the closeness by accumulating the probability differences of all the CLs and ground truth label.CL-PM shares a negative correlation with data vulnerability:data with larger/smaller CL-PM is safer/riskier and should have a smaller/larger weight.Experiments demonstrated that CL-PM is more reliable in indicating the closeness regarding multiple misclassified categories,and reweighting adversarial training based on CL-PM outperformed state-of-the-art counterparts.
基金the National Natural Science Foundation of China(No.U1764264)。
文摘In point cloud registration applications,noise and poor initial conditions lead to many false matches.False matches significantly degrade registration accuracy and speed.A penalty function is adopted in many robust point-to-point registration methods to suppress the influence of false matches.However,after applying a penalty function,problems cannot be solved in their analytical forms based on the introduction of nonlinearity.Therefore,most existing methods adopt the descending method.In this paper,a novel iterative-reweighting-based method is proposed to overcome the limitations of existing methods.The proposed method iteratively solves the eigenvectors of a four-dimensional matrix,whereas the calculation of the descending method relies on solving an eight-dimensional matrix.Therefore,the proposed method can achieve increased computational efficiency.The proposed method was validated on simulated noise corruption data,and the results reveal that it obtains higher efficiency and precision than existing methods,particularly under very noisy conditions.Experimental results for the KITTI dataset demonstrate that the proposed method can be used in real-time localization processes with high accuracy and good efficiency.
文摘新事件检测(new event detection,简称NED)的目标是从一个或多个新闻源中检测出报道一个新闻话题的第一个新闻.初步实验发现,在对不同类别的新闻报道进行新事件检测时,其不同类型的词元往往具有不同的敏感程度.而传统方法往往将所有的词元等同看待.重点研究在新事件检测模型中,对于不同词元的权重设定问题.提出利用统计方法优化不同类别新闻对于不同词性词元的权重参数;提出利用已有新闻簇信息动态更新词元权重的方法,采用在新闻之间(而非新闻与新闻簇之间)计算相似度的形式,发挥两种比较形式的优点.在Linguistic Data Consortium(LDC)公共数据集TDT2与TDT3上进行实验,实验结果表明,这两种改进方法的效果明显,性能与同类系统相比有显著提升.
