期刊文献+
共找到32篇文章
< 1 2 >
每页显示 20 50 100
Car-following model featured with factors reflecting emergency evacuation situation
1
作者 胡红 魏恒 +1 位作者 刘小明 杨孝宽 《Journal of Southeast University(English Edition)》 EI CAS 2008年第2期216-221,共6页
A new emergency evacuation car-following model (EECM) is proposed. The model aims to capture the main characteristics of traffic flow and driver behavior under an emergency evacuation, and it is developed on the bas... A new emergency evacuation car-following model (EECM) is proposed. The model aims to capture the main characteristics of traffic flow and driver behavior under an emergency evacuation, and it is developed on the basis of minimum safety distances with parts of the drivers' abnormal behavior in a panic emergency situation. A thorough questionnaire survey is undertaken among drivers of different ages. Based on the results from the survey, a safety-distance car-following model is formulated by taking into account two new parameters: a differential distributing coefficient and a driver' s experiential decision coefficient, which are used to reflect variations of driving behaviors under an emergency evacuation situation when compared with regular conditions. The formulation and derivation of the new model, as well as its properties and applicability are discussed. A case study is presented to compare the car-following trajectories using observed data under regular peak-hour traffic conditions and theoretical EECM results. The results indicate the consistency of the analysis of assumptions on the EECM and observations. 展开更多
关键词 emergency evacuation CAR-FOLLOWING minimum safety distance driving behavior
下载PDF
Pressure from surrounding rock of three shallow tunnels with large section and small spacing 被引量:18
2
作者 杨小礼 金启云 马军秋 《Journal of Central South University》 SCIE EI CAS 2012年第8期2380-2385,共6页
With the increasing traffic demand, the closely built three or more tunnels with large section play a significant role in the tunnel construction. However, the interaction among tunnels has important influences on the... With the increasing traffic demand, the closely built three or more tunnels with large section play a significant role in the tunnel construction. However, the interaction among tunnels has important influences on the security and economy of tunnel engineering, and the calculation of pressure from the surrounding rock during the excavation is one of the problems that need to be solved urgently. Based on the practical engineering of three tunnels, the load model of three tunnels was proposed in consideration of the interaction and excavation sequence between tunnels. In comparison with the load model of single tunnel, the construction mechanical characteristics of the three tunnels were analyzed. The results show that the rock pressure of three tunnels calculated by the current tunnel design code is not reliable, and the interaction force increases with the spacing between tunnels. 展开更多
关键词 three-tunnel model large section small clear spacing load model
下载PDF
Clustering method based on data division and partition 被引量:1
3
作者 卢志茂 刘晨 +2 位作者 S.Massinanke 张春祥 王蕾 《Journal of Central South University》 SCIE EI CAS 2014年第1期213-222,共10页
Many classical clustering algorithms do good jobs on their prerequisite but do not scale well when being applied to deal with very large data sets(VLDS).In this work,a novel division and partition clustering method(DP... Many classical clustering algorithms do good jobs on their prerequisite but do not scale well when being applied to deal with very large data sets(VLDS).In this work,a novel division and partition clustering method(DP) was proposed to solve the problem.DP cut the source data set into data blocks,and extracted the eigenvector for each data block to form the local feature set.The local feature set was used in the second round of the characteristics polymerization process for the source data to find the global eigenvector.Ultimately according to the global eigenvector,the data set was assigned by criterion of minimum distance.The experimental results show that it is more robust than the conventional clusterings.Characteristics of not sensitive to data dimensions,distribution and number of nature clustering make it have a wide range of applications in clustering VLDS. 展开更多
关键词 CLUSTERING DIVISION PARTITION very large data sets (VLDS)
下载PDF
Model test to investigate failure mechanism and loading characteristics of shallow-bias tunnels with small clear distance 被引量:10
4
作者 雷明锋 林大涌 +3 位作者 杨伟超 施成华 彭立敏 黄娟 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第12期3312-3321,共10页
Based on the similarity theory,a tunnel excavation simulation testing system under typical unsymmetrical loading conditions was established.Using this system,the failure mechanism of surrounding rock of shallow-bias t... Based on the similarity theory,a tunnel excavation simulation testing system under typical unsymmetrical loading conditions was established.Using this system,the failure mechanism of surrounding rock of shallow-bias tunnels with small clear distance was analyzed along with the load characteristics.The results show that:1) The failure process of surrounding rock of shallow-bias tunnels with small clear distance consists of structural and stratum deformation induced by tunnel excavation; Microfracture surfaces are formed in the tunnel surrounding rock and extend deep into the rock mass in a larger density; Tensile cracking occurs in shallow position on the deep-buried side,with shear slip in deep rock mass.In the meantime,rapid deformation and slip take place on the shallow-buried side until the surrounding rocks totally collapse.The production and development of micro-fracture surfaces in the tunnel surrounding rock and tensile cracking in the shallow position on the deep-buried side represent the key stages of failure.2) The final failure mode is featured by an inverted conical fracture with tunnel arch as its top and the slope at tunnel entrance slope as its bottom.The range of failure on the deep-buried side is significantly larger than that on the shallow-buried side.Such difference becomes more prominent with the increasing bias angle.What distinguishes it from the "linear fracture surface" model is that the model proposed has a larger fracture angle on the two sides.Moreover,the bottom of the fracture is located at the springing line of tunnel arch.3) The total vertical load increases with bias angle.Compared with the existing methods,the unsymmetrical loading effect in measurement is more prominent.At last,countermeasures are proposed according to the analysis results: during engineering process,1) The surrounding rock mass on the deep-buried side should be reinforced apart from the tunnel surrounding rock for shallow-buried tunnels with small clear distance; moreover,the scope of consolidation should go beyond the midline of tunnel(along the direction of the top of slope) by 4 excavation spans of single tunnel.2) It is necessary to modify the load value of shallow-bias tunnels with small clear distance. 展开更多
关键词 shallow-bias tunnels with small spacing failure mechanism loading characteristics model test
下载PDF
Fluid Flow Past a Circular Cylinder with Tandem Rod and Staggered Rod at Low Reynolds Number 被引量:2
5
作者 WU Wenbo WANG Jiasong 《Journal of Ocean University of China》 SCIE CAS CSCD 2018年第5期1053-1065,共13页
The flow past a primary cylinder with one tandem control rod and one staggered control rod is simulated in this paper through solving the Navier-Stokes equations. Two examples are simulated to validate the model, and ... The flow past a primary cylinder with one tandem control rod and one staggered control rod is simulated in this paper through solving the Navier-Stokes equations. Two examples are simulated to validate the model, and the results matched well with those of previous researches. The Reynolds number based on the diameter of the primary cylinder is 500. The diameter ratio between the control rod and the primary cylinder (d/D) is 0.25. It was found that the effect of the combination of one upstream tandem control rod and one staggered control rod on the hydrodynamics of the primary cylinder is a linear superposition of the effect of a corresponding single control rod, and the effect of the upstream tandem control rod is dominant at larger spacing ratios such as G/D=2. For the combination of a downstream tandem control rod and a staggered control rod, the effect of the control rods is different from that of the corresponding single control rod in the region of 0.2〈G/D〈0.5 & 30°〈a〈120° and 0.9〈G/D〈1.4 & 30°〈a〈50°, where the additional effect is obvious. In this case, the effect of the downstream tandem control rod is dominant at small spacing ratios (such as G/D=0.1). At moderate spacing ratios such as G/D=0.4, the effects of the tandem control rod and the staggered control rod are comparable in both cases. 展开更多
关键词 tandem and staggered control rods additional effect of double control rods vortex shedding drag and lift coefficients numerical simulation
下载PDF
Minimum distance constrained nonnegative matrix factorization for hyperspectral data unmixing 被引量:2
6
作者 于钺 SunWeidong 《High Technology Letters》 EI CAS 2012年第4期333-342,共10页
This paper considers a problem of unsupervised spectral unmixing of hyperspectral data. Based on the Linear Mixing Model ( LMM), a new method under the framework of nonnegative matrix fac- torization (NMF) is prop... This paper considers a problem of unsupervised spectral unmixing of hyperspectral data. Based on the Linear Mixing Model ( LMM), a new method under the framework of nonnegative matrix fac- torization (NMF) is proposed, namely minimum distance constrained nonnegative matrix factoriza- tion (MDC-NMF). In this paper, firstly, a new regularization term, called endmember distance (ED) is considered, which is defined as the sum of the squared Euclidean distances from each end- member to their geometric center. Compared with the simplex volume, ED has better optimization properties and is conceptually intuitive. Secondly, a projected gradient (PG) scheme is adopted, and by the virtue of ED, in this scheme the optimal step size along the feasible descent direction can be calculated easily at each iteration. Thirdly, a finite step ( no more than the number of endmem- bers) terminated algorithm is used to project a point on the canonical simplex, by which the abun- dance nonnegative constraint and abundance sum-to-one constraint can be accurately satisfied in a light amount of computation. The experimental results, based on a set of synthetic data and real da- ta, demonstrate that, in the same running time, MDC-NMF outperforms several other similar meth- ods proposed recently. 展开更多
关键词 hyperspectral data nonnegative matrix factorization (NMF) spectral unmixing convex function projected gradient (PG)
下载PDF
Personal Space of Small Mobile Robot Moving towards Standing or Sitting Elderly Individuals 被引量:1
7
作者 Masako Sakai Akiko Watanabe 《Journal of Civil Engineering and Architecture》 2013年第7期827-832,共6页
Recently, Japan has experienced a low birthrate and an aging population. The development of communication robots, such as cleaning and a care-giver robot, has been progressing. Care-giver robots provide daily assistan... Recently, Japan has experienced a low birthrate and an aging population. The development of communication robots, such as cleaning and a care-giver robot, has been progressing. Care-giver robots provide daily assistance, including contacting emergency services. This study is part of the "study on planning techniques of living space in harmony with robots", and focused on the elderly. Minimum distance was the subjects felt "I do not want any more approached". Subjects were 21 elderly persons (eight males and thirteen females), aged 66-86 years. The experimental room was an assembly room in a public accommodation (14 m× 6.5 m). The small mobile robot used in this experiment was external form dimensions of 120 mm (W)× 130 mm (D)× 70 mm (H), In this experiment, considering the personal space as the small mobile robot is watching robot without support function for person. The robot moved toward standing or sitting subjects at constant velocities from a distance 5 m apart. Research factors are 5 angles (0°, 45°, 90°, 135° and 180°) and 2 speeds (0.08 m/s and 0.24 m/s). 展开更多
关键词 Small mobile robot personal space elderly persons living space.
下载PDF
Minimizing Distance Using Just-in-Time Teaching and Flipped Classroom 被引量:1
8
作者 Mahmuda Akhter 《Sino-US English Teaching》 2015年第1期20-25,共6页
JiTT (Just-in-Time Teaching) and flipped classroom are two innovations in academia where high-tech and no-tech resources are blended to encourage more interaction and creativity among students. These two methods als... JiTT (Just-in-Time Teaching) and flipped classroom are two innovations in academia where high-tech and no-tech resources are blended to encourage more interaction and creativity among students. These two methods also help minimize the dependency on face-to-face lecture and make the class time more creative and effective. This study is the very first attempt of implementing these strategies in Bangladesh. It explores the prospect of JiTT and flipped classroom at tertiary level in Bangladesh. In the first part of this paper, recent studies on JiTT and flipped classroom are discussed to shed light on their effectiveness and problems. The latter part explains the data and research findings. Before collecting the data, JiTT and flipped classroom were used with 33 students of undergraduate level who were students of"ELT Methodology" course. After the implementation of the methods, a questionnaire survey was conducted to collect data regarding their response to these two methods. The study reveals that JiTT and flipped classroom help cover more topics in a short time while enhancing students' interaction and participation. They make students come to the class prepared and reflect on their learning. Teachers can understand students need better and provide required feedback. The overall interaction among students and teachers can be improved using JiTT and flipped classroom since everyone is clear about each other's existing knowledge and learning objectives. 展开更多
关键词 JUST-IN-TIME technology teaching strategies flipped classroom video lecture
下载PDF
Interaction analyses between tunnel and landslide in mountain area 被引量:6
9
作者 ZHANG Zhi-guo ZHAO Qi-hua +1 位作者 XU Chen XU Xiao-yang 《Journal of Mountain Science》 SCIE CSCD 2017年第6期1124-1139,共16页
This paper focuses on the analytical derivation and the numerical simulation analyses to predict the interaction influences between a landslide and a new tunnel in mountain areas. Based on the slip-line theory, the di... This paper focuses on the analytical derivation and the numerical simulation analyses to predict the interaction influences between a landslide and a new tunnel in mountain areas. Based on the slip-line theory, the disturbance range induced by tunneling and the minimum safe distance between the tunnel vault and the sliding belt are obtained in consideration of the mechanical analyses of relaxed rocks over the tunnel opening. The influence factors for the minimum safe crossing distance are conducted,including the tunnel radius, the friction angle of surrounding rocks, the inclination angle of sliding belt,and the friction coefficient of surrounding rocks. Secondly, taking account of the compressive zone and relaxed rocks caused by tunneling, the Sarma method is employed to calculate the safety factor of landslide. Finally, the analytical solutions for interaction between the tunnel and the landslide are compared with a series of numerical simulations, considering the cases for different perpendicular distances between the tunnel vault and the sliding belt. Resultsshow that the distance between the tunnel vault and the slip zone has significant influence on the rock stress and strain. For the case of the minimum crossing distance, a plastic zone in the landslide traversed by tunneling would be formed with rather large range, which seriously threatens the stability of landslide. This work demonstrates that the minimum safe crossing distance obtained from numerical simulation is in a good agreement with that calculated by the proposed analytical solutions. 展开更多
关键词 Tunnel excavation Landslide Safe crossing distance Analytical method Numerical simulation
下载PDF
Local information enhanced LBP
10
作者 张刚 苏光大 +1 位作者 陈健生 王晶 《Journal of Central South University》 SCIE EI CAS 2013年第11期3150-3155,共6页
Based on the observation that there exists multiple information in a pixel neighbor,such as distance sum and gray difference sum,local information enhanced LBP(local binary pattern)approach,i.e.LE-LBP,is presented.Geo... Based on the observation that there exists multiple information in a pixel neighbor,such as distance sum and gray difference sum,local information enhanced LBP(local binary pattern)approach,i.e.LE-LBP,is presented.Geometric information of the pixel neighborhood is used to compute minimum distance sum.Gray variation information is used to compute gray difference sum.Then,both the minimum distance sum and the gray difference sum are used to build a feature space.Feature spectrum of the image is computed on the feature space.Histogram computed from the feature spectrum is used to characterize the image.Compared with LBP,rotation invariant LBP,uniform LBP and LBP with local contrast,it is found that the feature spectrum image from LE-LBP contains more details,however,the feature vector is more discriminative.The retrieval precision of the system using LE-LBP is91.8%when recall is 10%for bus images. 展开更多
关键词 texture feature extraction LE-LBP minimum distance sum gray difference sum
下载PDF
A minimal-distance overlay for efficiently disseminating replicas in DHT-based P2P networks
11
作者 李文翔 Guo Chengcheng Wu Jing 《High Technology Letters》 EI CAS 2011年第2期126-133,共8页
In this paper, the problems of redundant traffic and redundant replicas tor efficient object replication in P2P overlay are studies. Firstly, a hierarchical and topology-aware P2P overlay is developed with κ-Medoids ... In this paper, the problems of redundant traffic and redundant replicas tor efficient object replication in P2P overlay are studies. Firstly, a hierarchical and topology-aware P2P overlay is developed with κ-Medoids partition algorithm to achieve the minimal physical distance of all super peer pairs. Secondly, a new idea of placing at most one replica in a cluster of physically adjacent nodes is introduced to achieve scattered distribution of replicas. Lastly, an efficient replicas-query algorithm based on multiple hash functions is proposed. Theoretical analysis and simulation experiment on several performance metrics are given, and it is verified that the method in this paper can efficiently disseminate replicas across the network, increase query-hit ratio, and decrease redundant messages and storage spaces required. 展开更多
关键词 PEER-TO-PEER REPLICATION OVERLAY redundancy CHORD k-Medoids clustering
下载PDF
Optimization Route Algorithm Based on the Minimal Transfer Time and Distance
12
作者 胡红萍 赵敏 白艳萍 《Journal of Measurement Science and Instrumentation》 CAS 2011年第4期333-336,共4页
The transfer system,an important subsystem in urban citizen passenger transport system,is a guarantee of public transport priority and is crucial in the whole urban passenger transport traffic.What the majority of bus... The transfer system,an important subsystem in urban citizen passenger transport system,is a guarantee of public transport priority and is crucial in the whole urban passenger transport traffic.What the majority of bus passengers consider is the convenience and comfort of the bus ride,which reduces the transfer time of bus passengers."Transfer time" is considered to be the first factor by the majority of bus passengers who select the routes.In this paper,according to the needs of passengers,optimization algorithm,with the minimal distance being the first goal,namely,the improved Dijkstra algorithm based on the minimal distance,is put forward on the basis of the optimization algorithm with the minimal transfer time being the first goal. 展开更多
关键词 TRANSFER DISTANCE optimization route
下载PDF
Numerical Prediction of Statistical Masonry Wall Fragment Distribution Induced by Blast Loading
13
作者 汪明 郝洪 +1 位作者 丁阳 李忠献 《Transactions of Tianjin University》 EI CAS 2008年第6期409-413,共5页
The hazard caused by the fragments of damaged structures is usually significant in acci-dental explosions or hostile blast events.A reliable and efficient method to estimate probable fragment size,velocity and launch ... The hazard caused by the fragments of damaged structures is usually significant in acci-dental explosions or hostile blast events.A reliable and efficient method to estimate probable fragment size,velocity and launch distance will be useful to assess and design countermeasures to mitigate the possible fragment hazards.This paper presents a numerical method for predicting the size and launch distance of the fragments caused by explosive damage of masonry wall.Numerical simulations with different scaled distances are carried out,and the statistical distribution functions of the fragment size and launch distance in terms of the scaled distance are derived. 展开更多
关键词 fragment size launch distance masonry wall statistical distribution function
下载PDF
On Infinitesimal Ⅱ-isometry of Surfaces
14
作者 杨纬隆 《Chinese Quarterly Journal of Mathematics》 CSCD 1996年第2期5-10,共6页
In this paper,we try to discuss the conjecture which says that infinitesimal Ⅱ-isome try of surface is infintesimal Ⅰ -isometry. i. e, infinitesimal rigid.Under some weakly suppositions of Guass curvature,some new ... In this paper,we try to discuss the conjecture which says that infinitesimal Ⅱ-isome try of surface is infintesimal Ⅰ -isometry. i. e, infinitesimal rigid.Under some weakly suppositions of Guass curvature,some new results are worked out They are generalizations of known theories. 展开更多
关键词 SURFACE infintesimal Ⅱ-isometry infintesimal rigid
下载PDF
A Study on the Distances of Small Mobile Robot Moves towards Infants
15
作者 Ami Yasaka Akiko Watanabe 《Journal of Civil Engineering and Architecture》 2014年第8期982-988,共7页
In recent years, it is remarkable that various robots are being developed, and the development of robot technology is beginning to be taken into an actual living space. There are still many questions that we will have... In recent years, it is remarkable that various robots are being developed, and the development of robot technology is beginning to be taken into an actual living space. There are still many questions that we will have to answer for the harmonization of living together with a robot. This study is focused on "the study of how to plan and design a living space in harmonizing with robots", and focused on the effects of infants (subjects) along with the distance between robots and themselves. The study is to seek for the minimum distance for the subjects who felt that "I do not want a robot to be any closer being approached to me". This experiment was conducted among 30 infants at the kindergarten, utilizing a small experimental robot. A small robot whose dimension is 120 mm (W) ×130 mm (D) × 70 mm (H), approaching infants as is to see if it would make any differences to the infant's reactions. 展开更多
关键词 Small mobile robot individual distance INFANTS living space
下载PDF
A Theorem on Infinitesimal I-isometry of Surfaces Immersed in a Space with Constant Curvature
16
作者 程新跃 杨文茂 邱敦元 《Chinese Quarterly Journal of Mathematics》 CSCD 1997年第4期63-69, ,共7页
In this paper we discuss the infinitesimal I-isometric de formations of surfaces immersed in a space with constant curvature. We obtain a sufficient condition for the de formation vector field to be zero vector field ... In this paper we discuss the infinitesimal I-isometric de formations of surfaces immersed in a space with constant curvature. We obtain a sufficient condition for the de formation vector field to be zero vector field which is generalization of the results in [1] and [2]. 展开更多
关键词 infinitesimal isometric deformation mean curvature vector sectional curvature
下载PDF
An empirical research of urbanization and urban-rural gap in China:1952-2005
17
作者 Ye Chao Cao Zhidong Chen Mingxing 《Ecological Economy》 2008年第4期403-409,共7页
There are two important problems of urban-rural relationship in China nowadays: the accelerated urbanization process and an enlarged urban-rural gap. The researchers can be divided into two schools according to their... There are two important problems of urban-rural relationship in China nowadays: the accelerated urbanization process and an enlarged urban-rural gap. The researchers can be divided into two schools according to their emphasis. One emphasizes particularly the urban development, and the other pays attention to the urban-rural income gap. However, there is a very strong association between urbanization rate and urban-rural inequality. As far as it goes, there is a paradox between urbanization and urban-rural inequality in China. This main reason lies' in the different temporal and spatial scales chosen by the scholars. Making use of correlative analysis and wavelet method, this paper rethinks and sums up the commonly evolving characteristics and trends between urbanization and urban-rural gap from 1950s to now. There is an intensively positive correlation between urbanization and urban- rural consumption gap. In general, with the acceleration of urbanization, urban-rural gap of China has undergone three stages of cyclical fluctuations. The rapid urbanization results in the increase of urban-rural highly risky. In addition, the special stage of urbanization is the other reason that expands urban-rural gap. 展开更多
关键词 URBANIZATION Urban-rural relation Urban-rural gap Correlative analysis Wavelet analysis
下载PDF
The influence of interstitial brachytherapy with ~(125)I seeds on Caspase-3 and Egr-1 expressions of Lewis lung carcinoma in C57BL mice
18
作者 Xiguang Liu Tingting Song +1 位作者 Lili Du Jun Liang 《The Chinese-German Journal of Clinical Oncology》 CAS 2010年第12期688-691,共4页
Objective:The aim of our study was to explore the influence of interstitial brachytherapy with 125I seeds on Caspase-3 and Egr-1 expressions of Lewis lung carcinoma in C57BL mice.Methods:Model mice of C57BL were plant... Objective:The aim of our study was to explore the influence of interstitial brachytherapy with 125I seeds on Caspase-3 and Egr-1 expressions of Lewis lung carcinoma in C57BL mice.Methods:Model mice of C57BL were planted with Lewis lung cells (LLC) and divided into the treatment group (n=18) and the control group (n=17).In each mouse of the treatment group,two BT-125-1 Model 125I seeds with apparent activity of 9.25 MBq were implanted into the tumor;whereas in each mouse of the control group two dummy seeds were implanted.The mice survival rates of both groups were recorded after 21 days.The tumor weights and dimensions of survived mice were measured,and the tumor volume inhibition rate was calculated.T-test was performed to compare differences of tumor weights and volumes between these two groups.Routine pathological slides of tumor tissue were observed under light microscope.The expression of Caspase-3 was detected by immunohistochemical method and the expression of Egr-1 was detected by RT-PCR method.Results:The survival rates were 88.88% in the treatment group and 70.59% in the control group,the difference had no statistical significance (P > 0.05).The tumor volume inhibition rate was 71.12%.Pathological examination showed degeneration and necrosis of cancer cells at the site nearby the seed in the treated group,but the tumor cells alive were still presented nearby the seed in the control group.The expressions of Caspase-3 and Egr-1 in the treated group were higher than those in the control group (t=12.825,P < 0.01;t=7.039,P < 0.01;respectively).Conclusion:The interstitial brachytherapy with 125I seeds could significantly inhibit the growth of Lewis lung carcinoma of mice.The possible mechanism may be that 125I interstitial brachytherapy can enhance the expressions of Egr-1 and Caspase-3,which could induce tumor cellular apoptosis. 展开更多
关键词 125I seeds interstitial brachytherapy Lewis lung cell EGR-1 CASPASE-3
下载PDF
Bridging the Achievement Gap for Students: A Blueprint for Success
19
作者 Kirk Gavin Rose Campbell Seward Hamilton 《Journal of Literature and Art Studies》 2016年第8期979-987,共9页
The purpose of this research is to identify and examine the achievement gaps between students. Over the past thirty years, emphasis has been placed on achievement levels of students in this country. State test results... The purpose of this research is to identify and examine the achievement gaps between students. Over the past thirty years, emphasis has been placed on achievement levels of students in this country. State test results, SAT Scores, ACT scores and other assessment instruments have been used to determine performance standards and test results for students. Data analyzed for White students compared to African American and Hispanic students have provided critical information in identifying academic progress and skill deficits for all students. This article will highlight some of the achievement gaps which exit among White, African American and Hispanic Students. Recommendations will also be emphasized to help improve student achievement levels in an effort to close the achievement gap. 展开更多
关键词 student achievement achievement gap comparative achievement levels
下载PDF
Seizure detection using earth movers' distance and SVM in intracranial EEG
20
作者 王芸 吴琦 +2 位作者 周卫东 袁莎莎 袁琦 《Journal of Measurement Science and Instrumentation》 CAS 2014年第3期94-102,共9页
Seizure detection is extremely essential for long-term monitoring of epileptic patients. This paper investigates the detection of epileptic seizures in multi-channel long-term intracranial electroencephalogram (iEEG... Seizure detection is extremely essential for long-term monitoring of epileptic patients. This paper investigates the detection of epileptic seizures in multi-channel long-term intracranial electroencephalogram (iEEG). The algorithm conducts wavelet decomposition of iEEGs with five scales, and transforms the sum of the three frequency bands into histogram for computing the distance. The proposed method combines a novel feature called EMD-L1, which is an efficient algorithm of earth movers' distance (EMD), with support vector machine (SVM) for binary classification between seizures and non-sei- zures. The EMD-LI used in this method is characterized by low time complexity and high processing speed by exploiting the L~ metric structure. The smoothing and collar technique are applied on the raw outputs of SVM classifier to obtain more ac- curate results. Several evaluation criteria are recommended to compare our algorithm with other conventional methods using the same dataset from the Freiburg EEG database. Experiment results show that the proposed method achieves a high sensi- tivity, specificity and low false detection rate, which are 95.73 %, 98.45 % and 0.33/h, respectively. This algorithm is char- acterized by its robustness and high accuracy with the possibility of performing real-time analysis of EEG data, and may serve as a seizure detection tool for monitoring long-term EEG. 展开更多
关键词 electroencephalograph (EEG)signals earth movers' distance (EMD) EMD-L1 support vector machine(SVM) wavelet decomposition seizure detection
下载PDF
上一页 1 2 下一页 到第
使用帮助 返回顶部