摘要:
In this paper, the logistic regression model is applied to analyze the influence of the factors affecting the Basics of Computer Application and College English B exam results. To model the logistic regression by using the two course exam results as a target variable, the analysis results show that: grade, specialty and learning center have great impact on the Basics of Computer Application, while the grade, learning center, age, specialty and gender are all have very important implications on the College English B exam results..
作者机构:
[Zhang, Xiaoming; Sun, Bingyu; Wang, Hailei; Gui, Yuanmiao; Li, Wenbo] Chinese Acad Sci, Inst Intelligent Machines, Hefei 230031, Peoples R China.;[Du, Zhiqiang] Wuhan Univ, State Key Lab Informat Engn Surveying Mapping & R, Wuhan 430079, Peoples R China.;[Ling, Feng] Chinese Acad Sci, Inst Geodesy & Geophys, Wuhan 430077, Peoples R China.;[Zhou, Dongbo] Cent China Normal Univ, Natl Engn Res Ctr E Learning, Wuhan 430079, Peoples R China.
通讯机构:
[Du, Zhiqiang] W;Wuhan Univ, State Key Lab Informat Engn Surveying Mapping & R, Wuhan 430079, Peoples R China.
关键词:
remote sensing;image segmentation;land surface water mapping;Advanced Land Imager (ALI);normalized difference water index;Landsat
摘要:
Remote sensing has more advantages than the traditional methods of land surface water (LSW) mapping because it is a low-cost, reliable information source that is capable of making high-frequency and repeatable observations. The normalized difference water indexes (NDWIs), calculated from various band combinations (green, near-infrared (NIR), or shortwave-infrared (SWIR)), have been successfully applied to LSW mapping. In fact, new NDWIs will become available when Advanced Land Imager (ALI) data are used as the ALI sensor provides one green band (Band 4), two NIR bands (Bands 6 and 7), and three SWIR bands (Bands 8, 9, and 10). Thus, selecting the optimal band or combination of bands is critical when ALI data are employed to map LSW using NDWI. The purpose of this paper is to find the best performing NDWI model of the ALI data in LSW map. In this study, eleven NDWI models based on ALI, Thematic Mapper (TM), and Enhanced Thematic Mapper Plus (ETM+) data were compared to assess the performance of ALI data in LSW mapping, at three different study sites in the Yangtze River Basin, China. The contrast method, Otsu method, and confusion matrix were calculated to evaluate the accuracies of the LSW maps. The accuracies of LSW maps derived from eleven NDWI models showed that five NDWI models of the ALI sensor have more than an overall accuracy of 91% with a Kappa coefficient of 0.78 of LSW maps at three test sites. In addition, the NDWI model, calculated from the green (Band 4: 0.525-0.605 m) and SWIR (Band 9: 1.550-1.750 m) bands of the ALI sensor, namely NDWIA4,9, was shown to have the highest LSW mapping accuracy, more than the other NDWI models. Therefore, the NDWIA4,9 is the best indicator for LSW mapping of the ALI sensor. It can be used for mapping LSW with high accuracy.
摘要:
With the ever-increasing wireless data application recently, considerable efforts have been focused on the design of distributed explicit rate scheme based on Network Utility Maximization (NUM) or wireless multi-hop mesh networks. This paper describes a novel wireless multi-hop multicast flow control scheme for wireless mesh networks via 802.11, which is based on the distributed self-turning Optimal Proportional plus Second-order Differential (OPSD) controller. The control scheme, which is located at the sources in the wireless multicast networks, can ensure short convergence time by regulating the transmission rate. We further analyze the theoretical aspects of the proposed algorithm. Simulation results demonstrate the efficiency of the proposed scheme in terms of fast response time, low packet loss and error ration.
会议名称:
IEEE International Conference on Information Science and Technology
会议时间:
2013-03-23
会议地点:
Yangzhou(CN)
会议主办单位:
[Wang, Lei;Zhang, Dengyi] Wuhan Univ, Sch Comp, Wuhan 430072, Hubei, Peoples R China.^[Yang, Hongyun] Cent China Normal Univ, Dept Natl Engn Res Ctr E learning, Wuhan 430076, Hubei, Peoples R China.
会议论文集名称:
2013 IEEE third international conference on information science and technology: ICIST 2013, Yangzhou, China, 23-25 March 2013, Pages 823-1645, [v.2]
关键词:
P2P-TV;QA-FNS;P2P
摘要:
Peer-to-Peer streaming systems (or P2P-TV) have been studied in the literature for some time, and are being considered as the most promising approach to deliver real-time video to large scale users over the Internet. Neighbor selection is one of the key components to construct overlay topology for P2P streaming system. The common QoS-awareness neighbor selection algorithms in existing overlay construction schemes usually select a fixed number of neighbors which satisfy the selection requirements, such as end-to-end delay or a peer's upload bandwidth. However, this fixed QoS-Awareness neighbor selection algorithm (QA-FNS) neglects the peers' upload bandwidth heterogeneity and therefore, the upload bandwidth cannot be efficiently used. In this paper, we propose a QoS-Awareness variable neighbor-selection (QA-VNS) scheme to alleviate the problem due to bandwidth heterogeneity, and in which the number of neighbors with different upload bandwidths is dynamically determined by the upload bandwidth information of peers. Simulation has shown that our proposed scheme is to outperform QA-FNS scheme.
期刊:
2013 IEEE 13TH INTERNATIONAL CONFERENCE ON ADVANCED LEARNING TECHNOLOGIES (ICALT 2013),2013年:112-114 ISSN:2161-3761
通讯作者:
Hu, Min
作者机构:
[Hu, Min; Li, Hao] Cent China Normal Univ, Natl Engn Res Ctr E Learning, 152 Luoyu Rd, Wuhan, Hubei, Peoples R China.;[Liu, Qingtang] Cent China Normal Univ, Dept Informat Technol, Wuhan, Peoples R China.
通讯机构:
[Hu, Min] C;Cent China Normal Univ, Natl Engn Res Ctr E Learning, 152 Luoyu Rd, Wuhan, Hubei, Peoples R China.
会议名称:
13th IEEE Annual International Conference on Advanced Learning Technologies (ICALT)
会议时间:
JUL 15-18, 2013
会议地点:
Beijing Normal Univ, Beijing, PEOPLES R CHINA
会议主办单位:
Beijing Normal Univ
会议论文集名称:
IEEE International Conference on Advanced Learning Technologies
摘要:
On the basis of the statistics of keywords from 5750 papers published in professional journals from 2007 to 2011 in educational technology, this paper selected the top 46 high-frequency keywords, generated co-word matrix by using SATI tools, made use of statistical analysis software SPSS for co-word clustering analysis, deeply analyzed the relationships and rules among the selected high-frequency keywords, and then explored hot topics and developing trends in the field of educational technology. After summing up, nine hot topics were finally determined, including student-centered learning activities, network education, distance education, educational informationalization.