检索结果-南通市图书馆

MOOC Learner’s Final Grade Prediction Based on an Improved Random Forests Method

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2020年第12期65卷 2413-2423页

作者： Yuqing Yang Peng Fu Xiaojiang Yang Hong Hong Dequn Zhou College of Economics and Management Nanjing University of Aeronautics and AstronauticsNanjing211106China School of Computer science and Engineering Nanjing University of Science and TechnologyNanjing210094China Office of International Cooperation and Exchanges Nanjing University of Finance&EconomicsNanjing210046China Jiangsu Guidgine Educational Evaluation Inc. Nanjing210046China Department of Electrical and Computer Engineering University of CaliforniaDavisCA 95616USA

Massive Open Online course(MOOC)has become a popular way of online learning used across the world by millions of ***,a vast amount of information has been collected from the MOOC learners and *** on the educational data,a lot of researches have been investigated for the prediction of the MOOC learner’s final ***,there are still two problems in this research *** first problem is how to select the most proper features to improve the prediction accuracy,and the second problem is how to use or modify the data mining algorithms for a better analysis of the MOOC *** order to solve these two problems,an improved random forests method is proposed in this ***,a hybrid indicator is defined to measure the importance of the features,and a rule is further established for the feature selection;then,a Clustering-Synthetic Minority Over-sampling Technique(SMOTE)is embedded into the traditional random forests algorithm to solve the class imbalance *** experiment part,we verify the performance of the proposed method by using the Canvas Network Person-course(CNPC)***,four well-known prediction methods have been applied for comparison,where the superiority of our method has been proved.

关键词： Random forests grade prediction feature selection class imbalance

A phase field study for influence of elastic energy on L1_0→L1_2 transient ordering in Ni_(75)Al_(17)Zn_8

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese science Bulletin 2010年第26期55卷 3044-3050页

作者： ZHAO Yan CHEN Zheng WANG YongXin ZHANG MingYi ZHANG Jing Department of Materials science and Engineering Northwestern Polytechnical University Xi'an 710072 China State Key Laboratory of Solidification Processing Northwestern Polytechnical University Xi'an 710072 China

The influence of the elastic energy on L10→L12 transient ordering transformation was investigated by microscopic phase field method. It is found that there are three stages experienced in atomic ordering: solute clustering+L10 short range ordering → L10 long range ordering → L12 long range ordering. Before the formation of the high ordered L12 phase, it has firstly taken place the transformation from matrix to L10 phase, and then held the L10→L12 secondary transformation. Elastic energy is proved to take little effect on the stage of short range ordering, but as the elastic energy is multiplied, it obviously shortened the course of the solute clustering, and speeded up the proceeding of the L10 long range ordering transition. Accordingly, the increased elastic energy also strengthens the single crystalline directionality of L10 phase projecting on 2D plane and makes the ordered degree of Al and Zn atoms enhanced. With the temperature elevation, Al's and Zn's ordered degree decreased in L10 phase.

关键词：原子排列弹性能能量 2型瞬态短程有序长程有序平面投影

The Study on Inorganic Chemistry Teaching Methods

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The Study on Inorganic Chemistry Teaching Methods

Integrative assessment of biomarker responses in teleostean fishes exposed to glyphosate-based herbicide(Excel Mera 71)

第5届教育教学改革与管理工程学术年会

作者： Lianwei Shan Limin Dong Wei Li Ze Wu Zhidong Han Department of Materials science and Engineering Harbin University of Science and Technology

In this paper, improved teaching methods were proposed through the characteristics and analysis of inorganic chemistry for the engineering teaching in order to improve the students’ interest in inorganic chemistry, as well as cultivate students’ ability to take the initiative to acquire knowledge. Introduction class reflects the degree of understanding and the control of the course for the teaching. We must attach great importance to teach introduction class. How to combine the characteristics of the professional and to select appropriate teaching entry points have played an active role on inspiring learning interest for students. According to characteristic of students, we try to form unique teaching styles. The relationship among classroom teaching, laboratory teaching and examination methods is probed.

关键词： inorganic chemistry teaching methods professional interests teaching entry points

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Emerging Contaminants 2016年第4期2卷 191-203页

作者： Sukhendu Dey Palas Samanta Sandipan Pal Aloke Kumar Mukherjee Debraj Kole Apurba Ratan Ghosh Ecotoxicology Lab Department of Environmental ScienceThe University of BurdwanGolapbagBurdwan 713104West BengalIndia Division of Environmental science and Ecological Engineering Korea UniversityAnam-dongSungbuk-guSeoul 02841Republic of Korea Department of Environmental science Aghorekamini Prakashchandra MahavidyalayaSubhasnagarBengaiHooghly 712611West BengalIndia P.G.Department of Conservation Biology Durgapur Govt.CollegeDurgapur 713214West BengalIndia

Present study deals with the effects of glyphosate-based herbicide,Excel Mera 71 on Anabas testudineus,Heteropnestes fossilis and Oreochromis niloticus in field conditions(1.85 kg/ha)based on anti-oxidative,metabolic and digestive *** this study following biomarkers viz.,acetylcholinesterase(AChE),lipid peroxidation(LPO),catalase(CAT),glutathione-S-transferase(GST),alkaline phosphatase(ALP),aspartate aminotransferase(AST),alanine aminotransferase(ALT),amylase,lipase and protease were investigated in gill,stomach,intestine,liver,kidney,brain,muscle and spinal cord of the concerned fish *** activities were significantly altered by glyphosate exposure after 30 days,these activities were tissue as well as species *** results suggested that these biomarkers could be used to assess the ecological risks of glyphosate on *** factor(BAF)studied in different aquatic natural macrophytes showed order of Alternanthera philoxeroides>Azolla pinnata>Lemna sp.(Minor)>Lemna sp.(Major)>Pistia stratiotes,while transfer factor(TF)showed the order of Pistia stratiotes>Alternanthera philoxeroides>Lemna *** factor(BCF)study showed maximum accumulation of glyphosate in liver,kidney or intestine,and minimum either in bone or stomach irrespective of fish *** integrated biomarker response(IBR),which uses a battery of biomarkers to calculate the standardized scores for each biomarker responses ranging from physiological to biochemical/molecular responses,was evaluated by combining the multiple biomarkers into a single value to evaluate quantitatively the toxicological effects of *** general,the multiple indices exhibited variations and *** was more affected than other fish species;maximum IBR value was observed for LPO and minimum in case of *** order of integrated biomarkers caused by glyphosate treatment was recorded as follows:LPO>Amylase>CAT>AST>Protease>Lipase>ALP>GST>AChE>ALT for ***,LP

关键词： Excel Mera 71 Biomarker Bioaccumulation factor(BAF) Bioconcentration factor(BCF) Transfer factor(TF) Integrated biomarker response(IBR)

Study on fault source diagnosis technology and air velocity trans- ducers placement for underground

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Coal science & Engineering(China) 2012年第1期18卷 67-72页

作者： Zhao, Dan Liu, Jian Pan, Jing-tao College of Safety science and Engineering Liaoning Technical University Fuxin China Department of Mechanical Engineering Southeast University Nanjing China

The current mine safety monitoring system used can only get the air volume change of roadway placed air velocity transducers, as this change is caused by this roadway, or for other roadway, and fault source has one point or more, which belongs to the problem of fault source diagnosis for ventilation system. Ventilation system fault can be attributed to the variation of air resistance of branch in the entire network. If the changes of air resistance for each branch in ventilation system are analyzed, then it is impossible to place air velocity transducers in every branch. Therefore, the problem of the minimum quantities and location for placing air velocity transducers should be mainly studied. The relationship of air resistance and air volume variation of matrix method has been proposed, which can reflect the variation relationship between the air volume of the branch and air resistance of the relevant branches. Fault roadway range library of ventilation network built to determine fault roadway range will cause air velocity to exceed the limit. Minimum and full coverage of distribution method has been proposed, and the concept of branch coverage degree and impact roadway range library has also been brought forword to get the macro-distribution of air velocity transducers.

关键词：空气速度故障源诊断技术煤矿安全监控系统速度传感器空气阻力安置通风系统

General awareness of symptoms of myocardial infarction and the need for urgent treatment:A cross-sectional,street survey in Chennai,Tamil Nadu

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Acute Disease 2023年第2期12卷 51-56,I0001-I0003页

作者： Thirumurugan E Gomathi K Swathy P Syed Ali Afrin Ponduri Lakshmi Alekhya Jishnu B Banashree Das Srinivas University MangaloreKarnatakaIndia Faculty of Allied Health science DR.M.G.R.Educational and Research InstituteACS Medical CollegeChennaiTamil NaduIndia

Objective:To investigate the golden-time-awareness of and the necessary actions in response to acute myocardial infarction among the general ***:This study was conducted with the use of a descriptive research design and convenience sampling.A sample of 800 subjects,using self-structured knowledge questionnaires,was selected for data collection and *** study was conducted at *** and Research Institute,India,from February to November *** of myocardial infarction symptoms and intervention timeline(the golden time)was investigated.A multivariate logistic regression analysis was performed to identify the demographic factors affecting the recognition of the golden time of acute myocardial ***:A total of 800 subjects were *** the subjects,367(45.8%)were male,433(54.2%)were female,and 443(55.3%)participants failed to recognize the golden *** multivariate logistic regression analysis showed that people with a bachelor’s degree(OR=0.41,95%CI:0.23-0.74,P=0.03)and a high school level diploma(OR=0.55,95%CI:0.31-0.97,P=0.03)are more likely to know about myocardial infarction(golden time)than illiterate ***,people who are employed(OR=0.59,95%CI:0.41-0.85,P=0.05)are more likely to know about myocardial infarction(golden time)than those who are ***:The majority of people in the awareness group realize that taking myocardial infarction patients to the hospital would be the best course of *** unawareness of the ideal treatment window for myocardial infarction may cause a delay in seeking medical attention,which can lead to an increase in mortality and morbidity.

关键词： Heart attack Intervention timeline Symptoms Treatment Myocardial infarction Percutaneous coronary intervention

Memory Efficient Two-Pass 3D FFT Algorithm for Intel~ Xeon Phi^(TM) Coprocessor

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Computer science & Technology 2014年第6期29卷 989-1002页

作者：刘益群李焱张云泉张先轶 Institute of Software Chinese Academy of Sciences University of Chinese Academy of sciences Department of Computer science and Technology Tsinghua University CCF ACM IEEE State Key Laboratory of Computer Architecture Institute of Computing TechnologyChinese Academy of Sciences

Equipped with 512-bit wide SIMD inst d large numbers of computing cores, the emerging x86-based Intel（R） Many Integrated Core （MIC） Architecture ot only high floating-point performance, but also substantial off-chip memory bandwidth. The 3D FFT （three-di fast Fourier transform） is a widely-studied algorithm; however, the conventional algorithm needs to traverse the three times. In each pass, it computes multiple 1D FFTs along one of three dimensions, giving rise to plenty of rided memory accesses. In this paper, we propose a two-pass 3D FFT algorithm, which mainly aims to reduce of explicit data transfer between the memory and the on-chip cache. The main idea is to split one dimension into ensions, and then combine the transform along each sub-dimension with one of the rest dimensions respectively erence in amount of TLB misses resulting from decomposition along different dimensions is analyzed in detail. el parallelism is leveraged on the many-core system for a high degree of parallelism and better data reuse of loc On top of this, a number of optimization techniques, such as memory padding, loop transformation and vectoriz employed in our implementation to further enhance the performance. We evaluate the algorithm on the Intel（R） PhiTM coprocessor 7110P, and achieve a maximum performance of 136 Gflops with 240 threads in offload mode, which ts the vendor-specific Intel（R）MKL library by a factor of up to 2.22X.

关键词： 3D-FFT memory efficie many-core Many Integrated Core Intel(R) Xeon PhiTM

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

米级高指数面单晶铜箔库制造

science Bulletin 2020年第20期65卷 1694-1695页

作者：张跃 Beijing Advanced Innovation Center for Materials Genome Engineering Beijing Key Laboratory for Advanced Energy Materials and TechnologiesUniversity of Science and Technology BeijingBeijing 100083China State Key Laboratory for Advanced Metals and Materials School of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 100083China

In the huge family of metal,copper(Cu)is one of the earliest documented used materials and is also widely applied in modern *** to the superior electrical,thermal,and mechanical properties,Cu has been extensively used as electrical conductors,thermal dissipaters and structure ***,most of these applications are based on the polycrystalline Cu that can be produced at large scale through mature manufacturing techniques.

关键词：高指数面 electrical thermal

Mining and Ranking Important Nodes in Complex Network by K-Shell and degree Difference

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

国际计算机前沿大会会议论文集 2018年第1期 28-28页

作者： Jianpei Zhang Hui Xu Jing Yang Lijun Lun College of Computer science and Technology Harbin Engineering University Harbin China library Heilongjiang University of Chinese Medicine Harbin China College of Computer science and Information Engineering Harbin Normal University Harbin China