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The Ups and Downs ofModern Dance in China
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《China & The World Cultural Exchange》 1997年第3期30-32,共3页
关键词 the ups and downs ofModern Dance in China In
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Theories of Reading and the Teaching of English Reading
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作者 陈春梅 《海外英语》 2012年第1X期112-114,120,共4页
English reading has gained much attention among teachers and students and become one of the research heatpots in English pedagogy.The paper gives a brief introduction of the theories of reading and attempts to apply t... English reading has gained much attention among teachers and students and become one of the research heatpots in English pedagogy.The paper gives a brief introduction of the theories of reading and attempts to apply the schema theory of reading into the classroom teaching.The classroom practice reveals that English reading under the guidance of schema theory proves effective and raises students' awareness of strategies. 展开更多
关键词 the "bottom-up" VIEW the "top-down" VIEW the "inte
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对“The Land of the Lock”的设计
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作者 秦德娟 王仕宗 马宁 《牡丹江教育学院学报》 2010年第4期147-148,共2页
英语课堂上“以教师为中心”的现象处处可见,为改变这一局面,本文对《大学英语》第三册第三课“The Land of the Lock”进行了设计。该设计主要以“top—down”阅读策略为主,用以提升学生把握篇章内容的能力和猜词能力,力争做到“... 英语课堂上“以教师为中心”的现象处处可见,为改变这一局面,本文对《大学英语》第三册第三课“The Land of the Lock”进行了设计。该设计主要以“top—down”阅读策略为主,用以提升学生把握篇章内容的能力和猜词能力,力争做到“以学生为中心”。 展开更多
关键词 STUDENT-CENTERED TOP-DOWN BOTTOM-UP
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Theoretical System of Sandstone-Type Uranium Deposits in Northern China 被引量:12
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作者 Ruoshi Jin Huajian Liu Xiaoguang Li 《Journal of Earth Science》 SCIE CAS CSCD 2022年第2期257-277,共21页
Many theoretical results on sandstone-type uranium mineralization in northern China obtained by the uranium research team of the Tianjin Center of Geological Survey in recent years are presented.From the source sink s... Many theoretical results on sandstone-type uranium mineralization in northern China obtained by the uranium research team of the Tianjin Center of Geological Survey in recent years are presented.From the source sink system of uranium-producing basins,sedimentary environment of uranium-bearing rock series,ore-forming fluid information,evolution of tectonic events,basin formation and development,we redefine and classify uranium orebodies,redox zoning,and ore-controlling structural styles.We then systematically propose a theoretical system of sandstone-type uranium deposits in northern China.We conclude that sandstone-type uranium deposits in northern China are mainly found in sedimentary environments such as rivers,deltas,and alluvial fans in the Mesozoic and Cenozoic lowstand systems tract and in gray sandstone layers in the vertical redox zoning.The orebodies are controlled by the tectonic slope belt,which is in the shape of a strip on the plane,and spreads in a layer or plate on the section.Vertical(ups and downs)tectonic movement triggers large-scale phreatic flow in the basin,which is the real driving force for controlling the ore-forming fluid.The theoretical system of sandstone-type uranium deposits in northern China should be based on global tectonic movement and environmental changes and take into account factors such as basins as a unit to study mineralization background,ore concentration areas as objects to study mineralization,and the correlation between regional tectonic movement and metallogenic process as a breakthrough point to study tectonic events and metallogenic events.It should also be based on different basin types to establish metallogenic models.The innovative research results and ideas are summarized with the aim of promoting the continuous improvement of sandstone-type uranium mineralization theory in northern China. 展开更多
关键词 theoretical system metallogenic background MINERALIZATION metallogenic model vertical(ups and downs)tectonic movement sandstone-type uranium deposits ore deposit geology
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Visible-light emission properties of α-TeO_2:Ho^(3+)/Yb^(3+)/Eu^(3+) nanoparticles via both up-and down-conversion modes 被引量:3
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作者 张遥 范国康 +2 位作者 胡辉 陈伟龙 白燕 《Journal of Rare Earths》 SCIE EI CAS CSCD 2016年第11期1069-1076,共8页
In this study,α-TeO2:Ho3+/Yb3+,α-TeO2:Eu3+ andα-TeO2:Ho3+/Yb3+/Eu3+ nanoparticles were prepared via a simple hydrothermal process. The up- and down-conversion properties of the as-prepared nanoparticles we... In this study,α-TeO2:Ho3+/Yb3+,α-TeO2:Eu3+ andα-TeO2:Ho3+/Yb3+/Eu3+ nanoparticles were prepared via a simple hydrothermal process. The up- and down-conversion properties of the as-prepared nanoparticles were tested at room temperature un-der a near-infrared photo source (980 nm) and UV-vis photo source, respectively.The results indicated thatα-TeO2 NPs were a kind of outstanding host material for both up- and down-conversion luminescence. Theα-TeO2:Ho3+/Yb3+nanoparticles showed sharp up-conversion emission at 545 and 660 nm under 980 nm excitation, ascribed to the5S2→5I8 and5F5→5I8(Ho3+) transitions, and weaker down-conversion emission at 545 nm under 455 nm excitation, ascribed to the5S2→5I8(Ho3+) transitions. Theα-TeO2:Eu3+nanoparticles showed strong down-conversion emission at 592 and 615 nm under 395 nm excitation, attributed to the5D0→7F1 and 5D0→7F2 (Eu3+) transitions. Possessing the advantages of these two luminescent materials, the as-prepared tri-doped samples ofα-TeO2:0.5Ho3+/10Yb3+/3Eu3+ (mol.%)nanoparticles could successfully emit visible light via both up- and down-conversion modes. 展开更多
关键词 UP-CONVERSION DOWN-CONVERSION LUMINESCENCE α-TeO2 nanoparticles rare earths
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Sensitivity Test and Data Analysis for Storage Reliability Assessment of Explosive Initiator 被引量:2
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作者 洪东跑 赵宇 《Defence Technology(防务技术)》 SCIE EI CAS 2010年第2期119-125,共7页
The explosive initiator is one kind of sensitivity products with long life and high reliability.In order to improve the storage reliability assessment,the method of storage reliability assessment for explosive initiat... The explosive initiator is one kind of sensitivity products with long life and high reliability.In order to improve the storage reliability assessment,the method of storage reliability assessment for explosive initiator was proposed based on time series model using the sensitivity test data.In the method,the up and down test was used to estimate the distribution parameters of threshold.And an approach to design the up and down test was present to draw better estimations.Furthermore,the method of shrinkage estimation was introduced to get a better estimation of scale parameter by combining the sample information with prior information.The simulation result shows that the shrinkage estimation is better than traditional estimation under certain conditions.With the distribution parameters estimations,the time series models were used to describe the changing trends of distribution parameters along with storage time.Then for a fixed storage time,the distribution parameters were predicted based on the models.Finally,the confidence interval of storage reliability was obtained by fiducial inference.The illustrative example shows that the method is available for storage reliability assessment of the explosive initiator with high reliability. 展开更多
关键词 system engineering storage reliability explosive initiator up and down test time series model shrinkage estimation
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Comparison Analysis of Efficiency Between Double-Synchronous Step-Down-Stress and Step-Up-Stress Accelerated Life Tests 被引量:1
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作者 寇海霞 安宗文 孙道明 《Journal of Shanghai Jiaotong university(Science)》 EI 2017年第3期361-364,共4页
Double-crossed-step-stress(DCSS) accelerated life test(ALT) method is widely used for estimating the lifetime of products with high reliability and long lifetime. In order to further reduce the test time and test cost... Double-crossed-step-stress(DCSS) accelerated life test(ALT) method is widely used for estimating the lifetime of products with high reliability and long lifetime. In order to further reduce the test time and test cost, a double-synchronous-step-stress(DSSS) ALT method which combines a double-synchronous-step-downstress(DSSDS) ALT method and a double-synchronous-step-up-stress(DSSUS) ALT method is proposed. The accelerated stresses decrease and increase in a synchronous way with one step in the DSSDS-ALT and DSSUSALT methods, respectively. Monte Carlo method is adopted to simulate the two methods, and the validity and efficiency of them are demonstrated by the simulation results. In addition, a comparison analysis of efficiency between DSSDS-ALT method and DSSUS-ALT method is carried out. The result shows that the DSSDS-ALT method compared with the DSSUS-ALT method can significantly improve the test efficiency under the same test condition. 展开更多
关键词 accelerated life test(ALT) double-synchronous-step-down-stress(DSSDS) double-synchronous-step-up-stress(DSSUS) efficiency Monte Carlo
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Pharmacological- and non-pharmacological therapeutic approaches in inflammatory bowel disease in adults 被引量:3
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作者 Gerda C Leitner Harald Vogelsang 《World Journal of Gastrointestinal Pharmacology and Therapeutics》 CAS 2016年第1期5-20,共16页
Inflammatory bowel diseases (IBDs) are a group of chronic inflammatory conditions mainly of the colon and small intestine. Crohn&rsquo;s disease (CD) and ulcerative colitis (UC) are the most frequent types of IBD.... Inflammatory bowel diseases (IBDs) are a group of chronic inflammatory conditions mainly of the colon and small intestine. Crohn&rsquo;s disease (CD) and ulcerative colitis (UC) are the most frequent types of IBD. IBD is a complex disease which arises as a result of the interaction of environmental, genetic and immunological factors. It is increasingly thought that alterations of immunological reactions of the patients to their own enterable bacteria (microfilm) may contribute to inflammation. It is characterized by mucosal and sub mucosal inflammation, perpetuated by infiltration of activated leukocytes. CD may affect the whole gastrointestinal tract while UC only attacks the large intestine. The therapeutic goal is to achieve a steroid-free long lasting remission in both entities. UC has the possibility to be cured by a total colectomy, while CD never can be cured by any operation. A lifelong intake of drugs is mostly necessary and essential. Medical treatment of IBD has to be individualized to each patient and usually starts with anti-inflammatory drugs. The choice what kind of drugs and what route administered (oral, rectal, intravenous) depends on factors including the type, the localization, and severity of the patient&rsquo;s disease. IBD may require immune-suppression to control symptoms such as prednisolone, thiopurines, calcineurin or sometimes folic acid inhibitors or biologics like TNF-&alpha; inhibitors or anti-integrin antibodies. For both types of disease (CD, UC) the same drugs are available but they differ in their preference in efficacy between CD and UC as 5-aminosalicylic acid for UC or budesonide for ileocecal CD. As therapeutic alternative the main mediators of the disease, namely the activated pro-inflammatory cytokine producing leukocytes can be selectively removed via two apheresis systems (Adacolumn and Cellsorba) in steroid-refractory or dependent cases. Extracorporeal photopheresis results in an increase of regulatory B cells, regulatory CD8<sup>+</sup> T cells and T-regs Type 1. Both types of apheresis were able to induce clinical remission and mucosal healing accompanied by tapering of steroids. 展开更多
关键词 Inflammatory bowel disease Crohn&rsquo s disease Ulcerative colitis Extracorporeal treatment Step up/top down Psychological aspects in inflammatory bowel disease Current medical treatment of inflammatory bowel disease Future therapeutical strategies
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A Cognitive Comparative Analysis of UP-DOWN Metaphorical Extension in Chinese and English
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作者 张长永 《科技信息》 2011年第20期177-179,共3页
This paper aims at making some research on spatial metaphor from cognitive angle.Spatial metaphor is a basic tool which can make us more familiar with our world,and lots of abstract concepts are based on it.Take "... This paper aims at making some research on spatial metaphor from cognitive angle.Spatial metaphor is a basic tool which can make us more familiar with our world,and lots of abstract concepts are based on it.Take "UP-DOWN" for example,this paper will mainly discuss the symmetry and dissymmetry of its extension in Chinese and English. 展开更多
关键词 英文文摘 内容介绍 期刊 《科技信息》
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Ups and Downs for China's Securities Dealers
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《China's Foreign Trade》 1999年第10期4-7,共4页
关键词 ups and downs for China’s Securities Dealers In
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THE DYNAMICS OF MAINTAINING THE TROPICAL CYCLONE 9012 AFTER ITS LANDING
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作者 梁力 吴志伟 严光华 《Journal of Tropical Meteorology》 SCIE 1996年第1期35-45,共11页
Using 2. 5 ×2. 5 winds and pressure grid data, the angular momentum budgets are studied in this paper for TC 9012 (Yancy) which was kept active 65 hours after land fall. It is found that the inland TC 9012 moved ... Using 2. 5 ×2. 5 winds and pressure grid data, the angular momentum budgets are studied in this paper for TC 9012 (Yancy) which was kept active 65 hours after land fall. It is found that the inland TC 9012 moved into the center of a relatively stable saddle, in which large amount of humid air was entrained into the storm from the southerly jet at low level to bund up the energy of latent heat, the weak cold air coming from the north provided it with baroclinic energy, while the vorticity transfer of geostrophic angular momentum on the radius 4°-8°from the cyclone center at upper troposphere and the input of cyclonic angular momentum produced by the βterm are immediate factors maintaining the central pressure and maximum winds. 展开更多
关键词 long maintenance ANGULAR MOMENTUM transport SPIN-UP or SPIN-DOWN
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GENERALIZED FATIGUE CONSTANT LIFE CURVE AND TWO-DIMENSIONAL PROBABILITY DISTRIBUTION OF FATIGUE LIMIT
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作者 熊峻江 武哲 高镇同 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2002年第10期1188-1193,共6页
According to the traditional fatigue constant life curve, the concept and the universal expression of the generalized fatigue constant life curve were proposed. Then, on the basis of the optimization method of the cor... According to the traditional fatigue constant life curve, the concept and the universal expression of the generalized fatigue constant life curve were proposed. Then, on the basis of the optimization method of the correlation coefficient, the parameter estimation formulas were induced and the generalized fatigue constant life curve with the reliability level p was given. From P-S-a-S-m curve, the two-dimensional probability distribution of the fatigue limit was derived. After then, three se, of tests of LY11 CZ corresponding to the different average stress were carried out in terms of the two-dimensional up-down method. Finally, the methods are used to analyze the test results, and it is found that the analyzed results with the high precision may be obtained. 展开更多
关键词 fatigue limit generalized constant life curve two-dimensional up-down method
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Population Dynamics of Large Herbivores and the Framing of Wildlife Conservation in Zimbabwe
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作者 Edson Gandiwa 《Open Journal of Ecology》 2014年第7期411-420,共10页
This article reviews: 1) The role of natural and human-induced controls in influencing large herbivore populations;2) how human controls (i.e., policy instruments, incentives and provisions) influence human activities... This article reviews: 1) The role of natural and human-induced controls in influencing large herbivore populations;2) how human controls (i.e., policy instruments, incentives and provisions) influence human activities and wildlife conservation;and 3) media framing of wildlife conservation using Zimbabwe as a case study, in particular Gonarezhou National Park and adjacent areas. The review shows that droughts are important in influencing large herbivore populations in semi-arid ecosystems;political instability and economic collapse does not necessarily lead to increased illegal hunting in situations where policy instruments, such as laws, are enforced. A higher perceived effectiveness of Communal Areas Management Programme for Indigenous Resources was partly associated with a decline in human-wildlife conflicts and there was a spill-over effect of frames from the political domain into wildlife conservation following Zimbabwe’s land reforms in 2000. It is concluded that natural bottom-up processes (e.g., droughts) influence large herbivore population dynamics whereas policy instruments, incentives, provisions and societal frames mainly have a top-down effect on wild large herbivore populations in savanna ecosystems. 展开更多
关键词 BOTTOM-UP CONTROL ILLEGAL HUNTING Law ENFORCEMENT Media FRAMING Top-Down CONTROL
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Comparison of Top down and Bottom up Cost Approaches in Colon and Rectal Cancer Treatment
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作者 Rukiye Numanoğlu Tekin Bayram Şahin 《Health》 2021年第2期90-109,共20页
Introduction: In recent years, health care expenditures have significantly risen across the world and in Turkey. Because of the limited resources allocated to health, it is very important for countries to conduct stud... Introduction: In recent years, health care expenditures have significantly risen across the world and in Turkey. Because of the limited resources allocated to health, it is very important for countries to conduct studies especially on cost of diseases such as colorectal cancer (CRC) with a high burden of disease and labor loss. The aim of this study was to calculate the cost of treatment for colon and rectal cancers based on two different cost approaches from the perspective of SSI (top-down and bottom-up) and to compare the results obtained. Materials and Methods: Data were obtained from the SSI MEDULA System a total of 62,970 colon and rectal cancer patient for the top-down cost approach. In the bottom-up cost approach, treatment costs were determined based on the expert opinions. Results: The average cost of treatment per patient for colon cancer was determined as 3055.5 TL, for rectal cancer was determined as 4146.2 TL with the top-down cost approach. The average cost of treatment per patient for colon cancer was determined as 14,920.4 TL, for rectal cancer was determined as 17,904.6 TL according to the bottom-up cost approach. Conclusion: Since the bottom-up cost approach provides more detailed information on the cost of illness, and thereby on the use of resources allocated to health, it is thought that the combined use of these two cost approaches completes each other’s weaknesses. 展开更多
关键词 Cost of Illness Colon Cancer Rectal Cancer Top Down Cost of Illness Bottom Up Cost of Illness
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UC/DC luminescence of Ho^(3+) doped pyrochlore structured La_(2(1–x))Yb_(2x)TiO_5 phosphor synthesized by sol-gel method 被引量:2
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作者 尤俊华 马理 +3 位作者 曲迎东 李荣德 刘宣文 郭瑞 《Journal of Rare Earths》 SCIE EI CAS CSCD 2016年第3期235-239,共5页
Ho^(3+) doped La_(2(1-x))Yb_(2x)TiO_5 samples were prepared by sol-gel method. Pyrochlore structured powders were obtained under the annealing of the as-prepared samples at 1100 °C for 3 h in the air. Al... Ho^(3+) doped La_(2(1-x))Yb_(2x)TiO_5 samples were prepared by sol-gel method. Pyrochlore structured powders were obtained under the annealing of the as-prepared samples at 1100 °C for 3 h in the air. All the samples were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM) and photoluminescent spectroscopy. When x=0, we obtained La_2TiO_5 phosphors. Monitored at 546 nm, the excitation spectrum of Ho^(3+) activated La_2TiO_5 phosphors consisted of a broad band originating from the charge-transfer band(CTB) between Ho^(3+) ions and the nearest neighboring O^(2-) ions at 250-280 nm and four sharp bands associated to f-f transitions of Ho^(3+) ions at 350-500 nm. Under the blue light excitation at 461 nm, Ho^(3+) ion in La_2TiO_5 emitted an intense green emission band at 546 nm due to the transition of ~5S_2, ~5F_4→~5I_8. Two intense bands were observed at 490 nm(blue, ~5F_3→I_8) and 663 nm(red, ~5F_5→~5I_8) in the up-conversion(UC) spectrum under 980 nm NIR laser excitation in La_2TiO_5 phosphors activated with Ho^(3+) alone, whereas they were much different from the down-conversion(DC) luminescent samples. When x=7.5 mol.%-17.5 mol.%, the UC emission spectra of them dominated at 546 nm(green, ~5S_2, ~5F_4→~5I_8) and enhanced significantly with the dose of Yb^(3+) ion. The decay curve also confirmed that the transitions of ~5F_4→~5I_8 and ~5S_2→~5I_8 were merged into one emission band at 546 nm. 展开更多
关键词 down/up-conversion Ho3+ La2TiO5 La2(1-x)YbaxTiO5 LUMINESCENCE rare earths
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Experimental study of rotating wind turbine breakdown characteristics in large scale air gaps 被引量:2
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作者 Yu WANG Lu OU +3 位作者 Tianjun SI Yang NI Jianwei XU Xishan WEN 《Plasma Science and Technology》 SCIE EI CAS CSCD 2017年第6期108-115,共8页
When a wind turbine is struck by lightning,its blades are usually rotating.The effect of blade rotation on a turbine's ability to trigger a lightning strike is unclear.Therefore,an arching electrode was used in a win... When a wind turbine is struck by lightning,its blades are usually rotating.The effect of blade rotation on a turbine's ability to trigger a lightning strike is unclear.Therefore,an arching electrode was used in a wind turbine lightning discharge test to investigate the difference in lightning triggering ability when blades are rotating and stationary.A negative polarity switching waveform of 250/2500 μs was applied to the arching electrode and the up-and-down method was used to calculate the 50%discharge voltage.Lightning discharge tests of a 1:30 scale wind turbine model with 2,4,and 6 m air gaps were performed and the discharge process was observed.The experimental results demonstrated that when a 2 m air gap was used,the breakdown voltage increased as the blade speed was increased,but when the gap length was 4 m or longer,the trend was reversed and the breakdown voltage decreased.The analysis revealed that the rotation of the blades changes the charge distribution in the blade-tip region,promotes upward leader development on the blade tip,and decreases the breakdown voltage.Thus,the blade rotation of a wind turbine increases its ability to trigger lightning strikes. 展开更多
关键词 wind turbine ROTATION up-and-down method breakdown characteristic large-scale air gap
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Precision Work-piece Detection and Measurement Combining Top-down and Bottom-up Saliency 被引量:2
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作者 Jia Sun Peng Wang +2 位作者 Yong-Kang Luo Gao-Ming Hao Hong Qiao 《International Journal of Automation and computing》 EI CSCD 2018年第4期417-430,共14页
In this paper, a fast and accurate work-piece detection and measurement algorithm is proposed based on top-down feature extraction and bottom-up saliency estimation. Firstly, a top-down feature extraction method based... In this paper, a fast and accurate work-piece detection and measurement algorithm is proposed based on top-down feature extraction and bottom-up saliency estimation. Firstly, a top-down feature extraction method based on the prior knowledge of work- pieces is presented, in which the contour of a work-piece is chosen as the major feature and the corresponding template of the edges is created. Secondly, a bottom-up salient region estimation algorithm is proposed, where the image boundaries are labelled as background queries, and the salient region can be detected by computing contrast against image boundary. Finally, the calibration method for vision system with telecentric lens is discussed, and the dimensions of the work-pieces are measured. In addition, strategies such as image pyramids and a stopping criterion are adopted to speed-up the algorithm. An automatic system embedded with the proposed detection and measurement algorithm combining top-down and bottom-up saliency (DM-TBS) is designed to pick out defective work-pieces without any manual auxiliary. Experiments and results demonstrate the effectiveness of the proposed method. 展开更多
关键词 Work-pieces detection salient region estimation top-down and bottom-up saliency(TBS) calibration visual measurement.
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The Application of The Top-down Approach in Teaching Extensive Reading
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作者 陈国静 《海外英语》 2011年第5X期36-37,39,共3页
The top-down and bottom-up are two main approaches used in teaching extensive reading and both of them should be used alternatively so that students can not only understand the details but also the main ideas of readi... The top-down and bottom-up are two main approaches used in teaching extensive reading and both of them should be used alternatively so that students can not only understand the details but also the main ideas of reading materials.The importance of using top-down approach is emphasized and some suggestions are given on the problem that students pay so much attention on vocabulary and grammar rather than main idea in reading. 展开更多
关键词 READING TOP-DOWN BOTTOM-UP
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“Top-down” and “Bottom-up” approaches to teaching listening,when and which approach may be more useful?
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作者 张颖 《疯狂英语(教师版)》 2012年第1期43-48,共6页
This paper mainly deals with two mainstreams in teaching listening comprehension:bottom-up processing approach and top-down processing approach.In the first part of the essay the importance of listening comprehension ... This paper mainly deals with two mainstreams in teaching listening comprehension:bottom-up processing approach and top-down processing approach.In the first part of the essay the importance of listening comprehension in language learning will be demonstrated briefly.Then the author will go on to explore the nature of top-down and bottom-up approaches in teaching listening.Lastly,at the third part of the essay,the author shall try to discuss the possibility of applying these approaches into practice,that is,when and why one of them is more useful.Furthermore in this section,a more integrated view will be introduced. 展开更多
关键词 BOTTOM-UP PROCESSING APPROACH TOP-DOWN PROCESSING APPROACH teaching LisTENING COMPREHENSION
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Characteristics of damaged layer in micro-machining of copper material
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作者 Dong-Hee KWON Jeong-Suk KIM +2 位作者 Myung-Chang KANG Se-Hun KWON Jong-Hwan LEE 《中国有色金属学会会刊:英文版》 CSCD 2009年第B09期295-300,共6页
The study on damaged layer is necessary for improving the machinability in micro-machining because the damaged layer affects the micro mold life and micro machine parts. This study examined the ultra-precision micro-m... The study on damaged layer is necessary for improving the machinability in micro-machining because the damaged layer affects the micro mold life and micro machine parts. This study examined the ultra-precision micro-machining characteristics, such as cutting speed, feed rate and cutting depth, of a micro-damaged layer produced by an ultra-high speed air turbine spindle. The micro cutting force, surface roughness and plastic deformation layer were investigated according to the machining conditions. The damaged layer was measured using optical microscope on samples prepared through metallographic techniques. The scale of the damaged layer depends on the cutting process parameters, particularly, the feed per tooth and axial depth of the cut. According to the experimental results, the depth of the damaged layer is increased by increasing the feed per tooth and cutting depth, also the damaged layer occurs less in down-milling compared with up-milling during the micro-machining operation. 展开更多
关键词 机械加工性 微观特征 损伤层 铜材 样品制备技术 微型机器 切削速度 切削深度
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