A non contact three dimensional measurement method is presented in this paper.This system consists of a laser triangulation probe,a probe head and a coordinate measuring machine (CMM).The measurement principle of th...A non contact three dimensional measurement method is presented in this paper.This system consists of a laser triangulation probe,a probe head and a coordinate measuring machine (CMM).The measurement principle of the system is discussed,and a system calibration method employing a reference ball is proposed.The geometric model involving four frames is established to calculate the data points based on the reading of the laser probe and position information from the CMM.A measuring experiment for gesso free form surface using this system is carried out.展开更多
In order to design the press bend forming path of aircraft integral panels,a novel optimization method was proposed, which integrates FEM equivalent model based on previous study,the artificial neural network response...In order to design the press bend forming path of aircraft integral panels,a novel optimization method was proposed, which integrates FEM equivalent model based on previous study,the artificial neural network response surface,and the genetic algorithm.First,a multi-step press bend forming FEM equivalent model was established,with which the FEM experiments designed with Taguchi method were performed.Then,the BP neural network response surface was developed with the sample data from the FEM experiments.Furthermore,genetic algorithm was applied with the neural network response surface as the objective function. Finally,verification was carried out on a simple curvature grid-type stiffened panel.The forming error of the panel formed with the optimal path is only 0.098 39 and the calculating efficiency has been improved by 77%.Therefore,this novel optimization method is quite efficient and indispensable for the press bend forming path designing.展开更多
A new load surface based approach to the reliability analysis of caisson-type breakwater is proposed. Uncertainties of the horizontal and vertical wave loads acting on breakwater are considered by using the so-called ...A new load surface based approach to the reliability analysis of caisson-type breakwater is proposed. Uncertainties of the horizontal and vertical wave loads acting on breakwater are considered by using the so-called load surfaces, which can be estimated as functions of wave height, water level, and so on. Then, the first-order reliability method（FORM） can be applied to determine the probability of failure under the wave action. In this way, the reliability analysis of breakwaters with uncertainties both in wave height and in water level is possible. Moreover, the uncertainty in wave breaking can be taken into account by considering a random variable for wave height ratio which relates the significant wave height to the maximum wave height. The proposed approach is applied numerically to the reliability analysis of caisson breakwater under wave attack that may undergo partial or full wave breaking.展开更多
The assessment of nanomechanical properties of a single amyloid fibril in a confined space provides important information for understanding the role of fibrils in a cell microenvironment. In this study, the structure ...The assessment of nanomechanical properties of a single amyloid fibril in a confined space provides important information for understanding the role of fibrils in a cell microenvironment. In this study, the structure and nanomechanical properties of different fibrils formed in water nanofilms on mica surface are carefully investigated by using the new atomic force microscopy imaging mode-peak force quantitative nanomechanics （PF-QNM）. We find that two types of fibrils with different morphologies are formed in water nanofilm on mica. The compression elasticities of these two types of fibrils are 3.9±0.9 and 2.5±0.6 GPa, respectively. The remarkable difference is possibly due to the structural discrepancy in two types of fibrils.展开更多
A numerical method is suggested to generate the blends with one of the blended surfaces being analytical.The method is more accurate, less complicated,more efficient and more intuitive.The formulation of equation set ...A numerical method is suggested to generate the blends with one of the blended surfaces being analytical.The method is more accurate, less complicated,more efficient and more intuitive.The formulation of equation set is presented in detail and the NURBS representation of the blending surface discussed.The algorithm has been implemented on PC.The method was tested by a couple of samples and got satisfactory results.展开更多
Friction stir welding [FSW） has achieved remarkable success in the joining and processing of aluminium alloys and other softer structural alloys. Conventional FSW, however, has not been entirely successful in the joi...Friction stir welding [FSW） has achieved remarkable success in the joining and processing of aluminium alloys and other softer structural alloys. Conventional FSW, however, has not been entirely successful in the joining, processing and manufacturing of different desired materials essential to meet the sophis- ticated green globe requirements. Through the efforts of improving the process and transferring the existing friction stir knowledge base to other advanced applications, several friction stir based daughter technologies have emerged over the timeline, A few among these technologies are well developed while others are under the process of emergence. Beginning with a broad classification of the scattered fric- tions stir based technologies into two categories, welding and processing, it appears now time to know, compile and review these to enable their rapid access for reference and academia. In this review article, the friction stir based technologies classified under the categol^J of welding are those applied for join- ing of materials while the remnant are labeled as friction stir processing （FSP） technologies. This review article presents an overview of four general aspects of both the developed and the developing friction stir based technologies, their associated process parameters, metallurgical features of their products and their feasibility and application to various materials. The lesser known and emerging technologies have been emphasized.展开更多
Cast blanks with large-scale free form surfaces are very difficult tomanufacture because of significant casting distortions. It is concerned that the development andapplication of a hogging algorithm for preparing the...Cast blanks with large-scale free form surfaces are very difficult tomanufacture because of significant casting distortions. It is concerned that the development andapplication of a hogging algorithm for preparing the blanks for an extended rough cutting. Theprocedure includes three main phases. They are the reconstruction of the free form surface withscattered points based on a special Hermite's interpolation, intersection of curved surfaces todefine the hogging areas, and the tool path planning. The result shows that the algorithm is greatlyvalid in reducing the invalid tool paths so that the work efficiency can be improved remarkably.展开更多
In this paper, the authors are presenting the approach to extract the multiword expression （MWEs） from monolingual corpora. It both validates and generates multiword candidates. The multiword expression provides a l...In this paper, the authors are presenting the approach to extract the multiword expression （MWEs） from monolingual corpora. It both validates and generates multiword candidates. The multiword expression provides a list of candidates which are extracted and filtered according to the number of criteria and a set of standard statistical association measures. The generation of the multiword candidates is based on the surface forms, while the validation consists of series of criteria for removing noise using language independent association measures. For generating corpus count, it provides both a corpus indexation facility. Also, this approach allows easy integration with a machine learning tool for thecreation and application of supervised multiword extraction models if annotated data is available. The authors present the use of multiword in a standard configuration, for extracting MWEs from a corpus of general purpose English.展开更多
One of the assumptions underlying theories of phonological derivation is that the phonological architecture of any language consists of,at least,an abstract underlying form,its surface form and conditions which derive...One of the assumptions underlying theories of phonological derivation is that the phonological architecture of any language consists of,at least,an abstract underlying form,its surface form and conditions which derive the surface form from its underlying form.It is further assumed that the conditions are serially ordered in frameworks which subscribe to the rule ordering such as orthodox generative phonology and lexical phonology.In the present study,these issues are engaged in the case of Uvwie.In particular,the study seeks to investigate the conditions(processes and rules)which derive surface forms from their corresponding underlying forms,and the order in which they apply.Thus the study will examine the different well-motivated phonological rules attested in the derivation of Uvwie formatives,and provide evidence for the order in which the processes apply.The study employe data documented in Ekiugbo(2016),and couched its analysis within rule ordering principle of generative phonology.The study identifies six rules,which are ordered thus:nasal assimilation>glide formation>vowel elision>tone fusion>vowel lengthening>consonant elision.展开更多
The basic principle of equal base circle bevel gear (EBCBG) is illustrated simply Thetooth surface equation of EBCBG manufactured by end milling cutter with involute profile is de-rived. The tooth form error is analy...The basic principle of equal base circle bevel gear (EBCBG) is illustrated simply Thetooth surface equation of EBCBG manufactured by end milling cutter with involute profile is de-rived. The tooth form error is analyzed on the basis of spherical involute展开更多
In this Letter, a test method based on oblique incidence is practically implemented in the interferometric measurement process. Three sets of wavefront data are achieved through cavity interference measurement with a ...In this Letter, a test method based on oblique incidence is practically implemented in the interferometric measurement process. Three sets of wavefront data are achieved through cavity interference measurement with a Fizeau interferometer and one oblique incidence measurement. An iterative algorithm is applied to retrieve the absolute surface shape of the test flat. By adding two sets of measurements, the absolute surface error of the interferometer＇s reference flat can be obtained. The new method can not only calibrate the reference flat error of interferometer, but also provide the absolute measurement method for high precision optical components applied in high power laser systems.展开更多
Precision flat surfaces finished by hand-scraping are extensively used in the sliding parts of precision positioning systems or the surface plates of precision measuring instruments.These hand-scraped surfaces are emp...Precision flat surfaces finished by hand-scraping are extensively used in the sliding parts of precision positioning systems or the surface plates of precision measuring instruments.These hand-scraped surfaces are employed to improve the flatness of the machined surfaces and the motion accuracy of the instruments.The numerous depressions of micrometer-scale depth on a scraped surface are thought to prevent wringing and improve the lubrication properties by forming oil pockets.Form measurement of the micrometer-scale features of a hand-scraped surface is one of the reasonable methods for investigating its effect on the motion accuracy of the positioning systems or the lubrication properties of the sliding parts.Because a hand-scraped surface is a rough surface composed of micrometric complex features,it is difficult to conduct precision measurement of the three-dimensional surface form using conventional measurement instruments,such as vertical-incident interferometers or stylus-type profilometers.In this study,an oblique-incident interferometer based on Abramson interferometry is introduced to measure the form of a rough surface produced by hand-scraping.Because this technique can detect high-intensity reflected light on a rough surface,it allows the measurement of the form of the hand-scraped surface in noncontact condition.In order to shorten the measurement time,the form calculation based on a five-step phase shifting method was introduced.展开更多
A new form of geodetic coordinate system based on geodesic coordinates instead of geodetic longitude and latitude was proposed.The vertical and horizontal geodesic coordinates measured with length were defined as coor...A new form of geodetic coordinate system based on geodesic coordinates instead of geodetic longitude and latitude was proposed.The vertical and horizontal geodesic coordinates measured with length were defined as coordinate parameters,but the two families of coordinate curves were still meridians and parallel circles.The first fundamental form on the ellipsoidal surface and its three coefficients were deduced by the geodesic coordinate.The formula for the latitudinal scale factor of length for geodetic parallel lines was derived,by which the obtained result conformed to that standard value calculated from geodetic latitude,and it is applicable in the range of 400 km from north to south.Therefore,it lays the foundation for establishing the differential equation and differential relationship based on this type of coordinate parameters;and consequently,it is convenient and accurate enough to operate on the ellipsoidal surface in this new form of geodetic coordinate system.展开更多
基金Supported by"863"High Technology Development Comittee ofChina (No."863"- 51 1 - 942 - 0 2 4 ) National Natural Science Foun-dation of China (No.50 0 750 64)
文摘A non contact three dimensional measurement method is presented in this paper.This system consists of a laser triangulation probe,a probe head and a coordinate measuring machine (CMM).The measurement principle of the system is discussed,and a system calibration method employing a reference ball is proposed.The geometric model involving four frames is established to calculate the data points based on the reading of the laser probe and position information from the CMM.A measuring experiment for gesso free form surface using this system is carried out.
基金Project(20091102110021)supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China
文摘In order to design the press bend forming path of aircraft integral panels,a novel optimization method was proposed, which integrates FEM equivalent model based on previous study,the artificial neural network response surface,and the genetic algorithm.First,a multi-step press bend forming FEM equivalent model was established,with which the FEM experiments designed with Taguchi method were performed.Then,the BP neural network response surface was developed with the sample data from the FEM experiments.Furthermore,genetic algorithm was applied with the neural network response surface as the objective function. Finally,verification was carried out on a simple curvature grid-type stiffened panel.The forming error of the panel formed with the optimal path is only 0.098 39 and the calculating efficiency has been improved by 77%.Therefore,this novel optimization method is quite efficient and indispensable for the press bend forming path designing.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education,Science and Technology(Grant No.NRF-2012R1A1A4A01010830)
文摘A new load surface based approach to the reliability analysis of caisson-type breakwater is proposed. Uncertainties of the horizontal and vertical wave loads acting on breakwater are considered by using the so-called load surfaces, which can be estimated as functions of wave height, water level, and so on. Then, the first-order reliability method（FORM） can be applied to determine the probability of failure under the wave action. In this way, the reliability analysis of breakwaters with uncertainties both in wave height and in water level is possible. Moreover, the uncertainty in wave breaking can be taken into account by considering a random variable for wave height ratio which relates the significant wave height to the maximum wave height. The proposed approach is applied numerically to the reliability analysis of caisson breakwater under wave attack that may undergo partial or full wave breaking.
基金Supported by the National Natural Science Foundation of China under Grant No 11474173the Natural Science Foundation of Zhejiang Province under Grant Nos LY14A040006 and LQ14F040002+1 种基金the Ningbo Natural Science Foundation under Grant Nos2014A610202 and 2014A610149the K.C.Wong Magna Fund in Ningbo University
文摘The assessment of nanomechanical properties of a single amyloid fibril in a confined space provides important information for understanding the role of fibrils in a cell microenvironment. In this study, the structure and nanomechanical properties of different fibrils formed in water nanofilms on mica surface are carefully investigated by using the new atomic force microscopy imaging mode-peak force quantitative nanomechanics （PF-QNM）. We find that two types of fibrils with different morphologies are formed in water nanofilm on mica. The compression elasticities of these two types of fibrils are 3.9±0.9 and 2.5±0.6 GPa, respectively. The remarkable difference is possibly due to the structural discrepancy in two types of fibrils.
文摘A numerical method is suggested to generate the blends with one of the blended surfaces being analytical.The method is more accurate, less complicated,more efficient and more intuitive.The formulation of equation set is presented in detail and the NURBS representation of the blending surface discussed.The algorithm has been implemented on PC.The method was tested by a couple of samples and got satisfactory results.
基金financial support on this work from the National Natural Science Foundation of China(Grant Nos.51475272 and 51550110501)Shandong University for the Postdoctoral fellowship
文摘Friction stir welding [FSW） has achieved remarkable success in the joining and processing of aluminium alloys and other softer structural alloys. Conventional FSW, however, has not been entirely successful in the joining, processing and manufacturing of different desired materials essential to meet the sophis- ticated green globe requirements. Through the efforts of improving the process and transferring the existing friction stir knowledge base to other advanced applications, several friction stir based daughter technologies have emerged over the timeline, A few among these technologies are well developed while others are under the process of emergence. Beginning with a broad classification of the scattered fric- tions stir based technologies into two categories, welding and processing, it appears now time to know, compile and review these to enable their rapid access for reference and academia. In this review article, the friction stir based technologies classified under the categol^J of welding are those applied for join- ing of materials while the remnant are labeled as friction stir processing （FSP） technologies. This review article presents an overview of four general aspects of both the developed and the developing friction stir based technologies, their associated process parameters, metallurgical features of their products and their feasibility and application to various materials. The lesser known and emerging technologies have been emphasized.
基金This project is supported by Visiting Scholar Foundation of Key Laboratory in University, Ministry of Education of China.
文摘Cast blanks with large-scale free form surfaces are very difficult tomanufacture because of significant casting distortions. It is concerned that the development andapplication of a hogging algorithm for preparing the blanks for an extended rough cutting. Theprocedure includes three main phases. They are the reconstruction of the free form surface withscattered points based on a special Hermite's interpolation, intersection of curved surfaces todefine the hogging areas, and the tool path planning. The result shows that the algorithm is greatlyvalid in reducing the invalid tool paths so that the work efficiency can be improved remarkably.
文摘In this paper, the authors are presenting the approach to extract the multiword expression （MWEs） from monolingual corpora. It both validates and generates multiword candidates. The multiword expression provides a list of candidates which are extracted and filtered according to the number of criteria and a set of standard statistical association measures. The generation of the multiword candidates is based on the surface forms, while the validation consists of series of criteria for removing noise using language independent association measures. For generating corpus count, it provides both a corpus indexation facility. Also, this approach allows easy integration with a machine learning tool for thecreation and application of supervised multiword extraction models if annotated data is available. The authors present the use of multiword in a standard configuration, for extracting MWEs from a corpus of general purpose English.
文摘One of the assumptions underlying theories of phonological derivation is that the phonological architecture of any language consists of,at least,an abstract underlying form,its surface form and conditions which derive the surface form from its underlying form.It is further assumed that the conditions are serially ordered in frameworks which subscribe to the rule ordering such as orthodox generative phonology and lexical phonology.In the present study,these issues are engaged in the case of Uvwie.In particular,the study seeks to investigate the conditions(processes and rules)which derive surface forms from their corresponding underlying forms,and the order in which they apply.Thus the study will examine the different well-motivated phonological rules attested in the derivation of Uvwie formatives,and provide evidence for the order in which the processes apply.The study employe data documented in Ekiugbo(2016),and couched its analysis within rule ordering principle of generative phonology.The study identifies six rules,which are ordered thus:nasal assimilation>glide formation>vowel elision>tone fusion>vowel lengthening>consonant elision.
文摘The basic principle of equal base circle bevel gear (EBCBG) is illustrated simply Thetooth surface equation of EBCBG manufactured by end milling cutter with involute profile is de-rived. The tooth form error is analyzed on the basis of spherical involute
基金supported by the National Natural Science Foundation of China(Nos.11602280 and 61705246)
文摘In this Letter, a test method based on oblique incidence is practically implemented in the interferometric measurement process. Three sets of wavefront data are achieved through cavity interference measurement with a Fizeau interferometer and one oblique incidence measurement. An iterative algorithm is applied to retrieve the absolute surface shape of the test flat. By adding two sets of measurements, the absolute surface error of the interferometer＇s reference flat can be obtained. The new method can not only calibrate the reference flat error of interferometer, but also provide the absolute measurement method for high precision optical components applied in high power laser systems.
基金This research is supported by the JSPS,JapanJapan Society for the Promotion of Science,Japan KAKENHI Grant Number JP 20K04195 and research grant of the Mitutoyo Association for Science and Technology Grant Number R1901.
文摘Precision flat surfaces finished by hand-scraping are extensively used in the sliding parts of precision positioning systems or the surface plates of precision measuring instruments.These hand-scraped surfaces are employed to improve the flatness of the machined surfaces and the motion accuracy of the instruments.The numerous depressions of micrometer-scale depth on a scraped surface are thought to prevent wringing and improve the lubrication properties by forming oil pockets.Form measurement of the micrometer-scale features of a hand-scraped surface is one of the reasonable methods for investigating its effect on the motion accuracy of the positioning systems or the lubrication properties of the sliding parts.Because a hand-scraped surface is a rough surface composed of micrometric complex features,it is difficult to conduct precision measurement of the three-dimensional surface form using conventional measurement instruments,such as vertical-incident interferometers or stylus-type profilometers.In this study,an oblique-incident interferometer based on Abramson interferometry is introduced to measure the form of a rough surface produced by hand-scraping.Because this technique can detect high-intensity reflected light on a rough surface,it allows the measurement of the form of the hand-scraped surface in noncontact condition.In order to shorten the measurement time,the form calculation based on a five-step phase shifting method was introduced.
基金supported by the National Natural Science Foundation of China(Grant No.40471114).
文摘A new form of geodetic coordinate system based on geodesic coordinates instead of geodetic longitude and latitude was proposed.The vertical and horizontal geodesic coordinates measured with length were defined as coordinate parameters,but the two families of coordinate curves were still meridians and parallel circles.The first fundamental form on the ellipsoidal surface and its three coefficients were deduced by the geodesic coordinate.The formula for the latitudinal scale factor of length for geodetic parallel lines was derived,by which the obtained result conformed to that standard value calculated from geodetic latitude,and it is applicable in the range of 400 km from north to south.Therefore,it lays the foundation for establishing the differential equation and differential relationship based on this type of coordinate parameters;and consequently,it is convenient and accurate enough to operate on the ellipsoidal surface in this new form of geodetic coordinate system.
