In computer aided geometric design(CAGD) ,it is often needed to produce a convexity-preserving interpolating curve according to the given planar data points. However,most existing pertinent methods cannot generate con...In computer aided geometric design(CAGD) ,it is often needed to produce a convexity-preserving interpolating curve according to the given planar data points. However,most existing pertinent methods cannot generate convexity-preserving in-terpolating transcendental curves;even constructing convexity-preserving interpolating polynomial curves,it is required to solve a system of equations or recur to a complicated iterative process. The method developed in this paper overcomes the above draw-backs. The basic idea is:first to construct a kind of trigonometric polynomial curves with a shape parameter,and interpolating trigonometric polynomial parametric curves with C2(or G1) continuity can be automatically generated without having to solve any system of equations or do any iterative computation. Then,the convexity of the constructed curves can be guaranteed by the appropriate value of the shape parameter. Performing the method is easy and fast,and the curvature distribution of the resulting interpolating curves is always well-proportioned. Several numerical examples are shown to substantiate that our algorithm is not only correct but also usable.展开更多
In this study, taking cultivated land fertility evaluation data for example, we conducted a preliminary study of GIS theory and spatial data management, and construct the frame system of mobile structure based on the ...In this study, taking cultivated land fertility evaluation data for example, we conducted a preliminary study of GIS theory and spatial data management, and construct the frame system of mobile structure based on the three layer structure model of application layer, business logic layer and data layer. Then we established a spatial data storage model, which has unified the data standards and achieved the management of spatial data and attribute database. Taking ArcGIS API for iOS as GIS platform, Xcode as the tool, we have realized the functions of data integration, data query, data statistics and fertilization recommendation, and constructed the management and service platform of mobile fertilization expert system.展开更多
The study investigates women＇s perception of the workwear, and their awareness about how garment fit can affect one＇s body image. Drawing on the theory of practice, we propose an ethnographic account of women＇s per...The study investigates women＇s perception of the workwear, and their awareness about how garment fit can affect one＇s body image. Drawing on the theory of practice, we propose an ethnographic account of women＇s perception of workwear and their preferred alternative. The study presents a comparative perspective of attitudes, and perceptions about the workwear of women in South Africa and Uganda explored through the habitus. We present pro-vocal recollections of women perceptions on the current workwear ideal for men which omits women＇ body physique. In particular, from the current personal protective equipment （PPE）, we examine ＂the overall＂ common attire at site and an integral part of the PPE. Overalls are designed following the men＇s physique, and women in work place are subjected to put them on yet, differences in body structure/shapes amongst women, namely, hour glass, bottom hourglass, spoon, and pear shape, are hardly considered. The identification of different female body shapes is made possible through the 3D anthropometric measurements using a Three Dimensional （3D） Body Scanner （TC2）. We develop endogenous explanations of what women would want to see as workwear based on the understanding of women found on site in men＇s workwear or without any work weal- in South Africa and Uganda. Using ethnographic design approach, we capture voices of 10 women from South Africa and Uganda through participant observation and unstructured interviews. We analyze data thematically to determine the patterns of their responses toward an appropriate workwear. Moreover, we （re）construct these responses into possible design models that would be ideal workwear for women, which gives them the pride, respect, dignity, and confidence as women.展开更多
Considering the essential and influential role of centrifugal compressors in a wide range of industries makes most of engineers research and study on design and optimization of centrifugal compressors. Centrifugal com...Considering the essential and influential role of centrifugal compressors in a wide range of industries makes most of engineers research and study on design and optimization of centrifugal compressors. Centrifugal compressors are the key to part ofoil, gas and petrochemical industries as well as gas pipeline transports. Since complete 3D design of the compressor consumes a considerable amount of time, most of active companies in the field, are profoundly interested in obtaining a design outline before taking any further steps in designing the entire machine. In this paper, a numerical algorithm, named ACDA （adapted compressor design algorithm） for fast and accurate preliminary design of centrifugal compressor is presented. The design procedure is obtained under real gas behavior, using an appropriate equation of state. Starting from impeller inlet, the procedure is continued on by resulting in numerical calculation for other sections including impeller exit, volute and exit diffuser. Clearly, in any step suitable correction factors are employed in order to conclude in precise numerical results. Finally, the achieved design result is compared with available reference data.展开更多
基金Project supported by the National Basic Research Program (973) of China (No. 2004CB719400)the National Natural Science Founda-tion of China (Nos. 60673031 and 60333010) the National Natural Science Foundation for Innovative Research Groups of China (No. 60021201)
文摘In computer aided geometric design(CAGD) ,it is often needed to produce a convexity-preserving interpolating curve according to the given planar data points. However,most existing pertinent methods cannot generate convexity-preserving in-terpolating transcendental curves;even constructing convexity-preserving interpolating polynomial curves,it is required to solve a system of equations or recur to a complicated iterative process. The method developed in this paper overcomes the above draw-backs. The basic idea is:first to construct a kind of trigonometric polynomial curves with a shape parameter,and interpolating trigonometric polynomial parametric curves with C2(or G1) continuity can be automatically generated without having to solve any system of equations or do any iterative computation. Then,the convexity of the constructed curves can be guaranteed by the appropriate value of the shape parameter. Performing the method is easy and fast,and the curvature distribution of the resulting interpolating curves is always well-proportioned. Several numerical examples are shown to substantiate that our algorithm is not only correct but also usable.
文摘In this study, taking cultivated land fertility evaluation data for example, we conducted a preliminary study of GIS theory and spatial data management, and construct the frame system of mobile structure based on the three layer structure model of application layer, business logic layer and data layer. Then we established a spatial data storage model, which has unified the data standards and achieved the management of spatial data and attribute database. Taking ArcGIS API for iOS as GIS platform, Xcode as the tool, we have realized the functions of data integration, data query, data statistics and fertilization recommendation, and constructed the management and service platform of mobile fertilization expert system.
文摘The study investigates women＇s perception of the workwear, and their awareness about how garment fit can affect one＇s body image. Drawing on the theory of practice, we propose an ethnographic account of women＇s perception of workwear and their preferred alternative. The study presents a comparative perspective of attitudes, and perceptions about the workwear of women in South Africa and Uganda explored through the habitus. We present pro-vocal recollections of women perceptions on the current workwear ideal for men which omits women＇ body physique. In particular, from the current personal protective equipment （PPE）, we examine ＂the overall＂ common attire at site and an integral part of the PPE. Overalls are designed following the men＇s physique, and women in work place are subjected to put them on yet, differences in body structure/shapes amongst women, namely, hour glass, bottom hourglass, spoon, and pear shape, are hardly considered. The identification of different female body shapes is made possible through the 3D anthropometric measurements using a Three Dimensional （3D） Body Scanner （TC2）. We develop endogenous explanations of what women would want to see as workwear based on the understanding of women found on site in men＇s workwear or without any work weal- in South Africa and Uganda. Using ethnographic design approach, we capture voices of 10 women from South Africa and Uganda through participant observation and unstructured interviews. We analyze data thematically to determine the patterns of their responses toward an appropriate workwear. Moreover, we （re）construct these responses into possible design models that would be ideal workwear for women, which gives them the pride, respect, dignity, and confidence as women.
文摘Considering the essential and influential role of centrifugal compressors in a wide range of industries makes most of engineers research and study on design and optimization of centrifugal compressors. Centrifugal compressors are the key to part ofoil, gas and petrochemical industries as well as gas pipeline transports. Since complete 3D design of the compressor consumes a considerable amount of time, most of active companies in the field, are profoundly interested in obtaining a design outline before taking any further steps in designing the entire machine. In this paper, a numerical algorithm, named ACDA （adapted compressor design algorithm） for fast and accurate preliminary design of centrifugal compressor is presented. The design procedure is obtained under real gas behavior, using an appropriate equation of state. Starting from impeller inlet, the procedure is continued on by resulting in numerical calculation for other sections including impeller exit, volute and exit diffuser. Clearly, in any step suitable correction factors are employed in order to conclude in precise numerical results. Finally, the achieved design result is compared with available reference data.
