The technical characteristics of Sichuan folk furniture were studied from craft aesthetic perspective. The features of Sichuan folk furniture material, technology and structure were analyzed through literature review,...The technical characteristics of Sichuan folk furniture were studied from craft aesthetic perspective. The features of Sichuan folk furniture material, technology and structure were analyzed through literature review, field investigation and expert interview methods, the technical characteristics of Sichuan folk furniture were re-analyzed from craft aesthetic perspective rather than the traditional material and technique research perspectives. The study shows that Sichuan folk furniture technical features contain not only cultural spirit and aesthetic consciousness, but distinctive aesthetic personality as well. Sichuan folk furniture technical characteristics convey Chinese traditional design philosophy, such as theory is based on objects, and it is highly concentrated and concise of aesthetic sentiment in Sichuan folk aesthetic temperament and interest.展开更多
The major restriction for learning in science and engineering education in Africa is the absence of equipped laboratories. Where laboratory is available, there is the problem of obsolete and antiquated materials, whic...The major restriction for learning in science and engineering education in Africa is the absence of equipped laboratories. Where laboratory is available, there is the problem of obsolete and antiquated materials, which are seldom available for use. In most Universities in Africa, there is inadequate supply of laboratory space and laboratory materials. The laboratories only have the items of equipment that were provided when the universities were established, this has hampered learning. An alternative educational approach is required to address the aforementioned problems and provide a cost-effective solution for education as well as a valuable complementary or learning tool for university students. The alternative approach is the use of Virtual Reality （VR） technology to simulate virtual learning environments such as virtual reality laboratories. This is a one solution to inadequate physical laboratories in Africa.展开更多
Traditional five-axis tool path planning methods mostly focus on differential geometric characteristics between the cutter and the workpiece surface to increase the material removal rate(i.e.,by minimizing path length...Traditional five-axis tool path planning methods mostly focus on differential geometric characteristics between the cutter and the workpiece surface to increase the material removal rate(i.e.,by minimizing path length,improving curvature matching,maximizing local cutting width,etc.) . However,material removal rate is not only related to geometric conditions such as the local cutting width,but also constrained by feeding speed as well as the motion capacity of the five-axis machine. This research integrates machine tool kinematics and cutter-workpiece contact kinematics to present a general kinematical model for five-axis machining process. Major steps of the proposed method include:(1) to establish the forward kinematical relationship between the motion of the machine tool axes and the cutter contact point;(2) to establish a tool path optimization model for high material removal rate based on both differential geometrical property and the contact kinematics between the cutter and workpiece;(3) to convert cutter orientation and cutting direction optimization problem into a concave quadratic planning(QP) model. Tool path will finally be generated from the underlying optimal cutting direction field. Through solving the time-optimal trajectory generation problem and machining experiment,we demonstrate the validity and effectiveness of the proposed method.展开更多
文摘The technical characteristics of Sichuan folk furniture were studied from craft aesthetic perspective. The features of Sichuan folk furniture material, technology and structure were analyzed through literature review, field investigation and expert interview methods, the technical characteristics of Sichuan folk furniture were re-analyzed from craft aesthetic perspective rather than the traditional material and technique research perspectives. The study shows that Sichuan folk furniture technical features contain not only cultural spirit and aesthetic consciousness, but distinctive aesthetic personality as well. Sichuan folk furniture technical characteristics convey Chinese traditional design philosophy, such as theory is based on objects, and it is highly concentrated and concise of aesthetic sentiment in Sichuan folk aesthetic temperament and interest.
文摘The major restriction for learning in science and engineering education in Africa is the absence of equipped laboratories. Where laboratory is available, there is the problem of obsolete and antiquated materials, which are seldom available for use. In most Universities in Africa, there is inadequate supply of laboratory space and laboratory materials. The laboratories only have the items of equipment that were provided when the universities were established, this has hampered learning. An alternative educational approach is required to address the aforementioned problems and provide a cost-effective solution for education as well as a valuable complementary or learning tool for university students. The alternative approach is the use of Virtual Reality （VR） technology to simulate virtual learning environments such as virtual reality laboratories. This is a one solution to inadequate physical laboratories in Africa.
基金supported by the National Basic Research Program of China ("973" Program) (Grant No. 2011CB706800)the National Natural Science Foundation of China (Grant No. 50835004)the National Funds for Distinguished Young Scientists of China (Grant No. 51025518)
文摘Traditional five-axis tool path planning methods mostly focus on differential geometric characteristics between the cutter and the workpiece surface to increase the material removal rate(i.e.,by minimizing path length,improving curvature matching,maximizing local cutting width,etc.) . However,material removal rate is not only related to geometric conditions such as the local cutting width,but also constrained by feeding speed as well as the motion capacity of the five-axis machine. This research integrates machine tool kinematics and cutter-workpiece contact kinematics to present a general kinematical model for five-axis machining process. Major steps of the proposed method include:(1) to establish the forward kinematical relationship between the motion of the machine tool axes and the cutter contact point;(2) to establish a tool path optimization model for high material removal rate based on both differential geometrical property and the contact kinematics between the cutter and workpiece;(3) to convert cutter orientation and cutting direction optimization problem into a concave quadratic planning(QP) model. Tool path will finally be generated from the underlying optimal cutting direction field. Through solving the time-optimal trajectory generation problem and machining experiment,we demonstrate the validity and effectiveness of the proposed method.
