Assembly sketch is not only the visualization of abstract function, but alsothe template of detail design. Two kinds of information are needed to create assembly sketch:structure and assembly constraint. Most research...Assembly sketch is not only the visualization of abstract function, but alsothe template of detail design. Two kinds of information are needed to create assembly sketch:structure and assembly constraint. Most researches are aimed at bow to obtain Structures fromfunction, but the problem of how to obtain assembly constraint from function is ignored. Followingthe definition of assembly unit and the classification of function, a hierarchical mapping methodfrom function to assembly constraint is put forward, and the mapping method includes two steps. Thefirst step is the mapping from function to assembly semantics which is assembly expression andaccordant with engineer's design habit. The second one is the mapping from assembly semantics tobasic assembly constraints that are convenient for computer to handle. The mapping method is appliedto DDMS (design, drafting and management system) successfully.展开更多
To facilitate users to access the desired information, many researches have dedicated to the Deep Web (i.e. Web databases) integration. We focus on query translation which is an important part of the Deep Web integr...To facilitate users to access the desired information, many researches have dedicated to the Deep Web (i.e. Web databases) integration. We focus on query translation which is an important part of the Deep Web integration. Our aim is to construct automatically a set of constraints mapping rules so that the system can translate the query from the integrated interface to the Web database interfaces based on them. We construct a concept hierarchy for the attributes of the query interfaces, especially, store the synonyms and the types (e.g. Number, Text, etc.) for every concept At the same time, we construct the data hierarchies for some concepts if necessary. Then we present an algorithm to generate the constraint mapping rules based on these hierarchies. The approach is suitable for the scalability of such application and can be extended easily from one domain to another for its domain independent feature. The results of experiment show its effectiveness and efficiency.展开更多
The mapping of vulnerability and resilience has become an important tool for vulnerability and resilience research.By definition,maps are selective representations.However,the predominant methods of mapping also have ...The mapping of vulnerability and resilience has become an important tool for vulnerability and resilience research.By definition,maps are selective representations.However,the predominant methods of mapping also have constraints.When addressing vulnerability and resilience,these limitations,barriers,and blind spots have to be taken into account.Some aspects cannot be easily mapped,such as specific forms of knowledge and interpretation,the processuality of vulnerability and resilience,the dynamics of social processes,the context of origin,the establishment of contingent interpretations,and so on.These limitations are not only theoretically important,but also are practically significant,since maps themselves become dispositifs.They are regarded as representations of reality,shape particular interpretations of vulnerability and resilience,and are used as a basis for decision-making.If the unmapped preconditions of mapping remain unconsidered,this can lead to problematic side effects.展开更多
This paper thoroughly investigates the problem of robot self-location by line correspondences. The original contributions are three-fold: (1) Obtain the necessary and sufficient condition to determine linearly the rob...This paper thoroughly investigates the problem of robot self-location by line correspondences. The original contributions are three-fold: (1) Obtain the necessary and sufficient condition to determine linearly the robot's pose by two line correspondences. (2) Show that if the space lines are vertical ones, it is impossible to determine linearly the robot's pose no matter how many line correspondences we have, and the minimum number of line correspondences is 3 to determine uniquely (but non-linearly) the robot's pose. (3) Show that if the space lines are horizontal ones, the minimum number of line correspondences is 3 for linear determination and 2 for non-linear determination of the robot's pose.展开更多
基金This project is supported by National Natural Science Foundation of China (No.50075080, No.50275133)Provincial Natural Science Foundation of Zhejiang (No.602039).
文摘Assembly sketch is not only the visualization of abstract function, but alsothe template of detail design. Two kinds of information are needed to create assembly sketch:structure and assembly constraint. Most researches are aimed at bow to obtain Structures fromfunction, but the problem of how to obtain assembly constraint from function is ignored. Followingthe definition of assembly unit and the classification of function, a hierarchical mapping methodfrom function to assembly constraint is put forward, and the mapping method includes two steps. Thefirst step is the mapping from function to assembly semantics which is assembly expression andaccordant with engineer's design habit. The second one is the mapping from assembly semantics tobasic assembly constraints that are convenient for computer to handle. The mapping method is appliedto DDMS (design, drafting and management system) successfully.
基金Supported by the National Natural Science Foundation of China (60573091)the Natural Science Foundation of Beijing(4073035)the Key Project of Ministry of Education of China (03044)
文摘To facilitate users to access the desired information, many researches have dedicated to the Deep Web (i.e. Web databases) integration. We focus on query translation which is an important part of the Deep Web integration. Our aim is to construct automatically a set of constraints mapping rules so that the system can translate the query from the integrated interface to the Web database interfaces based on them. We construct a concept hierarchy for the attributes of the query interfaces, especially, store the synonyms and the types (e.g. Number, Text, etc.) for every concept At the same time, we construct the data hierarchies for some concepts if necessary. Then we present an algorithm to generate the constraint mapping rules based on these hierarchies. The approach is suitable for the scalability of such application and can be extended easily from one domain to another for its domain independent feature. The results of experiment show its effectiveness and efficiency.
文摘The mapping of vulnerability and resilience has become an important tool for vulnerability and resilience research.By definition,maps are selective representations.However,the predominant methods of mapping also have constraints.When addressing vulnerability and resilience,these limitations,barriers,and blind spots have to be taken into account.Some aspects cannot be easily mapped,such as specific forms of knowledge and interpretation,the processuality of vulnerability and resilience,the dynamics of social processes,the context of origin,the establishment of contingent interpretations,and so on.These limitations are not only theoretically important,but also are practically significant,since maps themselves become dispositifs.They are regarded as representations of reality,shape particular interpretations of vulnerability and resilience,and are used as a basis for decision-making.If the unmapped preconditions of mapping remain unconsidered,this can lead to problematic side effects.
基金the National '863' High-Tech Programme of China under the grant No. 863-512-9915-01 and the National Natural Science Foundatio
文摘This paper thoroughly investigates the problem of robot self-location by line correspondences. The original contributions are three-fold: (1) Obtain the necessary and sufficient condition to determine linearly the robot's pose by two line correspondences. (2) Show that if the space lines are vertical ones, it is impossible to determine linearly the robot's pose no matter how many line correspondences we have, and the minimum number of line correspondences is 3 to determine uniquely (but non-linearly) the robot's pose. (3) Show that if the space lines are horizontal ones, the minimum number of line correspondences is 3 for linear determination and 2 for non-linear determination of the robot's pose.