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Kufoniyi O. - One of the best experts on this subject based on the ideXlab platform.

  • Spatial coincidence modelling, automated database updating and data consistency in vector GIS.
    Kufoniyi, 1995
    Co-Authors: Kufoniyi O.
    Abstract:

    This thesis presents formal approaches for automated database updating and consistency control in vector- structured spatial databases. To serve as a framework, a conceptual data model is formalized for the representation of geo-data from multiple map layers in which a map layer denotes a set of terrain objects of the same mapping context, e.g., cadastral, soil mapping, etc. The necessity for a generalised model arises from the frequent requirement in spatial analysis and planning for a geometric integration of several different views of the world, whereas most existing data models were designed from the perspective of a "single application" leading to ad hoc and repeated overlay computations (during query processing) when dealing with an integrated analysis. An alternative model is therefore proposed in this thesis for the geometric integration of geo-data from multiple map layers. The proposed model is an object-based, query-oriented 2.5D data model for multi-valued vector maps (DMMVM).A multi-valued vector map refers to the vector-based representation of terrain objects from multiple map layers whereby two objects of the same geometric type may be spatially coincident. Two objects of the same type are spatially coincident if they (partially) overlap in Space. In this model, positions of objects are defined in a 3D metric Space but embedded in 2D Topologic Space. The model is based on the 2D formal data structure (FDS) for singlevalued vector maps.Terrain objects play a central role in the terrain description; each object has a thematic component and a geometric component. In the thematic domain, the objects can be grouped into thematic classes in which each class has a specific attribute structure, and in the geometric domain the object types (points, lines and areas) are distinguished for a 2D or 2.5D terrain description.A geometric data type -- the m-dimensional container, or simply m-container, where m ε{0,1,2} -- is then introduced to model spatial coincidence among objects of the same geometric type. By introducing the container data type, overlapping sections across the layers are uniquely identified such that they have their own individual geometric data and nonspatial data, apart from those inherited from the overlapping objects; they can then be maintained and manipulated by the DBMS just like single objects. Using graph theory as a mathematical tool, the three container types are then represented by the Topologic primitives arc and node. A node defines one 0-container andlor the beginning or end of an arc, while an arc defines (part of) one 1-container andlor (part of) the boundary of a 2-container. The arc is defined by one start node and one end node, and a node is defined by a coordinate triplet X,Y,Z. A flexible integration of the model with a DTM is also presented in the thesis, using an edge-based TIN. Two primitives of the edge-based TIN (edge and vertex) are added to the data types of the DMMVM to define the integrated model.Research and development on the updating of geo-information have been confined mainly to the aspects of data collection and change detection, with little emphasis on the corresponding automated propagation of the updating in the database in a consistent manner. To address the latter aspect, procedures are formulated in the thesis for a consistent automated updating of a vector-structured database, using the DMMVM as a framework. Algorithms are provided for the automated update propagation such that topology is automatically updated by the system, while maintaining structural and semantic consistency. This will improve on the current practice in operational systems, which usually requires a delayed reconstruction of topology whenever there is a geometric change in the database. Algorithms are developed for the insertion, deletion or modification of each of the eight data types (area, line, point, 2- container, 1-container, 0-container, arc and node) in the DMMVM. The human operator interacts with the system at the object-level, while the system propagates the update. The topology of the database is updated dynamically by the system by evaluating, using computational geometry, the Topologic relationship between the new primitive (are or node) of an object and the existing primitives in the database. The type of relationship detected will then activate the relevant consistency rule (including update propagation) to validate the topology and consistency of the database. The system alerts the human operator if it is not possible for it to resolve the inconsistency.To enforce data consistency during geometric updating of the database, consistency rules are defined to ensure structural consistency, while a monitoring strategy is formulated for semantic (application-dependent, Topologic) constraints. In both cases, topology plays the central role as an "alerter" of constraint violations. Thus the possible Topologic relationships among the three elementary object types (area, line and point), and among the geometric primitives (arc and node) in the DMMVM are formalised and algorithms are defined for detecting the occurrence of any of the elementary relationships for any object combination. Then the consistency constraints can be translated to Topologic relationships and stored in the database as events, and the corresponding responses of the system to enforce consistency can be defined as actions, thus giving a rule-based procedure (using the if event then action convention) for the management of data consistency in spatial databases.The DMMVM was translated into a relational database structure and an object-oriented database structure to facilitate implementation in a variety of systems. The object-oriented data structure and the consistency rules and algorithms were tested experimentally using Postgres, an extended relational database management system. Data were acquired using the Kork digital mapping system, on a Planicomp C120 photogrammetric stereoplotter equipped with a Zeiss Videomap and a Calcomp drawing board digitizer.The thesis concludes with an evaluation of the proposed model and an outline of areas requiring further investigations

  • Spatial coincidence modelling, automated database updating and data consistency in vector GIS
    Kufoniyi, 1995
    Co-Authors: Kufoniyi O.
    Abstract:

    <p>This thesis presents formal approaches for automated database updating and consistency control in vector- structured spatial databases. To serve as a framework, a conceptual data model is formalized for the representation of geo-data from multiple map layers in which a map layer denotes a set of terrain objects of the same mapping context, e.g., cadastral, soil mapping, etc. The necessity for a generalised model arises from the frequent requirement in spatial analysis and planning for a geometric integration of several different views of the world, whereas most existing data models were designed from the perspective of a "single application" leading to ad hoc and repeated overlay computations (during query processing) when dealing with an integrated analysis. An alternative model is therefore proposed in this thesis for the geometric integration of geo-data from multiple map layers. The proposed model is an object-based, query-oriented 2.5D data model for multi-valued vector maps (DMMVM).<p>A multi-valued vector map refers to the vector-based representation of terrain objects from multiple map layers whereby two objects of the same geometric type may be spatially coincident. Two objects of the same type are spatially coincident if they (partially) overlap in Space. In this model, positions of objects are defined in a 3D metric Space but embedded in 2D Topologic Space. The model is based on the 2D formal data structure (FDS) for singlevalued vector maps.<p>Terrain objects play a central role in the terrain description; each object has a thematic component and a geometric component. In the thematic domain, the objects can be grouped into thematic classes in which each class has a specific attribute structure, and in the geometric domain the object types (points, lines and areas) are distinguished for a 2D or 2.5D terrain description.<p>A geometric data type -- the m-dimensional container, or simply m-container, where m ε{0,1,2} -- is then introduced to model spatial coincidence among objects of the same geometric type. By introducing the container data type, overlapping sections across the layers are uniquely identified such that they have their own individual geometric data and nonspatial data, apart from those inherited from the overlapping objects; they can then be maintained and manipulated by the DBMS just like single objects. Using graph theory as a mathematical tool, the three container types are then represented by the Topologic primitives arc and node. A node defines one 0-container andlor the beginning or end of an arc, while an arc defines (part of) one 1-container andlor (part of) the boundary of a 2-container. The arc is defined by one start node and one end node, and a node is defined by a coordinate triplet X,Y,Z. A flexible integration of the model with a DTM is also presented in the thesis, using an edge-based TIN. Two primitives of the edge-based TIN (edge and vertex) are added to the data types of the DMMVM to define the integrated model.<p>Research and development on the updating of geo-information have been confined mainly to the aspects of data collection and change detection, with little emphasis on the corresponding automated propagation of the updating in the database in a consistent manner. To address the latter aspect, procedures are formulated in the thesis for a consistent automated updating of a vector-structured database, using the DMMVM as a framework. Algorithms are provided for the automated update propagation such that topology is automatically updated by the system, while maintaining structural and semantic consistency. This will improve on the current practice in operational systems, which usually requires a delayed reconstruction of topology whenever there is a geometric change in the database. Algorithms are developed for the insertion, deletion or modification of each of the eight data types (area, line, point, 2- container, 1-container, 0-container, arc and node) in the DMMVM. The human operator interacts with the system at the object-level, while the system propagates the update. The topology of the database is updated dynamically by the system by evaluating, using computational geometry, the Topologic relationship between the new primitive (are or node) of an object and the existing primitives in the database. The type of relationship detected will then activate the relevant consistency rule (including update propagation) to validate the topology and consistency of the database. The system alerts the human operator if it is not possible for it to resolve the inconsistency.<p>To enforce data consistency during geometric updating of the database, consistency rules are defined to ensure structural consistency, while a monitoring strategy is formulated for semantic (application-dependent, Topologic) constraints. In both cases, topology plays the central role as an "alerter" of constraint violations. Thus the possible Topologic relationships among the three elementary object types (area, line and point), and among the geometric primitives (arc and node) in the DMMVM are formalised and algorithms are defined for detecting the occurrence of any of the elementary relationships for any object combination. Then the consistency constraints can be translated to Topologic relationships and stored in the database as <em>events,</em> and the corresponding responses of the system to enforce consistency can be defined as actions, thus giving a rule-based procedure (using the if <em>event</em> then <em>action</em> convention) for the management of data consistency in spatial databases.<p>The DMMVM was translated into a relational database structure and an object-oriented database structure to facilitate implementation in a variety of systems. The object-oriented data structure and the consistency rules and algorithms were tested experimentally using Postgres, an extended relational database management system. Data were acquired using the Kork digital mapping system, on a Planicomp C120 photogrammetric stereoplotter equipped with a Zeiss Videomap and a Calcomp drawing board digitizer.<p>The thesis concludes with an evaluation of the proposed model and an outline of areas requiring further investigations

Xu Wen - One of the best experts on this subject based on the ideXlab platform.

  • composite group Topologic Space method for estimating boiling point of organic compound
    Journal of Chemical Engineering of Chinese Universities, 2005
    Co-Authors: Xu Wen
    Abstract:

    Based on the traditional group division method, a Space design for the molecule of organic compounds was performed, and a composition group Topologic Space method for estimating boiling point of organic compounds was built by using the group module index to characterize the group position and using the adjacent atom pair group to characterize the specific environment of group in the molecule. With the numerical values of relative group and group-adjacent atom pair parameters presented, the expression for estimating boiling points was proposed. The average percentage deviation of boiling points estimation for 1171 organic compounds is 1.58. An extensive comparison was made between our method, Joback proposed method and the method proposed by our preceding work, and the results show that the new method proposed has wider applicability and higher accuracy.

  • a group Topologic Space method for estimatingenthalpies of vaporization at normal boiling pointsfor organic compounds
    Chemical Industry and Engineering, 2003
    Co-Authors: Xu Wen
    Abstract:

    A group Topologic Space method for estimating enthalpies of vaporization at normal boiling points for organic compounds has been proposed.Expression for estimating enthalpy of vaporization at boiling point has been proposed,with the numerical values of relative group parameters presented.The average percent deviation of estimation of the enthalpy of vaporization at boiling points is 1.052,comparing with the common used methods,our proposed method shows high accuracy and reliability.

Zhao Xinan - One of the best experts on this subject based on the ideXlab platform.

  • analysis of information requirement based on Topologic Space
    Journal of Northeastern University, 2008
    Co-Authors: Zhao Xinan
    Abstract:

    Topologic Space theory is used to analyze the customers' requirement in information management mode so as to classify rationally the customers in accordance to their values.The knowledge neighboring domain of each and every customer is composed of one's soft resources such as knowledge,skill,technological know-how,thought style,cultural connotation and credit level,and the Topologic Space and storeroom the customers will require are built.With an analysis made to the functions involving the informational element in customers' Topological Space,a development mode is proposed for the requirement of information in Topologic Space.The mode is available to guide the acquisition,processing,storage,transmission,application and feedback of information for businesses and social organizations.

  • the mode of information management based on Topologic Space
    International Conference on Management Science and Engineering, 2006
    Co-Authors: Sheng Qizhi, Zhao Xinan
    Abstract:

    Used Topologic Space theory in mathematics to build information management mode. Classified the valuable information sets rationally. Constructed information Topologic Space according to new information bringing Topologic power & crossing information producing knowledge and scientific fruit. Built the relationship among elements in information storeroom. Explained the elements in information storeroom with function style. Built information management process mode in Topologic Space based on the influence of information management to Internet enterprises. The mode can guide the enterprises in collecting, dealing, storing, communicating, applying & feeding the information back

Jajarmi Amin - One of the best experts on this subject based on the ideXlab platform.

  • Optimal Control of Nonlinear Systems Using the Homotopy Perturbation Method
    2014
    Co-Authors: Jajarmi Amin, Ramezanpour Hamidreza, Sargolzaei Arman, Shafaei Pouyan
    Abstract:

    This paper presents a new method for solving a class of nonlinear optimal control problems with a quadratic performance index. In this method, first the original optimal control problem is transformed into a nonlinear two-point boundary value problem (TPBVP) via the Pontryagin's maximum principle. Then, using the Homotopy Perturbation Method (HPM) and introducing a convex homotopy in Topologic Space, the nonlinear TPBVP is transformed into a sequence of linear time-invariant TPBVP's. By solving the presented linear TPBVP sequence in a recursive manner, the optimal control law and the optimal trajectory are determined in the form of infinite series. Finally, in order to obtain an accurate enough sub-optimal control law, an iterative algorithm with low computational complexity is introduced. An illustrative example demonstrates the simplicity and efficiency of proposed method.Comment: arXiv admin note: substantial text overlap with arXiv:1202.167

  • An Iterative Procedure for Optimal Control of Bilinear Systems
    'Academy and Industry Research Collaboration Center (AIRCC)', 2012
    Co-Authors: Ramezanpour Hamidreza, Setayeshi Saeed, Arabalibeik Hossein, Jajarmi Amin
    Abstract:

    This paper presents a new and straightforward procedure for solving bilinear quadratic optimal control problem. In this method, first the original optimal control problem is transformed into a nonlinear twopoint boundary value problem (TPBVP) via the Pontryagin's maximum principle. Then, the nonlinear TPBVP is transformed into a sequence of linear time-invariant TPBVPs using the homotopy perturbation method (HPM) and introducing a convex homotopy in Topologic Space. Solving the latter problems through an iterative process yields the optimal control law and optimal trajectory in the form of infinite series. Finally, sufficient condition for convergence of these series is proved by a theorem. Simplicity and efficiency of the proposed method is shown through an illustrative example.Comment: International Journal of Instrumentation and Control Systems (IJICS) Vol.2, No.1, January 201

Ramezanpour Hamidreza - One of the best experts on this subject based on the ideXlab platform.

  • Optimal Control of Nonlinear Systems Using the Homotopy Perturbation Method
    2014
    Co-Authors: Jajarmi Amin, Ramezanpour Hamidreza, Sargolzaei Arman, Shafaei Pouyan
    Abstract:

    This paper presents a new method for solving a class of nonlinear optimal control problems with a quadratic performance index. In this method, first the original optimal control problem is transformed into a nonlinear two-point boundary value problem (TPBVP) via the Pontryagin's maximum principle. Then, using the Homotopy Perturbation Method (HPM) and introducing a convex homotopy in Topologic Space, the nonlinear TPBVP is transformed into a sequence of linear time-invariant TPBVP's. By solving the presented linear TPBVP sequence in a recursive manner, the optimal control law and the optimal trajectory are determined in the form of infinite series. Finally, in order to obtain an accurate enough sub-optimal control law, an iterative algorithm with low computational complexity is introduced. An illustrative example demonstrates the simplicity and efficiency of proposed method.Comment: arXiv admin note: substantial text overlap with arXiv:1202.167

  • An Iterative Procedure for Optimal Control of Bilinear Systems
    'Academy and Industry Research Collaboration Center (AIRCC)', 2012
    Co-Authors: Ramezanpour Hamidreza, Setayeshi Saeed, Arabalibeik Hossein, Jajarmi Amin
    Abstract:

    This paper presents a new and straightforward procedure for solving bilinear quadratic optimal control problem. In this method, first the original optimal control problem is transformed into a nonlinear twopoint boundary value problem (TPBVP) via the Pontryagin's maximum principle. Then, the nonlinear TPBVP is transformed into a sequence of linear time-invariant TPBVPs using the homotopy perturbation method (HPM) and introducing a convex homotopy in Topologic Space. Solving the latter problems through an iterative process yields the optimal control law and optimal trajectory in the form of infinite series. Finally, sufficient condition for convergence of these series is proved by a theorem. Simplicity and efficiency of the proposed method is shown through an illustrative example.Comment: International Journal of Instrumentation and Control Systems (IJICS) Vol.2, No.1, January 201