Research On The Complexity Oriented Digital City

The purposes of digital city construction mainly can be explained as thefollowing reasons, such as the better understanding and more demands of the digitalin information era, adapting to the progress of society as well as maintaining theurban sustainable development. However, except for the detailed technical problems,the more important problem influencing the operation of digital city is systematicalcomplexity especially including uncertainty and non-linearity, which is hard to beforeseen and resolved with the general treatment technology.It is extremely important in theatrical and the practical aspects for enhancing thesuccess ratio of digital city and keeping the sustainable development of modern citythrough the researches on the complex problems taking place in digital cityimplementation. The dissertation does the following innovational researches by usinginformation technology combined with system science.1. It points out that the digital city is a dissipative structural system through theanalysis and reorganization of the urban information system with the theory ofdissipative structure and applies the entropy concept to explain the evolution of citysystem. The quantitative excess entropy model of urban information system is putforward according to the excess entropy in dissipative structural theory, and the steadystate spot of system development is also given in the dissertation. The maximuminformation entropy concept is introduced to the probability statistics of urbaninformation system by applying uncertainty idea and definition, in order to determinethe real probability distribution.2. Attribute dependent relation is proposed based on the information entropy andthe knowledge expression system. The dependent degree of the attribute tabulates isconfirmed according to the objective attribute value interrelation. The important scalecomputation method of the condition attribute is given so as to make decision and toimplement better.3. Coordinated relation between the systems is studied first. Then the digital citysystem organization model is adjusted depending on the distribute structure to makethe transmission and sharing of information quick and convenient. Finally, thecorrespondence mechanism is established based on the contract net model in the agenttechnology to make the transmission of demands and tasks issued better, at the sametime to effectively transfer the resources.4. The problems about uncertain information and generous data of urbaninformation systems are resolved based on rough-set theory, and the knowledgeexpression system of decision-making table is also described though the basicconcepts of the rough-set theory in this dissertation. Arithmetic of the minimaldecision-making regulations is put forward. The reduction attribute of decision tablewith above theory and method is given and the hidden knowledge is mined in theexample of urban spatial dada decision-making table, and the minimaldecision-making regulations are consequently got.5. Evaluation method of informatization indicator is improved in the dissertation.The weight definite method is presented through introducing the subjection relationsof the attribute data in rough-set theory. The subjective disadvantage is avoided todispose of weight in the original assessment method. Scientific nature and the validityare checked in the dissertation through appraisal result of the informatization levels inNorth China.