Coordinated Planning Transmission Tasks in Heterogeneous Space Networks:A Semi-Distributed Approach

This paper studies the coordinated planning of transmission tasks in the heterogeneous space networks to enable efficient sharing of ground stations cross satellite systems.Specifically,we first formulate the coordinated planning problem into a mixed integer liner programming(MILP)problem based on time expanded graph.Then,the problem is transferred and reformulated into a consensus optimization framework which can be solved by satellite systems parallelly.With alternating direction method of multipliers(ADMM),a semi-distributed coordinated transmission task planning algorithm is proposed,in which each satellite system plans its own tasks based on local information and limited communication with the coordination center.Simulation results demonstrate that compared with the centralized and fully-distributed methods,the proposed semi-distributed coordinated method can strike a better balance among task complete rate,complexity,and the amount of information required to be exchanged.

Spatial Heterogeneity of Agricultural Science and Technology Parks Technology Diffusion: A Case Study of Yangling ASTP

Agricultural science and technology parks(ASTPs) represent an important growth pole in China’s agricultural modernization.Clarifying their diffusion laws can optimize the technological diffusion process and improve its efficiency. Our study uses disaggregated spatial information in its model to analyze ASTP technology diffusion in a heterogeneous space. We constructed a comprehensive index system to evaluate the diffusion environmental quality and introduced the heterogeneous diffusion equation to calculate the technological diffusion probability. We applied this framework to a real-world scenario: the apple planting technology diffusion of the Yangling ASTP in the Loess Plateau, China. The results indicated: (1)the technological diffusion environment of the Loess Plateau advantageous apple producing area showed strong spatial heterogeneity caused by climate, topography, and external transportation links.(2) Under the combined effects of distance and spatial heterogeneity, the spatial diffusion pattern of the Yangling ASTP apple technology was expansion diffusion supplemented by hierarchical diffusion and banded diffusion, and (3) ASTP technology diffusion showed a strong distance attenuation effect, and the frictional effect of distance can be decreased by improving the diffusion environmental quality. These laws can promote regional balanced ASTP-driven development.

Heterogeneous Spaces in the City: Study on Spatial Characteristics of Tibetan Settlements in Chengdu

Settlement of the minorities is a particular heterogeneous space in a metropolis,and such spaces exist as inseparable parts of the city for historical,social and geopolitical reasons.Taking Tibetan settlement in Wuhou District,Chengdu City for example,this study analyzed spatial features and evolution history of minority settlements,and explored how to respect and accept historic signifi cance and cultural value of these heterogeneous spaces during the rapid urban development,and then use them reasonably and reform creatively,so as to maintain their original spatial features and integrate the spaces into the overall urban structure.

User activities and the heteroseneity of urban space:The case of Dahiyat Al Hussein park

Urban researchers have maintained a constant interest in the complexity and continuity of urban space usage.Some have applied actor-network theory(ANT)to investigate the heterogeneity of spaces and present them through the networks of their users'activities.However,these accounts are predominantly limited in examining the extent to which these spaces may be heterogeneous when exploring such networks.This paper draws on recent ANT scholarship,which employs an ethnographic research conducted in a main park in a housing project at Dahiyat Al Hussein in Amman,Jordan.The findings describe the complex and unpredictable negotiations that occur with in spaces by documenting the varieties and in terrelations among user activity networks within this common and shared urban space.This research reveals the extent to which spaces,parks in this case,may be heterogeneous by unpacking their usage.The conclusions and in sights assert then ecessity of paying attention to design detail and creating designs that are responsive to evolving user activities.