Multiscale Characteristics and Connection Mechanisms of Attraction Networks:A Trajectory Data Mining Approach Leveraging Geotagged Data

Urban tourism is considered a complex system,and multiscale exploration of the organizational patterns of attraction networks has become a topical issue in urban tourism,so exploring the multiscale characteristics and connection mechanisms of attraction networks is important for understanding the linkages between attractions and even the future destination planning.This paper uses geotagging data to compare the links between attractions in Beijing,China during four different periods:the pre-Olympic period(2004–2007),the Olympic Games and subsequent‘heat period’(2008–2013),the post-Olympic period(2014–2019),and the COVID-19(Corona Virus Disease 2019)pandemic period(2020–2021).The aim is to better understand the evolution and patterns of attraction networks at different scales in Beijing and to provide insights for tourism planning in the destination.The results show that the macro,meso-,and microscales network characteristics of attraction networks have inherent logical relationships that can explain the commonalities and differences in the development process of tourism networks.The macroscale attraction network degree Matthew effect is significant in the four different periods and exhibits a morphological monocentric structure,suggesting that new entrants are more likely to be associated with attractions that already have high value.The mesoscale links attractions according to the common purpose of tourists,and the results of the community segmentation of the attraction networks in the four different periods suggest that the functional polycentric structure describes their clustering effect,and the weak links between clusters result from attractions bound by incomplete information and distance,and the functional polycentric structure with a generally more efficient network of clusters.The pattern structure at the microscale reveals the topological transformation relationship of the regional collaboration pattern,and the attraction network structure in the four different periods has a very similar importance profile structure suggesting that the attraction network has the same construction rules and evolution mechanism,which aids in understanding the attraction network pattern at both macro and micro scales.Important approaches and practical implications for planners and managers are presented.

METAMORPHIC MECHANISMSAND THEIR CONFIGURATION MODELS

The concept of metamorphic mechanisms is presented, configuration models and configuration transformations relating to a set of new matrix operations are discussed and proposed. The configuration of a metamorphic mechanism reflects the connectivity change in the mechanism during motions which results in mobility change and presents the characteristics of the mechanism which is discussed in various applications particularly in decorative artifacts. The characteristics is further investigated with mobility analysis.

Intelligent Modularized Reconfigurable Mechanisms for Robots:Development and Experiment

With the development of intelligent flexible manufacturing,traditional industrial manipulators with a single configuration are difficult to meet a variety of tasks.Reconfigurable robots have developed rapidly which could change their configurations and end effectors for different tasks.The reconfigurable connecting mechanism(RCM)is a core component of reconfigurable robots.In this paper,two types of intelligent modularized RCMs with light weight,high payload,and large pose(position and attitude)error tolerance are developed.One is driven by shape memory alloy(SMA)and recovery spring.It is locked by steel balls and key.The other is driven by electromagnetic coil and locked by permanent magnet and key.The locking principle,mechanical system and control system of the two RCMs are detailed introduced.Both of them meet the requirements of high precision and high payload in the industrial field.Finally,the developed RCMs are respectively integrated to a practical robot and experimented.The experiment results verified the performance of the two RCMs.

A Modifi ed Molecular Structure Mechanics Method for Analysis of Graphene

Based on molecular mechanics and the deformation characteristics of the atomic lattice structure of graphene, a modifi ed molecular structure mechanics method was developed to improve the original one, that is, the semi-rigid connections were used to model the bond angle variations between the C-Cbonds in graphene. The simulated results show that the equivalent space frame model with semi-rigid connections for graphene proposed in this article is a simple, efficient, and accurate model to evaluate the equivalent elastic properties of graphene. Though the present computational model of the semi-rigid connected space frame is only applied to characterize the mechanical behaviors of the space lattices of graphene, it has more potential applications in the static and dynamic analyses of graphene and other nanomaterials.

Objective System and Coordination Mechanism Design for “Multi-Planning System Integration”

One of the hot issues to realize the multi-planning system integration is to explore the inter-planning coordination mechanism breaking current technical and system restrictions. The essence of planning disintegration is the disconnection of their objective system, indicator system, and spatial coordinate system. Few studies have been conducted on this issue. This paper analyzes the manifestations and causes of the "three-system dissociation," and proposes to establish a new objective system. In addition, it proposes to strengthen the connection design, aiming to explore effective ways to realize inter-planning connection and coordination.