DYNAMIC ANALYSIS OF TWO-DEGREE-OF-FREEDOM OBLIQUE IMPACT SYSTEM WITH NON-FIXED IMPACT POSITIONS

The dynamic behavior of a two-degree-of-freedom oblique impact system consisted of two pendulums with non-fixed impact positions is investigated. The relations between the restitution coefficient, the friction coefficient, as well as other parameters of the system and the states before or after impact, are clarified in this oblique impact process. The existence criterion of single impact periodic-n subharrnonic motions is deduced based on the Poincare map method and the oblique impact relations with non-fixed impact positions. The stability of these subharrnonic periodic motions is analyzed by the Floquet theory, and the formulas to calculate the Flocluet multipliers are given. The validity of this method is shown through numerical simulation. At the same time, the probability distribution of impact positions in this oblique system with nonfixed impact positions is analyzed.

Assessing the socio-cultural impact of urban revitalisation using Relative Positive Impact Index(RPII)

Urban heritage is a vital resource that connects communities to their local identity.Unplanned developments and rapid urbanisation often harm the authenticity of historic areas,disrupting the cultural fabric and altering their character.This study introduces the Relative Positive Impact Index(RPll),a novel technique for assessing the socio-cultural impacts of urban revitalisation.The significance of RPII lies in its ability to quantitatively evaluate the impacts on the cultural fabric and integrity of historic urban areas,which is crucial for sustainable urban development.The study's objective is to apply RPII in evaluating qualitative socio-cultural characteristics in historic urban areas,with a focus on four main criteria and 16 sub-criteria,in the case of the Kuttichira precinct.The methodology integrates the analysis of published literature,a quantitative survey mapping the stakeholders'perception,and qualitative insights.This approach facilitates an in-depth understanding of how urban revitalisation affects local socio-cultural dynamics,preserving the authenticity and character of historic areas.The study reveals that the revitalisation project in Kuttichira positively impacts the socio-cultural fabric of the area,maintaining cultural integrity and addressing social challenges.These findings offer valuable insights for sustainable urban development and policymaking in historic areas.The study recommends the application of RPll in other urban precincts for comparative analysis and further development of urban development practices,contributing to informed urban policy and planning decisions.

Impact of multipath effects on theoretical accuracy of TOA-based indoor VLC positioning system

This paper discusses the time-of-arrival(TOA) based indoor visible light communication(VLC) positioning system in a non-line-of-sight environment. The propagation delay is assumed to be gamma distributed. The generalized Cramer–Rao lower bound for multipath propagation is derived as the theoretical accuracy limitation. The performance of the positioning system is affected by the shape parameter and the scale parameter of gamma distribution.The influences on positioning accuracy of multipath effects are analyzed through discussing the physical meaning of the gamma distribution parameters. It is concluded that the lower bound of positioning accuracy is attained when variance of the non-line-of-sight propagation-induced path lengths is zero. The simulation result provesthat the theoretical positioning accuracy is in the order of centimeters with the given scenario.

Touristic Sustainability in Rural and Natural Spaces

This article aims to give the reader an overview of the development of nature tourism and its importance for the sustainability of rural and natural areas involving special protection. Once you have seen the end of mass tourism, tourism demand is much more heterogeneous and attends a difference of purposes for which such demand is diversified, representing a particularly important tourism and leisure activities that take place now in natural areas, thus giving rise to different types of leisure and tourism, such as Rural tourism, Ecotourism, Agrotourism, Nature and Adventures tourism, Sports tourism in natural areas, etc. What is important for the sustainability of these areas, that are subject to this type of tourism is getting some positive impacts maintaining sustainability and combating the negative impact, that such activities may have on certain protected areas or special conservation. From this point of view, we believe it is important to develop responsible tourism and committed to environmental conservation and for that the local population must be trained in order to achieve development of the territory without the activities that are the fruit of these typologies tourism and leisure pose a danger. Also, the tourist population must be more aware about what constitutes such practices of leisure and tourism for conservation of the environment and, at the same time, the development of the most depressed areas.

Impact of the invasion of the imported fire ant

The impact of the imported fire ant （IFA） is complex, in large part, because several very different species of＂Fire Ants＂ have invaded and one of these has two forms, all of which are hard to separate by the public, as well as, some investigators not focused on the ant. Each of these different ＂IFA＂ species and forms differ in their impact. Further, these ants impact a number of＂things＂ ranging from the environment and wildlife （plants and animals） as well as people, their environment and infrastructure. In addition, they can not only lead to death of living things （including people）, but they can destroy many aspects of our environment and infrastructure at the cost of millions of dollars. But there are some beneficial aspects and some people can make many thousands of dollars due to their presence. This is an attempt to look at these issues.