Application Strategy of Green Transportation Concept in Urban Road Design

Urban traffic and urban environmental pollution are important issues that must be taken into account in the process of urbanization,especially in China.Modernization has enabled many developed countries in the west to carry out rational city traffic planning.At the same time,the concept of green transportation has also emerged,integrating low-energy consumption,low pollution,comfort,and safety into urban traffic to effectively solve issues pertaining to traffic and pollution.The concept of green transportation has been widely adopted in China and made popular in many cities,thereby promoting the sustainable development of cities.

When LoRa meets distributed machine learning to optimize the network connectivity for green and intelligent transportation system

LoRa technology contributes to green energy by enabling efficient,long-range communication for the Internet of Things(IoT).This paper addresses the challenges related to coverage range in outdoor monitoring systems utilizing LoRa,where the network performance is affected by the density of gateways(GWs)and end devices(EDs),as well as environmental conditions.To mitigate interference,data throughput losses,and high-power consumption,the proposed spreading factor(SF)and hybrid(data rate|SF)models dynamically adjust the transmission parameters.The orchestration of concurrent data modifications within the network server(NS)is crucial for uninterrupted communication between GWs and EDs,especially in monitoring electric vehicle(EV)stations to reduce traffic congestion and pollution.Employing K-means and density-based spatial clustering of applications with noise(DBSCAN)algorithms optimizes ED allocation,averts data congestion,and improves the signal-tointerference noise ratio(SINR).These methods ensure seamless information reception by meticulously allocated EDs across various GW combinations.To estimate the free-space losses(FSL),a log-distance path loss model(log-PL)is used.Exploring various bandwidths(BWs),bidirectional communications,and duty cycles(DCs)helps to prevent saturation,thus prolonging the operational lifespan of EDs.Empirical findings reveal a notable packet rejection rate(PRR)of 0%for the DBSCAN(hybrid model).In contrast,the K-means exhibits a PRR ranging from 5%(hybrid model)to 35.29%(SF model)for the ten GWs combination.Notably,the network saturation is reduced to 10.185%and 9.503%,respectively,highlighting an improvement in the average efficiency of slotted ALOHA(91.1%)and pure ALOHA(90.7%).These enhancements increase the lifespan of EDs to 15,465.27 days.

Pedestrianisation and Parking Policy as a Solution towards Green Transport Plan： A Case Study of Zagreb

Strategy of development trends in this moment and at this stage of the traffic comes from understanding the possibilities of the implementation of measures to raise the quality of movement and life in the city. It also includes planning and implementation of targeted interventions in the transport network or facilities. Mobility is a complex process in the area, starting from the departure from the apartment, using various means of transportation, a number of activities in different goals until to return to the location of the apartment. It thus requires extensive transport infrastructure in the form of walkways, bicycle paths, street and railway network. At the same time, reshaping of public transport facilities is needed in which the pedestrian, biker and green concept shall be the main elements of the new spatial conditions. Pedestrian zones development in the city means to create pedestrian areas and green islands in all the places in the city where possible. This process is essential for the transformation of public spaces, in particular, transport corridors. To accomplish the concept of the green transport plan, the need for change in the parking policy is emphasized. This should be an integral part of the city planning and should go hand in hand with the traffic policy.

Dynamic evolution trend of comprehensive transportation green efficiency in China:From a spatio-temporal interaction perspective

It is urgent and important to explore the dynamic evolution in comprehensive transportation green efficiency(CTGE)in the context of green development.We constructed a social development index that reflects the social benefits of transportation services,and incorporated it into the comprehensive transportation efficiency evaluation framework as an expected output.Based on the panel data of 30 regions in China from 2003-2018,the CTGE in China was measured using the slacks-based measure-data envelopment analysis(SBM-DEA)model.Further,the dynamic evolution trends of CTGE were determined using the spatial Markov model and exploratory spatio-temporal data analysis(ESTDA)technique from a spatio-temporal perspective.The results showed that the CTGE shows a U-shaped change trend but with an overall low level and significant regional differences.The state transition of CTGE has a strong spatial dependence,and there exists the phenomenon of“club convergence”.Neighbourhood background has a significant impact on the CTGE transition types,and the spatial spillover effect is pronounced.The CTGE has an obvious positive correlation and spatial agglomeration characteristics.The geometric characteristics of the LISA time path show that the evolution process of local spatial structure and local spatial dependence of China’s CTGE is stable,but the integration of spatial evolution is weak.The spatio-temporal transition results of LISA indicate that the CTGE has obvious transfer inertness and has certain path-dependence and spatial locking characteristics,which will become the major difficulty in improving the CTGE.

Low Carbon Urban Design Concept Planning of Handan Eastern New District

Currently urban issues show a dramatically increasing rely on auto use,which seriously affects the sustainable development of the city and makes how to build low-carbon cities become one of the urgent problems to be solved in the process of urban development.Therefore,low-carbon cities have become principles for China’s next generation of growth and the research hot spot of urban traffic planning.By taking a look at the concepts such as Compact City,transit-oriented development(TOD)city and‘small block’zoning,the article combined the relationship between urban spatial layout patterns and traffic development mode to build a green,low-carbon and sustainable urban development model.Finally,taking the urban design of the new district in the east of Handan City as an example,this research applied the concepts and approaches to planning practice,hoping to provide reference for building low carbon cities.

Application of real space Kerker method in simulating gate-all-around nanowire transistors with realistic discrete dopants

We adopt a self-consistent real space Kerker method to prevent the divergence from charge sloshing in the simulating transistors with realistic discrete dopants in the source and drain regions. The method achieves efficient convergence by avoiding unrealistic long range charge sloshing but keeping effects from short range charge sloshing. Numerical results show that discrete dopants in the source and drain regions could have a bigger influence on the electrical variability than the usual continuous doping without considering charge sloshing. Few discrete dopants and the narrow geometry create a situation with short range Coulomb screening and oscillations of charge density in real space. The dopants induced quasilocalized defect modes in the source region experience short range oscillations in order to reach the drain end of the device.The charging of the defect modes and the oscillations of the charge density are identified by the simulation of the electron density.

Photon-assisted electronic and spin transport through two T-shaped three-quantum-dot molecules embedded in an Aharonov-Bohm interferometer

We investigate the time-modulated electronic and spin transport properties through two T-shaped three-quantum-dot molecules embedded in an Aharonov-Bohm（A-B） interferometer. By using the Keldysh non-equilibrium Green＇s function technique, the photon-assisted spin-dependent average current is analyzed. The T-shaped three-quantum-dot molecule A-B interferometer exhibits excellent controllability in the average current resonance spectra by adjusting the interdot coupling strength, Rashba spin-orbit coupling strength, magnetic flux, and amplitude of the time-dependent external field.Efficient spin filtering and multiple electron-photon pump functions are exploited in the multi-quantum-dot molecule A-B interferometer by a time-modulated external field.

Time-dependent density functional theory for quantum transport

The rapid miniaturization of elect, ronic devices motivates research interests in quantum transport.Recently time-dependent quantum transport has become an important research topic. Here we re- view recent progresses in the development of time-dependent density-functional theory for quantum transport including the theoretical foundation and numerical algorithms. In particular, the reducedsingle electron density matrix based hierarchical equation of motion, which can be derived from Liouville---von Neumann equation, is reviewed in details. The numerical implementation is discussed and simulation results of realistic devices will be given.

A first-principles study of dihydroazulene as a possible optical molecular switch

By applying nonequilibrium Green's function formalism combined with first-principles density functional theory, we investigate the electronic transport properties of the dihydroazulene optical molecular switch. Three kinds of adsorption sites including the hollow, bridge and top sites are studied. The two forms of this molecule, namely the open form and the closed form, can reversibly switch from each other upon photoexcitation. Their transmission spectra are remarkably distinctive. Theoretical results show that the current of the closed form is always significantly larger than that of the open form for all three adsorption sites, which promises this system as possibly one of the good candidates for optical switches due to its unique advantage, and which may have some potential applications in the future molecular circuit.

Study of Transport Properties in Armchair Graphyne Nanoribbons: A Density Functional Approach

In present paper, the non-equilibrium Green function(NEGF) method along with the density functional theory(DFT) are used to investigate the effect of width on transport and electronic properties of armchair graphyne(γ-graphyne) nanoribbons. The results show that all the studied nanoribbons are semiconductor and their band gaps decrease as the widths of nanoribbons increase, which will result in increasing current at a certain voltage. Also our results show the promising application of armchair graphyne nanoribbons in nano-electrical devices.