Study on the Distribution Characteristics and Influencing Factors of Park Green Space in Wuhan City

The distribution characteristics of park green space in Wuhan City were studied by standard deviation ellipse(SDE)method,average nearest neighbor index,kernel density estimation(KDE)method and scale index method.At the same time,the influencing factors of its distribution were discussed from three aspects of nature,social economy and culture with a geographical detector.The results show that(1)the distribution of park green space in Wuhan was relatively concentrated,and the directionality was not strong.The distribution mode was clustered mode.There were four main aggregation centers,which were located in Jianghan District,Qingshan District,Dongxihu District and Wuchang District respectively.Among them,the scale index of Jianghan District was the highest,up to 0.5902,while that of Xinzhou district was the lowest,only 0.0047.(2)The order of interpretation intensity of park green space distribution in Wuhan was population density(0.382)>regional GDP(0.278)>location of historical relics(0.165)>urbanization rate(0.136)>watershed zoning(0.069)>altitude(0.012).(3)The interaction of population density and watershed zoning had the strongest explanation for the distribution of park green space in Wuhan.Except for the influence of population density,the interaction of urbanization rate and regional GDP had the strongest explanation for the distribution of park green space in Wuhan.

Available parking space occupancy change characteristics and short-term forecasting model

Based on an available parking space occupancy （APSO） survey conducted in Nanjing, China, an APSO forecasting model is proposed. The APSO survey results indicate that the time series of APSO with different time-sections are periodical and self-similar, and the fluctuation of the APSO increases with the decrease in time-sections. Taking the short-time change behavior into account, an APSO forecasting model combined wavelet analysis and a weighted Markov chain is presented. In this model, an original APSO time series is first decomposed by wavelet analysis, and the results include low frequency signals representing the basic trends of APSO and several high frequency signals representing disturbances of the APSO. Then different Markov models are used to forecast the changes of low and high frequency signals, respectively. Finally, integrating the predicted results induces the final forecasted APSO. A case study verifies the applicability of the proposed model. The comparisons between measured and forecasted results show that the model is a competent model and its accuracy relies on real-time update of the APSO database.

Based on the Characteristics of Respondents and the Voice of the Urban Neighborhood Public Space Business Facilities Noise Environment Evaluation Research

Comfort is one of the important indicators evaluation of voice. In order to understand the urban neighborhood public space environment of comfort,this paper is to explore characteristics of consumer society on the public space environment evaluation of the effect,and using the questionnaire survey method,to evaluate the Harbin city neighborhood area public space as the typical case analysis. Based on one of the main sound source in neighborhood public space,environment,business facilities environment as the breakthrough point,it is to consider neighborhood public space environment evaluation and social characteristics.

Green Space System Planning in Shuangcheng City and Creation of the City's Characteristics

Characteristic urban construction has already become a trend of modern social development,in this context,components of characteristic urban green spaces,and ways of demonstrating features of urban green space system were analyzed.Shuangcheng City in Heilongjiang Province was taken for example to analyze planning objectives and principles of characteristic urban green space system.Moreover,the green space layout of "A Hundred Years Old Castle,A Hundred of Enterprises and A Hundred of Gardens" was introduced.It was proposed that green space system planning suited to the development features and ecological conditions of the city should be developed from the perspective of greater regional environment,historical and cultural deposits,urban development pattern and lifestyle of the locals,so as to create urban green space system with regional features.

Simulation analysis on microscopic discharge characteristics of the bipolar corona of a floating conductor

A floating conductor exhibits a bipolar corona phenomenon with microscopic discharge characteristics that are still unclear.In this study,a plasma simulation model of the bipolar corona with 108 chemical reaction equations is established by combining hydrodynamics and plasma chemical reactions.The evolution characteristics of electrons,positive ions,negative ions and neutral particles,as well as the distribution characteristics of space charges are analyzed,and the evolutionary flow of microscopic particles is summarized.The results indicate that the positive end of the bipolar corona initiates discharge before the negative end,but the plasma chemistry at the negative end is more vigorous.The electron generation rate can reach 1240 mol(m^(3) s)^(-1),and the dissipation rate can reach 34 mol(m^(3) s)^(-1).The positive ion swarm is dominated by O_(4)^(+),and the maximum generation rate can reach 440 mol((m^(3) s)^(-1).The negative ion swarm is mainly O_(2) and O_(4).The O_(2) content is approximately 1.5-3 times that of O_(4),and the maximum reaction rate can reach 51 mol(m^(3) s)^(-1).The final destination of neutral particles is an accumulation in the form of O_(3) and NO,and the amount of O3 produced is approximately 4-6 times that of NO.The positive end of the bipolar corona is dominated by positive space charges,which continue to develop and spread outwards in the form of a pulse wave.The negative end exhibits a space charge distribution structure of concentrated positive charges and diffused negative charges.The validity of the microscopic simulation analysis is verified by the macroscopic discharge phenomenon.

Configuration Selection for Reconfigurable Manufacturing Systems by Means of Characteristic State Space

The configuration selection for reconfigurable manufacturing systems（RMS） have been tackled in a number of studies by using analytical or simulation models. The simulation models are usually based on fewer assumptions than the analytical models and therefore are more wildly used in modeling complex RMS. But in the absence of an efficient gradient analysis method of the objective function, it is time-consuming in solving large-scale problems by using a simulation model coupled with a meta-heuristics algorithm. In this paper, a new approach by means of characteristic state space is presented to improve the efficiency of the configuration selection for an RMS. First, a characteristic state equation is set up to represent the input and the output resources of each basic activity in an RMS. A production process model in terms of matrix equations is established by iterating the equations of basic activities according to the resource flows. This model introduces the production process into a characteristic state space for further analysis. Second, the properties of the characteristic state space are presented. On the basis of these properties, the configuration selection in an RMS is considered as a path-planning problem, and the gradient of the objective function is computed. Modified simulated annealing（SA） is also presented, in which neighborhood generation is guided by the gradient to accelerate convergence and reduce the run time of the optimization procedure. Finally, several case studies on the configuration selection for some actual reconfigurable assembly job-shops are presented and compared to the classical SA. The comparison shows relatively positive results. This study provides a more efficient configuration selection approach by using the gradient of the objective function and presents the relevant theories on which it is based.

Acoustic characteristics of pulse detonation engine sound propagating in enclosed space

Acoustic characteristics of pulse detonation engine(PDE)sound propagating in enclosed space are numerically and experimentally investigated.The finite element software LS-DYNA is utilized to numerically simulate the PDE sound propagating in enclosed space.Acoustic measurement systems are established for testing the PDE sound in enclosed space,and the time-frequency characteristics of PDE sound in enclosed space are reported in detail.The experimental results show that the sound waveform of PDE sound in enclosed space are quite different from those in open space,and the reflection and superposition of PDE sound on the walls of enclosed space results in the sound pressure oscillating obviously.It is found that the peak sound pressure level(PSPL)and overall sound pressure level(OASPL)of PDE sound in enclosed space are higher than those in open space and their difference increases with the rise of propagation distance.The results of the duration of PDE sound indicate that the A duration of PDE sound in enclosed space is higher than that in open space except at measuring points located at 2-m and 5-m while the B duration is higher at each of all measuring points.Results show that the enclosed space has a great influence on the acoustic characteristic of PDE sound.This research is helpful in performing PDE experiments in enclosed laboratories to prevent the PDE sound from affecting the safety of laboratory environment,equipment,and staffs.

A CHARACTERISTIC OF RIEMANNIAN SPACES ADMITTING QUASI-CONCIRCULAR TRANSFORMATION

In this paper, we have considered some properties of quasi-umbilical hypersurfaces of a Riemannian space and obtained a characteristic of Riemannian spaces admitting quasi-concircular transformation.

The Fuzzy Neural Network Control Scheme With H∞ Tracking Characteristic of Space Robot System With Dual-arm After Capturing a Spin Spacecraft

In this paper,the dynamic evolution for a dualarm space robot capturing a spacecraft is studied,the impact effect and the coordinated stabilization control problem for postimpact closed chain system are discussed.At first,the pre-impact dynamic equations of open chain dual-arm space robot are established by Lagrangian approach,and the dynamic equations of a spacecraft are obtained by Newton-Euler method.Based on the results,with the process of integral and simplify,the response of the dual-arm space robot impacted by the spacecraft is analyzed by momentum conservation law and force transfer law.The closed chain system is formed in the post-impact phase.Closed chain constraint equations are obtained by the constraints of closed-loop geometry and kinematics.With the closed chain constraint equations,the composite system dynamic equations are derived.Secondly,the recurrent fuzzy neural network control scheme is designed for calm motion of unstable closed chain system with uncertain system parameter.In order to overcome the effects of uncertain system inertial parameters,the recurrent fuzzy neural network is used to approximate the unknown part,the control method with H∞tracking characteristic.According to the Lyapunov theory,the global stability is demonstrated.Meanwhile,the weighted minimum-norm theory is introduced to distribute torques guarantee that cooperative operation between manipulators.At last,numerical examples simulate the response of the collision,and the efficiency of the control scheme is verified by the simulation results.

Study of Spatial Characteristics of Streets and Alleys in Traditional Villages:Taking Pingtan Comprehensive Experimental Area as an Example

Taking the traditional residential street space in Pingtan Comprehensive Experimental Area as an example,the factors influencing the formation and development of lane space and the distribution characteristics of lanes were analyzed in this paper.Subsequently,an analysis was conducted on the scale and proportion of street and lane space enclosed in the settlement,the experiential aspects of street and lane space,as well as the node space.Lastly,a systematic summary of the street space characteristics in the settlements of Pingtan Island and Dongxiang Island is presented.

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.

Artistic Space Design of Subway Station Based on Regional Characteristics

On the basis of existing problems in the spatial design of subway station, this paper explored the principles that regional culture involves in the artistic space design of subway station; based on the analysis of three main design sections and site cases-spatial interface, public art and color, the paper also discussed the artistic application and design embodiment of regional culture characteristics reflected in every element of subway station space design, so as to provide a consolidated design example for subway station space design featuring regional characteristics in the future.

Characteristic Functions over C*-Probability Spaces

Various properties of the characteristic functions of random variables in a non-commutative C*-probability space are studied in this paper. It turns out that the distributions of random variables are uniquely determined by their characteristic functions. By using the properties of characteristic functions, a central limit theorem for a sequence of independent identically distributed random variables in a C*-probability space is established as well.

Study on the Production Space Characteristics and Impacts of Traditional Villages in the Pearl River Delta:A Case Study of Xiaozhou Village and Huangpu Village in Guangzhou

Traditional village production space is the basis of villagers’ survival and village development.Nowadays,its production function has been lost,but it still has ecological and cultural value.The formation of traditional village production space in the Pearl River Delta is closely related to the water system,soil,geology and landform,and three types of production space,including water transportation,agricultural production and manual workshop,have been formed.It has strong ecological adaptability,forms pastoral scenery with unique water village characteristics,and is closely related to the development of the village and the livelihood of the villagers.Under the influence of urbanization,they have undergone great changes,which are manifested in erosion and fragmentation.Therefore,they should be protected,inherited and developed.

The Form Characteristics and Construction of the Public Space of the Oasis Traditional Settlements in Turpan

Based on the analysis of the form characteristics and construction of the public space of oasis traditional settlements in Turpan,and from the analysis and summary of the types,elements,scales and functions of the public space of the traditional settlements,this study put forward that the public space of the oasis villages can be divided into point space,line space and plane space,and the formation and evolution rules of the public space of oasis traditional settlements in Turpan were obtained.Explore the role of public space in the construction of traditional settlements’ overall space,so as to provide reference for the development and renewal of public space of the current similar oasis settlements.

REFERENCE FUNCTIONAL AND CHARACTERISTIC SPACE FOR LAGRANGE AND BERNSTEIN OPERATORS

This paper deals with the description and the representation of polynomials defined over n-simplices, The polynomials are computed by using two recurrent schemes: the Neville-Aitken one for the Lagrange interpolating operator and the De Casteljau one for the Bernstein-Bezier approximating operator. Both schemes fall intothe framework of transformations of the form where the F iare given numbers (forexample, at the initial step they coincide with the values of the function on a given lattice), and the coefficients (x) are linear polynomials valued in x and x is fixed. A general theory for such sequence of transformations can be found in [2] where it is also proved that these tranformations are completely characterized in term of a linear functional, reference functional. This functional is associated with a linear space., characteristic space.The concepts of reference functionals and characteristic spaces will be used and we shall prove the existence of a characteristic space for the reference functional: associated with these operators.

基于NDVI-Albedo特征空间的大同煤田荒漠化遥感监测

荒漠化是威胁区域发展和人类生存的重要生态环境问题之一,因此开展荒漠化监测是荒漠化防治中的一项重要基础工作。本文以山西大同煤田为例,利用NDVI-Albedo特征空间构建2000—2021年荒漠化差值指数(DDI),监测其荒漠化时空变化,并利用地理探测器分析荒漠化的影响因素。结果显示,2000—2021年,大同煤田荒漠化由严重向轻度转换,重度和极重度荒漠化面积显著减少,而轻度荒漠化面积显著增加。整体而言,有57.75%的区域荒漠化呈显著改善趋势,但同时有0.03%的区域荒漠化呈加剧趋势。地理探测结果表明,植被是影响荒漠化的主要因子;植被与降水、高程等自然因素交互后的影响显著增大,与土地利用、人口密度等人类活动因素交互后的影响同样不可忽视。

Analysis on the Layout Evolution and External Space Characteristics of the Red Gate Palace in Taishan

This article organizes and analyzes the historical evolution as well as the current situation of the Red Gate Palace,and probes into the artistic characteristics of the exterior space of the building.The conclusions are as follows:Relying on the unique forest environment of Mount Tai,the Red Gate Palace forms an impression of negative yin-yang where it is overlooking waters and with hills at the back.The guiding space comprising of the climbing route,the archway,and the Feiyun Pavilion which is built on the crossroad plays the role of guidance and suggestion;forming a complete spatial sequence with rhythm.The courtyard space which constitutes the east and west courtyards,in addition to the Little Taishan Temple is reasonable and ingenious in layout along with rich as well as well-proportioned spaces,and pleasant in scale.

Space Development with Chinese Characteristics and its Practical Significance

China＇s space industry has been developed quickly and consistently setting new records for mankind in space exploration in the past 60 years. Four principles are uphetd during its development. Systems engineering and overall thinking have played an important role in the development of China＇s space industry. What＇s more, the concept of systems engineering which originated from the space industry, being rooted in society, is a successful example of ＂Chinese theory＂ answering ＂Chinese question＂ and ＂Chinese wisdom＂ guiding ＂Chinese development＂, which is a trump card for the country and provides a unique business governance mode with Chinese characteristics.

Nonlinear Current-Voltage Characteristics and Electroluminescence of cBN Crystal

The current-voltage（I-V） characteristics of cBN crystal sandwiched between two metallic electrodes are measured and found to be nonlinear. Over 20 samples are measured at room temperature with various electrodes, and the resulting curves are all similar in shape. When a voltage of about 560V is applied to the cBN crystal, the emitted light is visible to the naked eye in a dark room. We explain these phenomena by the space charge limited current and the electronic transition between the X and Г valleys of the conduction band.