Commuting Space of Primary and Secondary Schools in the Context of Child Friendly Cities:A Case Study of Bajiao Street of Shijingshan District

With the continuous promotion of the construction of child friendly cities,the school commuting space is an important component of the construction of child friendly roads.Based on the background of child friendly cities,the commuting space of 11 primary and secondary schools in Bajiao Street is analyzed through literature analysis and field research methods.Firstly,the relevant literature on school commuting space is sorted out,and the characteristics of school commuting space are summarized,including transportation,landscape,culture,leisure,and security.Secondly,the characteristics of commuting space of primary and secondary schools in Bajiao Street are analyzed from three aspects:in front of the school gate,path space,and node space.This paper aims to provide reference and guidance for the future construction of children’s walking school commuting and promote the construction of a child friendly city.

Nonadditive Skew(Anti-)commuting Maps on Operator Algebras

In this paper,we first give the general forms of skew commuting maps and skew anti-commuting maps by the Peirce decomposition on a unital ring with a nontrivial idempotent,respectively,and then,as applications,we obtain the concrete characterizations of all nonadditive skew(anti-)commuting maps on some operator algebras.

Analysis of Commuting Modal Shift in Consideration of Social Interaction of Consciousness for Environment

It is the matter for achievement of the low carbon transport system that the excessive use of private vehicles can be controlled appropriately.Not only improvement of service level of modes except private vehicle,but also consciousness for environmental problem of individual trip maker is important for eco-commuting promotion.On the other hand,consciousness for environment would be changed by influence of other person.Accordingly,it is aimed in the study that the structure of decision-making process for modal shift to the eco-commuting mode in the local city is described considering environmental consciousness and social interaction.For the purpose,the consciousness for the environment problem and the travel behavior of the commuter at the suburban area in the local city are investigated by the questionnaire survey.The covariance structure about the eco-consciousness is analyzed with the database of the questionnaire survey by structural equation modeling.As the result,it can be confirmed with the structural equation model that the individual environmental consciousness is strongly related with the intention of self-sacrifice and is influenced with the local interaction of the individual connections.On the other hand,the intention of modal shift for the commuting mode is analyzed with the database of the questionnaire survey.It can be found out that the environmental consciousness is not statistically significant for commuting mode choice with the present poor level of service of public transport.However,the intention of self-sacrifice for the prevention of the global warming is statistically confirmed as the factor of modal shift with the operation of eco-commuting bus service with the RP/SP integrated estimation method.As the result,the multi-agent simulation system with social interaction model for eco consciousness is developed to measure the effect of the eco-commuting promotion.For the purpose,the carbon dioxide emission is estimated based on traffic demand and road network condition in the traffic environment model.On the other hand,the relation between agents is defined based on the small world network.The proposed multi-agent simulation is applied to measure the effect of the eco-commuting promotion such as improvement of level of service on the public transport or education of eco-consciousness.The effect of the promotion plan can be observed with the proposed multi-agent system.Finally,it can be concluded that the proposed multi-agent simulation with social interaction for eco-consciousness is useful for planning of eco-commuting promotion.

新一代高韧性直流输电技术(二):高倍载模块化换向式换流器

针对高韧性直流输电技术对高倍载、高经济性直流换流器的需求,提出一种高倍载模块化换向式换流器(high-overload modular commutated converter,MCC)。首先,对MCC的拓扑构造和运行原理进行详细分析,指出其器件软开关特性、桥臂能量脉动优化和高倍载潜力;针对MCC的宽范围电压变比调节、串联模块电压均衡控制、架空线应用中的直流故障自清除等关键问题,给出解决方案;以±500 kV/2000 MW直流输电系统为例,分析MCC的元件用量、体积、效率、成本等技术特性,并与常规模块化多电平IGBT换流器进行综合对比;最后,研制基于IGCT-Plus器件的±15 kV/60 MVA MCC产品,开展综合性测试验证。结果表明,提出的MCC有望将现有换流器技术方案的体积、成本、损耗率分别减小达50%,在电能变换与传输中具有广阔的应用前景。

基于格拉姆角场和PCNN-GRU的换相失败诊断方法

高压直流输电作为一种高效的电力传输技术,其运行中的换相失败会导致直流电流迅速增加、直流电压急剧下降,对电网的安全稳定运行造成重大影响。针对换相失败,提出一种结合格拉姆角场(Gramian angular field,GAF)与并行卷积神经网络–门控循环单元(Parallel convolutional neural network-gated recurrent unit,PCNN-GRU)的换相失败诊断方法。利用GAF将一维时间序列信号转换为二维图像特征图,保留信号的时序信息。再利用PCNN-GRU模型的卷积神经网络的特征提取能力和门控循环单元的时序特征处理能力,使模型学习更多的故障特征,提高模型的诊断性能。以永富直流输电系统为对象,实验结果表明该方法诊断精度为99.33%,有较强的多特征提取能力和时序特性分析能力,诊断性能强,响应及识别换相失败快速。

可控换相换流阀可控关断试验研究及工程应用

高压直流可控换相换流(controllable line commutated converter,CLCC)阀采用晶闸管与绝缘栅双极晶体管(insulated gate bipolar transistor,IGBT)器件混联的方式,形成主、辅两条支路并联结构,主支路起正常通流作用,发生交流故障时由辅助支路承接主支路电流,待主支路恢复阻断后主动关断实现强迫换相,从根本上解决直流系统换相失败的难题,适用于我国多馈入直流受端电网。为等效复现可控换相换流阀稳态运行下电热应力以及交流故障期间连续强迫换相过程产生的瞬变高电压、大电流及脉冲能量,需开展阀组件可控关断试验方法研究,验证CLCC换流阀抵御换相失败能力。依托葛南直流改造工程系统仿真结果,分析了逆变侧单相接地故障下各子阀瞬变高压、大电流应力水平,提取实际工况下各子阀关键应力指标;其次,提出了多频谐振电流源、稳态高压源周期性复合试验方法,完成故障电流连续分断试验装置参数设计,实现无外部负向电压施加时桥臂可控阻断恢复能力的模拟。通过试验和仿真对比分析,验证了该试验方法的可行性及等效性,为后续不同电流等级可控换相换流阀可控关断试验提供理论和技术指导。

Excess Commuting in Transitional Urban China:A Case Study of Guangzhou

During the reform era, Chinese cities witnessed dramatic institutional transformation and spatial restructuring in general and profound change of commuting patterns in particular. Using household surveys collected in Guangzhou, China, in 2001, 2005 and 2010, excess commuting measurements are estimated. Excess commuting shows an overall trend of increasing during 1990–1999, and then declining during 2000–2010. We argue that deepening marketization of the jobs and housing sectors has induced spatial separation of jobs and housing. In other words, institutional transition and urban spatial restructuring are underpinning the changes of commuting patterns in Chinese cities. Excess commuting has strong relationship with individual socio-demographic status, which is by and large due to the increasing flexibilities of jobs and housing location choices enjoyed by urban residents. The findings call for considerations on balancing jobs-housing in making public policies relevant to urban development in general, and land use and transportation in particular.

通勤视角下上海及近沪地区劳动力供给与流动性研究

当前,国家及各省市对“1小时通勤圈协同发展”提出明确要求,上海2035总体规划、上海大都市圈规划等也进一步加快上海跨区域交通出行流动建设。本研究聚焦上海及近沪地区,通过通勤识别、劳动力供给与就业流动性指标构建等技术方法,从全域、区(县)、街道(镇)等多尺度分析其劳动力供给与就业流动性分布特征。研究初步显示,在区县层面,上海中心城区、昆山承担主要通勤体量,流动性指标聚类显著;在街道(镇)层面,近沪地区、上海郊区核心镇占据较大通勤总量,流动性差异分布明显。研究也提出分地区差异化构建区域服务目标、构建区域轨道交通体系与廊道、分模式明确职住平衡和流动性等策略建议,为超大城市及大城市跨区域劳动力供给与流动优化提供依据。

新型可控电网换相换流器故障特性及控制优化研究

基于可控电网换相型换流器(controllable line commutated converter,CLCC)的高压直流输电技术避免了常规直流换相失败问题,为高压直流馈入电网提供了崭新途径。文章揭示CLCC高压直流输电系统的故障响应机理,对比CLCC与电网换相型换流器、电压源型换流器等直流输电技术的功率特性差异。针对CLCC可控换流的技术特点,提出一种基于最大触发角提升的CLCC优化控制方法,改善了CLCC的故障响应特性,提升了受端电网交流电压的恢复速度。最后,基于PSD-PSModel电力系统仿真软件,建立送受端电网机电暂态和CLCC直流电磁暂态的混合仿真模型,验证理论分析的准确性和优化控制的有效性。

The spatial distribution of commuting CO_2 emissions and the influential factors:A case study in Xi'an,China

As the transport sector is a major source of greenhouse gas emissions, the effect of urbanization on transport CO2 emissions in developing cities has become a key issue under global climate change. Examining the case of Xi＇an, this paper aims to explore the spatial distribution of commuting CO2 emissions and influencing factors in the new, urban industry zones and city centers considering Xi＇an＇s transition from a monocentric to a polycentric city in the process of urbanization. Based on household survey data from 1501 respondents, there are obvious differences in commuting CO2 emissions between new industry zones and city centers： City centers feature lower household emissions of 2.86 kg CO2 per week, whereas new industry zones generally have higher household emissions of 3.20 kg CO2 per week. Contrary to previous research results, not all new industry zones have high levels of CO2 emissions; with the rapid development of various types of industries, even a minimum level of household emissions of 2.53 kg CO2 per week is possible. The uneven distribution of commuting CO2 emissions is not uniformly affected by spatial parameters such as job-housing balance, residential density, employment density, and land use diversity. Optimum combination of the spatial parameters and travel pattern along with corresponding transport infrastructure construction may be an appropriate path to reduction and control of emissions from commuting.

Spatial-temporal Characteristics and Factors Influencing Commuting Activities of Middle-class Residents in Guangzhou City, China

The middle class in metropolitan Chinese cities has become an important social group. With the rapid development of urbanization and constant advancement of suburbanization, the middle class has increasingly come to influence city traffic. Research into middle-class commuting activities thus has practical significance for improving traffic congestion and reducing the commuting burden in metropolitan cities. Based on a dataset formed by 816 completed surveys, this paper analyzes the commuting mode, time and distance of middle-class residents in Guangzhou City using the descriptive statistical method. The results indicate that private cars are the main commuting mode, followed by public transport. Meanwhile, middle-class residents mainly undertake medium-short time and medium-short distance commuting. The study subsequently uses multilevel logistic regression and multiple linear regression models to analyze the factors that influence commuting mode choice, time and distance. The gender, age, number of family cars, housing source and jobs-housing balance are the most important factors influencing commuting mode choice; housing, population density, jobs-housing balance and commuting mode significantly affect commuting time; and transport accessibility, jobs-housing balance and commuting mode are the notable factors affecting commuting distance. Finally, this paper analyzes what is affecting the commuting activities of middle-class residents and determines the differences in commuting activity characteristics and influence factors between middle-class and ordinary residents. Policy suggestions to improve urban planning and urban management are also proposed.

On Commuting Graph of Group Ring Z_nS_3

The commuting graph of an arbitrary ring R, denoted by Г（R）, is a graph whose vertices are all non-central elements of R, and two distinct vertices a and b are adjacent if and only if ab = ba. In this paper, we investigate the connectivity and the diameter of Г（ZnS3）. We show that Г（ZnS3） is connected if and only if n is not a prime number. If Г（ZnS3） is connected then diam（Г（ZnS3）） = 3, while ifГ（ZnS3） is disconnected then every connected component of Г（ZnS3） must be a complete graph with same size, and we completely determine the vertice set of every connected component.

Labor Market Aspects of the ＂New Rurality＂： Employment, Commuting and Entrepreneurship in Rural Sweden

Around two thirds of the Swedish rural areas experienced positive net migration during the period 2003-2005. This paper examines the development in the Swedish rural areas from the perspective of the ＂new rurality＂ or the new rural economic order with regard to migratory movements. The paper analyzes determinants of net migration to rural areas in general and to different types of regions, and the impacts of in-migration on rural labor markets, self-employment and other socio-economic conditions. The determinants of the migration pattern were mainly the size of adjacent local and regional centers, income and education levels that all had positive impacts, while commuting distance and unemployment rate had contrary effects. In comparison with the original inhabitants, the newcomers had lower incomes, a lower employment ratio and a lower degree of entrepreneurial activities, but higher education levels. These differences might be explained by the age differences between stayers （older） and in-migrants （younger）. This indicates that the two groups were in different stages of their life cycles. One central conclusion drawn from the paper is that the effect of in-migration on the composition of the rural population is about the same in rural areas all over Sweden.

City Size,Commuting Cost and Household Savings Rate:Evidence from China

Economics literature has long overlooked an important economic phenomenon:Residents in large cities tend to save a smaller percentage of their disposable income than their peers in small and medium-sized cities.As an explanation for this phenomenon,this paper puts forth the hypothesis that:Residents in large cities purchase more services to increase their leisure time,which is reduced by longer commuting time than in small and medium-sized cities,thus lowering their household savings rate.We conducted an empirical study using panel data of China’s prefecture-level cities and urban household survey data,and employed an instrumental variable to address the endogeneity problem.The result confirmed the accuracy of the above hypothesis.In identifying the economic phenomenon and putting forth the hypothesis,this paper(i)creates a theoretical link between city size and household savings rate,which helps unravel the determinants of the urban household savings rate;(2)provides important implications for China’s policy-making on domestic consumption,urban populations,and industrial development.Priority should be given to developing large and medium-sized cities given the positive effects on domestic consumption and service sector development,and migrant labor shall not be barred from entering large and medium-sized cities to provide services to local residents.

Common Fixed Point Theorem in Intuitionistic Fuzzy Metric Space Using <i>R</i>-Weakly Commuting Mappings

In this paper, we prove a common fixed point theorem in Intuitionistic fuzzy metric space by using pointwise R-weak commutativity and reciprocal continuity of mappings satisfying contractive conditions.

Linear Commuting Maps on Parabolic Subalgebras of Finite-dimensional Simple Lie Algebras

A map φ on a Lie algebra g is called to be commuting if [φ(x), x] = 0 for all x ∈ g. Let L be a finite-dimensional simple Lie algebra over an algebraically closed field F of characteristic 0, P a parabolic subalgebra of L. In this paper, we prove that a linear mapφon P is commuting if and only if φ is a scalar multiplication map on P.

Comparing the Extend of the Spread Effects: Rural-Urban Commuting in Finnish Working Regions

It has long been posited that rural areas can benefit from nearby urban agglomerations through commuting, and that their development could be a side product of urban growth, but the results from the sparsely populated regions have not been promising. In this study, we investigate the possibilities of rural-urban commuting to support rural development, and explore the spatial ex-tent of the working regions if jobs are concentrated in the regional centre as indicated by recent trends. Spread effects are simply operated by an economic possibility to rural-urban commuting determined by a sum of housing and commuting costs from disposable income. The results show that the population growth in city regions does not extend to distant rural areas. It, instead, leads to population losses in remote areas due to backwash effects as the low disposable incomes encourage especially low-income households to migrate from remote locations closer to the centre. The spread effects seem to work only in the limited rural areas located next to the urban core which encourages the support of remote rural areas through place-based policy.

Exposure Work Commuting： Case Study among Commuting Accidents in Klang Valley, Malaysia

Traffic accidents caused the most accidental deaths at work in Malaysia. The SOCSO （Social Security Organization） reported that the number of deaths due to commuting accidents was 760, nearly two times more than deaths caused by accidents that happened at the workplace （471 deaths）. The aim of this study is to investigate the relationship of socio-demographic background and the risk exposure of the drivers during their work commuting trips. The study was based on compensation claims to SOCSO where data were extracted from ＂Form 21＂ provided by SOCSO. A total of 377 respondents were selected through systematic random sampling method from a list of SOCSO claimants. It was found that majority of the traffic accidents （83%） involved males and most of them （92.2%） were on motorcycles. Male drivers have an average driving experience of 10.7 years and 8.6 years for females. The estimation of the travelled distance for the sample from home to the workplace is 0.65-131 km. Mean accident occurrence time was 23 rain whilst mean distance was 11.6 km. The multiple regression analysis showed that the accident distance was affected by the age of driver, actual travel distance, travel objective and speed.

Workers Survived from Commuting Road Crashes:Who Are They?

Commuting road crashes are road traffic crashes that involve workers while travelling in the course of work.The more worker travels,the higher the probability of the occurrence of commuting road crashes.The aim of this study was to determine baseline sociodemographic,employment and injury and characteristics of injured workers who survived from commuting road crash.Eligible 200 workers who were involved in commuting road crash were identified and invited to be part of this study.Sociodemographic,employment and injury-related questions were distributed to identified and consented injured workers.Majority(79.5%)of the respondents were aged 25 years old or older,male(86.0%),married or divorced(63.5%),and attained secondary and below education level at secondary or below(66.0%).Most of the injured workers consisted of blue-collar workers(69%),had fracture injury(93.0%),and had injury to their lower limbs(48.5%).A higher percentage(63.5%)of injured workers had returned to work compared to those who were still not working(36.5%)after involved in commuting road crash.Commuting road crashes are common to blue collar workers as they are more prone to use motorcycles to commute due to cheaper price compare to other type of transportation such as car.