Autonomous vehicles: scientometric and bibliometric review*

ABSTRACT

This paper presents a scientometric and bibliometric review of the research on autonomous vehicles (AVs) to identify its main characteristics, evolution, and potential trends for future studies. Relevant articles were searched on WoS, yielding a research corpus of 10,580 papers, and the software CiteSpace was subsequently used for analysis. The results showed that AV research is heterogeneous and registered a growing demand over time. Multidisciplinarity is present, with 96 science fields being identified. As in any other sector, it is necessary to understand broader aspects of this industry such as the market factors surrounding it, as well as other economic and managerial issues. In this sense, we observed a migration of the research field from multidisciplinarity to pluridisciplinarity with a greater number of studies focusing on the latter. We understand that terminology standardisation contributes to achieving pluridisciplinarity. As such, it is important to highlight that sustainability, public policies, liability, and safety, as well as business issues such as performance and business models are some of the tendencies in the field of AVs. For future studies, we suggest a more in-depth analysis of publications in terms of individual search terms, as well as the sub-areas identified as trends in this paper.     

A Strategic Diagnostic Tool Applied to Iberian Seaports: An Evolutionary Perspective

The highly competitive and rapidly changing environment faced by businesses has greatly increased the need for strategic planning. The importance of formulating strategies to reach competitive advantages with implications in the performance is becoming increasingly evident in the seaport context. Thus, it is relevant and appropriate to apply strategic positioning tools to seaports given the role of competitive strategies in the growth and development of this industry. This research aims to analyse the strategic positioning of the leading Iberian Peninsula seaports (Portuguese and Spanish seaports) using the Boston Consulting Group (BCG) matrix as a strategic tool in an evolutionary perspective. The portfolio analysis developed subsequently focuses on the annual data of eight seaports in a selected period of 18 years (1992–2009) and on five categories of traffic: liquid bulk (LB), dry bulk (DB), containers (CO), ro-ro (roll-on/roll-off) and conventional cargo (CC). This research allows us to compare and analyse different levels of performance and identify which of the seaports have improved their strategic positioning during the considered period. The findings reveal a better positioning of Spanish seaports in relation to total traffic and that most of the seaports in the BCG matrix had changed from the first to the third period. The seaport of Valencia is the only one that has maintained its Star Performer position in all the 18 years analysed. Furthermore, considering container traffic, the results evidence the seaports of Algeciras, Valencia and Barcelona as having attained a remarkable position of leadership.     

汽车发动机连杆的弹性改造研究

论述了用高弹性应变率高强度材料将连杆制成易于产生弹性弯曲而缩伸的形式 ,使排气更干净 ,进气更充分 ,小进气量时压缩比更高 ;在做功行程的起始点 (上止点 )时降压储能 ,增加推动曲柄的切向分力 ;上止点后释放能量 ,提高对曲柄的推动功率 ;分析了连杆弹性弯曲折断和弯曲干涉的可能原因 ,并有针对性地提出了防止折断和防止干涉的可行办法     

基于神经网络的部分预应力混凝土梁荷载-裂缝模型研究

混凝土结构裂缝形成和发展的过程十分复杂，具有一定的随机性，难于用常规的方法进行建模。应用神经网络较强的函数映射能力和联想、记忆功能，对部分预应力混凝土梁的荷载－裂缝关系进行建模，通过试验数据进行验证，效果良好，证明应用神经网络来对部分预应力混凝土梁的荷载－裂缝关系进行建模是可行的。     

海洋中晕船问题的案例研究(英文)

Motion sickness is one of the main reasons why travelling by sea becomes a bad memory for a number of people, mainly due to a nauseating symptom. The aim of this paper is to characterize a condition called seasickness that has affected many people from a mathematical and psychological point of view. Based on the mathematical characterization, an existing model will be reviewed and described. In the psychological aspects, a statistical study of two hundred and thirteen people was performed in order to provide a comprehensive view of the different psychological factors affecting the passengers. Motion sickness also impacts onboard safety, as it reduces the effectiveness and the operating capability of the crew when responding to hazardous situations.     

简述1511年至现代葡萄牙与暹逻的关系

我1979年居住于澳门的时候,由澳门政府官印局出版了一部名为<简述葡暹关系:1511-1900>的小册子,全书共28页.是根据存放在澳门历史档案馆的资料编成写的.全书分为五部份:(1)16世纪初的果亚:1510年;马六甲:1511年;澳门:1557年.(2)进一步接触:商人、传教士与17世纪时期暹逻王对澳门的借款.(3)葡人的衰落与18世纪接触的减少,贸易衰退.(4)19世纪旧有关系的复苏,不完全条约与葡人的厂房.(5)结语.     

Logistics resources in seaport performance: multi-criteria analysis

Studying the logistics resource relationship within the framework of the overall performance of the main Iberian seaports performance, this article discusses how to apply the linear additive multi-criteria analysis (MCA) model and principal component analysis (PCA) to such an industry. The model incorporates the contribution of two different performance indicators—operational performance and physical capacity—measured by several indicators. First, we gather the 2009 annual data on the total cargo throughput of 16 seaport container terminals. The PCA method is then applied to attain the loading factor of each indicator and to normalize the redundancy in indicators and thereby generate meaningful results. We correspondingly find (a) operational performance contributed 48.77% while the physical capacity contributed 51.23% to overall performance; (b) the majority of seaports reveal a direct proportionality between their positioning in terms of physical capacity and their overall performance positioning; (c) this relationship changes whenever the difference in indicator value proves significant; and hence (d) this model demonstrates both its applicability and reliability in the case of the Iberian seaport industry and the relevance of encouraging multiple decision-makers to carefully consider identifying key criteria out of a given set of alternatives.     

p-CenterProblem的一个基于中心图合并操作的启发式算法

设计的启发式算法从图的合并操作出发 ,降低了计算复杂度 ,从应用效果看接近最优的程度也较以往算法好     

Centrality indicators as an instrument to evaluate the integration of urban equipment in the area of influence of a rail corridor

The objective of this work is to formulate a structure of procedures to support projects to integrate neighborhoods in the area of influence of railway corridors and the urban facilities around each station. Based on the concept of centrality, formulated mathematically by graph theory and with the support of a geographic information system (GIS), we propose interventions aiming to create a more harmonious urban environment better in tune with sustainable mobility. We highlight the relevance of quantitative approaches in the study of urban concepts to foster integration between transportation and urban development, as well as the potential of their application in various Brazilian metropolises having commuter rail systems that are currently underutilized and in the process of revitalization.     

Persistence of walking in Chile: lessons for urban sustainability

ABSTRACT

An extensive body of work from the urban planning, health, and other disciplines has documented the importance of walking to urban sustainability from health, safety, security, environmental and other perspectives. These studies come mainly from countries in North America and Europe, where the majority of the population relies on cars for transportation. Notwithstanding, in many countries in the Global South, walking remains a majority transport mode, while cars increasingly dominate the urban streetscape, but are accessible only to a minority of the population. Chile provides fertile terrain for studying this phenomenon. This article reviews current practice and recent research of walking in Chile, in light of international findings regarding walkability, equity and urban sustainability. To elaborate an overview of the depth and breadth of walking in Chile, an interdisciplinary team conducted a literature review, examined relevant case study material from experience from Chile and in particular from Santiago, and triangulated this mainly qualitative data with results from the origin-destination survey applied in Chile’s main cities, Chilean traffic safety data) and results from official transport reports of other Latin American cities [Tirachini, A. (2019). South America: The challenge of transition. In J. Stanley & D. Hensher (Eds.), A research agenda for transport policy. Northampton, MA: Edward Elgar Publishing]. Findings show that despite priority public investments that have largely prioritised infrastructure for cars, walking in Chile has remained as the majority transport mode up until today, especially for lower-middle income groups, and particularly for care-related tasks performed mainly by women. In this sense, walking in Chile has proven remarkably persistent. The importance of walking as the main transport mode, against the odds, reflects economic, cultural, and urban form determinants, which are explored in this article. Furthermore, a recent upsurge in public interest and community design initiatives to improve walking, particularly the generation of a Chilean approach to “complete streets” has emerged, opening up opportunities to challenge Chile’s version of automobility in favour of more equitable, active and public transportation modes. There is, therefore, in Chile an opportunity to prioritise the walking mode, improve infrastructure for walkers and build from preserving current high pedestrian modal shares, rather than having to reverse widespread car use, as occurs in many countries in Europe and North America. This potential is highly relevant as these conditions are similar to those in other Latin American cities and, potentially, other cities elsewhere in the Global South.