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As a kind of large-scale connectivity infrastructure, submarine cables play a vital role in international telecommunication, socio-economic development and national defense security. However, the current understanding about the spatial pattern of global submarine cable network is relatively limited. In this article, we analyze the spatial distribution and connectivity pattern of global submarine cables, and identify their strategic pivots and strategic channels. The main conclusions are as follows: (1) The spatial distribution of global submarine cables is significantly unbalanced, which is characterized by the facts that the distribution of submarine cable lines is similar to that of sea lanes, and the agglomerations of landing stations are distributed unevenly along the coastline. (2) The connectivity pattern of global submarine cable network has a significant scale effect. At the micro, meso and macro scales, the connectivity structure presents chain model, cluster model and hub-and-spoke model, respectively. (3) The distribution of strategic pivots and strategic channels shows a pyramidal hierarchical feature. Singapore ranks highest among all the strategic pivots, while the Gulf of Aden and the Strait of Malacca rank highest among the strategic channels. Based on the identification of strategic pivots and channels, six strategic regions have been divided, which face various network security risks and need special attention and vigilance. [ABSTRACT FROM AUTHOR]

Submarine cable network is one of the most important connectivity infrastructures in the digital era. In the past 20 years, the submarine cable network of Chinese mainland has formed a complex connectivity structure. This paper focuses on exploring the structure and evolution of the submarine cable network of Chinese mainland. The results show that the evolution can be divided into four stages: an initial stage (1993–1998), a developmental stage (1999–2002), a stagnation stage (2003–2015) and an accelerated stage (2016–2018). The connectivity structure can be analyzed at micro, meso and macro scales. Statistically, the connectivity increased significantly overall, but showed significant differences in space. For the microscale, the landing cities were characterized by "extensive but low, exclusive and high"; for the mesoscale, the connectivity of countries or regions was characterized by "distance attenuation" as a whole, but, in part, by a "regional identity"; for the macroscale, intercontinental connectivity differences have been declining. The hierarchy has been upgraded from a "3 system" to a "2 + 3 system". Finally, this paper discusses the interaction between submarine cable network construction and international relations, and puts forward policy suggestions for China's submarine cable construction. [ABSTRACT FROM AUTHOR]

The ostrich (Struthio camelus) is characterized by high speed and heavy load when running. Its intertarsal joint (Fig. 1A) with double-nutrient foramina (DNF) exhibits excellent ability to withstand high impact during running, and is characterized by lightweight. We investigated the effect of DNF on the biomechanical properties of the intertarsal joints of the ostrich. The intertarsal joint was reconstructed according to computed tomography images, and four models were established to uncover the separate and combined effects of the compositional parameters (geometric features, material properties) on stress concentration reduction. We have revised the formula that can be used to predict the elasticity modulus (E) of ostrich bones and verified the accuracy of the formula with nano-indentation equipment. The results were analyzed by t tests, and the p value is less than 0.05. The finite element analysis was performed to evaluate the mechanical properties of the PT and models. Compared to the Filled model (DNF was filled), the maximum stress at the lateral and medial fossa in the Initial model was reduced by 15.4%, although there was no significant difference in the medial maximum stress. Compared with the stress value of models without holes, the models with holes have lower stress, with a reduction of 4.0%. Reasonable design of holes can improve the efficiency of material utilization. This paper investigated the mechanism of high mechanical properties of the intertarsal joints of ostrich and developed four bionic-bearing parts based on the characteristics of DNF and heterogeneity materials, which may provide ideas for the design of aircraft and robot parts with lightweight and high strength. [ABSTRACT FROM AUTHOR]

African ostriches are good at running in the desert, and their toenails can effectively improve the tractivetraction performance in the running process. To improve the tractivetraction trafficability of wheels on the lunar surface loose soil, a wheel with bionic wheel lugs was designed based on the bionic prototype of ostrich toenail and bionic engineering technology. Then, the rolling of the bionic wheel was simulated by using the three-dimensional (3D) discrete element method (DEM) simulation system of the interaction between irregular structure wheel and lunar soil, and the result was compared with that of the wheel with rectangular wheel lugs. Under the same working condition, the drawbar pull, torque, and sinkage of two kinds of wheels at slip ratios of 0.25, 0.375, and 0.625 were analyzed. The simulation results showed that the average drawbar pull and average torque of the bionic wheel are greater than that of the wheel with rectangular wheel lugs at three kinds of slip ratios. When the slip ratios were 0.25 and 0.375, there was almost no difference in the average sinkage of the two kinds of wheels, but the average sinkage of the bionic wheel was significantly less than that of the wheel with rectangular wheel lugs when the slip ratio was 0.625. The results show that, compared with the wheel with rectangular wheel lugs, the bionic wheel has better tractivetraction and anti-subsidence performance. This study provides a new design and research method for improving the tractive trafficability of wheels in the lunar loose surface environment. [ABSTRACT FROM AUTHOR]

The railway is an indispensable feature of a nation's infrastructure, and the gauge is an internal and objective technical regulation of the railway. In the large-scale regional space, the track gauges reflect the development differences, historical relations and mutual influences between countries and regions. This makes the railway, originally as a regional connection, have special social, political, military and other multiple attributes. Based on this, the paper, from the perspective of railway gauge, takes the Eurasian continent as the case region to explore the spatial pattern, formation mechanism and organizational mode of communication of the Eurasian continental railway geo-system. The results show that 11 kinds of railway gauge structures exist in Eurasia, which respectively belong to three types of wide-gauge, standard-gauge, and narrow-gauge, but the mainstream gauge only includes 1520 mm, 1435 mm and 1067 mm. Considerable variation in the coverage length and space range of different gauges is apparent, which provides a physical and technological basis for railway system differentiation and network fragmentation, which leads to the formation of eight railway geo-systems. Due to different modes for railway transport management in different geographical locations, the geographical pattern and geographical relationship of four transport organizations are formed. What especially important is the emergence of "1435 gauge space" and "1520 gauge space", as well as the railway geo-space confrontation between them, on the Eurasian continent. Besides, we also find that the railway geo-system of Eurasia is mainly affected by the technology dissemination, path dependence, geopolitics, national defense and the colonial expansion of military latitude, and on this basis, five geo-modes of railway gauge propagation are formed. [ABSTRACT FROM AUTHOR]

In concert with developments in global trade and energy resource transportation, there has been a marked increase in reliance on overseas shipping. Unimpeded marine transportation has therefore become a key issue which influences national maritime interests including the security of trade and energy resources. A strategic shipping pivot thus performs a vital controlling function for global shipping networks. In this study strategic shipping pivots are defined and subdivided into sea hubs, channels and areas. We then develop a model to identify strategic shipping pivots on a global scale. The results show that, depending on differences in location, function, and type, the concept of strategic shipping pivot permits the identification of both spatial and structural differentiation with respect to strategic hubs, corridors, and seas. Now 44 strategic hubs have formed across the globe. These hubs have become the control centers of local shipping network organization. At the same time, seven strategic corridors containing most shipping routes and transportation capacity connect important sea areas, and permit a high-degree of control over the transport of strategic materials. The strategic seas, the Caribbean, the Mediterranean, Southeast Asia, and the Pacific provide vital import and export pathways, so that the formation of strategic shipping pivots is mainly influenced by factors such as physical geographical conditions, the spatial distribution of socio-economic activities, business organization, technical progress, geopolitical patterns and geopolitical disputes. Physical geographical conditions provide the potential foundations for strategic shipping pivots, while the spatial distribution of socio-economic activities and communications determine the strategic value of these points. Finally, business organization, technical progress, and geopolitical disputes all function to strengthen the strategic mechanisms and the mutagenicity of strategic shipping pivots. [ABSTRACT FROM AUTHOR]

Coal is a basic resource and its use guarantees the development of national economies and human society. Thus, coal transportation is an important part of China's overall transportation system. In this system, ports are the vital transit nodes. This study considered coastal ports in China and analysed the evolution of coal transportation from 1973 to 2013. We focused on the spatial pattern of coal loading and unloading, and summarized the main characteristics and development of the processes. Then, we examined the volumes of coal transported and regional changes in these amounts using mathematical models and indicators. Finally, we analysed the specialized function and spatial differentiation of the ports involved in coal transportation to reveal their spatial relationship and temporal evolution. We found that the spatial pattern of coal transportation changed from "south input and north output" to "all input and north output". However, the prominent ports used for coal unloading are still concentrated in areas south of the Yangtze River. Coal loading is concentrated on the west bank of Bohai Bay. In addition, some ports around Bohai Bay, such as Dandong, Dalian, Yantai, and Qingdao, changed from traditional coal loading ports to unloading ports. This study further developed the theory of transport geography, and improved our understanding of China's coal transportation system. [ABSTRACT FROM AUTHOR]

The 'High-Level Forum of the Development of China's Human Geography Under the Background of Change' was held in Beijing on January 22-23, 2016. More than 30 professors attended this forum. At this conference, they discussed the major progress made towards developing China's human geography, as well as the existing problems, limiting factors, opportunities, international collaborations, emerging directions, and prospects in the development of this discipline. In recent years human geography has boomed, generating many important opportunities for its development. Establishing an academic community for joint research on major research issues and collaborative innovation is a promising and important route to take. We should embrace both domestic and international characteristics, to promote China's human geography onto the world stage. Meanwhile, the cultivation of various scholarly talents is also of great value to enrich and advance the discipline. [ABSTRACT FROM AUTHOR]

As an important branch of human geography, transportation geography has experienced three periods of evolution: foundation, systematization, and rapid development of the discipline. It has gradually become a relatively mature discipline. During the period 1930-1980, the development of transportation geography consisted mainly of the publication of theoretical texts. During 1980-2000, it gradually became a systematic discipline. Since the start of the 21st century, transportation geography has focused mainly on exploring the impacts of transportation on socio-economic development. Currently, studies on transportation geography have led to significant developments in a number of areas, including transportation theory, facility distribution and planning, transportation flows and network analysis, evaluation of transport modes, transportation planning, and simulation and assessment of urban transportation. Such studies have also enriched human geography research, provided a wider geographical overview and elucidated the development mechanism of transportation, as well as helped to understand the impacts of transport development on socio-economic systems. Some findings obtained by geographers have been widely used in transportation geography and related fields, including the four basic laws of transportation generation, the hub-spoke mode of transport organization, the subordinating and guiding functions of transportation on socio-economic development, regional transport dominance measures, accessibility measures, and spatial organization of port systems. [ABSTRACT FROM AUTHOR]

Over the past two decades, numerous ports located in China have participated in port integration strategies, thus influencing the entire port system. The current research is initiated in order to examine the nature of port integration in China, including associated temporal pathways, spatial patterns and dynamics. Results indicate that port integration in China has been characterized by a significant increase at the turn of the 21st century, comprising thirteen distinguishable pathways typified by differing dynamics, particularly between the northern and southern ports. Pathways were found to include 44 seaports and river ports, chiefly concentrated in the Bohai Rim, Yangtze (Changjiang) River Delta, Beibu Gulf and the southeastern Fujian, thus representing significant spatial regions. Categorically larger seaports have become the primary beneficiaries of port integration. Integration cases were divided into four categories based upon quantified dynamic magnitude including the government-driven mode, market-driven mode, government/market-driven mode and strategic alliance, and into five further categories based upon spatial extent including port internal integration, jurisdictional port integration, port integration across neighbor region, regional port integration and hub-feeder port integration. Results suggest that several factors have effectively driven port integration in China, including legislative tools and spatial planning, optimization of shoreline resources and port functionality, and port competition with the same hinterland. [ABSTRACT FROM AUTHOR]

Before the emergence of modern modes of transport, the traditional road infrastructure was the major historical means of carrying out nationwide socio-economic exchange. However, the history of transport infrastructure has received little attention from researchers. Given this background, the work reported here examined the long-term development of transport networks in China. The national road network was selected for study and the 3500 years from 1600 BC to 1900 AD was chosen as the study period. Indicators were designed for the maturity level of road networks and an accessibility model was developed for the paths of the shortest distance. The evolution of the road network in China since the Shang Dynasty (1600 BC) was described and its major features were summarized to reveal long-term regularities. The maturity level of the road network and its accessibility was assessed and regions with good and poor networks were identified. The relationship between China's natural, social, and economic systems and the road network were discussed. Our analysis shows that the road network in China has a number of long-term regularities. The continuously expanding road network follows a path of inland expansion especially towards the border areas. However, its coverage and accessibility are characterized by a core-peripheral configuration, which has close relationships with, not only the natural conditions, but also national defense and warfare. The centralization of national power, national land governance, postal transport, the transport of specialized cargos, and international trade are also related to the development of the road network. This research draws attention to the evolving regularities of transport networks. [ABSTRACT FROM AUTHOR]

The aim of this paper is to study the spatialtemporal differentiation of industrial eco-efficiency in China. Using methods based on the data envelopment analysis (DEA) model and exploratory spatial data analysis (ESDA) and data from 1985, 1995, 2005, and 2008 of 30 provinces in China, the spatial-temporal pattern changes in industrial eco-efficiency are discussed. The results show that: first, the patterns of industrial eco-efficiency are dominated by clustering of relatively low efficiency provinces; second, spatial relationships between the industrial eco-efficiencies of different provinces changed slightly throughout the period and the provinces persistently exhibit spatial concentration of relatively low industrial eco-efficiency; finally, there is an obvious trend in the polarization of industrial eco-efficiency, i.e., the higher level spatial units are concentrated in eastern China, and the lower level spatial units are mainly in western and central China. [ABSTRACT FROM AUTHOR]

Scientific development is an invaluable asset to a country. Policies and development modes should be carried out based on scientific findings not only in industry, but also in transportation infrastructure construction. Building an integrated transportation system, which is in line with the national requirements of China and supports sustainable socio-economic development, is a key strategic issue related to building a moderately prosperous society and achieving realistic goals of a medium-level developed country. Based on a systematic review of the advances in China's transportation infrastructure over the last 60 years, this paper explores the main drivers of transportation development, including national policy, transportation structure, investment efficiency, and technological innovation. Analysis shows that China's comprehensive transportation infrastructure construction since 1949 can be divided into five stages initiated by these drivers, which correspond to four transition modes: policy transition, structural transition, efficiency transition, and technology transition. The transition path of China's transportation development shows that the dominant factors have changed, and the interval for each transition has shortened. With the implementation of the '12th Five-Year Plan', China's transportation infrastructure construction is showing some new characteristics and facing a new development transition. Finally, this paper analyzes the trends in transportation development in China and concludes that technological innovation will be the main driving force to increase the transportation supply and service area in the future. [ABSTRACT FROM AUTHOR]

The growth of peripheral ports to dominant hubs has been well documented in North America and Europe, and has led to the elaboration of several theoretical models. However, although changes in containerization growth have been taking place in the South and East Asia in recent years, particularly in China, only a few studies have focused on this region. The Pearl (Zhujiang) River Delta (PRD) has a typical port system with hub and peripheral ports, and provides an excellent case for studying the Peripheral Challenge. This paper introduces the theoretical evidence of the Hayuth model and analyzes the evolution of the container port system in the PRD with five phases: 1) phase I: preconditions for change and phase II: initial container port development in the 1970s and early 1980s; 2) phase III: diffusion, consolidation, and port concentration in the middle and late 1980s; 3) phase IV: the load center in the 1990s; and (4) phase V: the Peripheral Challenge since the late 1990s. The results illustrate that the Shenzhen port presents mounting challenges to the Hong Kong port, descending from a transshipment hub of China to a regional load center of Southeast China. Furthermore, this paper explores five points that have led to the evolution of the port system in the PRD: 1) competition in the regional port systems; 2) different interested parties; 3) shift of investment strategies of international terminal operators; 4) integration of shipping networks and reorganization of carriers; and 5) cost-based competition. [ABSTRACT FROM AUTHOR]

Transport infrastructure plays an important role in shaping the configuration of spatial socio-economic structures and influences regional accessibility. This paper defines transport dominance from three aspects: quality, quantity, and advantage, measured by density, proximity, and accessibility indices. County is the basic unit for analysis. The results reveal: (1) Transport dominance statistically follows a partial normal distribution. A very few counties, 1.4% of the total, have extremely high transport dominance which strongly supports the socio-economic development in these areas. In contrast, one eighth of all counties have poor transport dominance which impedes local socio-economic development to some extent. The remaining areas, about 70% of the counties, have median transport dominance. (2) Transport dominance is spatially unevenly distributed, with values decreasing gradually from the coastal area to the inland area. Areas in the first-highest level of transport dominance are mainly concentrated in the Yangtze River Delta, the Greater Beijing area, and the Pearl River Delta. Areas in the second-highest level are focused in Chengdu, Chongqing, and Wuhan metropolitan areas. Provincial capitals and a few other counties belong to the third-highest level. [ABSTRACT FROM AUTHOR]

With the popularization of computers, artificial intelligence technology has become more and more mature, among which speech recognition technology in artificial intelligence is favored by people. In the past few years, the acoustic model combined with the Gaussian mixture model and the hidden Markov model has always been in the leading position. In the field of speech recognition technology, because the development of speech data has gradually expanded, and the complexity of the data has also increased. The larger the data, the traditional data network model is slowly showing inadequacy. However, the deep neural network model is easy to deal with large and complex data modeling. This article combines the advantages of basic learning theory and speech recognition technology, and launches in-depth research on embedding learning theoretical knowledge into the field of speech recognition. Nowadays, large-scale text information databases relying on computers are becoming more and more important in linguistic research, and a large-scale corpus that fully reflects language facts and contains rich language information has been constructed. The establishment of the text information database system is long, from word segmentation, part-of-speech tagging to syntactic tagging to semantic tagging. Therefore, the characteristic of information system processing is that the systematic description depends on the application environment of understanding vocabulary and reasoning. According to different scenarios, the realization methods of semantic description roles are also different, and the description of semantic roles in correct scenarios is clearer, more detailed and systematic. Therefore, this article is of great significance for solving the semantic problem of using Chinese frame network for Chinese information processing in the context of speech recognition. [ABSTRACT FROM AUTHOR]