GraphSTGAN:Situation understanding network of slow-fast high maneuvering targets for maritime monitor services of IoT data

With the rapid growth of the maritime Internet of Things(IoT)devices for Maritime Monitor Services(MMS),maritime traffic controllers could not handle a massive amount of data in time.For unmanned MMS,one of the key technologies is situation understanding.However,the presence of slow-fast high maneuvering targets and track breakages due to radar blind zones make modeling the dynamics of marine multi-agents difficult,and pose significant challenges to maritime situation understanding.In order to comprehend the situation accurately and thus offer unmanned MMS,it is crucial to model the complex dynamics of multi-agents using IoT big data.Nevertheless,previous methods typically rely on complex assumptions,are plagued by unstructured data,and disregard the interactions between multiple agents and the spatial-temporal correlations.A deep learning model,Graph Spatial-Temporal Generative Adversarial Network(GraphSTGAN),is proposed in this paper,which uses graph neural network to model unstructured data and uses STGAN to learn the spatial-temporal dependencies and interactions.Extensive experiments show the effectiveness and robustness of the proposed method.

China's Maritime Governance:Practical Evolution and Theoretical Construction

Increasingly engaged in maritime governance,China has developed its distinct vision and gradually established a complete theoretical system surrounding it.In terms of discourse,China has proposed a collection of concepts and ideas including a maritime community with a shared future,the 2lst Century Maritime Silk Road,Blue Partnerships,and marine ecological civilization.In terms of connotations,China champions such values as lasting peace,common prosperity,openness and inclusiveness,and cleanness and beautifulness.Exteriorly and interiorly,we can observe the unique character of China's vision concerning maritime governance,which will continue to upgrade and bear fruit in future practices,boosting the development of Chinese maritime governance theories,multilateral maritime cooperation,and ocean-related international legislation.Guided by its vision,China is expected to contribute more to global maritime security and marine ecological civilization.

Three-dimensional thermohaline structure estimation derived from HY-2 satellite data over the Maritime Silk Road and its applications

Estimated ocean subsurface fields derived from satellite observations provide potential data sources for operational marine environmental monitoring and prediction systems.This study employs a statistic regression reconstruction method,in combination with domestic autonomous sea surface height and sea surface temperature observations from the Haiyang-2(HY-2)satellite fusion data,to establish an operational quasi-realtime three-dimensional(3D)temperature and salinity products over the Maritime Silk Road.These products feature a daily temporal resolution and a spatial resolution of 0.25°×0.25°and exhibit stability and continuity.We have demonstrated the accuracy of the reconstructed thermohaline fields in capturing the 3D thermohaline variations through comprehensive statistical evaluations,after comparing them against Argo observations and ocean analysis data from 2022.The results illustrate that the reconstructed fields effectively represent seasonal variations in oceanic subsurface structures,along with structural changes resulting from mesoscale processes,and the upper ocean’s responses to tropical cyclones.Furthermore,the incorporation of HY-2 satellite observations notably enhances the accuracy of temperature and salinity reconstructions in the Northwest Pacific Ocean and marginally improves salinity reconstruction accuracy in the North Indian Ocean when compared to the World Ocean Atlas 2018 monthly climatology thermohaline fields.As a result,the reconstructed product holds promise for providing quasi-real-time 3D temperature and salinity field information to facilitate fast decisionmaking during emergencies,and also offers foundational thermohaline fields for operational ocean reanalysis and forecasting systems.These contributions enhance the safety and stability of ocean subsurface activities and navigation.

Beamforming Design for IRS-and-UAV-Aided Two-Way Amplify-and-Forward Relay Networks in Maritime IoT

In this paper,an intelligent reflecting surface(IRS)-and-unmanned aerial vehicle(UAV)-assisted two-way amplify-and-forward(AF)relay network in maritime Internet of Things(IoT)is proposed,where ship1(S1)and ship2(S2)can be viewed as data collecting centers.To enhance the message exchange rate between S1 and S2,a problem of maximizing minimum rate is cast,where the variables,namely AF relay beamforming matrix and IRS phase shifts of two time slots,need to be optimized.To achieve a maximum rate,a low-complexity alternately iterative(AI)scheme based on zero forcing and successive convex approximation(LC-ZF-SCA)algorithm is presented.To obtain a significant rate enhancement,a high-performance AI method based on one step,semidefinite programming and penalty SCA(ONSSDP-PSCA)is proposed.Simulation results show that by the proposed LC-ZF-SCA and ONS-SDP-PSCA methods,the rate of the IRS-and-UAV-assisted AF relay network surpass those of with random phase and only AF relay networks.Moreover,ONS-SDP-PSCA perform better than LC-ZF-SCA in aspect of rate.

TRADE DEPENDENCIES AND TRANSACTION COSTS: THE OC-CUPATION OF DECELEA HIGHLIGHTS BOTH THE BENEFITS AND THE DRAWBACKS OF A MARITIME ECONOMY

Thucydides asserts that the occupation of Decelea by the Spartans in 413 BC made the grain supply for Athens costly by forcing the transport from land onto the sea.This calls into question the well-established consensus that sea transport was far cheaper than land transport.This paper contends that the cost of protecting supply lines-specifically the expenses associated with the warships which escorted the supply ships-rendered the grain transported on the new route exceptionally costly.In this paper,the benefits and drawbacks of a maritime economy,including transaction costs,trade dependencies,and the capabilities of warships and supply ships are discussed.

Study on the Protection of Sites of“Maritime Silk Road”in Haikou from the Perspective of World Cultural Heritage

The sites of Maritime Silk Road in Haikou City are composed of sites of navigation and trade,religious temples and stone monuments,urban construction and coastal defense scattered on the south bank of the Qiongzhou Strait.They played a key role in the formation and shaping of the settlements in Haikou City,recorded the process of intercommunication and integration between Chinese civilization and other regional cultures,and witnessed the germination,flourishing and inheritance of Haikou’s unique marine culture.The mixture of points,lines and planes blends with the urban area and coastline of Haikou City in spatial distribution.In this paper,from the perspective of world cultural heritage,some suggestions for the protection planning of sites of Maritime Silk Road in Haikou City were proposed based on the analysis of historical and geographical background,comparison of domestic and foreign similar sites,and evaluation of cultural heritage value.

Structural Design Study of Air-Dropped Unmanned Maritime Mobile Search and Rescue Platforms

In order to improve the efficiency and safety of search and rescue(SAR)at sea,this paper proposes a kind of emergency rapid rescue unmanned craft(air-dropped unmanned maritime motorized search and rescue platform)that can be delivered by a large transport aircraft.This paper studies the structural design scheme of the platform,and the main scale of the platform,the choice of power system and the impact resistance performance are considered in the design process to ensure its rapid response and effective rescue capability under complex sea conditions.Simulation results show that the platform can withstand the impact of air injection into the water and the shipboard equipment can operate normally under the impact load,thus verifying the feasibility and safety of the design.This study serves to improve the maritime search and rescue system and enhance the oceanic emergency response capability.

Application of Traditional Chinese Culture in Cross-Cultural English Education:A Case Study of the Maritime Silk Road in Guangdong Province

The phenomenon of aphasia in Chinese culture is serious.The existing English teaching materials emphasize too much Western culture education and lack traditional Chinese cultural elements.Therefore,this paper takes the Guangdong Maritime Silk Road as an example to study the specific application of traditional Chinese culture in cross-cultural English education.This paper first summarizes the significance of cross-cultural integration into college English education and then points out the serious phenomenon of Chinese cultural aphasia.Next,the paper focuses on English education,using English textbooks as a starting point to explore and integrate strategies related to excellent traditional Chinese culture from the Guangdong Maritime Silk Road.By integrating traditional Chinese culture into business English classes(with the Guangdong Maritime Silk Road as an example),the study explores the influence of such cultural integration on students’cross-cultural communication skills,cultural identity,and learning effects.The results showed that the P value of the experimental group and the control group was<0.05,that is,cultural integration had a positive effect on improving the effect of cross-cultural English education.The overall scores and cultural confidence of the experimental group are higher than those of the control group,which proves that cross-cultural teaching has a positive effect on the improvement of students’scores.

Impacts of monsoon break events in the western North Pacific on the cross-equatorial flows over the Maritime Continent

本文利用ERA5逐日再分析资料,探讨了1979-2020年间西北太平洋季风中断事件对海洋性大陆越赤道气流的影响.合成结果表明,西北太平洋季风中断事件会造成高,低空越赤道气流减弱,即高层南风异常,低层北风异常,与此相关的环流异常表现为西北太平洋高层气旋,低层反气旋的斜压结构。特别的是,西北太平洋季风中断对高空越赤道气流的影响更为显著,92%的季风中断事件都导致高空越赤道气流减弱,而只有70%的事件造成低空越赤道气流减弱,这是由于低空越赤道气流同时还受到赤道中东太平洋海温异常的调控.

Environmental Information-Aided Electromagnetic Propagation Testbed for Maritime Communication

Maritime channel modeling can be affected by some key time-varying environmental factors.The ducting effect is one of the thorniest factors since it causes anomalous propagation enhancement and severe co-channel interference.Moreover,the atmospheric attenuation is much more severe in the ocean environment,resulting in shorter coverage distance and more link outage.In this paper,we propose an environmental information-aided electromagnetic propagation testbed.It is based on complex refractivity estimation and improved parabolic equation propagation model,taking into account both ducting effect and atmospheric attenuation.A large-scale temporal and spatial propagation measurement was conducted with meteorological acquisition.We consider practical path loss and ducting conditions to verify the testbed feasibility in these long-distance radio links.The simulation results are in good agreement with the measured data,which further reveal the basic temporal and spatial distribution of ducting effect at 3.5 GHz band.

Towards reinforcement learning in UAV relay for anti-jamming maritime communications

Maritime communications with sea surface reflections and sea wave occlusions are susceptible to jamming attacks due to the wide geographical area and intensive wireless communication services.Unmanned Aerial Vehicles(UAVs)help relay messages to improve communication performance,but the relay policy that depends on the rapidly changing maritime environments is difficult to optimize.In this paper,a reinforcement learning-based UAV relay policy for maritime communications is proposed to resist jamming attacks.Based on previous transmission performance,the relay location,the received power of the transmitted signal and the received jamming power,this scheme optimizes the UAV trajectory and relay power to save the energy consumption and decrease the Bit-Error-Rate(BER)of the maritime signals.A deep reinforcement learning-based scheme is also proposed,which designs a deep neural network with dueling architecture to further improve the communication performance and computational complexity.The performance bounds regarding the signal to interference plus noise ratio,energy consumption and the communication utility are provided based on the Nash equilibrium of the game against jamming,and the computational complexity of the proposed schemes is analyzed.Simulation results show that the proposed schemes improve the energy efficiency and decrease the BER compared with the benchmark.

Decarbonizing in Maritime Transportation: Challenges and Opportunities

As global warming caused by greenhouse gases grows (GHGs) into a global environmental threat, carbon dioxide emissions are drawing increasing attention in these years. Among all emission sources, transportation is a major contributor to climate change because of its high dependence on fossil fuels. The International Maritime Organization (IMO) has therefore been promoting the reduction of fuel usage and carbon emissions for container ships by such measures as improving shipping route selection, shipping speed optimization, and constructing clean energy propulsion systems. In this paper, a review of the impact of carbon dioxide emissions on climate change is presented;the current situations of carbon dioxide emissions, decarbonizing methods, IMO regulations, and possible future directions of decarbonizing in the maritime transportation industry are also discussed. Based on the result, it is found that in the case that non intelligent ships still occupy the vast majority of operating ships, the use of new energy as the main propulsion fuel has the defects of high renewal cost and long effective period. It is more likely to achieve energy conservation and emission reduction in the shipping industry in a short period of time by using intelligent means and artificial intelligence to assist ship operation. .

Revisiting The Maritime Silk Road In Penglai

Penglai,Yantai City,is located at the northern tip of the Shandong Peninsula,330 kilometers north of Langya Port in Qingdao.In 133 BC,Emperor Wudi(156-87 BC)of the Han Dynasty visited the region during an inspection tour of the eastern part of his empire.He gazed out into the sea in the direction of the mythical Mount Penglai,home of immortals.

The Struggle for Atlantic Maritime Security and Safety:Lessons From Africa’s Maritime Security Governance

The enormous economic potentials of the blue/ocean economy have made the maritime domain increasingly susceptible to transnational organized crime and a theater for great power competition,particularly in the Atlantic maritime domain.The maritime security threats are more prevalent in the Atlantic African maritime domain than in other continents.These threats are becoming increasingly detrimental to the African security,safety,and human security,particularly in the coastal countries of the Atlantic Africa.Despite its increasing susceptibility to maritime security threats including great powers competition and the presence of non-Atlantic great powers more than in other maritime domains in Africa,the coastal countries of the Atlantic Sub-Saharan Africa(SSA)have managed to forge strategic inter-regional maritime security partnership that has relatively improved maritime security and safety in the region.There is a growing interest in forging inter-continental partnership of the coastal Atlantic states to collectively respond and address the shared maritime security threats in the entire Atlantic maritime domain.Yet,the way such a complex multilateral partnership would be structured and operationalized has not been worked out.This article assesses the economic potentials,susceptibility to maritime security threats,and level of response to maritime security threats by the coastal countries of the Atlantic SSA with the aim of identifying some lessons that could be relevant for forging the Atlantic inter-continental maritime security partnership.Some of these lessons include genuine partnership that is based on sovereign equality and inter-dependence,a code of conduct,cooperation,and coordination framework,and shared common value system of democratic governance.

The Role of Chittagong Port Authority to Develop Other National Ports in Bangladesh to Provide Maritime Logistics Support in South Asia

Chittagong Port is the principal seaport in Bangladesh that has contributed to the national economy with the opportunity to be a world-class regional port in South Asia.Cooperation among the three national ports Chittagong,Mongla and Payra is essential to do maritime logistics business in the region after serving the nation proudly.Here,Chittagong Port Authority(CPA)has the opportunity to help others in the process of port development for increasing efficiency and productivity by providing financial and technical assistance because of its financial and technical capabilities as a pioneer seaport in the port world.This paper examines the role of CPA to bolster and develop the underutilized Mongla Port and newly established Payra Port,where qualitative research methodology is applied to explore the ways,by which CPA can assist,link and integrate with others effectively,especially in developing the port infrastructure and inland transport networks.In addition,the research found the prospectus of Mongla and Payra to supply port services to the neighbors India,Nepal,and Bhutan as well as serve the South-West part of China with the aim of increasing regional connectivity and promoting international trade in those basically landlocked areas and countries of Asia.

Development of Maritime Mix-Type Structures

Mixed-type structures combining the advantages of pile constructions(low material consumption and possibility to erect on weak soils)and gravity walls(high bearing capacity and stability,good reliability and durability)are considered and improved.The sphere of application,main peculiarities,and practical technological aspects of these structures’implementation are analyzed.

全球海洋中心城市的湾区实践——以粤港澳大湾区为例

粤港澳大湾区是加快实施海洋强国战略的重要支点,全球海洋中心城市建设则是进一步推动粤港澳大湾区建设的关键抓手。全球海洋中心城市作为当前海洋城市建设与评价最具影响力的目标对象,需要分别在全球与湾区视角下考察粤港澳大湾区的优势与挑战。本研究通过解读全球海洋中心城市的概念与内涵,剖析了典型全球海洋中心城市的显著特征,以及与国际一流湾区发展的关系。研究发现,粤港澳大湾区在全球海洋中心城市数量和航运物流方面具有优势,但是在海事技术、竞争力与吸引力等方面面临巨大的竞争挑战。粤港澳大湾区推进全球海洋中心城市建设,着重要加快提升国际航运能力、加强海洋科技创新、参与全球海洋治理、强化海洋战略规划等。

海洋观视角下海洋城市发展的历史回顾与国际比较

海洋观是人类在生产生活中对海洋的总体认识,随着海洋科技与国际关系发展而持续演变,为厘清不同历史时期海洋城市的差异特征提供了重要的研究视角。基于文献综述与类型归纳相结合的方法,重点关注海洋观变迁下全球典型海洋城市发展的空间演变与发展趋势。研究发现,在殖民、后殖民、全球化海洋观演变过程中,海洋城市职能从早期的贸易型逐渐转变为产业型与服务型,其战略属性主要体现为在全球、区域与国家多维空间尺度下的连通性、撬动性与支撑性。应充分发挥海洋城市战略属性,面向世界级海洋城市群开展现代海洋城市建设。

海洋强国视域下航海类专业实践课程混合式教学改革研究

在海洋强国战略背景下,分析了当前航海类专业实践教学资源不足、教学模式单调枯燥、教学项目与产业行业需求脱节、海洋强国等课程思政元素融入不够等现状困境,提出优化航海类专业实践教学特色定位,对航海类专业产教融合实践教学资源进行了融汇与创新重构,优化设计实践课程混合式教学模式,开展了航海类专业产教融合混合式实践教学改革实践,并基于PDCA的循环改进原则建立航海类专业实践教学实施、监督及反馈的质量管理模式。基于产教融合的航海类专业实践课程混式教学改革模式,可为进一步落实国家职业教育政策,深化产教融合,推进高水平实训基地建设提供借鉴。

俄乌冲突背景下全球海运网络的结构特征分析

在俄乌冲突背景下,基于AIS轨迹数据和复杂网络分析法,分析全球海运网络的整体和局部结构特征,探究海上通道的枢纽作用以及区域海运网络的抗毁性。结果表明:俄乌冲突加剧了全球海运网络的动态演变,干散货海运网络的稳定性强于集装箱海运网络和液化天然气(LNG)海运网络。全球枢纽港口呈现明显的地域性分布和结构性差异特征,中国仅少数核心港口在全球海运网络中具有优势地位。在俄乌冲突紧张局势下,俄罗斯港口在LNG海运网络中保持了一定的竞争力。欧洲地区的直布罗陀海峡和英吉利海峡在三类海运网络中起到关键的中介枢纽作用,同时海运网络对于亚洲地区的琉球群岛、新加坡海峡、朝鲜海峡等也具有较高依赖性。中国与“一带一路”沿线国家之间的集装箱海运网络和干散货海运网络、与金砖国家之间的干散货海运网络均表现出较高的发展水平和较强的抗毁性。