Comment on BFI

Almost everyone working in shiPPingcircle 15 familiarwith BFI(Baltiefreightindex),andeallitasaweatherglassreflecting the global dry bulk shiPPing market.Can BFIrefleets fully and truthfully the global dry bulk market?The comPonent routes of BFI(no more than 15脾ars old)10一10一10一10一10一10一75一10一7.5一75一书 USG/Contlnent Tansat{antie rOUnd USG/JaPan skaw/USG/A 3ia Paeifie NoPaC/Japan Transpae币e roundHamPton Roads/RotterdamE Asia/NoPaC/SkawPassoro T口ba旧O/ROtterdam T…     

Prediction analysis on propulsion shafting load based on grey system theory北大核心CSCD

[Objective]The propulsion shafting system is an important part of a ship, and the bearing load directly affects its operating state and service life. In this paper, bearing load under hull deformation is studied using grey system theory. [Method] First, according to the empirical formula of the relative displacement of each bearing caused by the deformation of the hull of a 57 000 DWT oil tanker, the relative displacement of each bearing is calculated and input into a finite element model, and the load value of each bearing is output. On this basis, grey relationship analysis of grey system theory is introduced to study the influence degree of stern bearing displacement on the load of each bearing, and the relative change of the load of each bearing caused by the displacement of the stern bearings is analyzed. A GM (1,1) prediction model is then established for the bearing load considering the bearing displacement conditions, and the hull deformation-fitting and prediction of each bearing load are made. [Results]The results show that grey relationship analysis can effectively reflect the influence of hull deformation on bearing load. The GM (1,1) prediction model has high accuracy and prediction errors less than 6.0%, and the model test indexes can represent the accuracy of the prediction. [Conclusion]Grey system theory is effective and practical in research on propulsion shaft load. It can accurately predict bearing load under bearing displacement, giving it certain reference value for research on bearing load under actual sailing conditions. © The Author(s) 2022.     

Sea Surface Effects on Sound Scattering in the Persian Gulf Region Based on Empirical Relations

In this paper, sound scattering from the sea surface in the Persian Gulf region is investigated. Chapman-Harris and Ogden-Erskine empirical relations coupled with perturbation theory are implemented. Based on the Ogden and Erskine’s experiments, sound scattering from the sea surface has three different regimes in which two mechanisms of surface roughness and subsurface bubble clouds are involved. Ogden-Erskine’s scattering relation which consists of perturbation theory and Chapman-Harris’ s scattering terms are verified by the experimental data of Critical Sea Tests 7. Subsequently, wind speed in the Persian Gulf is provided based on three data bases of Arzanah station, ERA40, and PERGOS. Accordingly, surface scattering strength in the Persian Gulf region is calculated at different grazing angles, frequencies and provided wind speeds. Based on the resulted values of scattering strength, scattered intensity from the sea surface is also studied. These studies indicate that both scattering strength and scattered intensity generally increase as grazing angle, frequency and wind speed increase.     

China''''s logistics industry on fast track

Although many Chinese businesses still deliver their products to retailers themselves, China's professional logistics industry has been growing at a rocketing annual rate.     

China's logistics industry on fast track

A lthough many Chi nese businesses stilldeliver their products to retail-ers themselves, China's profes-sional logistics industry hasbeen growing at a rocketing an-nual rate. The three countries, China,Japan and South Korea, boast-ing big trade volumes, showmuch potential for co-operation. TNT will grow as a com-pany with China, and to helpChina grow with activities in-strumental to the further eco-nomic development of China. Standardization will helpimprove the efficiency of logis-tics an…     

Research on the influence of action between fin and anti-rolling tank on the integrated stabilization effect

Through analyzing the roll model of the integrated system of fin and anti-rolling tank, this paper uses binomial equation to simplify the module and check how the approximate parameters simulate the original function. Based on the simplified module, the influence of fin and anti-rolling tank on the coefficient items of the roll module is discussed, and the influencing factors between fin and anti-rolling tank are analysed. And through simulation, the influence of action between fin and anti-rolling tank on the static characteristics, and the integrated stabilization effect, are analyzed.     

Prediction of Hull Deflection on Damaged Warship

The appropriate prediction of the hull deflection of a severely damaged warship is an important area in the research of the warship survivability. In this paper, the asymmetrical beam bending theory is applied to set up the damaged model, a comparison of the longitudinal strength, the deflections of damaged hull subjected to both hagging and sagging moments, and shear forces is carried out. The external loads are also calculated according to different damaged positions. Finally, some results and conclusions are obtained.     

Discussion on the parameters of design waves

In order to respond the discredit on the design wave standard and to recommend new consideration on design wave parameters,based on the long-term distribution of statistic characteristics of waves and the short-term probability properties of sea state defined by giving the return period,the calculation of the return period,the height,the period,and the oceanic wave parameters of the design wave and the forecasting methods are discussed in this paper.To provide references for the operation reliability of floating structures in the extreme sea state,the method of determining the design wave parameters is resurveyed.A proposal is recommended that the design wave,which can be either significant wave with 500-year of the return period,or the maximum wave with 1/N of exceeding probability,100-year of the return period,can be applied in the engineering design practice.     

Congratulations on COSCO achieving four awards on the Australia/ East Asia and North Asia liner services

Over 500 people of the shipping and transport fraternity gathered at Darling Harbor in Sydney on 17 October for the Australian Shipping and Transport Awards 2001 hosted by Lloyd's List DCN. Through shipping and transport industry voting, COSCO has overcome strong competition on the Australia/East Asia trade to become winner of Customer Service Award. Other awards include three Highly Commended Award for Customer Service on the Australia/North Asia trade, and Sailing Schedule Reliability on both Australia/East Asia and North Asia trades. This is the sixth time for COSCO to be rewarded by Australian shipping industry. The awards show that     

Impact of SARS on China''''s economy limited

China's economic upsurge cannot be reversed by the severe acute respiratory syndrome (SARS) now ravaging some parts of the country. China's economy will maintain its steady growth momentum despite the SARS' impact to some extent on investment, consumption and     

Experimental research on friction-reduction with super-hydrophobic surfaces

Many recent studies have confirmed the existence of liquid slip over particular types of solid surfaces, and these so-called super-hydrophobic surfaces have been shown to generate effective liquid slip because of the air trapped between the surface structures. In this paper, based on boundary layer theory, the microscopic structure of the super-hydrophobic surface is analyzed. The liquid slip effect on friction-reduction over super-hydrophobic surfaces under various flow conditions is investigated by experiments with a flume and water tunnel. The experimental results show that the greatest amount of drag-reduction that can be achieved is 8.76% at a low Re.     

Research on cylindrical shell vibration reduction systems

Longitudinal and horizontal vibration must both be reduced in an effective vibration isolation system. We present a cylindrical shell vibration isolator as a dynamic system composed of four springs and dampers. Vibration is directly produced by the motion of machinery, and more is subsequently generated by harmonic frequencies within their structure. To test the effectiveness of our isolator, we first determined equations for the transmission of vibration from the machine to its cylindrical shell. Damping effects produced by the vibration parameters of our system are then analyzed.     

海员英语趣谈 all hands on board

all hands on board 英语单词中常有一字多义,但拼法、读音完全相同,弄不好就出问题。比如: 一个略通英语的法籍海员,一天听到英籍船长命令“all hands on board”,只见各船员出室纷纷跑上甲板,他也赶快跑上甲板,忙将双手按在甲板上,船     

Competition model of cruise home ports based on the cruise supply chain – based on China cruise market

This paper addresses issues of cruise home port competition based on the cruise supply chain. A pricing model of the cruise market is developed considering the competitive cooperation behaviors of the participants in the cruise supply chain. Furthermore, a model of cruise home port competition is developed to investigate the impacts of subsidy participants in the cruise supply chain on cruise home ports. The results indicate that subsidy policies change the market equilibrium, promote the upstream and downstream integration of cruise supply chain, and enhance cruise home port competitiveness. Subsidies to cruise line increase the payoffs of cruise supply chain and ports’ profit. Subsidies to travel agency decrease passenger costs and improve all ports’ profits. For the long-term development of cruise home port, the consequents can be used as policy suggestions.     

Calculation of hydrodynamics for semi-submersibles based on NURBS

Accurate hydrodynamic calculations for semi-submersibles are critical to support modern rapid exploration and extraction of ocean resources. In order to speed hydrodynamic calculations, lines modeling structures were separated into structural parts and then fitted to Non-uniform Rational B-spline （NURBS）. In this way, the bow and stern section lines were generated. Modeling of the intersections of the parts was then done with the universal modeling tool MSC.Patran. Mesh was gererated on the model in order to obtain points of intersection on the joints, and then these points were fitted to NURBS. Next, the patch representation method was adopted to generate the meshes of wetted surfaces and interior free surfaces. Velocity potentials on the surfaces were calculated separately, on basis of which the irregular frequency effect was dealt with in the calculation of hydrodynamic coefficients. Finally, the motion response of the semi-submersible was calculated, and in order to improve calculations of vertical motion, a damping term was affixed in the vertical direction. The results show that the above methods can generate fine mesh accurately representing the wetted surface of a semi-submersible and thus improve the accuracy of hydrodynamic calculations.     

Underwater sonar image recognition based on gray-spatial histograms

A new gray-spatial histogram is proposed, which incorporates spatial information with gray compositions without sacrificing the robustness of traditional gray histograms. The purpose is to consider the representation role of gray compositions and spatial information simultaneously. Each entry in the gray-spatial histogram is the gray frequency and corresponding position information of images. In the experiments of sonar image recognition, the results show that the gray-spatial histogram is effective in practical use.     

Ocean planning focuses on scientific and technological innovations

With the advent of the 21st century,human beings have entered into a new era of large-scale ocean development. All competitions in terms of oceans are essentially competitions in science and technology,whatever the purpose is,either political or economic or military. Developing oceanic science and technology,especially high technology of oceans,has become an essential part of the world's new technologi-cal revolution. In the 11th Five-Year Plan period,China will take scientific develop-ment as the key instrument to develop our oceanic undertakings and use the inno-vative ability as the strategic base of science and technology development. In this context,innovation and re-innovation will become the central links in adjusting the oceanic industry structure and transforming the growth mode of oceanic economy.     

Research on catastrophe control in 1-D system

A new method of catastrophe control is described in one dimension nonlinear system. Catastrophe control based on catastrophe theory is a brand new area for control theory. A certain catastrophe is created at a desired location by appropriate control, which has preferred properties. Washout filter is presented and applied to preserve the original equilibrium of a system.Washout filter aided dynamic feedback controller is developed for the creation of eatastrophe, and an example is given to illustrate the process. Catastrophe control may provide a new way of designing warning signals of impending collapse or catastrophe for monitoring and control purposes.