浅议水雷寿命期内环境条件和边界参数

针对水雷全寿命剖面中环境变量的边界参数进行了深入探讨,为确定水雷全寿命剖面的环境条件边界参数提供了新的研究方向。以确定舰船部署水雷的环境边界参数为案例进行了深入探讨,特别关注了这类水雷在其整个生命周期中的环境条件边界参数,并据此构建了一套用于确定其环境条件边界参数的策略,为水雷产品在其生命周期中环境条件边界参数的确定提供了新的研究方向,这将有助于推动水雷环境工程分析技术的进步,能够更准确地评估水雷的性能和可靠性,从而为水雷的设计和应用提供科学依据。为了进一步提高水雷装备的可靠性和水雷环境工程分析技术,需要对现有的研究思路进行深化和完善,并将其应用于水雷环境条件边界参数的确定过程中,从而为装备建设提供更为坚实的技术支持和依据。

Develop Naval Cadets'Global Competence through"Belt and Road"Ini⁃tiative Cooperation and Exchanges

Since the 18th National Congress of Chinese Communist Party,the great call for building a maritime power and a power⁃ful military force has set higher standards for Navy’s development and the application of strategies.As a maritime military force,the navy bears considerable responsibilities of safeguarding territorial sovereignty,maritime rights and interests with security and development as core mission,and defending the role and image of China as a major county in the world.This paper analyzes and studies naval officers’global competence development from three aspects,and discusses the significance and recommendations of strengthening the development of naval cadets’global competence in cooperation and exchange guided by“Belt and Road”Initia⁃tive(BRI).

Medical rescue of naval combat: challenge and future

There has been no large-scale naval combat in the last 30 years. With the rapid development of battleships, weapons manufacturing and electronic technology, naval combat will present some new characteristics. Additionally, naval combat is facing unprecedented challenges. In this paper, we discuss the topic of medical rescue at sea: what challenges we face and what we could do. The contents discussed in this paper contain battlefield self-aid buddy care, clinical skills, organized health services, medical training and future medical research programs. We also discuss the characteristics of modern naval combat, medical rescue challenges, medical treatment highlights and future developments of medical rescue at sea.

Radar Cross Section Prediction and Reduction for Naval Ships

Radar cross section（RCS） is the measurement of the reflective strength of a target.Reducing the RCS of a naval ship enables its late detection,which is useful for capitalizing on elements of surprise and initiative.Thus,the RCS of a naval ship has become a very important design factor for achieving surprise,initiative,and survivability.Consequently,accurate RCS determination and RCS reduction are of extreme importance for a naval ship.The purpose of this paper is to provide an understanding of the theoretical background and engineering approach to deal with RCS prediction and reduction for naval ships.The importance of RCS,radar fundamentals,RCS basics,RCS prediction methods,and RCS reduction methods for naval ships is also discussed.

Hoist technology of a new agile naval gun shell-feeding system

Shell-feeding velocity is an important factor affecting naval gun shooting capacity. An agile shell-feeding system was designed to ensure quick implementation of the shell-feeding task. Based on composition of the agile shell-feeding system, hoist technology was studied. Working principles were discussed and the hydraulic pressure system of the hoist was constructed. The hydraulic pressure cylinder and the accumulator were analyzed and calculated. Finally, PRO/E and ADAMS were used to simulate the hoist and its hydraulic system. It was found that this type of virtual prototype provides a good method to actualize a physical prototype.

Modeling of Naval Vessels Combat System based on Complex Network

Naval Vessels Combat System is a kind of complex system.The modeling of combat system has become hot issues in the past years.This paper proposed a new method to establish models of combat system based on the theory of Complex Network.The method of modeling considered the operational entities as nodes.It considered flow of information,substance and energy as edges in a network.The research also carries on a simulation to prove the applicability.Ultimately,the paper concluded that this method is applicable and accurate.

The United States Naval Observatory

Sailors and pilots need three things to find their way: they musthave the correct time; they must know the exact position of the starsoverhead; and they must have a book that tells what the future positionof the stars will be. The information makes possible the science ofnavigation. And it is the job of the United States Naval Observatory tocollect and publish this information. The Headquarters of the

Design and analysis of a scheme for the naval gun test shell entering the bore

The test shell without projectile belt is widely used in the teaching,inspection and maintenance of modern automatic naval guns.In order to ensure the normal work of each mechanism,it is very important to design the buffer and limit of the test shell during the process of entering the bore.Taking a certain type of medium caliber naval gun as the research object,the design of colloidal fluid damper and cartridge lock was proposed to ensure the reliability of entering the bore and closing the breechblock.By combining the simulation methods of computational fluid dynamics(CFD)and multibody system dynamic(MBD),it was analyzed whether the structural design can meet the engineering requirements.The research results show that the colloidal fluid damper can dissipate a large amount of kinetic energy of the shell,and the cartridge lock can limit the rebound movement.The combination of the two ensures the smooth process of closing the breechblock.The research provides a design method for the process of the test shell entering the bore,and provides theoretical support for the feasibility of the method.

Numerical research on dynamic response of naval equipments subjected to impact loads

When subjected to underwater explosion,the anti-shock performance of naval equipment is a key factor affecting the fighting capacity and safety of a war ship. For large-scale naval equipment,it is costly to do the shock test for its huge mass and large size. Consequently,the numerical research was carried our to study the shock resistance of the equipment. Taking turbo-charger set for example,its anti-shock performance was studied using software ABAQUS based on the time-domain shock analysis method presented in BV043 /85. According to the analysis results,shock response of typical regions is obtained,some regularity curves are concluded by analyzing the Mises stress of the typical regions,and the weak regions are found out. The study can provide some references on design of turbo-charger set.

Simulation of Propagation Loss Models and Antenna Designs for Naval Troposcatter and Tropospheric Duct Communications

Tropospheric Scattering(Troposcatter) and Tropospheric Ducting are two different mechanisms due to in-homogenoueties in the lower part of the Earths atmosphere.Their common influence in propagation of microwaves is studied here in order to achieve a feasible naval communication system.Although not new,Troposcatter together with Tropospheric Ducting communications are regaining popularity in current military and civil applications such as isolated islands and oil extraction facilities in the open sea.The innovation proposed here is the application of such systems in naval communications where at least one of the stations is mobile.Several propagation together with fading models are simulated using appropriate programs and scientific simulation packets in order to predict maximum range of such communication systems in each dominant mode of operation.Then appropriate antenna design proposals are given to overcome the high propagation loss and minimize possible interferences.

Analysis of Naval Ship Evacuation Using Stochastic Simulation Models and Experimental Data Sets

The study of emergency evacuation in public spaces,buildings and large ships may present parallel characteristic in terms of complexity of the layout but there are also significant differences that can hinder passengers to reach muster stations or the lifeboats.There are many hazards on a ship that can cause an emergency evacuation,the most severe result in loss of lives.Providing safe and effective evacuation of passengers from ships in an emergency situation becomes critical.Recently,computer simulation has become an indispensable technology in various fields,among them,the evacuation models that recently evolved incorporating human behavioral factors.In this work,an analysis of evacuation in a Landing Helicopter Dock(LHD)ship was conducted.Escape routes specified by the ship’s procedures were introduced in the model and the six emergency scenarios of the Naval Ship Code were simulated.The crew and embarked troops were introduced with their different evacuation behavior,in addition,walking speeds were extracted from data set collected in experiments conducted at other warships.From the results of the simulations,the longest time was chosen and confidence intervals constructed to determine the total evacuation time.Finally,results show that evacuation time meets regulatory requirements and the usefulness and low cost of the evacuation simulation for testing and refining possible ships’layouts and emergency scenarios.

Research on localization algorithm of naval vessel for submarine based on bearing-range measurements

Combined with naval vessel practical antisubmarine equipment of towed linear array sonar,a mathematical model of naval vessel localization for submarine based on bearing measurement was built,and localization algorithm was given to solve submarine movement parameters.Localizaiton errors were analyzed.Based on localization model and algorithm,simulations were done to study the effect of factors such as initial distance between submarine and the naval vessel,submarine initial bearing angle measured by the naval vessel and submarine course on localization performance,and then simulation results were given and analyzed.The results have practical value to instruct real antisubmarine.Simulation results show that different target movement situations have great influence on sonar detection and localization performance,so the reasonable choice of sonar position and detection bearing according to the target movement situation can improve sonar detection and localization performance to some degree.

Role of Naval Architects in Ship Recycling

The paper identifies twelve elements of ship recycling recycling system. The source and items of knowledgebase for ship and highlights their respective roles and duties in a proposed ship recycling have been brought out. A new philosophy focusing clean and safe ship recycling namely design for ship recycling has been introduced based on principles such as ecofriendliness, engineering efficiency, energy conservation and ergonomics. The role of naval architects in ship recycling industry has been described based on the above factors. The paper brings out the role of naval architects in ship recycling the way it has been practiced worldwide and proposed by regulatory bodies. The authors have brought out the new concept of design for ship recycling and various aspects of it. The role of naval architects in the practice of this new design philosophy which is ready to be embraced by the maritime industry has been reiterated.

Design Scheme of New Type Shell Raising and Feeding System of Medium-large Caliber Naval Gun

The medium -large caliber naval gun is still playing an important role in modern war. The development of highly automatic Shell Raising and Feeding System (SRFS) in the world has been briefly outlined. Several typical SRFS of medium-large caliber naval guns have been analyzed. A re-design of the system is introduced, in which systematic design method has been used to demonstrate its feasibility. The design goal of the system is to realize rapid shell feeding, with application to many types of shells, quick change of shell types , accurate and reliable feeding operation, simple mechanical structure and easy realization of shell withdrawing.

Review on the Progress and Issues in Liquid Tank Sloshing of Ships

With the development of large liquid cargo ships,liquid tank sloshing has gradually become a hot research topic in the area of shipping and ocean Engineering.Liquid tank sloshing,characterized by strong nonlinearity and randomness,not only affects the stability of the ship but also generates a huge impact force on the wall of the tank.To further investigate liquid tank sloshing,a comprehensive review is given on the research process of the most focused subjects of liquid sloshing.Summarizing the existing research will help to identify issues in the current field and provide useful references.The methods for investigating sloshing,the research progress and the situations worldwide are discussed.The advantages and defects of experiments and numerical simulations are also explored.The problems which need to be explored in the future are subsequently proposed.

Case Series of 11 Patients Operated with Axial-LIF Technique in a Single Center in Mexico

Introduction: Since the earliest description of spinal fusion in 1911 and later by Dr. Fred H. Albee, it has become one of the most commonly performed procedures by orthopedist and neurosurgeons. The spinal fusion is now used to treat a variety of indications, such as traumatic injuries, deformities, primary and secondary tumors, infections and degenerative conditions of the spine. The risk of iatrogenic injury during traditional anterior, posterior, and transforaminal open fusion surgery is significant. The axial lumbar interbody fusion (Axia-LIF) is a minimal invasive technique which uses the retroperitoneumpresacral anatomical corridor to fuse the lumbar vertebral bodies L4-L5-S1 avoiding manipulation of the annular ligament, paravertebral muscles and facet joints. Methods: In this retrospective series, we report all the cases made in the Centro Medico Naval in México City in two years. A total of eleven patients with degenerative disc disease and spondylolisthesis underwent Axia-LIF one or two level systems with a 36 months clinical and radiographic follow-up. The outcomes included Oswestry Disability Index (ODI) score and leg/back pain severity. Radiographic outcome was evaluated with dynamics and orthogonal x-ray, as well as lumbosacral tomography scan to evaluate fusion status. Results: Nine patients underwent Axia-LIF one level system (L5-S1) and the rest two levels system (L4-S1). Ten patients were fixated with transpedicular percutaneous screws and one with facets joints screws. No intraoperative complications were reported. The mean back pain severity improved 57% in 12 months, and the mean leg pain severity improved 50% in the same time (P < 0.001). Mean ODI scores improved 58%, from 60% ± 16% at baseline to 25% ± 8% at twelve months (P < 0.001). At one year, a patient developed pseudoarthrosis that required posterolateral arthrodesis with transpedicular percutaneous screws. At 36 months monitoring, 100% patients presented a total interbody fusion in the tomography scans. At final follow-up, mean ODI score improved 73% (16% ± 5%;P < 0.001). Conclusion: The Axial Lumbar Interbody Fusion has demonstrated to be a safe treatment for the degenerative disc disease L5-S1 and L4-S1. The patients who underwent one or two level Axia-LIF showed an improvement in ODI and back/leg pain severity scores, with no intraoperative complications. The use of this technique and its indications are still in controversy;nevertheless, its use has increased as for pathologies such as spondylitis, scoliosis, patients with residual pain with previous surgeries. We recommended complementary pedicular fixation to avoid complications and improved interbody fusion.

马尔可夫链用于扫雷作战期望损失评估探讨

扫雷舰艇进行非接触平行搜扫时可以采取边缘渐进和中心航道两种清扫模式。为了比较这2种清扫模式下扫雷艇期望损失的大小,应用马尔可夫过程理论对这两种清扫模式的扫雷舰艇期望损失进行了一定条件下的分析。根据马尔可夫过程理论的分析,可以比较出2种清扫模式下扫雷艇期望损失在雷区边界未知或无限时是相同的,而对边界已知的有限雷区,边缘渐进模式的期望损失比中心航道模式小。这个结论可以用于扫雷作战中清扫模式的优选。

基于双Markov链的效果评估模型研究

当前基于单Markov链的扫雷作战效果评估模型是一个理论意义大于实际的模型,如应用于实际的多Markov扫雷过程则还有相当的距离.文中从正交分解的角度,指出Markov评估模型只能得到定性评估结果.进一步提出了用于定性评估的双Markov模型,计算结果表明:在引入先验知识后,能在小样本数据条件下取得较为准确的评估结果.

一种基于遗传算法的“正向”扫雷效果评估解法

基于Markov链的扫雷作战效果评估是一个小样本数据条件下的约束方程组求解问题,常规搜索加逐步回归算法的"反向"解法在处理约束条件时会遇到较大的困难。利用遗传算法强大的搜索能力,设计了一种"正向"解法,取得了较好的效果。

基于多Markov链的效果评估模型研究

基于单Markov链的扫雷作战效果评估模型是一个理论意义大于实际的模型,离实际的多Markov扫雷过程还有相当的距离.文中从正交分解的角度,指出Markov评估模型只能进行定性评估.提出了用于定性评估的多Markov模型,从"分解基"相关性的角度提出了多链模型结构选择的方式,实现了基于遗传算法的模型解法,计算结果表明:在引入先验知识后,能在小样本数据条件下取得较为准确的评估结果.