Research on Prevention of Ship Collisions with Oil Rigs

The consequences of ship collisions with an oil rig, offshore installation or platform can be far more expensive in relation to safety, environment and costs of damage. The damage due to a single incident of an Oil Rig Collision can be catastrophic due to the number of people on board and the added risk of explosion. However, the existing rules and regulations of collisions prevention are insufficient. The purpose of this article is to critically evaluate the risk of ships collisions with offshore platforms and installations and therefore propose an international regulation for the preventions of this type of collisions.

Selecting Optimal Drill Rigs by Grey Relational Analysis Method

Based upon the main properties of the relational analysis in grey system theory, a new method to select optimal drill rigs is proposed in this paper. Under the unified technique economic index, with the practical data of four kinds of drill rigs in the mining district, east of Sichuan, China, an optimal reference number series was constructed. Through calculating the relational grade between the technique economic indices of various drill rigs and the reference number series and making a relational sequence in accordance with priority, the results achieved are in conformity with that of reference by Fuzzy Set Theory, and grey situation decision making and yet this method is simple, easy and intuitive in analysis etc..

Generating animatable 3D cartoon faces from single portraits

Background With the development of virtual reality(VR)technology,there is a growing need for customized 3D avatars.However,traditional methods for 3D avatar modeling are either time-consuming or fail to retain the similarity to the person being modeled.This study presents a novel framework for generating animatable 3D cartoon faces from a single portrait image.Methods First,we transferred an input real-world portrait to a stylized cartoon image using StyleGAN.We then proposed a two-stage reconstruction method to recover a 3D cartoon face with detailed texture.Our two-stage strategy initially performs coarse estimation based on template models and subsequently refines the model by nonrigid deformation under landmark supervision.Finally,we proposed a semantic-preserving face-rigging method based on manually created templates and deformation transfer.Conclusions Compared with prior arts,the qualitative and quantitative results show that our method achieves better accuracy,aesthetics,and similarity criteria.Furthermore,we demonstrated the capability of the proposed 3D model for real-time facial animation.

Research on the strain gauge mounting scheme of track wheel force measurement system based on high-speed wheel/rail relationship test rig

Purpose-This paper aims to analyze the stress and strain distribution on the track wheel web surface and study the optimal strain gauge location for force measurement system of the track wheel.Design/methodology/approach-Finite element method was employed to analyze the stress and strain distribution on the track wheel web surface under varying wheel-rail forces.Locations with minimal coupling interference between vertical and lateral forces were identified as suitable for strain gauge installation.Findings-The results show that due to the track wheel web’s unique curved shape and wheel-rail force loading mechanism,both tensile and compressive states exit on the surface of the web.When vertical force is applied,Mises stress and strain are relatively high near the inner radius of 710 mm and the outer radius of 1110mmof the web.Under lateral force,high Mises stress and strain are observed near the radius of 670mmon the inner and outer sides of the web.As the wheel-rail force application point shifts laterally toward the outer side,the Mises stress and strain near the inner radius of 710 mm of the web gradually decrease under vertical force while gradually increasing near the outer radius of 1110 mm of the web.Under lateral force,the Mises stress and strain on the surface of the web remain relatively unchanged regardless of the wheel-rail force application point.Based on the analysis of stress and strain on the surface of the web under different wheel-rail forces,the inner radius of 870 mm is recommended as the optimal mounting location of strain gauges for measuring vertical force,while the inner radius of 1143 mm is suitable for measuring lateral force.Originality/value-The research findings provide valuable insights for determining optimal strain gauge locations and designing an effective track wheel force measurement system.

Analysis of wheel-rail adhesion redundancy considering the thirdbody medium on the rail surface

Purpose–In response to the problem of insufficient traction/braking adhesion force caused by the existence of the third-body medium on the rail surface,this study aims to analyze the utilization of wheel-rail adhesion coefficient under different medium conditions and propose relevant measures for reasonable and optimized utilization of adhesion to ensure the traction/braking performance and operation safety of trains.Design/methodology/approach–Based on the PLS-160 wheel-rail adhesion simulation test rig,the study investigates the variation patterns of maximum utilized adhesion characteristics on the rail surface under different conditions of small creepage and large slip.Through statistical analysis of multiple sets of experimental data,the statistical distribution patterns of maximum utilized adhesion on the rail surface are obtained,and a method for analyzing wheel-rail adhesion redundancy based on normal distribution is proposed.The study analyzes the utilization of traction/braking adhesion,as well as adhesion redundancy,for different medium under small creepage and large slip conditions.Based on these findings,relevant measures for the reasonable and optimized utilization of adhesion are derived.Findings–When the third-body medium exists on the rail surface,the train should adopt the low-level service braking to avoid the braking skidding by extending the braking distance.Compared with the current adhesion control strategy of small creepage,adopting appropriate strategies to control the train’s adhesion coefficient near the second peak point of the adhesion coefficient-slip ratio curve in large slip can effectively improve the traction/braking adhesion redundancy and the upper limit of adhesion utilization,thereby ensuring the traction/braking performance and operation safety of the train.Originality/value–Most existing studies focus on the wheel-rail adhesion coefficient values and variation patterns under different medium conditions,without considering whether the rail surface with different medium can provide sufficient traction/braking utilized adhesion coefficient for the train.Therefore,there is a risk of traction overspeeding/braking skidding.This study analyzes whether the rail surface with different medium can provide sufficient traction/braking utilized adhesion coefficient for the train and whether there is redundancy.Based on these findings,relevant measures for the reasonable and optimized utilization of adhesion are derived to further ensure operation safety of the train.

Experimental rigs for testing components of advanced industrial applications

This paper presents experimental rigs of the Research Centre for the Mechanics of Turbomachinery of the Department of Civil and Industrial Engineering of the University of Pisa. Most of them were designed and constructed to allow investigations of real machine components and to furnish more realistic results than basic tribological test rigs. Tilting pad journal bearings, as well as gears and complete gearboxes for advanced industrial applications, can be tested using the rigs described in the paper. A novel test rig with a power rating of approximately 1 MW allows investigations of the static and dynamic characteristics of high-performance tilting pad journal bearings for turbomachinery. A twin disc machine and closed loop gear test rig are used to investigate the different kinds of wear mechanisms occurring in gears. Functional and durability tests on planetary gearboxes for new turbo-fan engines could be performed using another novel large test rig. A circulating power configuration was adopted for most of the rigs so that only the power needed to cover the friction losses has to be supplied, while the circulating power can be more than 20 times higher. All the test rigs include very complex load applications and lubrication plants, as well as dedicated control and data acquisition systems. The rigs and related plants were designed and constructed through strong and fruitful collaborations between the university and some large and small–medium companies. Despite some limitations in the publication of the results as a result of the industrial sensitivity of the data, the synergy among these different actors was stimulating and fundamental for the realization of new advanced industrial applications.

DESIGN METHOD OF LEG STRUCTURE OF JACK-UP RIGS

The structural failures of jack-up rigs were mostly found in leg structures,due to cracks in way of connections between tubular members of leg structures.Although,stress calculations of leg structures can be made by using“finite element techniques”,it takes a lot of time to complete the calculations for the full cases of all working conditions because of many tubular members.Therefore,a simple method for the stress calculations for design purposes is strongly desired.This paper desribes a simple stress calculaiton method of leg structures and shows a satisfactory results as compared with the results obtained by a detailed calculation method.

放免指导手术系统(RIGS)可以改进原发性结直肠癌病人的传统治疗决策

原发性结直肠癌病例的传统治疗决策是根据肿瘤的范围及其扩散情况而作出的。近期应用的放免方法可以检出隐性微小病灶,帮助及时处理以提高疗放,RIGS由此可以根据所得信息及时修正癌肿的分期和治疗方案。在1990年6月至1991年6月期间,作者对Ohio州大学医院37例原发性结直肠癌均用RIGS指导治疗。先注射用1～2mCi碘125

Online asymmetry estimation for whole angle mode coriolis vibratory gyroscopes by high frequency injection

The whole angle mode gyroscope(WAMG)is considered to be the next generation architecture,but it is suffered from the asymmetry errors to conduct real products.This paper proposes a novel high frequency injection based approach for the error parameters online identification for the WAMG.The significance is that it can separate physical and error fingerprints to enable online calibration.The nonlinear WAMG dynamics are discretized to meet the requirement of numerical precision and computation efficiency.The optimized estimation methods are then constructed and compared to track asymmetry error parameters continuously.In the validation part,its results firstly prove that the proposed scheme can accurately identify constant asymmetry parameters with an overall tracking error of less than 1 ppm and the extreme numerical convergence can reach 10^(-12)ppm.Under the dynamic asymmetry variation condition,the root mean square errors(RMSE)indicate that the tracking accuracy can reach the level of10^(-3),which shows the robustness of the proposed scheme.In summary,the proposed method can effectively estimate the WAMG asymmetry errors online with satisfied performance and practical values.

Experimental research on the contact force of the bi-directional pig in oil and gas pipeline

The migration process of the pig in oil and gas pipeline is a complex dynamic problem.During the pigging operation,the variation of friction force caused by the nonlinear contact between the sealing disc and the pipe wall is the key factor affecting the dynamic characteristics of the pig motion.At present,the existed pigging models for predicting pigging behavior regard friction as an invariant constant.Experimental research indicates that the friction force of the pig varies with the contact force and the lubrication conditions.Therefore,the assumption that the friction force is constant cannot reflect the friction dynamic characteristics of the pig during pigging,and will also affect the accuracy of the pigging model.Exploring the variation of friction force of pig under different conditions is the basis of establishing the transient dynamic model of a pig.As a result,in this paper,a method of direct measurement of contact force between the pig and the pipeline is presented,the contact force,the friction force,as well as the friction coefficient of the pig are obtained from the experiment.Research results in this paper can help to establish a more accurate dynamic model of pig.

Inequalities for Scalar Curvature and Shape Operator of an R-Lightlike Submanifold in Semi-Riemannian Manifold

We establish the links between the lightlike geometry and basics invariants of the associated semi-Riemannian geometry on r-lightlike submanifold and semi-Riemannian constructed from a semi-Riemannian ambient. Then we establish some basic inequalities, involving the scalar curvature and shape operator on r-lightlike coisotropic submanifold in semi-Riemannian manifold. Equality cases are also discussed.

手持式肿瘤探测仪的研制及其应用

介绍手持式肿瘤γ探测仪（GDP），它遵循减少放射源至探头间的距离，增加空间分辨率，提高探测灵敏度和特异性的原理，利用GDP进行了体外探测和荷瘤动物体内探测应用，初步实验结果表明：该肿瘤探测仪用于肿瘤放射免疫导向手术是可行的。

Development of a Test Rig for Axial Strains Measurement in Automobile Wheel

In automobile wheel application, a test rig is vital and used to simulate conditions of the wheel in service in order to affirm the safety and reliability of the wheel. The present work designed a test rig for measuring axial strains in automobile wheel. The wheel used was a five-arm wheel (6JX14H2;ET 42) and Tyre (175 × 65 R 14). Experimental (EXP) test was carried out, with a radial load of 4750 N and inflation pressure of 0.3 MPa, to measure the axil strains which were converted to maximum principal strain values and, compared with data from Finite Element Analysis (FEA) using Creo-Element/Pro 5.0 at wheel’s contact angles of 90 degree (FEA 90 deg), 40 degree (FEA 40 deg) and 30.25 degree (FEA 30.25 deg), respectively. Results show that at the wheel’s point of contact with the ground, maximum principal strain values were highest at the inboard bead seat with a value of about 5.69 × 10-4 mm/mm, followed by the values at the well of about 5.66 × 10-4 mm/mm. The value at the outboard bead seat was least at about 2.22 × 10-4 mm/mm, which was due to the presence of spikes at this location that tends to resist imposed radial loads. However, the highest mean maximum principal strain values at the locations of inboard, well and outboard, were about 2.11 × 10-4 mm/mm, 3.78 × 10-4 mm/mm and .99 × 10-4 mm/mm, respectively. With the highest single value of about 5.69 × 10-4 mm/mm, the inboard bead seat was the most strained location of the wheel. Overall results showed that all values of maximum principal strains were below the threshold value of about 1 × 10-2 mm/mm. The values obtained for EXP and FEA could be said to be in close agreement when compared with the threshold value. With this in mind, the rig is recommended for use in related experimental procedures.

Finite Element Analysis of Jumbo Rig Assembly for Tunneling

This paper describes the force acting the assembly of the jumbo rig for tunneling.The finite element analysis is used to calculate this machine structure on its different working states.

航空飞行试验遥测标准概况

以遥测在航空飞行试验领域中的应用为背景,介绍了IRIG 106遥测标准2009年最新版各章节的内容要点和近几年来的发展变化,简述了最新发布的iNET遥测网络标准(航空推荐版V0.5)的进展、组成和要点,分析、对比了两个标准的应用背景、技术特点和面临的问题,展望了遥测标准的发展应用前景。

基于改进RIG算法的动态诊断策略生成

针对TEAMS生成的静态诊断策略无法满足现场诊断的需求,在研究rollout信息启发式(RIG)算法的基础上,提出了一种基于改进RIG算法的动态诊断策略生成方法。首先通过改进原有的RIG算法使之符合动态诊断的需要;然后根据现场诊断过程中出现的各种具体情况,获取局部D矩阵;在此基础上利用改进的RIG算法选择出下一步最佳的测试,最终实现了故障诊断策略的动态生成。仿真实例表明,若直接采用基于RIG算法的静态诊断策略,需要4种类型的测试;若采用基于改进RIG算法的动态诊断策略生成方法,只需选择一步测试即能诊断出系统故障。该方法能够实现维修人员的交互式诊断,有效地提高了故障诊断策略的实用性。

病毒诱导I型干扰素产生的机制

病毒的病原体相关分子模式被细胞的相关受体识别后,分别经过Toll样受体途径和核酸结合蛋白途径进行信号转导,启动β-干扰素的转录和合成。从感染细胞分泌的β-干扰素与细胞膜上I型干扰素共有的受体结合后,经Jak/STAT信号途径刺激细胞产生一系列具有抗病毒效应的的干扰素刺激因子。干扰素调节因子7作为一种干扰素刺激因子在启动随后的α-干扰素转录中起着重要作用。α、β-干扰素的产生进一步放大了产生干扰素刺激基因的信号,形成一个正反馈回路,加强了免疫应答的强度和延长免疫应答的时间。

模式识别受体介导的自噬在抗病原微生物感染中的研究进展

自噬作为机体自我保护的生理学行为,在抗病原微生物感染中发挥重要的免疫防御作用。模式识别受体通过诱导自噬的发生,加强对病原微生物的识别和清除能力。同时,自噬也可影响模式识别受体信号通路,负性调控炎症反应。除了TLRs(TOLL-like receptors)外,随着SLRs(sequestasome-like receptors)、NLRs(NOD-like receptors)、RLRs(RIG-like receptors)等新型或重要模式识别受体介导的自噬在机体抗病原微生物感染的作用相继被报导,人们对模式识别受体介导的自噬在抗病原微生物感染中作用的认识越来越深入和丰富。了解此方面的研究进展,对揭示病原微生物的致病机理、发展新的有效的抗感染治疗手段具有重要的理论指导意义。