Two-Staged Method for Ice Channel Identification Based on Image Segmentation and Corner Point Regression

Identification of the ice channel is the basic technology for developing intelligent ships in ice-covered waters,which is important to ensure the safety and economy of navigation.In the Arctic,merchant ships with low ice class often navigate in channels opened up by icebreakers.Navigation in the ice channel often depends on good maneuverability skills and abundant experience from the captain to a large extent.The ship may get stuck if steered into ice fields off the channel.Under this circumstance,it is very important to study how to identify the boundary lines of ice channels with a reliable method.In this paper,a two-staged ice channel identification method is developed based on image segmentation and corner point regression.The first stage employs the image segmentation method to extract channel regions.In the second stage,an intelligent corner regression network is proposed to extract the channel boundary lines from the channel region.A non-intelligent angle-based filtering and clustering method is proposed and compared with corner point regression network.The training and evaluation of the segmentation method and corner regression network are carried out on the synthetic and real ice channel dataset.The evaluation results show that the accuracy of the method using the corner point regression network in the second stage is achieved as high as 73.33%on the synthetic ice channel dataset and 70.66%on the real ice channel dataset,and the processing speed can reach up to 14.58frames per second.

An angular blinking jamming method based on electronically controlled corner reflectors

Passive jamming is believed to have very good potential in countermeasure community.In this paper,a passive angular blinking jamming method based on electronically controlled corner reflectors is proposed.The amplitude of the incident wave can be modulated by switching the corner reflector between the penetration state and the reflection state,and the ensemble of multiple corner reflectors with towing rope can result in complex angle decoying effects.Dependency of the decoying effect on corner reflectors’radar cross section and positions are analyzed and simulated.Results show that the angle measured by a monopulse radar can be significantly interfered by this method while the automatic tracking is employed.

Topological edge and corner states of valley photonic crystals with zipper-like boundary conditions

We present a stable valley photonic crystal(VPC)unit cell with C_(3v)symmetric quasi-ring-shaped dielectric columns and realize its topological phase transition by breaking mirror symmetry.Based on this unit cell structure,topological edge states(TESs)and topological corner states(TCSs)are realized.We obtain a new type of wave transmission mode based on photonic crystal zipper-like boundaries and apply it to a beam splitter assembled from rectangular photonic crystals(PCs).The constructed beam splitter structure is compact and possesses frequency separation functions.In addition,we construct a box-shaped triangular PC structures with zipper-like boundaries and discover phenomena of TCSs in the corners,comparing its corner states with those formed by other boundaries.Based on this,we explore the regularities of the electric field patterns of TESs and TCSs,explain the connection between the characteristic frequencies and locality of TCSs,which helps better control photons and ensures low power consumption of the system.

Topological laser on square lattice with gain–loss-induced higher-order corner modes

We investigate the higher-order topological laser in the two-dimensional(2D) coupled-cavity array. By adding staggered on-site gain and loss to the 2D Hermitian array with a trivial phase, the system will emerge degenerate topological corner modes, which are protected by bulk band gap. For such a non-Hermitian model, by adjusting the parameters of the system and introducing the pumping into the cavity at the corner, a single-mode lasing with topological protection emerges.Furthermore, single-mode lasing exists over a wide range of pumping strengths. No matter where the cavity is initially stimulated, after enough time evolution, all the cavities belonging to the topological corner mode can emit a stable laser.

The cornerstone of fiber-optic distributed vibration/acoustic sensing: Ф-OTDR

Fiber-optic distributed vibration/acoustic sensing(DVS/DAS) technology achieves breakthrough performance and explores broad cornerstone industrial applications.

Three Dimensional Modeling of Pulverized Coal Combustion in a 600 MW Corner Fired Boiler

The three-dimensional code ESTET developed at the LNH has been used to predict the reactive flow in a 600 MW coal fired boiler. Assuming a no-slip condition between the gas and the coal, the equations for a gas-particle mixture can be written. The pulverized coal particle size distribution is represented by a discrete number of particle size groups determined by the measured fineness distribution. The combustion models taking into account the pyrolysis of the particle and the heterogeneous combustion of char have been validated using intensive measurements performed on the 600 MW utility boiler. Heat fluxes were measured along the walls of the furnace and satisfactory agreement between computation and measurements has been achieved in terms of maximum flux location and heat flux intensity. Local measurements of velocities using LDV probe, gas temperature and gas species concentrations were performed in the vicinity of one burner and compared with the computed variables. Again we have observed a good agreement between the computations and the measurements in terms of jet penetration, temperature distribution, oxygen concentration and ash content.

Tailoring topological corner states in photonic crystals by near-and far-field coupling effects

We explore the behaviors of optically coupled topological corner states in supercell arrays composed of photonic crystal rods,where each supercell is a second-order topological insulator.Our findings indicate that the coupled corner states possess nondegenerate eigenfrequencies at theΓpoint,with coupled dipole corner states excited resonantly by incident plane waves and displaying a polarization-independent characteristic.The resonance properties of coupled dipole corner states can be effectively modulated via evanescently near-field coupling,while multipole decomposition shows that they are primarily dominated by electric quadrupole moment and magnetic dipole moment.Furthermore,we demonstrate that these coupled corner states can form surface lattice resonances driven by diffractively far-field coupling,leading to a dramatic increase in the quality factor.This work introduces more optical approaches to tailoring photonic topological states,and holds potential applications in mid-infrared topological micro-nano devices.

Closed corner divertor with B×▽B away from the divertor:a promising divertor scenario for tokamak power exhaust

A major challenge facing the steady-state operation of tokamak fusion reactors is to develop a viable divertor solution with order-of-magnitude increase in power handling capability as compared with present experience.A recently developed divertor concept for this end has been tested recently on EAST tokamak through combining the effects of a closed divertor corner and E×B drifts.The E×B drifts in the divertor move particles towards the outer divertor corner area in the scrape-off layer for B×▽B directed away from the divertor,which can significantly enhance the particle concentration there,facilitating divertor detachment.In recent EAST experiments,the effects have been demonstrated where the lowest electron temperature at the divertor plate is obtained with strike point located close to the corner in the horizontal target and with B×▽B away from the divertor.These experimental results are in reasonable agreement with SOLPS-ITER simulations including drift effects,suggesting that the new divertor concept potentially provides a promising divertor solution for long-pulse operations of future tokamak fusion reactors with much higher power fluxes.

DELIVERING THE GOODS China’s courier and logistics sector has thrived in its huge market and become a cornerstone of global supply chains

As China moves to fundamentally improve its virus response by downgrading COVID-19 management to Class B from top-level Class A,one sector that has remained crucial yet bruised by the three-year battle against the disease finally released a sigh of relief.

Passengers gathering-scattering analysis at the corners of subway stations

During both daily operation and emergency evacuation,the corners of walking facilities in subway stations play an important role in efficient circulation.However,the effectiveness of the corner is difficult to assess.In this paper,a method of passenger gathering and scattering analysis based on queueing models was proposed to investigate the corner performance in subway stations.Firstly,we constructed a set of state spaces of passenger flow according to passenger density and proposed the state transition model of passenger flow.Moreover,the model of passenger flow blocking and unblocking probability were also presented.Then,to illustrate the validity of the method and model,several passenger gathering-scattering scenarios and were simulated to verify the influence of passenger distribution and facility width on passenger walking,and the blocking probability,throughput,and expected time were also analyzed under various widths of the target corridor and arrival rates.Results showed that the proposed model can reproduce the trend of walking parameters changing and the self-organizing phenomenon of'faster is lower'.With the increase of arrival rates of passengers,walking speeds of passengers decrease and the expected walking time is prolonged,and the blocking probability sharply increased when the arrival rate exceeded 7 peds/s.In addition,with change of width of the target facility,efficiency of capacity of walking circulation facility fluctuated.With the width of the target corridor enlarged by 10%,the steady state of passenger flow was less crowded.Therefore,corridor width is critical to the circulation efficiency of passengers in subway stations.The conclusions will help to develop reasonable passenger flow control plans to ease the jam and keep passengers walking safely.

Intel Knights Corner的结点级内存访问优化

传统编程优化(Traditional Programming Optimization,TPO)在Intel Knights Corner(KNC)上收效甚微,因此提出内存访问优化(Memory Access Optimization,MAO)。将MAO应用到已经过TPO的程序Diffusion 3D上,发现其性能仍然提高了39.1%。主要有2个贡献:1)提出MAO,认为TPO+MAO有助于在KNC上获取最优化性能;2)发现对于stencil代码,基于intrinsic的MAO比基于编译器的MAO更高效。这些发现对于在KNC上优化大规模应用有启发意义。

The Decarbonization of Construction—How Can Alkali-Activated Materials Contribute?

1.Introduction and context Enormous emphasis is currently being paid to the decarbonization of the global built environment as a leading priority for the engineering community and related industrial sectors[1].One of the main contributors to the overall emissions footprint of the built environment-and thus a cornerstone of efforts to achieve decarbonization-is the emissions profile of construction materials during their production and utilization.The cement and concrete sector is the largest-volume contributor to the emissions incurred in meeting the world’s construction material needs and is therefore targeted in the discussion of the deep,rapid decarbonization that must be achieved in order to minimize irreversible damage to the Earth and its ecosystems.

Theoretical optimization of micropillar arrays for structurally stable bioinspired dry adhesives

Inspired by the excellent adhesion performances of setae structure from organisms,micro/nano-pillar array has become one of the paradigms for adhesive surfaces.The micropillar arrays are composed of the resin pillars for adhesion and the substrate with different elastic modulus for supporting.The stress singularity at the bi-material corner between the pillars and the substrate can induce the failure of the micropillar-substrate corner and further hinder the fabrication and application of micropillar arrays,yet the design for the stability of the micropillar array lacks systematical and quantitative guides.In this work,we develop a semi-analytical method to provide the full expressions for the stress distribution within the bi-material corner combining analytical derivations and numerical calculations.The predictions for the stress within the singularity field can be obtained based on the full expressions of the stress.The good agreement between the predictions and the FEM results demonstrates the high reliability of our method.By adopting the strain energy density factor approach,the stability of the pillar-substrate corner is assessed by predicting the failure at the corner.For the elastic mismatch between the pillar and substrate given in this paper,the stability can be improved by increasing the ratio of the shear modulus of the substrate to that of the micropillar.Our study provides accurate predictions for the stress distribution at the bi-material corner and can guide the optimization of material combinations of the pillars and the substrate for more stable bioinspired dry adhesives.

A modified stochastic finite-fault method for estimating strong ground motion:Validation and application

We developed a modified stochastic finite-fault method for estimating strong ground motions.An adjustment to the dynamic corner frequency was introduced,which accounted for the effect of the location of the subfault relative to the hypocenter and rupture propagation direction,to account for the influence of the rupture propagation direction on the subfault dynamic corner frequency.By comparing the peak ground acceleration(PGA),pseudo-absolute response spectra acceleration(PSA,damping ratio of 5%),and duration,the results of the modified and existing methods were compared,demonstrating that our proposed adjustment to the dynamic corner frequency can accurately reflect the rupture directivity effect.We applied our modified method to simulate near-field strong motions within 150 km of the 2008 MW7.9 Wenchuan earthquake rupture.Our modified method performed well over a broad period range,particularly at 0.04-4 s.The total deviations of the stochastic finite-fault method(EXSIM)and the modified EXSIM were 0.1676 and 0.1494,respectively.The modified method can effectively account for the influence of the rupture propagation direction and provide more realistic ground motion estimations for earthquake disaster mitigation.

Thailand and China Cooperate to Improve the Stability of Regional Supply Chain

"Trade and investment cooperation has always been one of the cornerstones of the bilateral relations between Thailand and China.In the past two years,China has become Thailand's largest source of foreign investment,and next year will witness the 50th anniversary of the establishment of diplomatic relations between the two countries.Both sides will also strive to build a more stable.

China-ROK: Promoting Pragmatic Cooperation Between Enterprises

On May 27,China-ROK Economic Exchange Meeting,organized by the CCPIT,was held in Seoul.More than 200 business entrepreneurs from China and South Korea attended the meeting to celebrate this great event for the business communit y of the two countries.CCPIT Chairman Ren Hongbin said in his speech that the trade and economic cooperation between China and South Korea has achieved remarkable results and has become the“cornerstone”of bilateral relations.China has been South Korea’s largest trading partner for 20 consecutive years,and South Korea is China’s third-largest trading partner.Since 2021,against the backdrop of sluggish global trade,the trade volume between the two countries has remained at a high level of over USD 310 billion for three consecutive years.As of March 2024,South Korea has set up a total of 75,000 enterprises in China,with actual investment exceeding USD 100 billion.These fully reflect the profound foundation and strong resilience of pragmatic cooperation between the two countries.

Sowing Friendship,Harvesting Progress

Agriculture has been a cornerstone of cooperation between China and Ethiopia,with numerous aid projects enhancing this partnership.Among these,the China-Ethiopia Agricultural Technical Vocational Education and Training(ATVET)Project stands out for its long history.Initiated in 2001,this project has organised 23 batches comprising a total of 524 experts to support Ethiopia’s agricultural education and training.These Chinese experts have trained approximately 100,000 local students,bringing advanced knowledge and methods into Ethiopian villages.

神东矿区新型无机膏体防灭火充填材料制备及性能研究

为解决神东矿区回采工作面两端巷道附近采空区遗煤多、易自燃、难封堵的难题,提出一种新型无机膏体防灭火充填材料,高效快速充填回采工作面上下隅角。采用神东矿区附近易获取的粉煤灰、炉渣和P·O·42.5硅酸盐水泥作为膏体主要原料,通过室内实验对材料的物理性质和化学成分进行研究,并通过膏体流动性、凝固特性、膨胀特性、充填体强度测试实验,确定出膏体最佳材料配比及外加剂参量。实验结果表明:炉渣基膏体具有良好自膨胀性,7 d自膨胀率可达5.6%,且初凝时间短,满足工程所需强度要求;膏体防灭火材料的最佳配比方案为水泥∶粉煤灰∶炉渣=1∶4∶20,质量分数为78%,J85型速凝剂的添加量为6%。工程应用表明:采用优选的膏体充填材料进行隅角充填封堵后,采空区漏风量整体下降至充填前的30%,CO体积分数从120×10^(-6)降至46.5×10^(-6),O2体积分数在深入采空区走向长度约80 m处降至10%以下,采空区内“散热带+氧化带”的走向长度由未充填前的160 m缩短为80 m。

An Analysis of College Students’ Learning Motivationin English Corner——Take Xi’An Innovation College of Yan’an University as An Example

There are many factors affecting English learning,and motivation of learner is crucial to it.The purpose of this paper is to explore some measures to stimulate English learning motivation and help college students to learn English better.Based on the investigation of college students’participation in English corner,this paper focuses on the main factors affecting the English learning motivation of Chinese college students.The paper investigates the situation of college students taking part in English corner,and analyzes what is the English learning motivation of college students,based on a questionnaire survey of 180 random students in Xi’an Innovation College of Yan’an University,as well as uses other relevant scholars’ideas for reference.And then it puts forward some efficient measures to promote college students’English learning.

机器学习驱动的多Corner STA加速方法

静态时序分析在芯片的物理设计中扮演着重要的作用,其贯穿设计流程始终,耗时巨大,多数时间用于在不同工艺、电压、温度条件下的多Corner组合分析。论文研究多Corner在时序分析方面的相关性并利用机器学习的方法对其进行建模,以利用已知Corner时序结果预测未知Corner时序结果而不需额外的运行时间。实验结果表明,线性模型可以有效地进行预测,在利用7个已知时序结果的Corner预测余下7个未知时序结果的Corner时,能达到2.07ps(1.76%)的平均绝对误差。同时,基于模型的强稳健性,可以采用约束驱动的Corner选取策略,有效地减少多Corner角组合时序分析所需的时间,加速物理设计流程。