舰艇作战系统雷达统一对准模型及其误差分析

针对舰艇作战系统对准工程的需要,根据坐标变换原理推导了一种统一的舰载雷达探测角度和探测距离的对准计算模型。分析了对准过程中舰艇姿态变化以及仪器测量误差等动态不确定因素对作战系统对准精度的影响,并基于误差理论推导了雷达探测角度和探测距离对准理论真值的最大绝对误差计算公式。根据上述模型计算舰载雷达对准的理论真值及其最大绝对误差,可以为舰艇作战系统对准精度分析提供辅助依据。Matlab数值仿真结果验证了本文方法的有效性。

Nikon光刻机对准系统概述及模型分析

对准系统是光刻机中最精密复杂的部分,掌握对准原理是设计和使用光刻机的关键之一。阐述Nikon步进投影光刻机(Stepper)的对准机制,详细介绍目前应用于Nikon步进光刻机硅片对准的三种对准方式:LSA、FIA、LIA,比较它们的优缺点。并结合数学模型对影响Nikon对准模型信号强度进行分析,为提高对准精度提供了依据,对实际应用有一定的指导作用。

掩模硅片自动对准误差校正算法

为了改善对准精度,对100nm级线宽尺寸建立了掩模硅片自动对准数学模型,应用于同轴离轴混合对准系统的硅片模型、掩模模型以及工件台模型中。掩模硅片自动对准算法决定机器坐标系、掩模坐标系、硅片坐标系相互的位置关系,可很好地校正由掩模硅片引起的平移、线变、旋转、正交性的偏差。

100nm线宽的掩模硅片自动对准算法

对100nm线宽尺寸建立了掩模硅片自动对准数学模型,应用于同轴加离轴对准系统的硅片模型、掩模模型以及工件台模型中,该对准算法模型有一定可行性,能很好地满足100nm线宽对准精度的要求。

惯导系统传递对准技术研究现状与展望

对惯性导航系统传递对准技术进行了综合评述,回顾了近年来国内外传递对准技术最新的研究进展,并对传递对准技术的未来研究方向进行了展望。首先介绍了传递对准模型和估计方法,并按照基于滤波方法和基于优化方法对现有方法进行了分类;随后讨论了传递对准中的可观测性和可观测度问题,详细地分析了各种方法的优缺点;接着对传递对准中的误差建模以及相应的补偿方法进行了介绍,包括传感器误差、变形误差、杆臂误差和主惯导信息误差;最后,针对传递对准技术还需重点研究的方向给出了建议。

基于双目立体视觉的水下RGB-D相机

为满足水下机器人水下目标识别、精细作业的需要,研制了一种融合3D点云和二维RGB图像为一体的RGB-D水下相机工程样机。针对水下环境的特殊性,考虑水下多层折射效应,建立水下相机成像及双目立体成像模型。将水下图像转换为空气中的图像来消除折射对重建精度的影响,进行对应点像素匹配,重建3D点云。采用基于颜色校正和暗原色先验的水下图像增强算法对左、右水下图像进行图像增强处理。最后,构建对准叠加模型将3D点云和二维彩色数据叠加融合,获得水下RGB-D图像数据。实验表明:研制的水下RGB-D工程样机具有较好的三维测量精度,3 m远处的系统重建误差为2.6 mm,颜色再现真实,3D点云数据与RGB二维图像对准精准。这对于水下目标识别和水下机器人精细作业具有重要意义。

纳米焦点X射线管和纳米CT检测集成电路封装中的微型互联(英文)

IC封装中嵌入的微型电路连接可以通过纳米焦点X光光管技术和纳米焦点CT来检测;包括铜或金焊线、堆叠芯片、倒装焊接、微穿孔连接的封装形式。生动地描述了2维3维X射线影像技术,并且呈现了亚微米分辨率的各种分析结果和缺陷案例。

Time varying congestion pricing for multi-class and multi-mode transportation system with asymmetric cost functions

This paper considers the problem of time varying congestion pricing to determine optimal time-varying tolls at peak periods for a queuing network with the interactions between buses and private cars.Through the combined applications of the space-time expanded network（STEN） and the conventional network equilibrium modeling techniques,a multi-class,multi-mode and multi-criteria traffic network equilibrium model is developed.Travelers of different classes have distinctive value of times（VOTs）,and travelers from the same class perceive their travel disutility or generalized costs on a route according to different weights of travel time and travel costs.Moreover,the symmetric cost function model is extended to deal with the interactions between buses and private cars.It is found that there exists a uniform（anonymous） link toll pattern which can drive a multi-class,multi-mode and multi-criteria user equilibrium flow pattern to a system optimum when the system＇s objective function is measured in terms of money.It is also found that the marginal cost pricing models with a symmetric travel cost function do not reflect the interactions between traffic flows of different road sections,and the obtained congestion pricing toll is smaller than the real value.

Unparticle Effects on Top Quark Pair Production at Photon Collider

The unparticle effects on tt^- production at the future photon collider are investigated. Distributions of tt^- invariant mass and that for transverse momentum of top quark with respect to Standard Model and unparticle production are predicted. An odd valley with scalar unparticle contribution appears for some values of du, which is due to the big cancellation between the contribution from SM and that from unparticle. This character may be used to study the properties of scalar unparticle. Our investigations also show that scalar unparticle may play a significant role in tt^- production at the photon collider if it exists.

Dirac Neutrino Masses in NCG

Several models in noncommutative geometry (NCG) with mild changes to the standard model are introduced to discuss the neutrino mass problem. We use two constraints, Poincaré duality and gauge anomaly free, to discuss the possibility of containing right-handed neutrinos in them. Our work shows that no model in this paper, with each generation containing a right-handed neutrino, can satisfy these two constraints at the same time. So, to consist with neutrino oscillation experiment results, maybe fundamental changes to the present version of NCG are usually needed to include Dirac massive neutrinos.

Production of Top-Pions Associated with W Boson at Next Generation γγ Colliders

In the context of topcolor-assisted technicolor （TC2） model, we study the charged and neutral top-pions production process γγ →W＋ ∏t-∏t^0. We find that the production cross section is larger than that of the process γγ→ W＋ H-H in the minimal supersymmetric standard model. With reasonable values of the parameters in the TC2 model, the cross section can reach the level of a few fb. Furthermore, the flavor-changing （FC） decay mode ∏t^0 → te^- is the best channel to detect the neutral top-pion due to the clean SM background. With a large number of events and the clean background, the neutral top-pion should be observable at future linear colliders operating in γγ mode at the TeV energy scale.

Ωω States in a Chiral Quark Model

The structures of Ωω states with spin-parity JP= 5/2^-, 3/2^-, and 1/2^- are dynamically studied in both the chlral SU（3） quark model and the extended chiral SU（3） quark model by solving a resonating group method （RGM） equation. The model parameters are taken from our previous work, which gave a satisfactory description of the energies of the baryon ground states, the binding energy of the deuteron, the nucleon-nucleon （NN） scattering phase shifts, and the hyperon-nucleon （YN） cross sections. The calculated results show that the Ωω state has an attractive interaction, and in the extended chiral SU（3） quark model such attraction can make for a Ωω quasi-bound state with spin-parity JP = 3/2^- or 5/2^- and the binding energy of about several MeV.

Neutral Higgs Boson Pair Production in Standard Model with the Fourth GenerationQuarks at LHC

We investigated the neutral Higgs boson pair production at the CERN Large Hadron Collider (LHC) in the SM with four families. We found that the gluon-gluon fusion mode is the most dominant one in producing neutral Higgs boson pair at the LHC, and it can be used to probe the trilinear Higgs coupling. If the heavy quarks of the fourth generation really exist within the SM, they can manifest their effect on the cross section of the Higgs pair production process at the LHC. Our numerical results show that there will be neutral Higgs boson pair production events per year if the next generation heavy quarks really exist, while there will be only events produced per year if there are only three families in the SM.

RUIN PROBABILITIES WITH PAIRWISE QUASI-ASYMPTOTICALLY INDEPENDENT AND DOMINATEDLY-VARYING TAILED CLAIMS

This paper considers the nonstandard renewal risk model in which a part of surplus is invested into a Black-Scholes market whose price process is modelled by a geometric Brownian motion, claim sizes form a sequence of not necessarily identically distributed and pairwise quasi-asymptotically independent random variables with dominatedly-varying tails.The authors obtain a weakly asymptotic formula for the finite-time and infinite-time ruin probabilities.In particular,if the claims are identically distributed and consistently-varying tailed,then an asymptotic formula is presented.

Discovery of the Higgs boson by the ATLAS and CMS experiments at the LHC

The Standard Model （SM） Higgs boson was predicted by theorists in the 1960s during the development of the electroweak theory. Prior to the startup of the CERN Large Hadron Collider （LHC）, experimental searches found no evidence of the Higgs boson. In July 2012, the ATLAS and CMS experiments at the LHC reported the discovery of a new bosun in their searches for the SM Higgs boson. Subsequent experimental studies have revealed the spin-0 nature of this new boson and found its couplings to SM particles consistent to those of a Higgs boson. These measurements confirmed the newly discovered boson is indeed a Higgs bosun. More measurements will be performed to compare the properties of the Higgs boson with the SM predictions.

General relative error criterion and M-estimation

Relative error rather than the error itself is of the main interest in many practical applications. Criteria based on minimizing the sum of absolute relative errors （MRE） and the sum of squared relative errors （RLS） were proposed in the different areas. Motivated by K. Chen et al.＇s recent work [J. Amer. Statist. Assoc., 2010, 105： 1104-1112] on the least absolute relative error （LARE） estimation for the accelerated failure time （AFT） model, in this paper, we establish the connection between relative error estimators and the M-estimation in the linear model. This connection allows us to deduce the asymptotic properties of many relative error estimators （e.g., LARE） by the well-developed M-estimation theories. On the other hand, the asymptotic properties of some important estimators （e.g., MRE and RLS） cannot be established directly. In this paper, we propose a general relative error criterion （GREC） for estimating the unknown parameter in the AFT model. Then we develop the approaches to deal with the asymptotic normalities for M-estimators with differentiable loss functions on R or R／{0} in the linear model. The simulation studies are conducted to evaluate the performance of the proposed estimates for the different scenarios. Illustration with a real data example is also provided.

Low energy SUSY confronted with new measurements of W-boson mass and muon g-2

The new CDF II measurement of W-boson mass shows a 7σdeviation from the standard model(SM)prediction,while the recent FNAL measurement of the muon g-2 shows a 4.2σdeviation(combined with the BNL result)from the SM.Both of them strongly indicate new physics beyond the SM.In this work,we study the implication of both measurements on low energy supersymmetry.With an extensive exploration of the parameter space of the minimal supersymmetric standard model(MSSM),we find that in the parameter space allowed by current experimental constraints from colliders and dark matter detections,the MSSM can simultaneously explain both measurements on the edge of 2σlevel,taking theoretical uncertainties into consideration.The favored parameter space,characterized by a compressed spectrum between bino,wino and stau,with the stop being around 1 TeV,may be covered in the near future LHC searches.

Large Hierarchy from Non-Minimal Coupling

In this paper, a model is proposed to solve the gauge hierarchy problem. Beyond the standard model, we introduce an extra scalar field that non-minimally couples to gravity. The fundamental scale is set at weak scale and Planck scale emerges dynamically by a spontaneous symmetry breaking mechanism.

Type 1 2HDM as Effective Theory of Supersymmetry

It is generally believed that the low energy effective theory of the minimal supersymmetric standard model is the type 2 two Higgs doublet model. We will show that the type 1 two Higge doublet model can also be as the effective of supersymmetry in a specific ease with high scale supersymmetry breaking and gauge mediation. If the other electroweak doublet obtain the vacuum expectation value after the electroweak symmetry breaking, the Higgs spectrum is quite different. A remarkable feature is that the physical Higgs boson mass can be 125 GeV unlike in the ordinary models with high scale supersymmetry in which the Higgs mass is generally around 140 GeV.

NLO QCD corrections to Bc(B＊c) production around the Z pole at an e＋e- collider

The production of Bc and B＊ mesons at a Z-factory （an e＋e- collider operating at energies around the Z pole） is calculated up to the next-to-leading order （NLO） QCD accuracy. The results show that the dependence of the total cross sections on the renormalization scale/1 is suppressed by the corrections, and the NLO corrections enhance the total cross sections of B,. by 52% and of Bc＊ by 33% when the renormalization scale is taken at μ = 2mb. To observe the various behaviors of the production of the mesons Bc and Bc＊, such as the differential cross section vs. the out-going angle, the forward-backward asymmetry, and the distribution vs. the energy fraction z up to NLO QCD accuracy as well as the relevant K-factor （NLO to LO） for the production, are calculated, and it is pointed out that some of the observables obtained in the present work may be used as a specific precision test of the standard model.