Optical encryption of multiple three-dimensional objects based on multiple interferences and single-pixel digital holography

We present an optical encryption method of multiple three-dimensional objects based on multiple interferences and single-pixel digital holography. By modifying the Mach-Zehnder interferometer, the interference of the multiple objects beams and the one reference beam is used to simultaneously encrypt multiple objects into a ciphertext. During decryption, each three-dimensional object can be decrypted independently without having to decrypt other objects. Since the single- pixel digital holography based on compressive sensing theory is introduced, the encrypted data of this method is effectively reduced. In addition, recording fewer encrypted data can greatly reduce the bandwidth of network transmission. Moreover, the compressive sensing essentially serves as a secret key that makes an intruder attack invalid, which means that the system is more secure than the conventional encryption method. Simulation results demonstrate the feasibility of the proposed method and show that the system has good security performance.

Multi-objective strategy to optimize dithering technique for high-quality three-dimensional shape measurement

Dithering optimization techniques can be divided into the phase-optimized technique and the intensity-optimized technique. The problem with the former is the poor sensitivity to various defocusing amounts, and the problem with the latter is that it cannot enhance phase quality directly nor efficiently. In this paper, we present a multi-objective optimization framework for three-dimensional(3D) measurement by utilizing binary defocusing technique. Moreover, a binary patch optimization technique is used to solve the time-consuming issue of genetic algorithm. It is demonstrated that the presented technique consistently obtains significant phase performance improvement under various defocusing amounts.

Analysis of Object Depth Effects on Accuracy of Dimensional Shape in X and Y Directions Using Single Non-metric Image

In general, to reconstruct the accurate shape of buildings, we need at least one stereomodel （two photographs） for each building. In most cases, however, only a single non-metric photograph is available, which is usually obtained either by an amateur, such as a tourist, or from a newspaper or a post card. To evaluate the validity of 3D reconstruction from a single non-metric image, this study analyzes the effects of object depth on the accuracy of dimensional shape in X and Y directions using a single non-metric image by means of simulation technique, as this was considered to be, in most cases, a main source of data acquisition in recording and documenting buildings.

A Robust Optical Encryption Method for Three-Dimensional Object Based on the Fresnel Transform

An optical encryption of three-dimensional (3D) object with digital holography was implemented. In the process of encryption, two holograms involved recording key information and 3D object were obtained. In the process of decryption, the 3D object was reconstructed from the two holograms by extracting the object and key information, followed by multiplication of the two holograms and inverse Fresnel transform numerically. The robustness of the method was also tested for different occlusions attacks and Gaussian noises. The results showed that the method was able to encrypt and decrypt the 3D object while being robust under different occlusions attacks and Gaussian noises.

Numerical study on three-dimensional flow field of continuously rotating detonation in a toroidal chamber

Gaseous detonation propagating in a toroidal chamber was numerically studied for hydrogen/oxygen/nitrogen mixtures. The numerical method used is based on the three-dimensional Euler equations with detailed finiterate chemistry. The results show that the calculated streak picture is in qualitative agreement with the picture recorded by a high speed streak camera from published literature. The three-dimensional flow field induced by a continuously rotating detonation was visualized and distinctive features of the rotating detonations were clearly depicted. Owing to the unconfined character of detonation wavelet, a deficit of detonation parameters was observed. Due to the effects of wall geometries, the strength of the outside detonation front is stronger than that of the inside portion. The detonation thus propagates with a constant circular velocity. Numerical simulation also shows three-dimensional rotating detonation structures, which display specific feature of the detonation- shock combined wave. Discrete burning gas pockets are formed due to instability of the discontinuity. It is believed that the present study could give an insight into the interest- ing properties of the continuously rotating detonation, and is thus beneficial to the design of continuous detonation propulsion systems.

Infinite Three-Dimensional Coordination Polymers: Synthesis and Structures of [Cd (4,4'-bpy)_2 (H_2O)_2]_n (pic)_(2n),[Zn (4,4'-bpy)_2 (H_2O)_2]_n(pic)_(2n) (H_2O)_(2n), and [Zn (4,4'-bpy)_2 (H_2O)_2]_n (4,4'-bpy)_n(H_2O)_n (pic)_(2n)

Three Complexes of the formula [Cd (4,4'-bpy)_2 (H_2O)_2]_n. (pic)_(2n) (1) [Zn (4,4'-bpy)_2 (H_2O)]_n (4,4'-bpy)_n(H_2O)_n (pic)-(2n) (2) and [Zn (4,4'-bpy)_2 (H_2O)]_n (4,4'-bpy)_n (pic)-(2n)(H_2O)_n (3) (4.4'-bpy = 4.4'-bipyridine. pic = picric anion ) have been synthesized and characterized by elemental analysis and single-crystal x-ray diffraction. They all have infinite three-dimensional network structure. crystallizing in the monoclinic space group C2/c (1) and Cc (2.3).

3-Dimensional Body Measurement Technology

3 - dimensional body measurement technology, the basis of developing high technology in industry, accelerates digital development of aplparel industry. This paper briefly introduces the history of 3 - dimensional body measurement technology, and recounts the principle and primary structure of some types of 3 - dimensional automatic body measurement system. With this understanding, it discusses prospect of 3- dimensional CAD and virtual technology used in apparel industry.

Gamma-ray Emission from the γ-ray-loud BL Lac Objects

Using the HST observation data of BL Lac objects by Urry et al. and γ-ray observation data, we find that there is a correlation between Fγ and Fonuclei forγ-ray-loud BL Lac objects (correlation coefficients: 7γ=0.63,p = 4.0 × 10-2), but no correlation between Fγ and Fohost, where Fonuclei and Fohost are the fluxes of nuclei and host galaxy in V-band. For 19γ-ray-loud BL Lac objects with observed spectral index in multi-wavebands, the spectral index correlations between any two bands are as follow: (1) there is a strong correlation between aγ and aK for 15 BL Lac objects(γ = 0.84,p = 3.11 × 10-4); (2) the correlation between aγ and ao for 12 BL Lac objects isγ = 0.82, p = 1.5 × 10-3; (3) there is no correlation between a7 and ax for 16 BL Lac objects. The results, together with characteristic double-humped shape of their SEDs, show that the synchrotron self-Compton mechanism might be a main mechanism for theγ-ray emission of the BL Lac objects. The electrons emitting JR and optical radiation via synchrotron are also responsible for upscattering these photons toγ-rays, and a variability in IR-optical regime should be accompanied by a change in theγ-rays.

A Study of the Energy Sources of Herbig-Haro Objects

We make a statistical study of the energy sources of high-velocity phenomena, Herbig-Haro (HH) objects. IRAS counterparts of HH objects are identified. Their colors, brightness, geometric relation to the RH objects and SED are analysed. The sources are found to be concentrated in a band-shaped region in the IRAS color-color diagram. We suggest an explanation of thick surrounding material for this distribution. We propose a new method for identifying the energy sources based on color arid brightness. This method is applied to more than 200 HR objects whose energy sources are still unknown. Finally, a group of very young stellar object candidates which have similar properties to the RH energy sources is picked out. Their large-scale distribution is discussed.

Researches on Cartographic Database-Based Interactive Three-Dimensional Topographic Map

With the development of computer graphics, the three-dimensional (3D) visualization brings new technological revolution to the traditional cartography. Therefore, the topographic 3D-map emerges to adapt to this technological revolution, and the applications of topographic 3D-map are spread rapidly to other relevant fields due to its incomparable advantage. The researches on digital map and the construction of map database offer strong technical support and abundant data source for this new technology, so the research and development of topographic 3D-map will receive greater concern. The basic data of the topographic 3D-map are rooted mainly in digital map and its basic model is derived from digital elevation model (DEM) and 3D-models of other DEM-based geographic features. In view of the potential enormous data and the complexity of geographic features, the dynamic representation of geographic information becomes the focus of the research of topographic 3D-map and also the prerequisite condition of 3D query and analysis. In addition to the equipment of hardware that are restraining, to a certain extent, the 3D representation, the data organization structure of geographic information will be the core problem of research on 3D-map. Level of detail (LOD), space partitioning, dynamic object loading (DOL) and object culling are core technologies of the dynamic 3D representation. The object- selection, attribute-query and model-editing are important functions and interaction tools for users with 3D-maps provided by topographic 3D-map system, all of which are based on the data structure of the 3D-model. This paper discusses the basic theories, concepts and cardinal principles of topographic 3D-map, expounds the basic way to organize the scene hierarchy of topographic 3D-map based on the node mechanism and studies the dynamic representation technologies of topographic 3D-map based on LOD, space partitioning, DOL and object culling. Moreover, such interactive operation functions are explored, in this paper, as spatial query, scene editing and management of topographic 3D-map. Finally, this paper describes briefly the applications of topographic 3D-map in its related fields.

Myvoxel R-CNN:基于体素的三维点云目标检测模型

围绕目前三维点云目标检测中存在的特征提取不充分、困难(Hard)目标检测准确率低、模型泛化能力有待提高等问题,提出了一种新的单模态三维点云目标检测模型Myvoxel R-CNN,该模型由3个主要模块组成,分别是3D主干网络、2D鸟瞰区域建议网络(2D主干网络+区域建议网络(RPN))以及检测头,在3D主干网络中添加了多头自注意力模块和基于稀疏卷积的残差块,增强了3D主干网络的体素特征学习能力,捕获了更多数据和特征内部的相关性.设计了一个由注意力融合模块组成的2D主干网络,增加了原模型对2D特征的关注度.为了进一步增加所提出模型的泛化性,引入了一种新的数据增强方案——随机局部金字塔数据增强方法,以形状感知的方式生成增强对象样本.在KITTI数据集上,本模型对汽车Hard级别的检测精度AP 3D提升了约2.23%,此外简单(Easy)和中等(Moderate)类别分别提高了约0.60%和0.62%,对行人Easy级别的检测精度AP 3D、AP BEV分别提升了约0.62%和0.86%,Hard级别的AP 3D、AP BEV分别提升了约1.45%和1.53%,实验结果表明,Myvoxel R-CNN在KITTI数据集上的表现优于其他方法.

Discovery of a variable broad absorption line in the BL Lac object PKS B0138-097

We report the discovery of a broad absorption line （BAL） of - 10^4 km s^-1 in width in the previously known BL Lac object PKS 0138-097, which we tentatively identified as an Mg II BAL. This is the first detection of a BAL, which is sometimes seen in powerful quasars with high accretion rates, in a BL Lac object. The BAL was clearly detected in its spectra spanning two epochs at a high luminosity state taken in the Sloan Digital Sky Survey （SDSS）, while it disappeared in three SDSS spectra taken at a low luminosity state. The BAL and its variability pattern were also found in its historical multi-epoch spectra in the literature, but have been overlooked previously. In its high resolution radio maps, PKS 0138-097 shows a core plus a one- sided parsec-scale jet. The BAL variability can be interpreted as follows： The optical emission is dominated by the core in a high state and by the jet in a low state and the BAL material is located between the core and jet so that the BAL appears only when the core is shining. Our discovery suggests that outflows may also be produced in active galactic nuclei at a low accreting state.

Parametric study on single shot peening by dimensional analysis method incorporated with finite element method

Shot peening is a widely used surface treatment method by generating compressive residual stress near the surface of metallic materials to increase fatigue life and re- sistance to corrosion fatigue, cracking, etc. Compressive re- sidual stress and dent profile are important factors to eval- uate the effectiveness of shot peening process. In this pa- per, the influence of dimensionless parameters on maximum compressive residual stress and maximum depth of the dent were investigated. Firstly, dimensionless relations of pro- cessing parameters that affect the maximum compressive residual stress and the maximum depth of the dent were de- duced by dimensional analysis method. Secondly, the in- fluence of each dimensionless parameter on dimensionless variables was investigated by the finite element method. Fur- thermore, related empirical formulas were given for each di- mensionless parameter based on the simulation results. Fi- nally, comparison was made and good agreement was found between the simulation results and the empirical formula, which shows that a useful approach is provided in this pa- per for analyzing the influence of each individual parameter.

Properties of BL Lac Objects with Redshift ≤ 0.2

We present a large sample which includes 82 BL Lac objects with red- shifts below 0.2 from recent literature. We find strong correlations in both flux and luminosity between the radio (5 GHz) and optical bands (5500 A). The correlations in other bands are very weak. Five TeV BL Lacs and two suspect sources are found to have similar properties as high- frequency- peaked BL Lacs (HBLs). Our results suggest that both the radio and optical emissions are from the same radiation mech- anism in the SSC model. The TeV BL Lac candidates should be HBLs or HBL-like objects with small redshifts.

改进NSGA-III求解高维多目标绿色柔性作业车间调度问题

为解决NSGA-III在求解上述模型存在初始解质量差与局部搜索效率低的问题,提出一种改进的NSGA-III(NSGA-III-TV)。基于MSOS编码,分别对OS和MS染色体采取不同混合初始化策略以提高初始解质量;基于关键路径,采用改进N6邻域结构进行邻域搜索,有效缩短完工时间并降低搜索盲目性,同时采用3种有效变异算子扩大算法搜索空间,提高后期收敛能力。结果表明:NSGA-III-TV在求解高维多目标柔性作业车间调度问题上具有较好的性能以及实用性,为企业生产制造车间的智能绿色转型升级提供了有力支持。

Object-Oriented Design for FDTD Visual Scientific Computing

A scheme for general purposed FDTD visual scientific computing software is introduced in this paper using object-oriented design (OOD) method. By abstracting the parameters of FDTD grids to an individual class and separating from the iteration procedure, the visual software can be adapted to more comprehensive computing problems. Real-time gray degree graphic and wave curve of the results can be achieved using DirectX technique. The special difference equation and data structure in dispersive medium are considered, and the peculiarity of parameters in perfectly matched layer are also discussed.

基于多目标均衡优化的2PRU&1PRS-XY型混联机器人尺度设计方法

面向复杂结构件机器人加工装备设计需求,提出一种2PRU&1PRS-XY型混联机器人。为将该混联机器人应用于高性能机械加工任务,在其工作空间、运动/力传递性以及灵巧度分析的基础上,定义了用于工作全域性能评价的传递稳定性指标与精度差异性指标,提出了一种基于多目标均衡优化思想的尺度设计方法。该方法采用标准化方法简化多参数设计空间,应用响应面法与主成分分析法提高优化求解效率,结合主客观组合赋权法与基于TOPSIS的Pareto前沿法实现多指标综合性能评分。运用所提方法,得到了4种兼顾优化求解效率和多目标均衡优化的尺度参数设计方案,实现了2PRU&1PRS-XY型混联机器人主要尺度参数的优化设计,为设计者提供了具有不同工程设计倾向的多目标均衡决策参考。

Additional Space Dimension in Bound Spaces Created by a Central Object

Space is a common entity in any static or dynamic system of objects whether the system is a bound system or an open system. Space is described by either measured or abstract dimensions. All motions, momentum and energy transfers take place in space in any given system of objects. By understanding space we understand many physical phenomena happening in space. One method is to observe similarities among phenomena, deduce possible relations and validate the relations through known results. De Broglie wavelength for matter waves is a typical theorized abstract dimension existence of which is established through experiments later. In this paper, the author studies two bound spaces in two bound systems, namely, atomic bound systems and gravitationally bound systems. Both these bound systems have similar characteristics;they have inertial masses in motion with constant kinetic energies for a given orbital distance around the respective central object. In atomic bound space, the central object is the central positive charge which plays the role of creating the bound space around it. In gravitationally bound space, it is the central mass that plays the same role. Thus for these two bound systems a common constitutive relation between the energies of inertial masses in kinetic state, their distance from central object could be present. By noticing the similarities of the two systems, the author proposes such a relation through introduction of an additional space dimension. The existence of the proposed additional dimension is proved in this paper by considering hydrogen atom for atomic bound space and by considering any gravitational system for gravitationally bound space. Though the magnitude of the additional space dimension is different in both the situations, the additional space dimension exists. It is observed that in hydrogen atom the additional space dimension is a constant for the given positive charge of hydrogen atom when electron is in any energy state having principal quantum number of any value from 1 to 5 and with the orbital quantum number zero. For other quantum numbers additional space dimension exists. In the case of gravitational bound space, the additional space dimension is constant for a given mass of the central object for any energy of orbiting inertial mass. The author concludes that total mass energy of an inertial mass having a constant kinetic energy in any bound space is related to an additional space dimension defined by the constitutional property of the central object creating that bound space. As the relation is generic, it throws opportunity to examine other known similar macro, micro or quantum bound spaces created by central objects with different constitutive properties.

Objective Assessment of Skin Tightening Using Multisource, Phase-Controlled Radiofrequency in Asians

Background: Radiofrequency has been proven to penetrate deeper than optical light sources independent of skin color allowing a safer treatment for the Asian skin type. Many studies have indicated the efficacy of various types of devices, but have not included a sufficient objective evaluation. Multisource radiofrequency uses multiple phase controlled radiofrequency generators with real time impedance control, allowing painless, deeper dermal heating with better adaptation to differences in individual skin impedance. In this study we used three-dimensional imaging for the objective evaluation of facial skin tightening by multisource phase-controlled radiofrequency. Methods: Twenty Japanese patients were treated with a multisource phase-controlled radiofrequency device. Three-dimensional imaging was performed with a Canfield Scientific Vectra camera and software, and quantitative volume measurements were taken to evaluate the change in the post-treatment volume. The patients then provided subjective assessments. Results: Objective assessments of the treated cheek volume evaluated by a three-dimensional color schematic representation with quantitative volume measurements showed significant improvement three months after the final treatment. The mean volume reduction at the last post-treatment visit was 3.878 ± 2.86 mL. The post-treatment volume was significantly reduced compared to the pretreatment volume in all of the volunteers (P = 0.0007). Ninety-five percent of volunteers reported satisfaction with the improvement of skin laxity, and ninety percent of volunteers reported satisfaction with the improvement of wrinkles, such as the nasolabial folds. Conclusions: The advantages of these multisource phase-controlled radiofrequency treatments are its high efficacy for skin tightening associated with minimal level of discomfort, minimal side effects, and low cost. Taken together, these characteristics facilitate the ability to give repeated treatments as a stand alone treatment or adjunct to surgery. This study provides for the first time a qualitative and quantitative volumetric assessment, proving the ability of the technology to reduce the volume through non invasive skin tightening.

The BL Lac Object PKS 0537-441: A Lens or Being Lensed?

We present and discuss deep high resolution images taken with the ESO NTT as well as spectra taken with the ESO VLT in the field of the BL Lac object PKS 0537 441. We could neither detect the host galaxy nor a galaxy along the line of sight to the BL Lac as claimed from previous observations. We found 4 nearby companion galaxies which could be a splitted and magnified image of a distant background galaxy. Our VLT spectra, however, rule out this possibility. All 4 companions have similar redshifts as the BL Lac and may (at least in part) trigger the enormous activity in this source. PKS 0537 441 might be located in a galaxy cluster as rich as Abell 1. Alternatively, the BL Lac could also be located in the outskirts of a galaxy cluster or even be projected on a large scale structure as indicated by spectra of 30 galaxies in the field. Either lensing hypothesis (lens or being lensed) is considerably weakened by our observations.