Hiding a secret colour image in two colour images

Abstract

Visual cryptography is different from traditional cryptography. That is, neither time-consuming computation nor complex cryptographic knowledge is needed. Stacking is the only operation required to recover a secret image, and the individual image does not give the hackers any information about the secret image. None of researches tried to deal with meaningful colour share transparencies. Hence, two methods are proposed for hiding a colour image in two meaningful colour share transparencies in this paper. To achieve this goal, the colour decomposition approach and halftone technology are first applied to cope with secret colour images. Then the concept of the human visual system is utilized to generate two colour meaningful sharing transparencies. To support various applications, two variants are presented. The first proposed method, method-1, is suitable for simple colour images, and the second, method-2, provides better visibility of complex colour images.     

The Photography of Radioactive Materials

This paper discusses some or the many problems peculiar to the photography or radioactive materials. Specialized apparatus and techniques are described, such as telephotography via mirrors, illumination systems and macro techniques.     

Mechanisms of Adsorption from Aqueous Solutions: Some Basic Problems

Despite its wide occurrence and practical importance, adsorption at the interface between a solid and an aqueous solution still presents one of the most complicated problems in surface chemistry. Some of the factors known to influence adsorption processes are pointed out and the present need for more thorough investigation of well-characterized systems is emphasized.     

Some Detector Characteristics of the Photographic Process

The influence of the quantum nature of radiation on the sensitivity-resolution-noise characteristics of photographic processes is discussed. It is described how practical quantum efficiency and resolution properties may be compared with those of an ideal imaging process in terms of detective quantum efficiency (DQE). Some of the principles which are involved in the photographic application to detection problems are reviewed. A model which includes most of the established photographic quantum inefficiencies is used to interpret the measured values of DQE, and to indicate the various ways in which the photographic process is open to future improvements.     

Energy-Band Structure Features of Some Crimped-Shape Nanotubes

Abstract

Energy spectra of four stereoregular carbon quasi-1D-macromolecules with polyhedral elementary units containing 60 or 58 atoms were calculated by the crystalline orbital method in the valence approach. The EHT (see R. Hoffmann, J. Chem. Phys. 1963, 39, 1397) with standardized weighted non-diagonal elements of the matrix Hamiltonian was used. Atomic coordinates of the elementary units of carbon systems under consideraton were determined as a result of energy optimization of conforming trimers by the MNDO/PM3 methods. Geometries of inner monomers were used for modeling macromolecule structures. It was found that the widths of energy gaps of three systems [C₆₀]_n under consideration are located in the interval from 1.3 to 1.5 eV. Besides, quasi-localized energy levels were found in the spectrum gaps of these carbon quasi-1D-systems.     

Energy-Band Structure Features of Some Crimped-Shape Nanotubes

Energy spectra of four stereoregular carbon quasi-1D-macromolecules with polyhedral elementary units containing 60 or 58 atoms were calculated by the crystalline orbital method in the valence approach. The EHT (see R. Hoffmann, J. Chem. Phys. 1963, 39, 1397) with standardized weighted non-diagonal elements of the matrix Hamiltonian was used. Atomic coordinates of the elementary units of carbon systems under consideraton were determined as a result of energy optimization of conforming trimers by the MNDO/PM3 methods. Geometries of inner monomers were used for modeling macromolecule structures. It was found that the widths of energy gaps of three systems [C₆₀]_n under consideration are located in the interval from 1.3 to 1.5 eV. Besides, quasi-localized energy levels were found in the spectrum gaps of these carbon quasi-1D-systems.     

几个国外制冷装置的设计特点

本文通过对国外几个独具特色、构思新颖的制冷装置实例的介绍，并与国内相关设计方案进行了分析对比，说明了制冷装置设计方案的多样性。     

医疗仪器管理过程中的几点体会

医疗仪器管理工作是一项复杂的系统工程,涉及到诸多方面,要在工作中不断学习,积累经验,确保医疗仪器有效、稳定运作。     

Some Features of the X-Ray Spectrum of Micropinch Radiation with Single-Pulse Registration

Technical Physics Letters - A technique for and results of studying the characteristic X-ray spectrum of micropinch radiation are presented. A compact diffusion chamber of the original design has...     

非正态过程能力指数研究中的几个问题

非正态分布条件下过程能力指数的研究是目前关于过程能力分析中的热点之一。针对该领域中存在的若干问题,分析了正态性假设的重要性,指出导致质量特性呈现非正态分布的原因及其后果,以及如何进行质量特性分布的一维和多维正态性检验。对非正态过程能力指数的估计方法进行了分析和归类,简要指出在非正态过程能力指数研究中需要继续深入的几个方向。     

Some Features in the Absorption Spectra of Silver Halides and Thin Metallic Layers

Kirillov and his school in the Soviet Union, using a differential method, observed a fine-structure in the absorption spectra of photographic emulsions, silver-halide crystals, and thin layers of metallic silver. This fine-structure was ascribed to impurity centres, and the method was taken up by a number of other Soviet authors to study the nature and reactions of the sensitivity centres and latent-image centres of photographic materials. Some authors, however, have questioned the findings and suggested that the fine-structure could be an interference effect. The Russian work is reviewed in some detail, and it is shown that the possibility of the results being due to interference has been eliminated, and that the fine-structure is best explained as due to the absorption of light by impurity centres consisting of a few atoms of metallic silver in an aggregate of sub-colloidal dimensions.     

句子学习过程中的眼动特征

为了探讨重复学习对于汉语句子理解的作用,采用眼动仪记录10名研究生被试连续5次阅读20个句子时的眼动模式.研究结果表明：①随着阅读次数的增加,句子阅读时间依次缩短;注视点数目和回视次数逐渐减少;注视点的平均持续时间波动较小;平均眼跳距离逐渐加长;瞳孔尺寸逐渐变大.②其中瞳孔尺寸的变化模式揭示了句子学习过程中可能存在作业难度和认知负荷之间的分离--随着阅读次数的增加,作业难度降低,而认知负荷逐渐升高.③多种指标表明句子学习过程中知觉广度随阅读次数增加而加大.     

影响电磁约束定向生长样件表面质量的因素分析

用相机后摄记录了Ａｌ－２％Ｃｕ合金在不同工艺条件下进行电磁约束定向凝固时，在液柱头表面被氧化以及氧化皮形成皱褶的过程，并对此进行了分析。发现增大抽拉速度，减小液柱头最大工与最小厚度的幽会以及抑上电磁搅拌都能减少氧化和经皱褶的形成，最终改善表面质量。     

Research on the Forming Mechanism of Micro/Nano Features during the Cast Molding Process

Nano-Micro Letters - Cast molding process has provided a reliable, simple and cost-effective way to fabricate micro structures since decades ago. In order to obtain structures with fine, dense and...     

Features of the Measurement of Vibration Acceleration with Selection of Part of a Broadband Process

Possible reasons for the occurrence of unreliable results when measuring vibration acceleration and methods of preventing them are analyzed.     

工序能力分析与评价中的几个问题

在工序质量分析与控制中,计算与评价工序能力指数是一项非常重要的工作,也是计算机辅助质量系统的一个重要模块。文章针对目前在工序能力计算与分析中出现的问题,提出了如何合理地进行抽样、样本数据的正态性检验以及对非正态性数据的处理、Ｃｐ的置信区间以及与样本含量的关系,旨在为实际生产过程中质量工程师进行工序能力分析和评价提供指导。     

电子平台称在生产过程中出现的一些实际问题以及解决方法

电子平台称作为一种准确、方便、快捷的承重计量设备,近年来伴随着市场经济的高速发展,其已经越来越多的被购买和使用。但是由于某些企业在对其进行安装和使用过程中出现的一些错误,使企业蒙受了一些不必要的经济损失。所以本文作者以自己的工作经验为基础,提出了在安装和使用过程中解决相关问题的方法。     

中央空调的调试过程及易出现的若干问题

文章介绍了中央空调的调试过程,对调试中常见的系统漏水、堵塞、噪声过大、结露等现象分析了主要原因,并针对性的提出了解决的办法。     

Specific Features of the Temperature Dependence of the Mechanical Properties of Some Transition Metals and Their Alloys

On the basis of the results of theoretical investigations confirmed by the experimental data, it is established that, at certain temperatures and strain rates, the interstitial atoms in transition metals and alloys based on these metals participate in the dynamic interaction with dislocations, which facilitates the process of hardening of these metals. We compute the temperatures of dynamic interaction for hydrogen, nitrogen, oxygen, and carbon in two modifications of iron and metals from the VA group. It is shown that these effects can be significant after holding in environments. Dynamic strain aging is also typical of alloys based on the investigated metals.