方案驱动的产品造型设计迭代模式

目的研究实际产品造型设计项目中的设计迭代新模式。方法通过对实际设计案例的剖析,界定了设计方案与设计目标的范畴,梳理了产品造型设计中的设计方案与设计要求的关系,重构了两者在设计迭代时序里的位置和作用。结果结合"解驱动"的设计范式理论,描述了方案驱动的产品造型设计迭代模式。结论方案驱动是设计迭代创新的有效机制之一。     

A New Encryption-then-Compression Scheme on Gray Images Using the Markov Random Field

Compressing encrypted images remains a challenge. As illustrated in our previous work on compression of encrypted binary images, it is preferable to exploit statistical characteristics at the receiver. Through this line, we characterize statistical correlations between adjacent bitplanes of a gray image with the Markov random field (MRF), represent it with a factor graph, and integrate the constructed MRF factor graph in that for binary image reconstruction, which gives rise to a joint factor graph for gray images reconstruction (JFGIR). By exploiting the JFGIR at the receiver to facilitate the reconstruction of the original bitplanes and deriving theoretically the sum-product algorithm (SPA) adapted to the JFGIR, a novel MRF-based encryption-then-compression (ETC) scheme is thus proposed. After preferable universal parameters of the MRF between adjacent bitplanes are sought via a numerical manner, extensive experimental simulations are then carried out to show that the proposed scheme successfully compresses the first 3 and 4 most significant bitplanes (MSBs) for most test gray images and the others with a large portion of smooth area, respectively. Thus, the proposed scheme achieves significant improvement against the state-of-the-art leveraging the 2-D Markov source model at the receiver and is comparable or somewhat inferior to that using the resolution-progressive strategy in recovery.     

A Robust Resource Allocation Scheme for Device-to-Device Communications Based on Q-Learning

One of the most effective technology for the 5G mobile communications is Device-to-device (D2D) communication which is also called terminal pass-through technology. It can directly communicate between devices under the control of a base station and does not require a base station to forward it. The advantages of applying D2D communication technology to cellular networks are: It can increase the communication system capacity, improve the system spectrum efficiency, increase the data transmission rate, and reduce the base station load. Aiming at the problem of co-channel interference between the D2D and cellular users, this paper proposes an efficient algorithm for resource allocation based on the idea of Q-learning, which creates multi-agent learners from multiple D2D users, and the system throughput is determined from the corresponding state-learning of the Q value list and the maximum Q action is obtained through dynamic power for control for D2D users. The mutual interference between the D2D users and base stations and exact channel state information is not required during the Q-learning process and symmetric data transmission mechanism is adopted. The proposed algorithm maximizes the system throughput by controlling the power of D2D users while guaranteeing the quality-of-service of the cellular users. Simulation results show that the proposed algorithm effectively improves system performance as compared with existing algorithms.     

抗几何攻击的鲁棒计算全息零水印算法

结合计算全息技术,提出一种新颖的抗几何攻击的鲁棒零水印算法.零水印构造过程中,先对小波变换后的宿主图像的低频子带进行分块,然后对每个分块进行奇异值分解并量化它们的最大奇异值,最后用得到的量化矩阵与全息水印构造零水印,并在IPR数据库注册获得版权保护.检测过程中,先用基于Zernike矩和不变质心的改进图像校正算法对几何失真图像进行校准,然后用校正后的图像进行水印检测.与传统的零水印算法及数字全息水印算法相比,本文算法具有更好的抗几何攻击性能.实验表明,该算法能有效地抵抗旋转,缩放、平移、翻转和旋转-缩放组合等几何攻击,同时对滤波、加噪声、JPEG 压缩、图像模糊、裁剪和对比度增强等常规攻击也有很强的鲁棒性.     

平稳随机信号AR模型的一种新观点

从平稳随机信号自相关的准周期性对AR模型进行了深入研究,提出平稳随机信号AR模型的一种新观点,即认为平稳随机信号的AR模型的成立不应基于信号熵原理,而应基于其自相关的准周期性,论文以此为基础,导出了许多熵原理AR模型无法得到的性质。     

基于随机逼近动态带宽分配的CAC研究

ATM网络中，基于动态带宽分配的CAC，即可以提高ATM网络资源的利用率又能保证业务的QoS要求。本文运用自适应随机逼近算法研究了ON／OFF信源模型的带宽估计及接入问题，数值计算的结果表明，随机逼近能较好地逼近实际值，与社会网络方法相比，随机逼近算法的特点是不需要离线训练，也不需要已准好的样本，这能在网络实际运行中自动调整自动收敛。     

Content Uniformity of a Low Dose Pharmaceutical Product

ABSTRACT

Optimum homogeneity and physical stability for a Roche compound (RO) low dose formulations (0,125 and 0.250 mg Tablets i.e. 0.07 to 0.14% w/w drug load, respectively) were achieved. Direct compression powder formulations were prepared by mixing the active drug substance with Starch 1500 (ST) to form an active pre-mix. Other ingredients were added subsequently. The final powder mix was subjected to a vibration of 4 Hz frequency using a specially designed segregation unit and content uniformity was assessed for these formulations. ST was considered superior to both lactose anhydrous and Avicel PH 102 in preparing homogeneous and physically stable mixes. Production-size batches of the product were successfully manufactured (Mean Drug content = 98 100%, RSV = 2%).     

A Robust Image Watermarking Scheme Using Z-Transform,Discrete Wavelet Transform and Bidiagonal Singular Value Decomposition

Watermarking is a widely used solution to the problems of authentication and copyright protection of digital media especially for images, videos, and audio data. Chaos is one of the emerging techniques adopted in image watermarking schemes due to its intrinsic cryptographic properties. This paper proposes a new chaotic hybrid watermarking method combining Discrete Wavelet Transform (DWT), Z-transform (ZT) and Bidiagonal Singular Value Decomposition (BSVD). The original image is decomposed into 3-level DWT, and then, ZT is applied on the HH3 and HL3 sub-bands. The watermark image is encrypted using Arnold Cat Map. BSVD for the watermark and transformed original image were computed, and the watermark was embedded by modifying singular values of the host image with the singular values of the watermark image. Robustness of the proposed scheme was examined using standard test images and assessed against common signal processing and geometric attacks. Experiments indicated that the proposed method is transparent and highly robust.     

Signal Quality Improvement Using a New TMSSE Algorithm: Application in Delamination Detection in Composite Materials

This paper introduces a novel method to improve the quality of ultrasonic phased array signals for localizing with accuracy delamination defects. The improvement is achieved by the introduction of a new threshold for the Shannon energy. In first, we have applied the threshold modified S-transform algorithm (TMST) in the case of ultrasound B-scan. Thereafter, we have adapted and applied the S-transform Shannon energy (SSE) algorithm in the field of ultrasonic testing. At last, we have proposed a novel algorithm based on threshold modified S-transform and Shannon energy (TMSSE) to increase the improvement of the ultrasound B-scan. A simulation study has been carried out simulating a composite material containing three defects in different positions in order to highlight the phenomenon of delamination. Experimental tests were performed on a sample of carbon fiber reinforced polymer composite material (CFRP) with a delamination defect close to the front face. Both experimental and simulated results show that the proposed method can improve the quality of ultrasound B-scan which enhances the localization of delamination defects.     

Spherical Geometry HOC Scheme to Capture Low Pressures within a Wake

The solution of the pressure Poisson equation in spherical polar coordinates using a higher order compact (HOC) scheme effectively captures low pressure values in the wake region for viscous flow past a sphere. In the absence of an exact solution, the fourth-order of accuracy of the results is illustrated. Low pressure circular contours occur in the wake region when the Reynolds number $Re = 161$, which is a lower value than previously identified in the literature, and closed pressure contours appear in two regions when $Re = 250$.     

曲线造型的新方法研究

本文提出可通过对形状参数的适当选择来实现对极限曲线形状调整和控制的三参数四点细分曲线造型方法,并对其收敛性进行了分析,同时给出并证明了曲线C~1到C~2连续的充分条件。数值试验证明所给方法是有效的。     

Studies on Low Altitude Clouds Over New Delhi,India Using Lidar

This study reports the altitude distribution of physical and optical properties of clouds in the lower troposphere over the urban tropical region Delhi using an UV (355 nm) lidar which is capable of operating in both day and night time. Most of the low altitude clouds are observed above the planetary boundary layer during the observation period. The low altitude cloud bottom and top height varies between 0.58 ± 0.21 and 1.5 ± 0.61 km respectively during the observation period. The depolarization ratio of the observed clouds varies from 0.18 ± 0.01 to 1.2 ± 0.58. The role of the atmospheric region below the cloud in the growth process of the cloud cell is studied. Cloud turbulence is derived to show its role in maintaining the strength of the cloud.     

Effect of Strain Rate on the Ferrite Grain Refinement in a Low Carbon Nb-Ti Microalloyed Steel during Low Temperature Deformation

1. IntroductionThe thermomechanical controlled processing(TMCP) of microalloyed steels has been employed fosome times in the production of plates and sheet material to optimize mechanical properties. The centrafeature of thermomechanically processed steel is the ul-trafine grain size in the final product. Therefore, theferrite grain refinement of structural steels has attractedconsiderable interest from engineering scientists due toits unique role of increasing both strength and toughnessDem…     

一类中立型时滞系统新的鲁棒稳定性准则

本文考虑了一类具有时变时滞和非线性扰动的中立型系统的鲁棒稳定性问题.基于Lyapunov稳定性理论和自由权矩阵方法,得到保证系统鲁棒渐近稳定的新的充分条件.所得结果同时依赖于离散时滞和中立时滞,并用LMIs表示.由于对Lyapunov泛函导数采用了无保守的估计,因此所得结果具有较小的保守性,能够给出时变时滞较大的允许时...     

Cost Prediction of a Turbofan Engine Using the Robust Partial Least Squares Method

In recent years,the cost of engines has become increasingly important to engine manufacturers,who are consistently faced with major problems on how to reduce cost to a minimum.Cost has become a decisive factor for aircraft design.To control the continual rapid increased cost,engine cost prediction is indispensable early in the design phase.But the cost data of an aircraft engine is small;we introduce the Robust Partial Least Squares Method in solving this problem,and reducing or removing the effect of outlying data points,which is different from the Classical PLS.We use the MATLAB software doing several simulations;results and analysis of a real turbofan engine data set show the effectiveness and robustness of the Robust PLS method.The Robust PLS method can effectively be used to estimate Turbofan Engine cost with reasonable accuracy.     

一种基于自验证公钥的门限代理签名方案的安全性分析

Xue和Cao提出了一种基于自验证公钥的门限代理签名方案,然而,该方案是不安全的。给出了对该方案一种攻击：攻击者获得一个合法的原始签名人发送给代理签名人的签名了的授权证书以及代理签名人生成的一个有效的代理签名后,能够伪造出一个新的对相同消息的代理签名,而原始签名人变为攻击者自己,由于验证者并不能验证代理签名人到底是代表谁生成了代理签名,这样,攻击者就获得了与合法原始签名人相同的权益。特别地,代理签名人代表原始签名人生成的门限代理签名可以被转化为普通的门限签名。分析了该方案存在安全漏洞的原因并提出了改进措施,改进措施能有效地弥补原方案存在的安全缺陷。     

Low Concentration Monitoring of Exhaust Gases Using a UV-Based Optical Sensor

The development of an ultra-violet (UV) differential optical absorption spectroscopy (DOAS) fibre-optic sensor for the monitoring of vehicle exhaust gases is described in this paper. Experimental results describing the operation of this sensor with NO₂, SO₂ , and NO are shown. These experimental results are compared with existing published spectroscopic absorption measurements. It is shown that the minimum detectable concentration of NO₂ is 1 ppm, SO ₂ is 1 ppm, and NO is 26 ppm. The sensor was found to have a low susceptibility to interference between the detection of these gases     

A Rapid and Robust Diagnostic for Liver Fibrosis Using a Multichannel Polymer Sensor Array

Liver disease is the fifth most common cause of premature death in the Western world, with the irreversible damage caused by fibrosis, and ultimately cirrhosis, a primary driver of mortality. Early detection of fibrosis would facilitate treatment of the underlying liver disease to limit progression. Unfortunately, most cases of liver disease are diagnosed late, with current strategies reliant on invasive biopsy or fragile lab‐based antibody technologies. A robust, fully synthetic fluorescent‐polymer sensor array is reported, which, rapidly (in 45 minutes), detects liver fibrosis from low‐volume serum samples with clinically relevant specificity and accuracy, using an easily readable diagnostic output. The simplicity, rapidity, and robustness of this method make it a promising platform for point‐of‐care diagnostics for detecting and monitoring liver disease.     

Critical Flow Method: A New Reliability Allocation Approach for a Thermonuclear System

In the present work, starting from well‐known methodologies, a new reliability allocation method [critical flow method (CFM)] has been proposed. We focused on the most important conventional methods and discussed their limitations in order to motivate the current research. The results show the main common problem of the most conventional reliability allocation methods: they are developed for complex systems with series configurations but not for series–parallel ones. The consequence is an increase of the required units' reliability (series configuration) in order to guarantee the reliability system target. Actually, the design and manufacturing of a subsystem with an extremely low failure rate would consume a considerable amount of economic resources. The proposed method can solve the shortcomings of the conventional methods with a new reliability approach useful to series–parallel configurations in order to obtain an important cost saving. The CFM has been applied to a liquid nitrogen cooling installation in a thermonuclear system, with many series–parallel configurations in order to guarantee the whole safety system. The proposed technique can be applied to working complex systems, and, in general, in the design phase of new installations. By comparing the CFM application results with real parameters, the new technique has been validated. The computational results clearly demonstrate the advantages of the proposed method. In particular, by applying the method to series–parallel configurations, it allocates failure rates higher than conventional methods, with a component cost reduction. Copyright © 2015 John Wiley & Sons, Ltd.