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71.
Mahesh Kumar G. Janardhana Reddy G. Ravi Kiran M. A. Mohammed Aslam O. Anwar Beg 《亚洲传热研究》2019,48(3):1067-1092
Entropy generation is an important aspect of modern thermal polymer processing optimization. Many polymers exhibit strongly non‐Newtonian effects and dissipation effects in thermal processing. Motivated by these aspects in this study, a numerical analysis of the entropy generation with viscous dissipation effect in an unsteady flow of viscoelastic fluid from a vertical cylinder is presented. The Reiner‐Rivlin physical model of grade 2 (second‐grade fluid) is used, which can envisage normal stress variations in polymeric flow‐fields. Viscosity variation is included. The obtained governing equations are resolved using implicit finite difference method of Crank‐Nicolson type with well imposed initial and boundary conditions. Key control parameters are the second‐grade viscoelastic fluid parameter (), viscosity variation parameter (), and viscous dissipation parameter (). Also, group parameter (), Grashof number (Gr), and Prandtl number (Pr) are examined. Numerical solutions are presented for steady‐state flow variables, temperature, time histories of friction, wall heat transfer rate, entropy, and Bejan curves for distinct values of control parameters. The results specify that entropy generation decreases with augmenting values of , , and Gr. The converse trend is noticed with increasing Pr and . Furthermore, the computations reveal that entropy and Bejan lines only occur close to the hot cylinder wall. 相似文献
72.
Muhammad Maqbool Alruwaili Amani Milinovic Dunja Khan Tahirzeb Ali Ghafar Ahmad Iftikhar 《Semiconductors》2018,52(16):2039-2045
Semiconductors - Thin films of AlN:Tm are deposited on a Si(111) and Si(100) substrates and optical fiber by rf magnetron sputtering method. 200–400 nm thick films are deposited at various... 相似文献
73.
This article presents a 12‐bit frequency coded chipless RFID system in the frequency range of 3 to 6 GHz. The system consists of a fully printable chipless tag and a pair of high‐gain reader antennas. The tag also incorporates its own antennas to improve the read range. Information is encoded into frequency spectrum using a multi‐resonant circuit. The circuit consists of multiple microstrip U and L‐shaped open stub resonators patterned in a unique configuration. The proposed configuration aids in capturing more data in a reduced space as well as tunable frequency operation. Tag and reader antennas utilize techniques such as stepped impedance feeding line, defective partial ground plane, and stair‐step patch structure to achieve wide‐band impedance bandwidth in miniature size. The results of the wireless measurements in the non‐anechoic environment show that the proposed system has a reading range of more than 20 cm. The presented system possesses great potential for low‐cost short‐range inventory tracking. 相似文献
74.
Wu Xiaoqi Li Jingbing Tu Rong Cheng Jieren Bhatti Uzair Aslam Ma Jixin 《Multimedia Tools and Applications》2019,78(7):8463-8480
Multimedia Tools and Applications - In the current medical system, the privacy and security of the medical information with respect to its transmission and storage is a key challenge. In pursuit of... 相似文献
75.
Muhammad Shamrooz Aslam Baoyong Zhang 《International journal of systems science》2018,49(8):1587-1602
This paper focuses on the design of H ∞ filter and event-triggered scheme for a class of continuous non-linear networked control systems (NCSs) based on fuzzy system appeared with time delays. First, we consider the discrete event-triggered (ET) scheme to make efficient utilisation of bandwidth. Under this ET-scheme, sensor releases the data only when our sampled-data plant violates the specific event-triggered condition. Second, the T-S fuzzy system is used to model the non-linear NCSs. Another purpose of this paper is to design filters involving delays. Such filters have a more general form than the delay-free filters that have been mostly considered in the traditional studies. By using the time-delay system, co-design of event-triggered scheme and H ∞ filter for the delayed NCSs is presented in a unified frame work. To choose the latest data packet and discard the dis-ordered packet logic, zero-order hold is inserted between the fuzzy filter and event generator. Then, by using the novel fuzzy Lyapunov–Krasovskii function approach with free-weighting matrix technique, H ∞ filter design of event-triggered delay NCSs is proposed. Finally, to show the effective result of our co-design method, a tunnel-diode example is given. 相似文献
76.
Jialing Liu Jingbing Li Yenwei Chen Xiangxi Zou Jieren Cheng Yanlin Liu Uzair Aslam Bhatti 《计算机、材料和连续体(英文)》2019,61(1):363-378
Remote medical diagnosis can be realized by using the Internet, but when transmitting medical images of patients through the Internet, personal information of patients may be leaked. Aim at the security of medical information system and the protection of medical images, a novel robust zero-watermarking based on SIFT-DCT (Scale Invariant Feature Transform-Discrete Cosine Transform) for medical images in the encrypted domain is proposed. Firstly, the original medical image is encrypted in transform domain based on Logistic chaotic sequence to enhance the concealment of original medical images. Then, the SIFT-DCT is used to extract the feature sequences of encrypted medical images. Next, zero-watermarking technology is used to ensure that the region of interest of medical images are not changed. Finally, the robust of the algorithm is evaluated by the correlation coefficient between the original watermark and the attacked watermark. A series of attack experiments are carried out on this method, and the results show that the algorithm is not only secure, but also robust to both traditional and geometric attacks, especially in clipping attacks. 相似文献
77.
78.
Sadeeq Jan Omer Bin Tauqeer Fazal Qudus Khan George Tsaramirsis Awais Ahmad Iftikhar Ahmad Imran Maqsood Niamat Ullah 《计算机、材料和连续体(英文)》2021,66(1):631-645
Over the last decade, a significant increase has been observed in the use
of web-based Information systems that process sensitive information, e.g., personal, financial, medical. With this increased use, the security of such systems
became a crucial aspect to ensure safety, integrity and authenticity of the data.
To achieve the objectives of data safety, security testing is performed. However,
with growth and diversity of information systems, it is challenging to apply security testing for each and every system. Therefore, it is important to classify the
assets based on their required level of security using an appropriate technique.
In this paper, we propose an asset security classification technique to classify
the System Under Test (SUT) based on various factors such as system exposure,
data criticality and security requirements. We perform an extensive evaluation of
our technique on a sample of 451 information systems. Further, we use security
testing on a sample extracted from the resulting prioritized systems to investigate
the presence of vulnerabilities. Our technique achieved promising results of successfully assigning security levels to various assets in the tested environments and
also found several vulnerabilities in them. 相似文献
79.
80.
Muhammad Shujaat Nawaz Muhammad Azam Muhammad Aslam 《Quality and Reliability Engineering International》2019,35(8):2677-2686
A control chart based on double exponentially weighted moving average and Benjamini‐Hochberg multiple testing procedure is proposed that controls the false discovery rate (FDR). The proposed control chart is based on probabilities (or P values) to accept or reject the null hypothesis of the underlying process is in control. To make a decision, instead of using only the current probability, previous “m” probabilities are considered. The performance of the control chart is evaluated in terms of average run length (ARL) using Monte Carlo simulations. Procedure for estimation of parameters used in the control chart is also discussed. The proposed control chart is compared with previous control charts and found to be more efficient in controlling the false discovery rate. 相似文献