|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | A Novel Robust Watermarking Algorithm for Encrypted Medical Image Based on DTCWT-DCT and Chaotic Map显示文摘In order to solve the problem of patient information security protection in medical images,whilst also taking into consideration the unchangeable particularity of medical images to the lesion area and the need for medical images themselves to be protected,a novel robust watermarking algorithm for encrypted medical images based on dual-tree complex wavelet transform and discrete cosine transform(DTCWT-DCT)and chaotic map is proposed in this paper.First,DTCWT-DCT transformation was performed on medical images,and dot product was per-formed in relation to the transformation matrix and logistic map.Inverse transformation was undertaken to obtain encrypted medical images.Then,in the low-frequency part of the DTCWT-DCT transformation coefficient of the encrypted medical image,a set of 32 bits visual feature vectors that can effectively resist geometric attacks are found to be the feature vector of the encrypted medical image by using perceptual hashing.After that,different logistic initial values and growth parameters were set to encrypt the watermark,and zero-watermark technology was used to embed and extract the encrypted medical images by combining cryptography and third-party concepts.The proposed watermarking algorithm does not change the region of interest of medical images thus it does not affect the judgment of doctors.Additionally,the security of the algorithm is enhanced by using chaotic mapping,which is sensitive to the initial value in order to encrypt the medical image and the watermark.The simulation results show that the pro-posed algorithm has good homomorphism,which can not only protect the original medical image and the watermark information,but can also embed and extract the watermark directly in the encrypted image,eliminating the potential risk of decrypting the embedded watermark and extracting watermark.Compared with the recent related research,the proposed algorithm solves the contradiction between robustness and invisibility of the watermarking algorithm for encrypted medical images,and it has good results against both conventional attacks and geometric attacks.Under geometric attacks in particular,the proposed algorithm performs much better than existing algorithms. | Jing Liu Jingbing Li Jieren Cheng Jixin Ma Naveed Sadiq Baoru Han Qiang Geng Yang Ai | 2019 | Computers, Materials & Continua2019，，8： | 1 |
| 2 | Th-Shaped Tunable Multi-Band Antenna for Modern Wireless Applications显示文摘A compact,reconfigurable antenna supporting multiple wireless services with a minimum number of switches is found lacking in literature and the same became the focus and outcome of this work.It was achieved by designing a Th-Shaped frequency reconfigurable multi-band microstrip planar antenna,based on use of a single switch within the radiating structure of the antenna.Three frequency bands(i.e.,2007–2501 MHz,3660–3983MHz and 9341–1046 MHz)can be operated with the switch in the ON switch state.In the OFF state of the switch,the antenna operates within the 2577–3280MHz and 9379–1033MHz Bands.The proposed antenna shows an acceptable input impedance match with Voltage Standing Wave Ratio(VSWR)less than 1.2.The peak radiation efficiency of the antenna is 82%.A reasonable gain is obtained from 1.22 to 3.31 dB within the operating bands is achieved.The proposed antenna supports UniversalMobile Telecommunication System(UMTS)-1920 to 2170 MHz,Worldwide Interoperability and Microwave Access(WiMAX)/Wireless Broadband/(Long Term Evolution)LTE2500–2500 to 2690 MHz,Fifth Generation(5G)-2500/3500 MHz,Wireless Fidelity(Wi-Fi)/Bluetooth-2400 to 2480 MHz,and Satellite communication applications in X-Band-8000 to 12000 MHz.The overall planar dimension of the proposed antenna is 40×20mm2.The antennawas designed,along with the parametric study,using Electromagnetic(EM)simulation tool.The antenna prototype is fabricated for experimental validation with the simulated results.The proposed antenna is low profile,tunable,lightweight,cheap to fabricate and highly efficient and hence is deemed suitable for use in modern wireless communication electronic devices. | Wasi Ur Rehman Khan Muhammad Fawad Khan Muhammad Irfan Sadiq Ullah Naveed Mufti Usman Ali Rizwan Ullah Fazal Muhammad Saifur Rahman Faisal Althobiani Mohammed Alshareef Mohammad E.Gommosani | 2023 | Computers, Materials & Continua2023，，2： | 0 |
| 3 | Cactus-Shaped Frequency Reconfigurable Antenna for Sub 10 GHz Wireless Applications显示文摘This paper presents,a novel cactus shaped frequency reconfigurable antenna for sub 10 GHz wireless applications.PIN diode is utilized as an electrical switch to achieve reconfigurability,enabling operation in four different frequency ranges.In the switch ON state mode,the antenna supports 2177-3431 and 6301-8467 MHz ranges.Alternatively,the antenna resonates within 2329-3431 and 4951-6718 MHz while in the OFF state mode.Radiation efficiency values,ranging from 68%to 84%,and gain values,ranging from 1.6 to 4 dB,in the operating frequency bands.the proposed antenna satisfy the practical requirements and expectations.The overall planner dimensions of the proposed antenna model is 40×21 mm^(2).Moreover,the measurement results from the prototype support the simulation results.Based on the frequency ranges supported by the antenna,it can be used for multiple wireless standards and services,including Worldwide interoperability and Microwave Access(WiMAX),Wireless Fidelity(Wi-Fi),Bluetooth,Long Term Evolution(LTE)and satellite communications.This increases its applicability for use in mobile terminals. | Muhammad Irfan Wasi Ur Rehman Khan Sadiq Ullah Naveed Mufti Muhammad Fawad Khan Rizwan Ullah Usman Ali Fazal Muhammad Faisal Althobiani Mohammed Alshareef Shadi Alghaffari Saifur Rehman V.R.Shamji | 2023 | Computer Systems Science & Engineering2023，45，6： | 0 |
| 4 | Flower Pollination Heuristics for Parameter Estimation of Electromagnetic Plane Waves显示文摘For the last few decades,the parameter estimation of electromagnetic plane waves i.e.,far field sources,impinging on antenna array geometries has attracted a lot of researchers due to their use in radar,sonar and under water acoustic environments.In this work,nature inspired heuristics based on the flower pollination algorithm(FPA)is designed for the estimation problem of amplitude and direction of arrival of far field sources impinging on uniform linear array(ULA).Using the approximation in mean squared error sense,a fitness function of the problem is developed and the strength of the FPA is utilized for optimization of the cost function representing scenarios for various number of sources non-coherent located in the far field.The worth of the proposed FPA based nature inspired computing heuristic is established through assessment studies on fitness,histograms,cumulative distribution function and box plots analysis.The other worthy perks of the proposed scheme include simplicity of concept,ease in the implementation,extendibility and wide range of applicability to solve complex optimization problems.These salient features make the proposed approach as an attractive alternative to be exploited for solving different parameter estimation problems arising in nonlinear systems,power signal modelling,image processing and fault diagnosis. | Sadiq Akbar Muhammad Asif Zahoor Raja Naveed Ishtiaq Chaudhary Fawad Zaman Hani Alquhayz | 2021 | Computers, Materials & Continua2021，，8： | 0 |
您所在的机构暂未开通此部分的功能，请联系管理员