Autor: Li, Hua - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Particle Swarm Optimization Fuzzy Systems for the Age Reduction Imperfect Maintenance Model
Autorzy:: Li, Che-Hua
Tematy:: imperfect maintenance
preventive maintenance
reliability
fuzzy modeling
particle swarm optimization (PSO); Pokaż więcej
Wydawca:: Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Powiązania:: https://bibliotekanauki.pl/articles/301843.pdf Link otwiera się w nowym oknie
Opis:: This research includes two topics: (1) the modeling of periodic preventive maintenance policies over an infi nite time span for repairable systems with the reduction of the degradation rate after performing an imperfect preventive maintenance (PM) activity; (2) the parameter estimation of failure distribution and the restoration effect of PM from the proposed PM policy for deteriorating systems. The concept of the improvement factor method is applied to measure the restoration effect on the degradation rate for a system after each PM. An improvement factor is presented as a function of the system's age and the cost of each PM. A periodic PM model is then developed. The optimal PM interval and the optimal replacement time for the proposed model can be obtained by minimizing the objective functions of the cost rate through the algorithms provided by this research. An example of using Weibull failure distribution is provided to investigate the proposed model. The method is proposed to estimate the parameters of the failure process and the improvement effect after each PM by analyzing maintenance and failure log data. In this method, a PSO-based method is proposed for automatically constructing a fuzzy system with an appropriate number of rules to approach the identifi ed system. In the PSO-based method, each individual in the population is constructed to determine the number of fuzzy rules and the premise part of the fuzzy system, and then the recursive least-squares method is used to determine the consequent part of the fuzzy system constructed by the corresponding individual. Consequently, an individual corresponds to a fuzzy system. Subsequently, a fi tness function is defi ned to guide the searching procedure to select an appropriate fuzzy system with the desired performance. Finally, two identifi cation problems of nonlinear systems are utilized to illustrate the effectiveness of the proposed method for fuzzy modeling.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Robust dual color images watermarking scheme with hyperchaotic encryption based on quaternion DFrAT and genetic algorithm
Autorzy:: Luo, Hui-Xin
Gong, Li-Hua
Chen, Su-Hua
Tematy:: color image watermarking
hyperchaotic encryption
quaternion discrete fractional angular transform
quaternion singular value decomposition
genetic algorithm; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/27310094.pdf Link otwiera się w nowym oknie
Opis:: A robust dual color images watermarking algorithm is designed based on quaternion discrete fractional angular transform (QDFrAT) and genetic algorithm. To guarantee the watermark security, the original color watermark image is encrypted with a 4D hyperchaotic system. A pure quaternion matrix is acquired by performing the discrete wavelet transform (DWT), the block division and the discrete cosine transform on the original color cover image. The quaternion matrix is operated by the QDFrAT to improve the robustness and the security of the watermarking scheme with the optimal transform angle and the fractional order. Then the singular value matrix is obtained by the quaternion singular value decomposition (QSVD) to further enhance the scheme’s stability. The encryption watermark is also processed by DWT and QSVD. Afterward, the singular value matrix of the encryption watermark is embedded into the singular value matrix of the host image by the optimal scaling factor. Moreover, the values to balance imperceptibility and robustness are optimized with a genetic algorithm. It is shown that the proposed color image watermarking scheme performs well in imperceptibility, security, robustness and embedding capacity.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Interaction between turbidity currents and a contour current – a rare example from the Ordovician of Shaanxi province, China
Autorzy:: Li, Hua
van Loon, A. J. (Tom)
He, Youbin
Tematy:: contourites
turbidites
reworking
Ordos basin
Pingliang formation
kontury
turbidyty
przeróbka
zlewnia
Ordos
Pingliang; Pokaż więcej
Wydawca:: Uniwersytet im. Adama Mickiewicza w Poznaniu
Powiązania:: https://bibliotekanauki.pl/articles/950462.pdf Link otwiera się w nowym oknie
Opis:: The silty top parts of graded turbidites of the Late Ordovician Pingliang Formation, which accumulated along the southern margin of the Ordos Basin (central China), have been reworked by contour currents. The reworking of the turbidites can be proven on the basis of paleocurrent directions in individual layers: the ripple-cross-bedded sandy divisions of some turbidites show transport directions consistently into the downslope direction (consistent with the direction of other gravity flows), but in the upper, silty fine-grained division they show another direction, viz. alongslope (consistent with the direction that a contour current must have taken at the same time). Both directions are roughly perpendicular to each other. Moreover, the sediment of the reworked turbidites is better sorted and has better rounded grains than the non-reworked turbidites. Although such type of reworking is well known from modern deep-sea environments, this has rarely been found before in ancient deep-sea deposits. The reworking could take place because the upper divisions of the turbidites involved are silty and consequently relatively easily erodible, while the contour current had locally a relatively high velocity – and consequently a relatively large erosional capability – because of confinement within a relatively narrow trough.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Image compression and encryption algorithm based on advanced encryption standard and hyper-chaotic system
Autorzy:: Nie, Zhe
Liu, Zheng-Xin
He, Xiang-Tao
Gong, Li-Hua
Tematy:: hyper-chaotic system
advanced encryption standard
discrete cosine transform
image encryption
image compression; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/174108.pdf Link otwiera się w nowym oknie
Opis:: An image compression and encryption algorithm by combining the advanced encryption standard (AES) with the hyper-chaotic system is designed, in which Arnold map is employed to eliminate part of the block effect in the image compression process. The original image is compressed with the assistance of a discrete cosine transform and then its transform coefficients are encrypted with the AES algorithm. Besides, the hyper-chaotic system is adopted to introduce the nonlinear processfor image encryption. Numerical simulations and theoretical analyses demonstrate that the proposed image compression and encryption algorithm is of high security and good compression performance.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Hybrid watermarking scheme based on singular value decomposition ghost imaging
Autorzy:: Wu, Jun-Yun
Huang, Wei-Liang
Wen, Ru-Hong
Gong, Li-Hua
Tematy:: digital watermarking
SVD ghost imaging
discrete wavelet transform
imperceptibility; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/1835818.pdf Link otwiera się w nowym oknie
Opis:: A hybrid watermarking algorithm with an optical watermark image based on singular value decomposition (SVD) ghost imaging is designed. Simultaneously, the blended watermarking algorithm is designed based on 4-level discrete wavelet transform (DWT), discrete cosine transform (DCT) and singular value decomposition (SVD). The 4-level diagonal sub-band image is obtained by performing 4-level two-dimensional wavelet transform on the original image, and the coefficient matrix is produced by applying the discrete cosine transform on the 4-level diagonal sub-band image. Then, three matrices are obtained by performing the singular value decomposition on the coefficient matrix. In addition, the optical watermark image is encrypted by an SVD ghost imaging system. The system could generate a secret key, and unauthorized users could not decrypt and reconstruct the original watermark image without this key. Later the encrypted watermark image is generated into the other three matrices by singular value decomposition. Afterwards, the encrypted watermark is embedded in the host image by mutual operation of different matrices in the algorithm. Simulation results validate the feasibility of the proposed hybrid watermarking scheme.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Double-image encryption algorithm based on discrete fractional angular transform and fractional Fourier transform
Autorzy:: Qiu, Tian
Dai, Wei-Hua
Chen, Su-Hua
Zhou, Hang
Gong, Li-Hua
Tematy:: chaotic system
fractional transform
discrete fractional angular transform
double-image encryption; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/2172857.pdf Link otwiera się w nowym oknie
Opis:: By combining fractional Fourier transform with discrete fractional angular transform, a double-image encryption algorithm is designed. The discrete cosine transform is performed on two grayscale images to generate a spectrum image, and then the generated spectrum image is compressed into an image with Zigzag scanning. The compressed image is processed with the discrete fractional angular transform, and then fractional Fourier transform and double random phase coding are executed on the image. The DNA operation controlled by chaotic system is introduced to change the pixel values. Finally, the ciphertext image is obtained through bit-level permutation and pixel adaptive diffusion. The statistical information of the plaintext images is employed as the input of the SHA-256 to calculate the initial conditions of the chaotic map. Simulation experiments demonstrate that the double-image encryption algorithm can effectively reduce the correlation among adjacent pixels of the plaintext images.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Multi-color-image compression-encryption scheme in the quaternion discrete Fresnel domain
Autorzy:: Hu, Ze-Ting
Zeng, Ping-Ping
Ding, Hong-Xing
Gong, Li-Hua
Chen, Su-Hua
Tematy:: compressive sensing
quaternion discrete Fresnel transform
2D-LSCM chaotic system
image compression-encryption algorithm; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/58970442.pdf Link otwiera się w nowym oknie
Opis:: A multiple color images compression-encryption scheme is designed with compressive sensing in the quaternion discrete Fresnel transform. To tackle multiple color images in a holistic manner, the discrete Fresnel transform is extended into the quaternion domain and the images are encrypted with the quaternion discrete Fresnel transform. In this scheme, the RGB color components of plaintext images are simultaneously compressed and encrypted in three mutually independent channels. Then the red, green and blue components are scrambled respectively by a chaos sequence generated by the 2D logistic-sine-coupling map. Each color component matrix is compressed with sparse representation and matrix measurement. Subsequently, the compressed matrices are integrated into the quaternion algebras and re-encrypted by the defined quaternion discrete Fresnel transform. The devised nonlinear cryptosystem originates from the asymmetric phase truncation operation. In decryption, the original color images are reconstructed by the gradient descent with a sparsification algorithm. The proposed multiple color images compression-encryption algorithm is feasible, effective, secure and robust.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Color image encryption scheme based on quaternion discrete multi-fractional random transform and compressive sensing
Autorzy:: Ye, Huo-Sheng
Dai, Jing-Yi
Wen, Shun-Xi
Gong, Li-Hua
Zhang, Wen-Quan
Tematy:: color image encryption
quaternion discrete multi-fractional random transform
compressive sensing
confusion-diffusion strategy; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/2033985.pdf Link otwiera się w nowym oknie
Opis:: A color image compression-encryption algorithm by combining quaternion discrete multi-fractional random transform with compressive sensing is investigated, in which the chaos-based fractional orders greatly improve key sensitivity. The original color image is compressed and encrypted with the assistance of compressive sensing, in which the partial Hadamard matrix adopted as a measurement matrix is constructed by iterating Chebyshev map instead of utilizing the entire Guassian matrix as a key. The sparse images are divided into 12 sub-images and then represented as three quaternion signals, which are modulated by the quaternion discrete multi-fractional random transform. The image blocking and the quaternion representation make the proposed cryptosystem avoid additional data extension existing in many transform-based methods. To further improve the level of security, the plaintext-related key streams generated by the 2D logistic-sine-coupling map are adopted to diffuse and confuse the intermediate results simultaneously. Consequently, the final ciphertext image is attained. Simulation results reveal that the proposed cryptosystem is feasible with high security and has strong robustness against various attacks.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Reliability optimization design method based on multi-level surrogate model
Autorzy:: Li, Yong-Hua
Liang, Xiao-Jia
Dong, Si-Hui
Tematy:: Kriging model
reliability-based optimization
multi-level surrogate model
adaptive dynamic penalty function; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Powiązania:: https://bibliotekanauki.pl/articles/1841935.pdf Link otwiera się w nowym oknie
Opis:: In this work, a genetic-algorithm-based Kriging model with multi-point addition sequence optimization strategy is addressed to make up for the shortcomings of Kriging model with single point criterion. This approach combines the multi-point addition strategy with genetic algorithm to enable the Kriging model to efficiently capture the globally optimal solution. Based on this, a multi-level surrogate method is presented by employing a local surrogate model to modify the Kriging global surrogate model, and then applied to design optimization to improve the accuracy and efficiency of global optimization. Meanwhile, a reliability design optimization method based on multi-level surrogate model is studied by dealing with the reliability constraints with an adaptive reliability penalty function. Numerical examples show that the proposed method can find the optimal solution of the object problem with the least calculation cost under the condition of satisfying the reliability constraint.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Exosome-hydrogels loaded with metal-organic framework improve skin aging by inhibiting oxidative stress
Autorzy:: Li, Li-Jie
Han, Qing-Ling
Feng, Wen-Jie
Wang, Zhan-Peng
Li, Hong-Hua
Tematy:: Ba(II) compound
luminescence
hydrogels
exosome
skin aging; Pokaż więcej
Wydawca:: Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Powiązania:: https://bibliotekanauki.pl/articles/59124214.pdf Link otwiera się w nowym oknie
Opis:: Solvothermal reactions of Ba(NO3)2 with 1,3,5-benzenetricarboxylic acid gave rise to a new coordination polymer of [Ba6(BTC)4(H2O)9]}n (1 H3BTC = benzenetricarboxylic acid). The complex 1 was characterized soundly by Fourier transform infrared (FT-IR) spectroscopy, elemental analysis (EA), single-crystal X-ray diffraction (SCXRD), and thermogravimetric analysis (TGA). The framework of 1 has high thermal stability and shows intense luminescence at room temperature. Hyaluronic acid (HA) and carboxymethyl chitosan (CMCS) have good biocompatibility, based on the chemical synthesis method, the HA/CMCS hydrogel was prepared. With exosomes as drug models, we further synthesized novel exosome-loaded metal gel particles and evaluated their effects on oxidative stress in human dermal fibroblasts.
Dostawca treści:: Biblioteka Nauki

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