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Wyszukujesz frazę "Liu, Xin" wg kryterium: Autor


Tytuł:
Camouflage Assessments with Digital Pattern Painting Based on the Multi-Scale Pattern-in-Picture Evaluation Model
Autorzy:
Jia, Qi
Xu, Weidong
Yi, Yang
Liu, Jun
Hu, Jianghua
Zhu, Liyan
Yang, Xin
Powiązania:
https://bibliotekanauki.pl/articles/24200962.pdf
Data publikacji:
2023
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
computer-aided
camouflage assessment
pattern painting
evaluation
simulation
military camouflage
Opis:
In general, traditional evaluations of target camouflage effects are usually conducted based on observational data and general results of statistical analysis. This widely applied methodology quantifies the detection and identification probabilities of camouflage objects but has considerable shortcomings. This data evaluation process is laborious and time-consuming and very low in reproducibility, which sheds light on the necessity of developing a more efficient method in this study field. The growth of computeraided image processing technology provides technical support for camouflage effect evaluation based on digital image processing. Digital pattern painting, which has been previously applied to combat utility uniforms, is a new methodology full of potential due to its broad geographical adaptability. This study proposes a multi-scale pattern-in-picture method to evaluate camouflage effects at different distances. We also established a computer-aided background image library and camouflage assessments with digital simulation and created an evaluation system that could be effectively applied to combat utility uniforms. More than 40 testers participated in this study, who were asked to score the designed camouflage schemes using the evaluation system proposed. The data from simulation assessments and individual evaluations show that the computer-aided simulation assessments conducted as part of this research can efficiently and objectively evaluate the camouflage effect on military objects.
Źródło:
Fibres & Textiles in Eastern Europe; 2023, 31, 2; 39--50
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exact approaches to late work scheduling on unrelated machines
Autorzy:
Liu, Xinbo
Wang, Wen
Chen, Xin
Sterna, Malgorzata
Blazewicz, Jacek
Powiązania:
https://bibliotekanauki.pl/articles/11542692.pdf
Data publikacji:
2023
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
late work scheduling
unrelated machine
mathematical model
branch algorithm
bound algorithm
dynamic programming
planowanie pracy
model matematyczny
algorytm podziału
algorytm ograniczeń
programowanie dynamiczne
Opis:
We consider the scheduling problem on unrelated parallel machines in order to minimize the total late work. Since the problem is NP-hard, we propose a mathematical model and two dedicated exact approaches for solving it, based on the branching and bounding strategy and on enumerating combined with a dynamic programming algorithm. The time efficiencies of all three approaches are evaluated through computational experiments.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2023, 33, 2; 285--295
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical analysis of resistance characteristics of a novel high-speed quadramaran
Autorzy:
Liu, Xin
Yang, Jinglei
Wu, Defeng
Hou, Liang
Li, Xiaowen
Wan, Qian
Powiązania:
https://bibliotekanauki.pl/articles/34605384.pdf
Data publikacji:
2023
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
high-speed quadramaran
high-speed catamaran
resistance characteristic
wave-making interference
resistance hump
Opis:
This paper utilised computational fluid dynamics (CFD) technology to calculate the resistance of a novel high-speed quadramaran in calm water using the Navier‒Stokes (N‒S) equation, analysed the total resistance, frictional resistance, and residual resistance characteristics of this novel high-speed quadramaran at different length Froude numbers, and compared them with the results of a conventional high-speed catamaran with the same displacement. The results showed that the total resistance of the quadramaran had a significant hump at the Froude number of 0.6, due to the complexity of the wave interference among the four demihulls, and the hump value was about 1.6 times that of the catamaran. Above the hump speed, the total resistance of the quadramaran decreased with the increase of the Froude number, until reaching the Froude number of 1.06, when the curve became flat, and it showed a maximum resistance reduction of 40% at the Froude number of 1.66 compared with the catamaran, where the total resistance curve was steep. The frictional resistance of the quadramaran increased gradually with the growth of the Froude number, which was basically consistent with the change trend of the catamaran. The residual resistance of the quadramaran first rose and then reduced with the rising Froude number, the curve showed a large hump due to the adverse wave interference, and the hump value was about 1.7 times that of the catamaran. Above the Froude number of 1.06, as the wave interference changed from adverse to favourable, the quadramaran had lower residual resistance than the catamaran. The bow and stern demihulls of the quadramaran were also analysed for their resistance characteristics. The total resistance of the bow demihulls increased gradually with the increase of the Froude number, the curve had a small hump at the Froude number of 0.7, and above the hump speed, the curve was steep. The total resistance of the stern demihulls first increased and then decreased with the growth of the Froude number, the hump value at the Froude number of 0.85 was significant and was about 2 times that of the bow demihulls, and the curve became flat above the Froude number of 1.51.
Źródło:
Polish Maritime Research; 2023, 2; 11-27
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation of magnesium hydroxide by modifier-directed hydration and its effect on flame retardancy and mechanical properties of polypropylene
Autorzy:
Wang, Mei Jia
Bai, Li Mei
Zhang, Meng Ting
Ma, Yu Xin
Zhao, Liu Cheng
Li, Shao Ying
Powiązania:
https://bibliotekanauki.pl/articles/27323651.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
modifier
hydration preparation
magnesium hydroxide
polypropylene
Opis:
With the rapid development of the polymer materials industry and the improvement of people's environmental awareness, magnesium hydroxide has been widely used in polymer materials due to its high decomposition temperature, non-toxic smoke suppression, and the advantages of neutralizing harmful gases produced by polymer combustion. However, the conventional preparation methods of magnesium hydroxide exhibit several issues, including high hydrophilicity, elevated polarity, and limited compatibility with polymers. This research proposes an improved method by adding sodium stearate and KH560 modifier, controlling the rate of magnesium oxide and preparing magnesium hydroxide flame retardants using a modifier-directed hydration method. Various characterizations confirmed its morphology, particle size and structure. The magnesium hydroxide exhibits low polarity, small particle size, stable structure and excellent hydrophobicity (with a contact angle of 120.32°, and a free energy of 1.34mN/m). In parallel, the magnesium hydroxide/polypropylene composites demonstrate excellent flame retardancy (LOI of 25%, V-1 grade) and simultaneously enhance the dispersion of magnesium hydroxide within the polypropylene matrix, improving the material's toughness and strength.
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 6; art. no. 175706
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on characteristics of embedded resonator sensor based on PtS2
Autorzy:
Li, Xin
Li, Xieyuan
Zhang, Haitao
Chen, Shuang
Liu, Shurong
Li, Yang
Powiązania:
https://bibliotekanauki.pl/articles/27310092.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
embedded
microring resonator
U-shaped feedback waveguide
PtS2 core layer
Opis:
An embedded microring resonator model using PtS2 as the core layer was designed and optimized for sensing. The inner layer is made of PtS2, and SiO2 and Si3N4 are used as cladding. The overall structure is Si3N4-SiO2-PtS2-SiO2-Si3N4. Field strength distribution of longitudinal section of single straight waveguide and the longitudinal section of coupling part of straight and annular waveguides are simulated according to the coupled-mode theory. The transfer matrix method is used to analyze characteristics between the length of the U-shaped feedback waveguide and the circumference of microring and the change of attenuation factor and coupling coefficient on the output spectrum. The simulation results showed that the embedded microring resonator with PtS2 as the core presents excellent optical properties. The resonance depth is more than –50 dB, and the sensitivity can reach 1806.61 dB/RIU. When the resonance wavelength is 1550.86 nm and the self-coupling coefficient is 0.9849. The corresponding detection limit is about 1.66056×10–7 dB/RIU, and the quality factor is 2.8848×10–5 under the measurement system with a signal-to-noise ratio of 30 dB. Compared with the traditional single microring structure, the proposed microring presents a higher free spectral range and more suitable for the fabrication of high-sensitivity, low-detection limit, and large-measurement range sensors.
Źródło:
Optica Applicata; 2023, 53, 2; 213--226
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on the modified echo highlight model for underwater vehicles with combined structures
Autorzy:
Xie, Xin
Liu, Fanghua
Jin, Guangwen
Liu, Jinwei
Xu, Cong
Peng, Zilong
Powiązania:
https://bibliotekanauki.pl/articles/34609383.pdf
Data publikacji:
2023
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
modified highlight model
wedge-shaped convex structure
piecewise synthesis method
acoustic scattering calculation software
Opis:
The highlight model is widely used as a simple and convenient method in the radar field but its accuracy is not high. Based on the traditional highlight model, the algorithm has been improved to address the acoustic scattering problems of underwater vehicles with more complex line shapes. The basic idea is to partition the model into micro-bodies to calculate the scattered sound pressure, consider the phase interference of each part, and then synthesise the scattered sound pressure to approximate the target’s actual shape. A computational model of the wedge-shaped convex structure on the back of the underwater vehicles is developed using a highlight model of a trapezoidal plate. The results of the calculations using the highlight model approach are consistent with those of the planar element method. Utilising the modified highlight model method, the accuracy of acoustic scattering characteristics calculations for the stern and overall structures of underwater vehicles has proven satisfactory. Finally, fast acoustic scattering prediction software is developed for underwater vehicles, enabling the calculation of the acoustic scattering characteristics for individual structures, combined structures, and coated silent tiles. This software provides algorithmic support for the fast prediction of the acoustic stealth performance of underwater vehicles.
Źródło:
Polish Maritime Research; 2023, 3; 163-173
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Flow field characteristic analysis of cushion system of partial air cushion support catamaran in regular waves
Autorzy:
Yang, Jinglei
Sun, Han-bing
Li, Xiao-wen
Liu, Xin
Powiązania:
https://bibliotekanauki.pl/articles/32910719.pdf
Data publikacji:
2022
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
regular waves
partial air cushion support catamaran (PACSCAT)
cushion system
fluid structure interaction (FSI)
flow field characteristics
Opis:
In order to study the flow field characteristics of cushion system of partial air cushion support catamaran (PACSCAT) in waves, an analysis was carried out involving flexible treatment on the bow and stern air seals to simulate air seal shape under test conditions by means of computational fluid dynamics method and fluid structure interaction (FSI) method. On this basis, the pressure conditions of the air cushion chamber and the pressurized chamber at different wavelengths and different speeds are studied and compared with experimental results. The experimental results show that: for the air cushion pressure, the nonlinear characteristics of the numerical calculation results are more subtle than the experimental values, after linear transformation, the amplitudes of the experimental values are obviously greater than the calculated values after linear transformation, but the average values are not much different; At low speed of 2.0m/s, the spatial pressure distribution of the pressurized chamber and the air cushion chamber are uniformly distributed, at high speed of 3.6m/s, except for a certain pressure jump occurred in the air cushion chamber near the stern air seal, the pressure in other spaces is also evenly distributed, it proves that the pressurized chamber type of air intake can effectively meet the air cushion pressure balance.
Źródło:
Polish Maritime Research; 2022, 3; 21-32
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of differential serum expression of three factors and pulmonary function in patients with silicosis
Autorzy:
Zhu, Ying
Duan, Xia Yu
Cheng, Yun Qi
Yao, Xin Jing
Xu, Hong
Zhang, Kui Sheng
Li, Feng Shi
Yang, Fang
Liu, Liang He
Yuan, Xiang Ju
Powiązania:
https://bibliotekanauki.pl/articles/2086531.pdf
Data publikacji:
2021-08-05
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
silicosis
pulmonary function
early diagnosis
ROC
PTPN2
factor B
Opis:
ObjectivesSilicosis is a chronic occupational lung disease. As was previously found by the authors, some proteins increased in the lung tissue of activated rats, and protein tyrosine phosphatase non-receptor type 2 (PTPN2), factor B, and vaccinia-related kinase 1 (VRK1) showed highly differential expressions.Material and MethodsIn this study, serum and bronchoalveolar lavage fluid samples were collected from patients with silicosis and healthy people to verify the expression of PTPN2, factor B, and VRK1. The diagnostic value of differentially expressed proteins for silicosis was judged.ResultsThe expression levels of serum PTPN2, VRK1, and factor B in patients with silicosis were significantly higher than those in the control group (p < 0.01). Higher serum PTPN2 and factor B concentrations significantly and negatively correlated with the ratio of forced expiratory volume in 1 s to forced vital capacity (FEV1/FVC), maximum vital capacity (VCmax), FEV1, and FVC, suggesting that the high expression of PTPN2 and factor B is associated with decreased pulmonary ventilation function and restrictive ventilatory impairment in patients with silicosis. All area under curve (AUC) measurements generated from single detection events were >0.744, with PTPN2 reaching the highest value (0.858). The AUC, sensitivity, and specificity for the combined diagnosis using factor B and PTPN2 were 0.907, 86.91% and 85.07%, respectively, for factor B and PTPN2. The 3 differentially expressed proteins are potential classes of predictive biomarkers for silicosis.ConclusionsRegarding the economy and test practicality, the best diagnostic combination is factor B and PTPN2 for the analysis of AUC, sensitivity and specificity.
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2021, 34, 4; 527-540
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fatigue life prediction of wire rope based on grey particle filter method under small sample condition
Autorzy:
Zhao, Dan
Liu, Yu-Xin
Ren, Xun-Tao
Gao, Jing-Zi
Liu, Shao-Gang
Dong, Li-Qiang
Cheng, Ming-Shen
Powiązania:
https://bibliotekanauki.pl/articles/2038206.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
wire rope
fatigue life prediction
small sample size
grey theory
particle filter method
Opis:
The fatigue life prediction of wire ropes has two main characteristics: a large test sample size and uncertain factors. In this paper, based on the small number of wire rope fatigue life data, the grey particle filter method has been used to realize the fatigue life prediction of wire rope under different load conditions. First, the GOM(1,1) model is constructed and the reliability life data of wire rope is predicted under small sample size. Then, P-S-N curve of the dangerous part is determined by combining the equivalent alternating stress of the dangerous part of the wire rope during the fatigue test. Subsequently, the particle filter method is used to modify P-S-N curve. Finally, the fatigue life prediction model of wire rope is obtained based on fatigue damage accumulation, which realized the fatigue life prediction under different load conditions, and the results were compared with that from the test. The results show that the proposed method is effective and has high accuracy in wire rope fatigue life prediction under single, combined loading conditions and small sample size.
Źródło:
Eksploatacja i Niezawodność; 2021, 23, 3; 454-467
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Green Fabrication of Nanoscale Energetic Molecular Perovskite (H2dabco)[Na(ClO4)3] with Reduced Mechanical Sensitivity
Autorzy:
Hu, Li-shuang
Du, Zelin
Liu, Yang
Gong, Shida
Guang, Chunyu
Li, Xin
Yang, Zhi
Jia, Qi
Liang, Kaili
Powiązania:
https://bibliotekanauki.pl/articles/27787996.pdf
Data publikacji:
2021
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
molecular perovskite
(H2dabco)[Na(ClO4)3]
ball milling
thermal decomposition
mechanical sensitivity
Opis:
High-energy-density molecular perovskite energetic materials with high detonation performance have attracted much attention, but poor safety performance has limited their potential applications. In this paper, nano sodium perchlorate-based molecular perovskite (H2dabco)[Na(ClO4)3] (nano DAP-1) was fabricated by green ball-milling technology. The structure and morphology of the samples were characterized and the results showed that nano DAP-1 with nearly spherical morphology has a narrow particle size distribution, < 1 μm. The thermal decomposition properties were investigated by differential scanning calorimetry (DSC). The exothermic peak of nano DAP-1 thermal decomposition was 330.0 °C, a decrease of 51.7 °C compared with that of raw DAP (381.7 °C). The apparent activation energy (Ea) of nano DAP-1 was calculated to be 160.9 kJ·mol–1, which is lower than that of raw DAP-1 (168.6 kJ·mol–1). Mechanical sensitivity studies showed that nano DAP-1 (H50: 64 cm) exhibited a lower impact sensitivity than that of the raw DAP-1 (H50: 51 cm). This work provides a simple and effective way for improving the thermal decomposition properties and safety performance of molecular perovskite energetic materials.
Źródło:
Central European Journal of Energetic Materials; 2021, 18, 3; 369--384
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation Evaluation Method for Fusion Characteristics of the Optical Camouflage Pattern
Metoda oceny symulacji charakterystyk wzoru kamuflażu optycznego
Autorzy:
Yang, Xin
Xu, Wei-Dong
Liu, Jun
Jia, Qi
Zhu, Wan-Nian
Powiązania:
https://bibliotekanauki.pl/articles/1419455.pdf
Data publikacji:
2021
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
camouflage pattern evaluation
effect evaluation
sampling statistics
visual feature
kamuflaż
efekt oddziaływania
próbkowanie
funkcja wizualna
Opis:
A comprehensive evaluation system for a camouflage design combining local effect evaluation and global sampling is developed. Different from previous models, this method can sample and evaluate target camouflage in a wide range of combat areas, thereby obtaining a comprehensive evaluation effect. In evaluating local effects, the Gaussian pyramid model is adopted to decompose the image on a multi-scale so that it can conform to the multi-resolution property of human eyes. The Universal Image Quality Index (UIQI) conforming to features of eye movements is then adopted to measure the similarities between multi-scale targeted and background brightness, color and textural features. In terms of the imitation camouflage pattern design algorithm, uniform sampling is used to obtain the evaluation distribution in the background; while for the deformation camouflage pattern, the sampling distribution is improved to make it conform to the movement rule of the target in the background. The evaluation results of the model for different designs were investigated. It is suggested by the experimental results that the model can compare and evaluate the indicators involved in the process of camouflage design, including integration, polychromatic adaptability and algorithm stability. This method can be applied in the evaluation and contrast of camouflage pattern design algorithms, in parameter optimisation of camouflage design and in scheme comparison in engineering practice, and can provide support of evaluation methodology for camouflage design theories.
W pracy opracowano kompleksowy system oceny projektu kamuflażu, łączący ocenę efektu lokalnego i próbkowanie globalne. W odróżnieniu od poprzednich modeli, ta metoda może próbkować i oceniać kamuflaż celu w szerokim zakresie obszarów walki, uzyskując w ten sposób kompleksowy efekt oceny. Oceniając efekty lokalne, przyjęto model piramidy Gaussa w celu dekompozycji obrazu w wielu skalach, tak aby mógł on być zgodny z właściwościami i rozdzielczością ludzkiego oka. Następnie przyjęto uniwersalny wskaźnik jakości obrazu (UIQI) zgodny z cechami ruchów oczu, tak aby zmierzyć podobieństwa między celowaniem w wielu skalach a jasnością tła, kolorem i cechami tekstury. Jeśli chodzi o algorytm projektowania imitacji wzoru kamuflażu, w celu uzyskania rozkładu oceny w tle zastosowano jednolite próbkowanie; podczas gdy w przypadku wzoru kamuflażu deformacji poprawiono rozkład próbkowania, tak aby był zgodny z regułą ruchu celu w tle. Zbadano wyniki oceny modelu dla różnych projektów. Wyniki eksperymentów wykazały, że model może służyć do porównania i oceny wskaźników procesu projektowania kamuflażu, w tym integrację, polichromatyczną adaptowalność i stabilność algorytmu. Metoda przedstawiona w pracy może znaleźć zastosowanie w ocenie algorytmów projektowania wzorów kamuflażu, w optymalizacji parametrów projektowania kamuflażu i przy porównywaniu schematów w praktyce inżynierskiej, a także może stanowić wsparcie dla metodologii oceny teorii projektowania kamuflażu.
Źródło:
Fibres & Textiles in Eastern Europe; 2021, 3 (147); 103-110
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A dynamic model for the heat transfer behavior of a cooling system
Autorzy:
Liu, Wen
Zhang, Chi
Hu, Xiao-Xiong
Cao, Jian-Bo
Liu, Li-Jiao
Ye, Xin-Y
Lin, Li
Qi, Xun-Ji
Powiązania:
https://bibliotekanauki.pl/articles/2050060.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
adsorption system
refrigerating system
desorption
simulation
Opis:
For purposes of studying the heat transfer behavior of various fluids in a refrigeration system, a dynamic model is established, obtained on the basis of analysis concerning the effects of adsorption velocity, adsorbent bed temperature, condensing temperature, and heat transfer fluids, as well as changes of external conditions. It is demonstrated that adsorption velocity increases sharply in the initial phase of adsorption process and gradually declines after reaching a peak value, whereas condensing temperature increases sharply in the initial phase of desorption process and decreases after reaching a peak value with the desorption quantity decreasing. Furthermore, the increase of heat source temperature and the decrease of cooling water temperature can advance the adsorption process. The present study therefore suggests some ways of improving the performance of such a refrigeration system by increasing heat source temperature, decreasing ambient air temperature, increasing return air temperature and decreasing cooling water temperature.
Źródło:
Control and Cybernetics; 2020, 49, 3; 315--332
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Die Wall Lubrication on High Velocity Compaction Behavior and Sintering Properties of Fe-Based PM Alloy
Autorzy:
Liu, Zili
Li, Dong
Liu, Xiqin
Li, Haohao
Huang, Xin
Tang, Zhihao
Zou, Yuwen
Powiązania:
https://bibliotekanauki.pl/articles/352101.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
high velocity compaction
die wall lubrication
green density
impact force
cold welding
Opis:
Fe-based PM alloy powder of Fe-2.5Ni-0.5Mo-2Cu-0.4C was pressed by high velocity compaction combined with die wall lubrication, and the effect of die wall lubrication on high velocity compaction behavior and sintering properties of the Fe-based PM alloy were studied. The results indicate that the impact force, green density, sintered density of samples increase with the augment of the impact velocity and die wall lubrication. Compared with that without die wall lubrication, the green density and sintered density of the sample with die wall lubrication are about 0.07-0.12 g/cm3 and 0.08~0.11 g/cm3 higher at the same impact velocity, respectively, while the ejection force of the die wall lubricated sample is much smaller, and reduced about 26%~36%. The green compact with die wall lubrication has much fewer porosity than that without die wall lubrication, and more mechanical bonding and cold welding regions are observed. The sintered samples mainly consists of gray pearlite and white ferrite, and more pearlite is observed in the sintered sample with die wall lubrication.
Źródło:
Archives of Metallurgy and Materials; 2020, 65, 2; 677-684
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
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
Powiązania:
https://bibliotekanauki.pl/articles/174108.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
hyper-chaotic system
advanced encryption standard
discrete cosine transform
image encryption
image compression
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.
Źródło:
Optica Applicata; 2019, 49, 4; 545-558
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Smart Substation Network Fault Classification Based on a Hybrid Optimization Algorithm
Autorzy:
Xia, Xin
Liu, Xiaofeng
Lou, Jichao
Powiązania:
https://bibliotekanauki.pl/articles/227220.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
smart substation
network fault classification
improved separation interval method (ISIM)
support vector
machine (SVM)
Anti-noise processing (ANP)
Opis:
Accurate network fault diagnosis in smart substations is key to strengthening grid security. To solve fault classification problems and enhance classification accuracy, we propose a hybrid optimization algorithm consisting of three parts: anti-noise processing (ANP), an improved separation interval method (ISIM), and a genetic algorithm-particle swarm optimization (GA-PSO) method. ANP cleans out the outliers and noise in the dataset. ISIM uses a support vector machine (SVM) architecture to optimize SVM kernel parameters. Finally, we propose the GA-PSO algorithm, which combines the advantages of both genetic and particle swarm optimization algorithms to optimize the penalty parameter. The experimental results show that our proposed hybrid optimization algorithm enhances the classification accuracy of smart substation network faults and shows stronger performance compared with existing methods.
Źródło:
International Journal of Electronics and Telecommunications; 2019, 65, 4; 657-663
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł

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