Autor: Xu, Jun - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: On the (2,2)-domination number of trees
Autorzy:: Lu, You
Hou, Xinmin
Xu, Jun-Ming
Powiązania:: https://bibliotekanauki.pl/articles/744559.pdf
Data publikacji:: 2010
Wydawca:: Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:: domination number
total domination number
(2,2)-domination number
Opis:: Let γ(G) and $γ_{2,2}(G)$ denote the domination number and (2,2)-domination number of a graph G, respectively. In this paper, for any nontrivial tree T, we show that $(2(γ(T)+1))/3 ≤ γ_{2,2}(T) ≤ 2γ(T)$. Moreover, we characterize all the trees achieving the equalities.
Źródło:: Discussiones Mathematicae Graph Theory; 2010, 30, 2; 185-199
2083-5892
Pojawia się w:: Discussiones Mathematicae Graph Theory
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: A characterization of (γₜ,γ₂)-trees
Autorzy:: Lu, You
Hou, Xinmin
Xu, Jun-Ming
Li, Ning
Powiązania:: https://bibliotekanauki.pl/articles/744036.pdf
Data publikacji:: 2010
Wydawca:: Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:: domination
total domination
2-domination
(λ,μ)-tree
Opis:: Let γₜ(G) and γ₂(G) be the total domination number and the 2-domination number of a graph G, respectively. It has been shown that: γₜ(T) ≤ γ₂(T) for any tree T. In this paper, we provide a constructive characterization of those trees with equal total domination number and 2-domination number.
Źródło:: Discussiones Mathematicae Graph Theory; 2010, 30, 3; 425-435
2083-5892
Pojawia się w:: Discussiones Mathematicae Graph Theory
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Analysis of Clothing Image Classification Models: A Comparison Study between Traditional Machine Learning and Deep Learning Models
Autorzy:: Xu, Jun
Wei, Yumeng
Wang, Aichun
Zhao, Heng
Lefloch, Damien
Powiązania:: https://bibliotekanauki.pl/articles/2200761.pdf
Data publikacji:: 2022
Wydawca:: Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:: e-commerce
clothing image classification
traditional machine learning
CNN
HOG
SVM
small VGG network
Opis:: Clothing image in the e-commerce industry plays an important role in providing customers with information. This paper divides clothing images into two groups: pure clothing images and dressed clothing images. Targeting small and medium-sized clothing companies or merchants, it compares traditional machine learning and deep learning models to determine suitable models for each group. For pure clothing images, the HOG+SVM algorithm with the Gaussian kernel function obtains the highest classification accuracy of 91.32% as compared to the Small VGG network. For dressed clothing images, the CNN model obtains a higher accuracy than the HOG+SVM algorithm, with the highest accuracy rate of 69.78% for the Small VGG network. Therefore, for end-users with only ordinary computing processors, it is recommended to apply the traditional machine learning algorithm HOG+SVM to classify pure clothing images. The classification of dressed clothing images is performed using a more efficient and less computationally intensive lightweight model, such as the Small VGG network.
Źródło:: Fibres & Textiles in Eastern Europe; 2022, 5 (151); 66--78
1230-3666
2300-7354
Pojawia się w:: Fibres & Textiles in Eastern Europe
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: A novel multiple attribute decision-making method based on Schweizer-Sklar t-norm and t-conorm with q-rung dual hesitant fuzzy information
Autorzy:: Xu, Yuan
Wang, Jun
Powiązania:: https://bibliotekanauki.pl/articles/2106503.pdf
Data publikacji:: 2022
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: multiple attribute decision-making
Schweizer-Sklar t-norm and t-conorm
q-rung dual hesitant fuzzy Schweizer-Sklar Hamy mean operator
q-rung dual hesitant fuzzy Schweizer-Sklar weighted Hamy mean operator
Opis:: The recently proposed q-rung dual hesitant fuzzy sets (q-RDHFSs) not only deal with decision makers’ (DMs’) hesitancy and uncertainty when evaluating the performance of alternatives, but also give them great liberty to express their assessment information comprehensively. This paper aims to propose a new multiple attribute decision-making (MADM) method where DMs’ evaluative values are in form of q-rung dual hesitant fuzzy elements (q-RDHFEs). Firstly, we extend the powerful Schweizer-Sklar q-norm and t-conorm (SSTT) to q-RDHFSs and propose novel operational rules of q-RDHFEs. The prominent advantage of the proposed operations is that they have important parameters q and r, making the information fusion procedure more flexible. Secondly, to effectively cope with the interrelationship among attributes, we extend the Hamy mean (HM) to q-RDHFSs and based on the newly developed operations, we propose the q-rung dual hesitant fuzzy Schweizer-Sklar Hamy mean (q-RDHFSSHM) operator, and the q-rung dual hesitant fuzzy Schweizer-Sklar weighted Hamy mean (q-RDHFSSWHM) operator. The properties of the proposed operators, such as idempotency, boundedness and monotonicity are discussed in detail. Third, we propose a new MADM method based on the q-RDHFSSWHM operator and give the main steps of the algorithm. Finally, the effectiveness, flexibility and advantages of the proposed method are discussed through numerical examples.
Źródło:: Archives of Control Sciences; 2022, 32, 1; 175--228
1230-2384
Pojawia się w:: Archives of Control Sciences
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Assessing system impedance based on data regrouping
Autorzy:: Xu, Shuangting
Xiao, Xianyong
Wang, Yang
Wu, Jun
Powiązania:: https://bibliotekanauki.pl/articles/1848954.pdf
Data publikacji:: 2021
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: system impedance
passive method
Thevenin equivalent
power system
Opis:: In recent years, assessing supply system impedance has become crucial due to the concerns on power quality and the proliferation of distributed generators. In this paper, a novel method is shown for passive measurement of system impedances using the gapless waveform data collected by a portable power quality monitoring device. This method improves the overall measurement accuracy through data regrouping. Compared with the traditional methods that use the consecutive measurement data directly, the proposed method regroups the data to find better candidates with less flotation on the system side. Simulation studies and extensive field tests have been conducted to verify the effectiveness of the proposed method. The results indicate that the proposed method can serve as a useful tool for impedance measurement tasks performed by utility companies.
Źródło:: Metrology and Measurement Systems; 2021, 28, 1; 191-208
0860-8229
Pojawia się w:: Metrology and Measurement Systems
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Assessing system impedance based on data regrouping
Autorzy:: Xu, Shuangting
Xiao, Xianyong
Wang, Yang
Wu, Jun
Powiązania:: https://bibliotekanauki.pl/articles/1848965.pdf
Data publikacji:: 2021
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: system impedance
passive method
Thevenin equivalent
power system
Opis:: In recent years, assessing supply system impedance has become crucial due to the concerns on power quality and the proliferation of distributed generators. In this paper, a novel method is shown for passive measurement of system impedances using the gapless waveform data collected by a portable power quality monitoring device. This method improves the overall measurement accuracy through data regrouping. Compared with the traditional methods that use the consecutive measurement data directly, the proposed method regroups the data to find better candidates with less flotation on the system side. Simulation studies and extensive field tests have been conducted to verify the effectiveness of the proposed method. The results indicate that the proposed method can serve as a useful tool for impedance measurement tasks performed by utility companies.
Źródło:: Metrology and Measurement Systems; 2021, 28, 1; 191-208
0860-8229
Pojawia się w:: Metrology and Measurement Systems
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Effect of ISO (9001) Certification and Article Type Produced on Lean Six Sigma Application Successes: a Case Study Within Textile Companies
Autorzy:: Nedra, Abbes
Jun, Xu
Nèjib, Sejri
Jiajia, Duan
Powiązania:: https://bibliotekanauki.pl/articles/2171948.pdf
Data publikacji:: 2022
Wydawca:: Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:: textile
SMEs
small and medium enterprises
ISO 9001 standard
Lean Six Sigma
Opis:: This study focused on how the ISO 9001:2008 standard has influenced organisational Lean Six Sigma (LSS) implementation success. Data were collected through a survey, followed by interviews with the quality managers/representatives of 85 small and medium enterprises (SMEs) in the textile industry. Additionally, case studies on four of the textile SMEs were carried out to validate the results. Our analysis revealed that the main benefits of LSS, among others, are problem solving improvement, reduction of the quality problem, waste reduction, and increase of productivity. However, certified companies are aware of continuous improvements to tools, which ensures the continuity of improvements made by the LSS project and facilitates the integration of Lean Six Sigma tools, which can help to make better use of the Lean Six Sigma project. The type of article produced was also found to have a considerable effect on the success of the Lean Six Sigma project.
Źródło:: Fibres & Textiles in Eastern Europe; 2022, 2 (151); 17--22
1230-3666
2300-7354
Pojawia się w:: Fibres & Textiles in Eastern Europe
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Reliability assessment of the port power system based on integrated energy hybrid system
Autorzy:: Fang, Liang
Xu, Xiao-Yan
Xia, Jun
Tarasiuk, Tomasz
Powiązania:: https://bibliotekanauki.pl/articles/2173637.pdf
Data publikacji:: 2022
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: Markov model
distributed generation
reliability assessment
integrated energy
distribution power system
model Markowa
generacja rozproszona
ocena wiarygodności
energia zintegrowana
system zasilania dystrybucyjny
Opis:: The conventional port distribution power system is being disrupted by increasing distributed generation (DG) levels based on integrated energy. Different new energy resources combine with conventional generation and energy storage to improve the reliability of the systems. Reliability assessment is one of the key indicators to measure the impact of the distributed generation units based on integrated energy. In this work, an analytical method to investigate the impacts of using solar, wind, energy storage system (ESS), combined cooling, heating and power (CCHP) system and commercial power on the reliability of the port distribution power system is improved, where the stochastic characteristics models of the major components of the new energy DG resources are based on Markov chain for assessment. The improved method is implemented on the IEEE 34 Node Test Feeder distribution power system to establish that new energy resources can be utilized to improve the reliability of the power system. The results obtained from the case studies have demonstrated efficient and robust performance. Moreover, the impacts of integrating DG units into the conventional port power system at proper locations and with appropriate capacities are analyzed in detail.
Źródło:: Bulletin of the Polish Academy of Sciences. Technical Sciences; 2022, 70, 2; art. no. e140372
0239-7528
Pojawia się w:: Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Thermoelastic strongly nonlinear vibration of rotating functionally graded ring plate
Autorzy:: Hu, Yu Da
Bao, Hai Jun
XU, Hao Ran
Powiązania:: https://bibliotekanauki.pl/articles/1839696.pdf
Data publikacji:: 2021
Wydawca:: Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:: functionally graded ring plate
natural vibration
rotational motion
strong nonlinearity
improved L-P method
Opis:: For a metal ceramic functionally graded (FGM) ring plate, considering variations in physical properties with temperature and a power-law distribution of material components along the thickness direction, thermoelastic coupled nonlinear vibration equation in thermal environment is derived by means of Kirchhoff’s thin plate theory and the Hamiltonian principle. The transverse nonlinear vibration differential equation of the inner and outside-clamped ring plate under static load is obtained by using the Galerkin method; moreover, perturbation solution of static deflection is carried out. An improved L-P method is employed to solve the strongly nonlinear vibration equation. The vibration response and nonlinear natural frequency expression are developed. Through numerical examples, natural frequency characteristic curves of the rotating FGM ring plate are plotted. The Runge Kutta method is applied to obtain vibration response, phase and power spectrum diagrams. The influence of different parameters on natural vibration characteristics is analyzed. The results show that analytical solutions are consistent with numerical solutions, and the natural frequency decreases with an increase in the metal content and surface temperature, but grows with an increase in the rotational speed.
Źródło:: Journal of Theoretical and Applied Mechanics; 2021, 59, 1; 157-171
1429-2955
Pojawia się w:: Journal of Theoretical and Applied Mechanics
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

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

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Skocz do pozycji: 11.

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

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Skocz do pozycji: 12.

Tytuł:: Effects of cations on rare earth adsorption and desorption in binding sites of montmorillonite
Autorzy:: He, Zhengyan
Nie, Wenrui
Yang, Huifang
Tang, Yuchen
Sha, Aoyang
Qu, Jun
Xu, Zhigao
Chi, Ruan
Powiązania:: https://bibliotekanauki.pl/articles/24085808.pdf
Data publikacji:: 2023
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:: adsorption
desorption
external site
interlayer site
basal spacing
Opis:: The exchangeability of rare earth (RE) in weathered crust elution-deposited rare earth ores largely depends on its interaction with clay minerals, which may be significantly influenced by various cations. Therefore, the effects of K+, Ca2+ and Al3+ on RE3+ adsorption and desorption in binding sites of montmorillonite (MMT) were investigated. Through the pre-saturation, the interlayer ions of MMT had been replaced by K+, Ca2+ or Al3+. RE3+ can adsorb on the interlayer sites of Ca-MMT and K-MMT, but nearly not Al-MMT. The basal spacing of Ca-MMT is larger than K-MMT, which provides a smaller hinder effect of interlayer collapse for the interlayer diffusion of RE3+. The adsorption capacity followed the order: Ca-MMT＞K-MMT＞Al-MMT and La3+＞Y3+＞Eu3+. It can predict that the grade of the exchangeable RE in ores abundant in Ca2+ is the most, followed by the ore rich in K+ and Al3+ the least. Clay minerals tend to adsorb light RE and hard to adsorb middle and heavy RE. The reversibility of RE adsorbed in interlayers, especially in collapsed interlayers, is far worse than that on externals. The desorption rates of RE were in the order of RE-Al-MMT＞RE-K-MMT＞RE-Ca-MMT and Eu3+＞Y3+＞La3+. For the desorption of interlayer RE3+, NH4+ is better than Mg2+ because the larger change of the basal spacings (Δd) provides more minor activation energy barriers (ΔE) for NH4+ diffusion within interlayers. It can enrich the metallogeny theory of weathered crust elution-deposited rare earth ores and provide a certain theoretical basis for its efficient exploitation.
Źródło:: Physicochemical Problems of Mineral Processing; 2023, 59, 3; art. no. 168280
1643-1049
2084-4735
Pojawia się w:: Physicochemical Problems of Mineral Processing
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 13.

Tytuł:: Development and verification of a high-precision laser measurement system for straightness and parallelism measurement
Autorzy:: Xu, Peng
Li, Rui Jun
Zhao, Wen Kai
Chang, Zhen Xin
Ma, Shao Hua
Fan, Kuang Chao
Powiązania:: https://bibliotekanauki.pl/articles/1849006.pdf
Data publikacji:: 2021
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: straightness
parallelism
laser measurement system
machine tool
Opis:: A laser measurement system for measuring straightness and parallelism error using a semiconductor laser was proposed. The designing principle of the developed system was analyzed. Addressing at the question of the divergence angle of the semiconductor laser being quite large and the reduction of measurement accuracy caused by the diffraction effect of the light spot at the long working distance, the optical structure of the system was optimized through a series of simulations and experiments. A plano-convex lens was used to collimate the laser beam and concentrate the energy distribution of the diffraction effect. The working distance of the system was increased from 2.6 m to 4.6 m after the optical optimization, and the repeatability of the displacement measurement is kept within 2.2 m in the total measurement range. The performance of the developed system was verified by measuring the straightness of a machine tool through the comparison tests with two commercial multi-degree-of-freedom measurement systems. Two different measurement methods were used to verify the measurement accuracy. The comparison results show that during the straightness measurement of the machine tool, the laser head should be fixed in front of the moving axis, and the sensing part should move with the moving table of the machine tool. Results also show that the measurement error of the straightness measurement is less than 3 m compared with the commercial systems. The developed laser measurement system has the advantages of high precision, long working distance, low cost, and suitability for straightness and parallelism error measurement.
Źródło:: Metrology and Measurement Systems; 2021, 28, 3; 479-495
0860-8229
Pojawia się w:: Metrology and Measurement Systems
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 14.

Tytuł:: Development and verification of a high-precision laser measurement system for straightness and parallelism measurement
Autorzy:: Xu, Peng
Li, Rui Jun
Zhao, Wen Kai
Chang, Zhen Xin
Ma, Shao Hua
Fan, Kuang Chao
Powiązania:: https://bibliotekanauki.pl/articles/1849049.pdf
Data publikacji:: 2021
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: straightness
parallelism
laser measurement system
machine tool
Opis:: A laser measurement system for measuring straightness and parallelism error using a semiconductor laser was proposed. The designing principle of the developed system was analyzed. Addressing at the question of the divergence angle of the semiconductor laser being quite large and the reduction of measurement accuracy caused by the diffraction effect of the light spot at the long working distance, the optical structure of the system was optimized through a series of simulations and experiments. A plano-convex lens was used to collimate the laser beam and concentrate the energy distribution of the diffraction effect. The working distance of the system was increased from 2.6 m to 4.6 m after the optical optimization, and the repeatability of the displacement measurement is kept within 2.2 m in the total measurement range. The performance of the developed system was verified by measuring the straightness of a machine tool through the comparison tests with two commercial multi-degree-of-freedom measurement systems. Two different measurement methods were used to verify the measurement accuracy. The comparison results show that during the straightness measurement of the machine tool, the laser head should be fixed in front of the moving axis, and the sensing part should move with the moving table of the machine tool. Results also show that the measurement error of the straightness measurement is less than 3 m compared with the commercial systems. The developed laser measurement system has the advantages of high precision, long working distance, low cost, and suitability for straightness and parallelism error measurement.
Źródło:: Metrology and Measurement Systems; 2021, 28, 3; 479-495
0860-8229
Pojawia się w:: Metrology and Measurement Systems
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 15.

Tytuł:: Development and verification of a high-precision laser measurement system for straightness and parallelism measurement
Autorzy:: Xu, Peng
Li, Rui Jun
Zhao, Wen Kai
Chang, Zhen Xin
Ma, Shao Hua
Fan, Kuang Chao
Powiązania:: https://bibliotekanauki.pl/articles/1849061.pdf
Data publikacji:: 2021
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: straightness
parallelism
laser measurement system
machine tool
Opis:: A laser measurement system for measuring straightness and parallelism error using a semiconductor laser was proposed. The designing principle of the developed system was analyzed. Addressing at the question of the divergence angle of the semiconductor laser being quite large and the reduction of measurement accuracy caused by the diffraction effect of the light spot at the long working distance, the optical structure of the system was optimized through a series of simulations and experiments. A plano-convex lens was used to collimate the laser beam and concentrate the energy distribution of the diffraction effect. The working distance of the system was increased from 2.6 m to 4.6 m after the optical optimization, and the repeatability of the displacement measurement is kept within 2.2 m in the total measurement range. The performance of the developed system was verified by measuring the straightness of a machine tool through the comparison tests with two commercial multi-degree-of-freedom measurement systems. Two different measurement methods were used to verify the measurement accuracy. The comparison results show that during the straightness measurement of the machine tool, the laser head should be fixed in front of the moving axis, and the sensing part should move with the moving table of the machine tool. Results also show that the measurement error of the straightness measurement is less than 3 m compared with the commercial systems. The developed laser measurement system has the advantages of high precision, long working distance, low cost, and suitability for straightness and parallelism error measurement.
Źródło:: Metrology and Measurement Systems; 2021, 28, 3; 479-495
0860-8229
Pojawia się w:: Metrology and Measurement Systems
Dostawca treści:: Biblioteka Nauki

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Tytuł:: Theoretical Simulations on Physicochemical Performance of Novel High-energy BHDBT-based Propellants
Autorzy:: Wang, Ke
Huang, Hai-tao
Xu, Hui-xiang
Li, Huan
Li, Jun-qiang
Fan, Xue-zhong
Pang, Wei-qiang
Powiązania:: https://bibliotekanauki.pl/articles/27787879.pdf
Data publikacji:: 2021
Wydawca:: Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:: molecular dynamic
BHDBT
migration
mechanical properties
safety
Opis:: Based on Energy Calculation Star program and molecular dynamic method, three designed 2,3-bis(hydroxymethyl)-2,3-dinitro-1,4-butanediol tetranitrate-based (BHDBT) propellants are firstly reported and their physicochemical performance are investigated. Results suggest that compared with HMX-based and CL-20-based propellants, the specific impulses of all BHDBT-based propellants surpass or approximate 280 s, which indicates the latter have the potential to be high-energy propellants. The diffusion coefficient of plasticizers in BHDBT-based propellant decrease as the temperature reduces, and reduce in the order: Bu-NENA > TMETN > BTTN. The densities of all BHDBT-based propellants surpass or approximate 1.7 g/cm3. The comparison of elastic constants, Poisson’s ratios and K/G values indicates that the mechanical properties of three BHDBT-based propellants increase in the order (by plasticizer): Bu-NENA < TMETN < BTTN. The bond length analysis of C–NO2 and O–NO2 bond in BHDBT suggests that the former is the trigger bond in the BHDBT-based propellants, and the safety of BHDBT-based propellants and BHDBT crystal decreases in the order: GAP/BTTN/Al/BHDBT > GAP/Bu-NENA/Al/BHDBT ≈ GAP/TMETN/Al/BHDBT > BHDBT. In conclusion, GAP/BTTN/Al/BHDBT propellant has the potential to be a novel high-energy propellant.
Źródło:: Central European Journal of Energetic Materials; 2021, 18, 1; 5--24
1733-7178
Pojawia się w:: Central European Journal of Energetic Materials
Dostawca treści:: Biblioteka Nauki

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