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Wyszukujesz frazę "Chen, Chang" wg kryterium: Autor


Tytuł:
Weighted integrability and L¹-convergence of multiple trigonometric series
Autorzy:
Chen, Chang-Pao
Powiązania:
https://bibliotekanauki.pl/articles/1291177.pdf
Data publikacji:
1994
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
multiple trigonometric series
rectangular partial sums
Cesàro means
weighted integrability
L¹-convergence
conditions of generalized bounded variation
Opis:
We prove that if $c_{jk} → 0$ as max(|j|,|k|) → ∞, and $∑_{|j|=0±}^∞ ∑_{|k|=0±}^∞ θ(|j|^⊤)ϑ(|k|^⊤)|Δ_{12}c_{jk}| < ∞$, then f(x,y)ϕ(x)ψ(y) ∈ L¹(T²) and $∬_{T²} |s_{mn}(x,y) - f(x,y)|·|ϕ(x)ψ(y)|dxdy → 0$ as min(m,n) → ∞, where f(x,y) is the limiting function of the rectangular partial sums $s_{mn}(x,y)$, (ϕ,θ) and (ψ,ϑ) are pairs of type I. A generalization of this result concerning L¹-convergence is also established. Extensions of these results to double series of orthogonal functions are also considered. These results can be extended to n-dimensional case. The aforementioned results generalize work of Balashov [1], Boas [2], Chen [3,4,5], Marzuq [9], Móricz [11], Móricz-Schipp-Wade [14], and Young [16].
Źródło:
Studia Mathematica; 1994, 108, 2; 177-190
0039-3223
Pojawia się w:
Studia Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Uniform convergence of double trigonometric series
Autorzy:
Chen, Chang-Pao
Chen, Gwo-Bin
Powiązania:
https://bibliotekanauki.pl/articles/1287625.pdf
Data publikacji:
1996
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Opis:
It is shown that under certain conditions on ${c_{jk}}$, the rectangular partial sums $s_{mn}(x,y)$ converge uniformly on $T^2$. These conditions include conditions of bounded variation of order (1,0), (0,1), and (1,1) with the weights |j|, |k|, |jk|, respectively. The convergence rate is also established. Corresponding to the mentioned conditions, an analogous condition for single trigonometric series is $∑_{|k|= n}^∞ |Δc_k| = o(1/n)$ (as n → ∞). For O-regularly varying quasimonotone sequences, we prove that it is equivalent to the condition: $nc_{n} = o(1)$ as n → ∞. As a consequence, our result generalizes those of Chaundy-Jolliffe [CJ], Jolliffe [J], Nurcombe [N], and Xie-Zhou [XZ].
Źródło:
Studia Mathematica; 1996, 118, 3; 245-259
0039-3223
Pojawia się w:
Studia Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Two-parameter Hardy-Littlewood inequality and its variants
Autorzy:
Chen, Chang-Pao
Luor, Dah-Chin
Powiązania:
https://bibliotekanauki.pl/articles/1206123.pdf
Data publikacji:
2000
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Opis:
Let s* denote the maximal function associated with the rectangular partial sums $s_{mn}(x,y)$ of a given double function series with coefficients $c_{jk}$. The following generalized Hardy-Littlewood inequality is investigated: $||s*||_{p,μ}≤C_{p,α,β} {Σ_{j=0}^∞Σ_{k=0}^∞(j̅ )^{p-α-2}(k̅)^{p-β-2}|c_{jk}|^p }^{1/p}$, where ξ̅=max(ξ,1), 0 < p < ∞, and μ is a suitable positive Borel measure. We give sufficient conditions on $c_{jk}$ and μ under which the above Hardy-Littlewood inequality holds. Several variants of this inequality are also examined. As a consequence, the ||·||_{p,μ}-convergence property of $s_{mn}(x,y)$ is established. These results generalize the work of Askey-Wainger [1], Balashov [2], Boas [3], Chen [5], [6], [8], [9], Marzug [15], Móricz [16]-[18], [19], Móricz-Schipp-Wade [20], Ram-Bhatia [22], Stechkin [24], Weisz [26]-[28], and Young [30].
Źródło:
Studia Mathematica; 2000, 139, 1; 9-27
0039-3223
Pojawia się w:
Studia Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Almost everywhere convergence of Laguerre series
Autorzy:
Chen, Chang-Pao
Lin, Chin-Cheng
Powiązania:
https://bibliotekanauki.pl/articles/1290468.pdf
Data publikacji:
1994
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
almost everywhere convergence
Cesàro means
Laguerre polynomials
Riesz means
Opis:
Let $a ∈ ℤ^+$ and $f ∈ L^p (ℝ^+), 1 ≤ p ≤ ∞ $. Denote by $c_j$ the inner product of f and the Laguerre function $ℒ^a_j$. We prove that if ${c_j}$ satisfies $lim_{λ↓1} \overline lim_{n→∞} ∑_{n
Źródło:
Studia Mathematica; 1994, 109, 3; 291-301
0039-3223
Pojawia się w:
Studia Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An intelligent multimodal framework for identifying children with autism spectrum disorder
Autorzy:
Chen, Jingying
Liao, Mengyi
Wang, Guangshuai
Chen, Chang
Powiązania:
https://bibliotekanauki.pl/articles/331151.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
autism spectrum disorder
eye fixation
facial expression
cognitive level
improved random forest
spektrum zaburzeń autystycznych
wyraz twarzy
poziom poznawczy
las losowy
Opis:
Early identification can significantly improve the prognosis of children with autism spectrum disorder (ASD). Yet existing identification methods are costly, time consuming, and dependent on the manual judgment of specialists. In this study, we present a multimodal framework that fuses data on a child’s eye fixation, facial expression, and cognitive level to automatically identify children with ASD, to improve the identification efficiency and reduce costs. The proposed methodology uses an optimized random forest (RF) algorithm to improve classification accuracy and then applies a hybrid fusion method based on the data source and time synchronization to ensure the reliability of the classification results. The classification accuracy of the framework was 91%, which is higher than that of the RF, support vector machine, and discriminant analysis methods. The results suggest that data on a child’s eye fixation, facial expression, and cognitive level are useful for identifying children with ASD. Because the proposed framework can separate ASD children from typically developing (TD) children, it can facilitate the early identification of ASD and may improve intervention programs for children with ASD.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2020, 30, 3; 435-448
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on the Acoustic Scattering Characteristics of Multi-Sections Conning Tower Geometries in Monostatic Configuration
Autorzy:
Han, Lin-Jiang
Song, Hao
Chen, Chang-Xiong
Peng, Xi-Rui
Peng, Zi-long
Powiązania:
https://bibliotekanauki.pl/articles/2141632.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
conning tower
Kirchhoff approximation
target strength
monostatic configuration
Opis:
The overall acoustic echo of a submarine is greatly dependent on the conning tower. For enhancing the acoustic stealth performance of a submarine, it is necessary to research an innovative design scheme of the conning tower to reduce its target strength (TS). The aim of this work is to reduce the TS of a conning tower by varying its geometry and streamlining. The accuracy in modelling the acoustic scattering of a conning tower using the Kirchhoff approximation (KA) was validated, compared with finite element analysis (FEA). Several angular conning tower geometries were designed to analyze the effect of streamlining and the number of lateral facets on TS using the KA method. In consideration of the actual situation, the acoustic effect of backing medium was analyzed by compared water-filled elastic hulls with rigid hulls. From the observed TS calculation results, it is shown that the non-streamlined four lateral-facet conning tower geometries are optimal for acoustic stealth performance during the range of incidence angles from −10° to 10°, whereas the streamlined versions have better performance at incidence angles beyond this range. Furthermore, elastic hulls and rigid hulls provide similar spatial distribution regularities in monostatic configuration with the rigidity affecting the magnitude of the TS.
Źródło:
Archives of Acoustics; 2022, 47, 3; 307-317
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Physiological responses of the eustigmatophycean Nannochloropsis salina to aqueous diesel fuel pollution
Autorzy:
Mohammady, Nagwa Gamal-El-Din
Chen, Yean-Chang
El-Mahdy, Abd-El-Ruhman Aly
Mohammad, Rania Farag
Powiązania:
https://bibliotekanauki.pl/articles/47635.pdf
Data publikacji:
2005
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
microalga
diesel fuel pollution
physiological response
Nannochloropsis salina
eustigmatophycean microalga
Opis:
The marine eustigmatophycean microalga Nannochloropsis (Monallantus) salina Hibberd was cultivated in a batch culture in the presence of various concentrations (0, 25, 50, 75 and 100%) of an aqueous extract of diesel fuel oil in order to assess the influence of the pollutant on the growth and certain physiological responses of the microalga. The growth data revealed a significant negative effect of the various pollutant concentrations on the algal cell number (p≤0.05). However, at the midlogarithmic growth phase (day 8), the algal cells were analysed for chlorophyll a, β-glucan, amino acid pool, C/N ratio and elemental composition. According to our results, N. salina was significantly affected by the pollution with regard to the different physiological parameters examined, and this significance may be negative, positive or variable. The effect of the pollutant on cellular β-glucan and the total amount of amino acids was negative;h owever, the composition of the cellular amino acid pool remained unaffected. A positive effect of the pollutant on cellular chl a and the C/N ratio was observed. In addition, the pollutant showed variable effects on the composition of different elements, as shown by energy-dispersive X-ray microanalysis. Also, an existence correlation between different elements was statistically reported.
Źródło:
Oceanologia; 2005, 47, 1
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal buckling of temperature-dependent functionally graded Timoshenko beams
Autorzy:
Chen, Wei-Ren
Chen, Chun-Sheng
Chang, Heng
Powiązania:
https://bibliotekanauki.pl/articles/139902.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
thermal buckling
functionally graded material
transformed-section method
temperature-dependent properties
Opis:
Thermal buckling behavior of a functionally graded material (FGM) Timoshenko beam is studied based on the transformed-section method. The material and thermal properties of the FGM beam are assumed to vary across the beam thickness according to a power-law function, a sigmoid function and an exponential function. The results of buckling temperature for the FGM beams with respective temperature-dependent and temperature-independent properties under uniform and non-linear temperature rises are presented. Some results are compared with those in the published literature to verify the accuracy of the present work. The effects of the material distributions, temperature fields, temperature-dependent properties and slenderness ratios on the thermal buckling behaviors of FGM beams are discussed. It is believed that the present model provides engineers with a simple and effective method to study the effects of various parameters of the FGM beam on its thermal buckling behavior.
Źródło:
Archive of Mechanical Engineering; 2019, LXVI, 4; 393-415
0004-0738
Pojawia się w:
Archive of Mechanical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental study of the nonlinear dynamics of a smooth and discontinuous oscillator with different smoothness parameters and initial values
Autorzy:
Chang, Yujian
Chen, Enli
Feng, Ming
Powiązania:
https://bibliotekanauki.pl/articles/281961.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
SD oscillator
experimental system
nonlinear dynamic characteristic
initial value sensitivity
smoothness parameters
Opis:
The dynamic response of a nonlinear system is very sensitive to initial conditions. Both the irrational nonlinearity and the large displacement of a smooth and discontinuous (SD) oscillator have been studied in this paper. An experimental study has been conducted on a model of the SD oscillator with different initial conditions and smoothness parameters. Experimental results indicate that tiny variation in the initial displacement will lead to different kinds of vibrations, and the system exhibits a wide range of nonlinear dynamical phenomena with the change of smoothness parameters. All experimental results are in good conformity with numerical simulation results.
Źródło:
Journal of Theoretical and Applied Mechanics; 2019, 57, 4; 935-946
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A roadway in close distance to coal seam in deep mine: location selection and supporting practice based on creep characteristics of surrounding rocks
Autorzy:
Wang, Xufeng
Wang, Jiyao
Chen, Xuyang
Chang, Zechao
Powiązania:
https://bibliotekanauki.pl/articles/2073870.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
kopalnia głębinowa
pokłady węgla
pełzanie
deep mine
close distance
coal seam group
location of roadway
creep
Opis:
In deep mines, since the broken surrounding rocks & high-stress level of a roadway being near a coal seam, the creep characteristics of surrounding rocks should be considered as the main influencing factor in the selection for the roadway’s location of the lower coal seam. Both VI15 and VI16-17 coal seams of the Pingdingshan No. 4 Coal Mine, in China, Henan province, are close coal seams with a depth of around 900 m. According to the traditional formula calculation results, when the lower coal seam roadway is staggered 10 m to the upper coal seam goaf, the roadway pressure behaviour is significant, and the support becomes difficult. In this paper, the properties of surrounding rock were tested and the influence of lower coal seam on the stress state of surrounding rock is analysed by numerical simulation, and systematic analysis on the stress and creep characteristics of the surrounding rock of the mining roadway and its effects on the deformation is performed. The results demonstrated that the roadway’s locations in the lower coal seam can be initially divided into three zones: the zone with accelerated creep, the transition creep zone and the insignificant creep zone. The authors believed that the roadway layout in an insignificant creep zone can achieve a better supporting effect. Based on the geological conditions of the roadway 23070 of the VI16-17 coal seam of the Pingdingshan No. 4 Coal Mine, combined with the above analysis, a reasonable location of roadway (internal offset of 30 m) was determined using numerical simulation method. The reliability of the research results is verified by field measurement. The above results can provide a reference for selecting the roadway’s location under similar conditions.
Źródło:
Archives of Mining Sciences; 2021, 66, 3; 407--419
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Social Impacts on the Maritime Education – a Case Study of National Kaohsiung Marine University in Taiwan
Autorzy:
Hu, Jia-Shen
Chang, S. W.
Chen, T. S.
Powiązania:
https://bibliotekanauki.pl/articles/116312.pdf
Data publikacji:
2008
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
Maritime Education and Tr
Maritime Education
human resources
Shipping Industry
educational reform
STCW-95
Quality Assurance
Opis:
Recent developments in Taiwan toward the technology intensive country, the employment of cost effective foreign labors by shipping companies, the widespread of universities and the internationalization of shipping industries propose considerable threats on the quality assurance of maritime education. A resultant crisis for lacking on-board seafarers with managerial levels has urged the consolidation of governmental, private and educational organizations in the attempts to further improve the quality of maritime education and to promote the on-board career incentives. The process from the formulation of problems to the implementation of strategies undertaken by the National Kaohsiung Marine University (NKMU) is reviewed. A chain reaction initiated from the degradation of students’ entry performances due to the widespread of universities has formed a viscous cycle leading to the outsourcing of foreign human resources by shipping industry. Strategies in the aspects of course reform, joint ventures of lectureship with shipping industry, pre-courses for students’ extended career plans and the establishment of educational center that consolidates the departments of navigation, marine engineering and fishery in NKMU are illustrated.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2008, 2, 2; 197-203
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Noether Theorems and Discrete Variational Integrators in Field Theory
Autorzy:
Xia, Li-Li
Chen, Li-Qun
Liu, Chang-Xin
Powiązania:
https://bibliotekanauki.pl/articles/1398640.pdf
Data publikacji:
2015-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
02.20.Sv
11.30.-j
Opis:
The discrete analogue of the Noether-type identities in field theory is investigated by means of the difference discrete variational principle in which the difference is regarded as an entire geometric object. The discrete counterparts of the Noether theorems are obtained. It is proved that there exists the discrete version of the Noether conservation law in field theory. The discretization for the nonlinear Schrödinger equation is presented to illustrate the results.
Źródło:
Acta Physica Polonica A; 2015, 127, 3; 669-673
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimal screw orientation for the fixation of cervical degenerative disc disease using nonlinear C3-T2 multi-level spinal models and neuro-genetic algorithms
Autorzy:
Chang, T.-K.
Hsu, C.-C.
Chen, K.-T.
Powiązania:
https://bibliotekanauki.pl/articles/306375.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
stabilizacja
optymalizacja
kątownik
bioinżynieria
cervical plate
insertion angle
fixation stability
optimization
Opis:
Purpose: Anterior cervical discectomy and fusion is a common surgical procedure performed to remove a degenerative or herniated disc in cervical spine. Unfortunately, clinical complications of anterior cervical plate (ACP) systems still occur, such as weak fixation stability and implant loosening. Previous researchers have attempted to ameliorate these complications by varying screw orientations, but the screw orientations are mainly determined according to the investigator’s experiences. Thus, the aim of this study was to discover the optimal screw orientations of ACP systems to achieve acceptable fixation stability using finite element simulations and engineering algorithms. Methods: Three-dimensional finite element models of C3-T2 multi-level segments with an ACP system were first developed to analyze the fixation stability using ANSYS Workbench 14.5. Then, artificial neural networks were applied to create one objective function, and the optimal screw orientations of an ACP system were discovered by genetic algorithms. Finally, the numerical models and the optimization study were validated using biomechanical tests. Results: The results showed that the optimal design of the ACP system had highest fixation stability compared with other ACP designs. The neuro-genetic algorithm has effectively reduced the time and effort required for discovering for the optimal screw orientations of an ACP system. Conclusions: The optimum screw orientation of the ACP system could be successfully discovered, and it revealed excellent fixation stability for the treatment of cervical degenerative disc disease. This study could directly provide the biomechanical rationale and surgical suggestion to orthopedic surgeons.
Źródło:
Acta of Bioengineering and Biomechanics; 2015, 17, 3; 59-66
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Saving water used for vegetable production by applying regulated deficit irrigation practices
Autorzy:
Chang, Y.-S.
Lin, K.-H.
Chen, Y.-J.
Wu, C.-W.
Chang, Y.-J.
Powiązania:
https://bibliotekanauki.pl/articles/13003875.pdf
Data publikacji:
2021
Wydawca:
Uniwersytet Przyrodniczy w Lublinie. Wydawnictwo Uniwersytetu Przyrodniczego w Lublinie
Źródło:
Acta Scientiarum Polonorum. Hortorum Cultus; 2021, 20, 3; 27-36
1644-0692
Pojawia się w:
Acta Scientiarum Polonorum. Hortorum Cultus
Dostawca treści:
Biblioteka Nauki
Artykuł

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