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1

An equivalent characterization of weak BMO martingale spaces

Zhou D., Li W., Jiao Y.

Probability and Mathematical Statistics

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2018

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Vol. 38, Fasc. 2

287--298

EN

In this paper, we give an equivalent characterization of weak BMO martingale spaces due to Ferenc Weisz (1998).

2

A design approach based on a correlative relationship between maintainability and functional construction

Guo C., Lyu C., Chen J., Zhou D.

Eksploatacja i Niezawodność

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2018

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Vol. 20, no. 1

115--124

EN

As an important quality characteristic, maintainability is the ability of a product to be repaired efficiently and economically. Because it is mainly determined at the design stage, maintainability is mostly affected by the construction of a product. Traditional product design methods put more focus on design for function and production, neglecting design for maintainability, which causes a gap between functional construction design and maintainability design. The delay of maintainability design results in huge costs for design changes and even irrevocable design flaws. Because of the weak relationship between functional construction and maintainability in product design, the influence of maintainability design on the product is limited. To resolve this problem, this paper proposes a design approach considering the relationship between maintainability and functional construction. First, maintainability design factors (MDFs) and functional construction design factors (FCDFs) are defined and classified. Second, based on topology graphic theory, a correlative relationship model is constructed by graphically combining the MDFs and FCDFs into a network diagram. Third, to determine primary design factors, a quantization matrix is developed to perform importance evaluation of the correlative relationship. Finally, a practical case is studied by implementing the proposed approach for the lubrication system of an armoured vehicle. The results validate the effectiveness and feasibility of the approach.

PL

Konserwowalność to ważna charakterystyka jakościowa, którą można zdefiniować jako możliwość wydajnej i ekonomicznej naprawy produktu. Ponieważ o konserwowalności produktu decydują głównie wybory dokonane na etapie projektowania, największy wpływ na nią ma budowa produktu. Tradycyjne metody projektowania produktów kładą większy nacisk na projektowanie funkcji i produkcji, zaniedbując projektowanie pod kątem łatwości konserwacji, co powoduje powstanie luki między projektowaniem funkcjonalnej budowy produktu a projektowaniem jego konserwowalności. Opóźnienie etapu projektowania konserwowalności generuje ogromne koszty związane z koniecznością zmian projektu i może nawet prowadzić do nieodwracalnych wad projektowych. Ze względu na słabą zależność między budową funkcjonalną a konserwowalnością w projektowaniu produktu, wpływ projektowania konserwowalności na produkt jest ograniczony. Aby rozwiązać ten problem, w niniejszej pracy zaproponowano podejście projektowe uwzględniające związek między konserwowalnością a budową funkcjonalną wyrobu. Po pierwsze, zdefiniowano i sklasyfikowano czynniki konstrukcyjne (projektowe) dotyczące konserwowalności (MDF) oraz czynniki konstrukcyjne związane z budową funkcjonalną produktu (FCDF). Po drugie, w oparciu o teorię graficznej reprezentacji topologii, zbudowano model zależności korelacyjnych między MDF i FCDF w postaci diagramu sieciowego. Po trzecie, w celu określenia podstawowych czynników konstrukcyjnych, opracowano macierz kwantyzacji, pozwalającą na ocenę ważności relacji korelacyjnych. Wreszcie, przeanalizowano przypadek układu smarowania pojazdu opancerzonego jako przykład zastosowania proponowanego podejścia w praktyce. Wyniki potwierdzają skuteczność omawianego podejścia oraz możliwość jego praktycznego wykorzystania.

3

Właściwości zapraw cementowych z dodatkiem nanokrzemionki i włókien węglowych

Cui X., Zhou D., Wang Y., Han B.

Cement Wapno Beton

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2018

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R. 21/83, nr 4

317--332

PL

Do zapraw cementowych dodawano nanokrzemionkę [NS] i włókna węglowe [WW] o różnej długości, oddzielnie i razem, badając ich wpływ na właściwości mechaniczne i przewodność zapraw cementowych. Przeprowadzone doświadczenia wykazały, że dodatek WW o długości 3 mm daje większą wytrzymałość od dodatku WW o długości 6 mm. Dodatek NS zwiększa wytrzymałość zapraw, jak można tego było oczekiwać. Równoczesny dodatek NS i WW zapewnia wyższą wytrzymałość niż ich oddzielny dodatek. Przypuszczalnie jest to wpływ bardziej równomiernego rozproszenia obu domieszek w zaprawie. Oporność elektryczna zapraw maleje z rosnącym dodatkiem WW i jest większa w przypadku włókien o długości 3 mm. NS nie ma na tę właściwość wpływu.

EN

Nano-silica [NS] and carbon fibers [CF] of different lengths were added separately and together to the cement mortars and their influence on mechanical and electrical properties were examined. The experimental results have shown that addition of 3 mm CF gives higher strength of cement mortars than 6 mm CF. NS addition is assuring higher strength, as should be expected. The simultaneous addition of CF and NS causes higher increase of strength than separate addition of these admixtures. Probably it is the influence of more uniformly dispersion of both CF and NS in cement paste. The electrical resistivity of cement mortars decrease with increasing CF content and is higher with 3 mm CF w than with 6 mm CF addition. NS has no influence on the electrical resistivity.

4

Super-resolution reconstruction of face images based on pre-amplification non-negative restricted neighborhood embedding

Yang X., Liu D., Zhou D., Fei S.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2018

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Vol. 66, nr 6

899--905

EN

The traditional super-resolution (SR) reconstruction algorithm based on neighborhood embedding preserves the local geometric structure of image block manifold to reconstruct high-resolution (HR) manifold. However, when the magnification is large, the low resolution (LR) image is seriously degraded and most of the information is lost after down-sampling. The neighborhood relation of the LR manifold can not reflect the inherent data structure. In order to solve the problem effectively, we propose a face image SR algorithm based on pre-amplification non-negative restricted neighborhood embedding. In the training phase, the LR image is pre-amplified so that there are more similar manifold structures between the HR and LR resolution images. The constraints of the reconstructed coefficients are loosened and the HR image blocks are iteratively updated to obtain the reconstructed weights. The experimental results show that the proposed method has a better reconstruction effect compared with some traditional learning algorithms.

5

Moving cast shadow detection using block nonnegative matrix factorization

Yang X., Liu D., Zhou D., Yang R.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2018

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Vol. 66, nr 2

229--234

EN

In recent years, moving cast shadow detection has become a critical challenge in improving the accuracy of moving object detection in video surveillance. In this paper, we propose two novel moving cast shadow detection methods based on nonnegative matrix factorization (NMF) and block nonnegative matrix factorization (BNMF). First, the algorithm of moving cast shadow detection using NMF is given and the key points such as the determination of moving shadow areas and the choice of discriminant function are specified. Then BNMF are introduced so that the new training samples and new classes can be added constantly with lower computational complexity. Finally, the improved shadow detection method is detailed described according to BNMF. The effectiveness of proposed methods is evaluated in various scenes. Experimental results demonstrate that the method achieves high detection rate and outperforms several state-of-the-art methods.

6

Comparison of compressive strength and electrical resistivity of cementitious composites with different nano- and micro-fillers

Jiang S., Zhou D., Zhang L., Ouyang J., Yu X., Cui X., Han B.

Archives of Civil and Mechanical Engineering

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2018

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Vol. 18, no. 1

60--68

EN

Cementitious composites with 0–1.5 wt.% Nano-SiO2 (NS), nano-TiO2 (NT), carbon nanotubes (CNTs), carbon nanofibers (CNFs) and carbon microfibers (CFs) are fabricated and tested. The enhancing effects of different fillers on the compressive strength and electrical resistivity of composites are compared, and the underlying modification mechanisms of fillers to composites are investigated by analyzing the difference in the morphology of fillers and rheology of composites. The compressive strength of composites containing 0.1% NS, 0.5% NT, 0.1% CNTs and 0.5% CFs by weight of cement presents approximately 12.5%, 20.8%, 16.8% and 21.4% higher than that of control sample, respectively. It is revealed that CFs also have improving effect on the compressive strength of composites besides flexural strength. When the composites with nano-fillers cannot be processed to ideal state, the reinforcing effect of nano-fillers is no better but even worse than that of micro-fillers. Composites with CNTs, CNFs and CFs possess good electrical conductivity. Composites with CNFs and CFs have a percolation threshold of electrical resistivity below 0.5%, while the percolation threshold of electrical resistivity of composites with CNTs is about 1%. Although CNFs do not have significant effect on compressive strength of composites, they have the best improvement to electrical resistivity.

7

Multiscale simulation of major crack/minor cracks interplay with the corrected XFEM

Liu G., Zhou D., Bao Y., Ma J., Han Z.

Archives of Civil and Mechanical Engineering

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2017

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Vol. 17, no. 2

410--418

EN

The present work aims at saving computational cost of multiscale simulation on major crack/minor crack interaction problems. The multiscale extended finite element method (MsXFEM) used for the numerical simulation is developed on multiscale projection technique which enables different scale decomposition, and transition of field variables between different scales. Both macroscale and microscale problems are solved independently and alternatively, in the framework of XFEM. The improvement made in this paper is to employ corrected XFEM on the macroscale level, so that a more accurate boundary condition can be obtained for the microscale problem. The modification leads to a reduced necessary microscale domain size, meanwhile a solution of higher accuracy and enhanced convergence rate can be achieved. The numerical examples of minor cracks near a major one are studied, which show that the effect of minor cracks on major crack can be efficiently captured.

8

The Response of Wetland Plant Communities to Disturbance : Alleviation through Symmetric Disturbance and Facilitation

Xu F., Li M., Zhou D., Liu X., Wang R., Guo W.

Polish Journal of Ecology

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2016

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Vol. 64, nr 3

327--338

EN

The study pays attention to disturbances in early successional communities of wetland vegetation. We conducted artificial disturbances in a community of Suaeda salsa and Phragmites australis in the Yellow River Delta (China). Eight types of disturbances combining mowing treatments with species treatments were applied. Removal of the standing litters of P. australis or not was defined as mowing treatments, and removal of two species solo or both was defined as species treatments. We sampled 80 quadrats from the treatments plots at different intervals after the disturbance to investigate plant height, abundance, aboveground biomass, the distance between plants to reflect the effect of disturbance on composition, structure, productivity, and function of the plant communities. The strategies of seedling emergence and height growth differed as the canopy changed. Biomass contribution of different species, combined with disturbance intensity, was the main factors that affected the productivity. Homogeneity of disturbance was better for maintaining the functions of plant community in compared with the competitiveness (C), stress-tolerance (S) and ruderality (C-S-R) signatures with the control. Facilitations were reflected by the stagger arrangements in relative growth rates of the two species and in plant-plant interactions calculated by a modified function of competition. Adapting to symmetric disturbance and developing facilitative interactions are important requirements for early succession terrestrial vegetation to establish and stabilize in the seriously saline environments of wetlands.

9

Airborne Sensor Resource Management in Air Battles based on Fuzzy Bayesian Networks

Zhou D., He P., Hang K.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 1b

181--183

EN

A method for air combat sensor resource management based on fuzzy Bayesian networks (FBN) is presented. Using the fuzzy value of target information gain, target threat level and pilot command, probabilistic reasoning among the networks is carried out. Simulation results indicate that FBN method performances better in the allocation of sensor resource compared to information gain (IG) method.

PL

W artykule przedstawiono zastosowanie sieci Bayes’a (ang. FBN) w zarządzaniu zasobem czujników w czasie walki powietrznej. Wykorzystując wartość rozmytą informacji o celu, poziom możliwego zagrożenia oraz komendy pilota, zbudowano sieć argumentowania probabilistycznego. Wyniki symulacyjne wykazują, że metoda FBN wykazuje lepsze właściwości alokacji zasobów niż metoda dywergencji Kullbacka-Leiblera (DKL, IG).

10

Maintainability Allocation Method Based on Time Characteristics for Complex Equipment

Zhou D., Jia X., Lv C., Li Y.

Eksploatacja i Niezawodność

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2013

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Vol. 15, no. 4

441--448

EN

Maintainability allocation is an important step in product quality design. Traditional allocation methods are limited such that the allocated mean time to repair for each unit design apartment cannot be totally controlled by the corresponding design apartment. This paper proposesa new time characteristics-based maintainability allocation method to solve the aforementioned problem. The relationship between design content and repair time is considered in this method, and repair time is divided into common and individual repair time. Common repair time, which isdetermined by the overall system design,is deducted from the total repair time. Individual repair time is allocated to the specific unit through proper traditional allocation method. A case study is performed,and results demonstrate that the new method is more suitable and effective than original methods in terms ofmaintainability allocation.

PL

Alokacja obsługiwalności jest ważnym krokiem w projektowaniu jakości produktów. Tradycyjne metody alokacji są ograniczone w takim sensie, że alokowany średni czas do naprawy dla każdego działu projektowania jednostki produktu nie może być całkowicie kontrolowany przez odpowiedni dział projektowania. W niniejszej pracy zaproponowano rozwiązanie tego problemu wykorzystujące nową metodę alokacji obsługiwalności opartą na charakterystykach czasowych. W proponowanej metodzie bierze się pod uwagę związek między zawartością projektu a czasem naprawy, czas naprawy zaś dzieli się na wspólny i indywidualny. Wspólny czas naprawy, który zależy od ogólnej konstrukcji systemu, odejmuje się od całkowitego czasu naprawy. Indywidualny czas naprawy alokuje się do konkretnej jednostki za pomocą odpowiedniej tradycyjnej metody alokacji. W pracy przeprowadzono studium przypadku, którego wyniki pokazują, że nowa metoda jest bardziej odpowiednia i skuteczna jeśli chodzi o alokację obsługiwalności niż metodystosowane pierwotnie.

11

Fast leak detection and location of gas pipelines based on an adaptive particle filter

Liu M., Zang S., Zhou D.

International Journal of Applied Mathematics and Computer Science

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2005

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Vol. 15, no 4

541-550

EN

Leak detection and location play an important role in the management of a pipeline system. Some model-based methods, such as those based on the extended Kalman filter (EKF) or based on the strong tracking filter (STF), have been presented to solve this problem. But these methods need the nonlinear pipeline model to be linearized. Unfortunately, linearized transformations are only reliable if error propagation can be well approximated by a linear function, and this condition does not hold for a gas pipeline model. This will deteriorate the speed and accuracy of the detection and location. Particle filters are sequential Monte Carlo methods based on point mass (or “particle”) representations of probability densities, which can be applied to estimate states in nonlinear and non-Gaussian systems without linearization. Parameter estimation methods are widely used in fault detection and diagnosis (FDD), and have been applied to pipeline leak detection and location. However, the standard particle filter algorithm is not applicable to time-varying parameter estimation. To solve this problem, artificial noise has to be added to the parameters, but its variance is difficult to determine. In this paper, we propose an adaptive particle filter algorithm, in which the variance of the artificial noise can be adjusted adaptively. This method is applied to leak detection and location of gas pipelines. Simulation results show that fast and accurate leak detection and location can be achieved using this improved particle filter.