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1

Fault diagnosis for complex systems based on reliability analysis and sensors data considering epistemic uncertainty

Duan R., Lin Y., Zeng Y.

Eksploatacja i Niezawodność

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2018

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Vol. 20, no. 4

558--566

EN

This paper presents an information fusion method to diagnose system fault based on dynamic fault tree (DFT) analysis and dynamic evidential network (DEN). In the proposed method, firstly, it uses a DFT to describe the dynamic fault characteristics and evaluates the failure rate of components using interval numbers to deal with the epistemic uncertainty. Secondly, qualitative analysis of a DFT is to generate the characteristic function via a traditional zero-suppressed binary decision diagram, while quantitative analysis is to calculate some importance measures by mapping a DFT into a DEN. Thirdly, these reliability results are updated according to sensors data and used to design a novel diagnostic algorithm to optimize system diagnosis. Furthermore, a diagnostic decision tree (DDT) is obtained to guide the maintenance workers to recover the system. Finally, the performance of the proposed method is evaluated by applying it to a train-ground wireless communication system. The results of simulation analysis show the feasibility and effectiveness of this methodology.

PL

W artykule przedstawiono metodę fuzji informacji służącą do diagnozowania błędów systemu w oparciu o analizę dynamicznego drzewa błędów (DFT) oraz dynamiczną sieć dowodową (DEN). W proponowanej metodzie, pierwszym krokiem jest wykorzystanie DFT do opisania dynamicznych charakterystyk błędów oraz ocena intensywności uszkodzeń komponentów przy użyciu liczb przedziałowych, która rozwiązuje problem niepewności epistemicznej. Krok drugi stanowi jakościowa analiza DFT, która polega na wygenerowaniu funkcji charakterystycznej za pomocą tradycyjnego binarnego diagramu decyzyjnego typu "zero-suppressed" (w którym zostały wyeliminowane wszystkie węzły, których krawędź „1” prowadzi do liścia „0”), oraz analiza ilościowa polegająca na obliczeniu pewnych miar ważności poprzez odwzorowanie DFT w DEN. W kroku trzecim, otrzymane wyniki niezawodnościowe aktualizuje się zgodnie z danymi z czujników a następnie wykorzystuje do stworzenia nowego algorytmu diagnostycznego do optymalizacji diagnostyki systemu. Powstaje diagnostyczne drzewo decyzyjne (DDT), które stanowi dla pracowników utrzymania ruchu wytyczną w procesie odzyskiwania systemu. Działanie proponowanej metody oceniano poprzez zastosowanie jej do diagnostyki systemu łączności radiowej pociąg–ziemia. Wyniki analizy symulacyjnej wskazują na możliwość praktycznego wykorzystania i skuteczność omawianej metodologii.

2

Computational Modeling of the Elastic Property of Three-Dimensional Open Cell Foams

Nie Z., Lin Y., Tong Q.

Archives of Metallurgy and Materials

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2018

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Vol. 63, iss. 3

1153--1165

EN

The work reports on the development of random three-dimensional Laguerre-Voronoi computational models for open cell foams. The proposed method can accurately generate foam models having randomly distributed parameter values. A three-dimensional model of ceramic foams having pre-selected cell volumes distribution with stochastic coordinates and orientations was created in the software package ANSYSTM. Different groups of finite element models were then generated using the developed foam modeling procedure. The size sensitivity study shows that each of foam specimens at least contains 125 LV-cells. The developed foam models were used to simulate the macroscopic elastic properties of open cell foams under uni-axial and bi-axial loading and were compared with the existing open cell foam models in the literature. In the high porosity regime, it is found that the elastic properties predicted by random Laguerre-Voronoi foam models are almost the same as those predicted by the perfect Kelvin foam models. In the low porosity regime the results of the present work deviate significantly from those of other models in the literature. The results presented here are generally in better agreement with experimental data than other models. Thus, the Laguerre-Voronoi foam models generated in this work are quite close to real foam topology and yields more accurate results than other open cell foam models.

3

Fault diagnosis for complex systems based on dynamic evidential network and multi-attribute decision making with interval numbers

Duan R., Hu L., Lin Y.

Eksploatacja i Niezawodność

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2017

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Vol. 19, no. 4

580--589

EN

The complexity of modern system structures and failure mechanisms makes it very difficult to locate the system fault. It has characteristics of dynamics of failure, diversity of distribution and epistemic uncertainties, which increase the challenges in the fault diagnosis significantly. This paper presents a fault diagnosis framework for complex systems within which the failure rates of components are expressed in interval numbers. Specifically, it uses a dynamic fault tree (DFT) to model the dynamic fault behaviors and deals with the epistemic uncertainties using Dempster-Shafer (D-S) theory and interval numbers. Furthermore, a solution is proposed to map a DFT into a dynamic evidential network (DEN) to calculate the reliability parameters. Additionally, diagnostic importance factor (DIF), Birnbaum importance measure (BIM) and heuristic information values (HIV) are taken into account comprehensively in order to obtain the best fault search scheme using an improved VIKOR algorithm. Finally, an illustrative example is given to demonstrate the efficiency of this method.

PL

Złożoność nowoczesnych struktur systemowych oraz mechanizmów uszkodzeń powoduje trudności w lokalizacji uszkodzeń systemu. Systemy złożone charakteryzują się cechami, takimi jak dynamika uszkodzeń, różnorodność rozkładów oraz niepewność epistemiczna, które czynią wyzwania dotyczące diagnostyki uszkodzeń znacznie trudniejszymi. W niniejszym artykule przedstawiono metodę diagnozowania uszkodzeń systemów złożonych, w której intensywność uszkodzeń poszczególnych składników wyraża się za pomocą liczb przedziałowych. W szczególności, podejście to wykorzystuje dynamiczne drzewo błędów (DFT) do modelowania dynamicznych zachowań związanych z uszkodzeniami oraz rozwiązuje problem niepewności epistemicznej przy użyciu teorii Dempstera-Shafera (DS) oraz liczb przedziałowych. W celu obliczenia parametrów niezawodności, zaproponowano rozwiązanie polegające na odwzorowaniu DFT w dynamiczną sieć dowodową (DEN). Dodatkowo, w sposób kompleksowy wykorzystano czynnik ważności diagnostycznej (DIF), miarę ważności Birnbauma (BIM) oraz wartości informacji heurystycznej (HIV), aby przy użyciu udoskonalonego algorytmu VIKOR uzyskać najlepszy system wyszukiwania błędów. Skuteczność omawianej metody zilustrowano na podstawie przykładu.

4

Preparation and Optical Properties of PS @Au–Cu Core-Shell Nano Composite

Rudainah A., Farkad A., Lin Y.

International Letters of Chemistry, Physics and Astronomy

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2015

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Vol. 49

81--89

EN

An appropriate low-cost uncomplicated chemical method has been used to obtain the optical properties in the production of plasmon by manufacturing nanomaterial's consisting of dielectric core and a shell that grows on its surface . This core consists of the polystyrene PS and a gold – copper shell. The synthesis was made in two steps . In the first step PS core was fabricated , then coated by a shell consisting of Au –Cu particles . The shell shape differs according to the change in the amount of molar concentrations of Cu, and H2O2. It is found that variation of this materials amount gives us absorbance measurements (Localised Surface Plasmon Resonance, LSPR) that increase proportionally with changing quantities directly, where the size of core is constant .And the peak position in blue shift high energy then changes to red shift low energy . This change depends on the size and shape of particles. The same case applies for the transmittance of its change with the change of this material. The nano shell was characterized by using Scanning electron microscopy,SEM and UV –vis spectroscopy by varying the amount of Cu and H2O2.

5

Passing-beam headlamps and the possibilities of assessment of road obstacles by a driver at night

Targosiński T., Lin Y.

Archiwum Motoryzacji

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2015

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Vol. 67, no. 1

83--112, 211--238

EN

In most cases, passing beam is used when this is required because of the current traffic conditions. Due to the necessity of limiting the dazzling effect, the passing beam is divided into two parts: the lower one (“light”), which is to illuminate the road correctly and over as long a distance ahead of the vehicle as possible, and the upper one (“shadow”), which is to inform about the presence of a moving vehicle on the road. The headlamps must be precisely aimed to obtain the maximum range of road illumination with limited dazzle. The minimum requirements for passing beam have been laid down in type-approval and operational regulations. Based on the maximum acceptable range of headlamp aiming tolerances as specified in UN ECE Regulation No. 48, the illuminated road length ahead of the vehicle may vary from 20 m to 200 m. If the operational tolerances (i.e. those applicable to vehicles during normal operation) are taken as a basis, this variability range may be even wider. On the other hand, the photometric characteristics of the light beam close to the road surface depend on the said requirements, on the photometric characteristics of the headlamps actually installed on the vehicle, and on the actual headlamp aiming and alignment. From the traffic safety point of view, a matter of great significance for a vehicle being in use is the actual distance to which the road is illuminated. This issue is also important in the case of a need for accident reconstruction. The factors that affect the road illumination range, which is critical for the detection of road obstacles, have been analysed herein, with taking into account the measurements and calculations carried out for real headlamps that can be found in vehicles as well as the possible values of the vertical inclination and horizontal deflection of the light beam. Conclusions drawn from an assessment of the current state of laws and technologies have also been presented.

PL

Światła mijania są najczęściej używane ze względu na warunki ruchu drogowego. Z powodu konieczności ograniczenia olśnienia światła te mają podzieloną wiązkę świetlną na dwie części: dolną czyli „światło”, która ma za zadanie prawidłowo i możliwie daleko oświetlić drogę i górną czyli „cień” której zadaniem jest sygnalizowanie obecności na drodze pojazdu znajdującego się w ruchu. Światła te powinny być precyzyjnie ustawione w celu uzyskania maksymalnego zasięgu oświetlanej drogi przy ograniczonym olśnieniu. Minimalne wymagania dotyczące świateł mijania zawarte są w przepisach homologacyjnych i eksploatacyjnych. Przyjmując zakres dopuszczalnych tolerancji ustawienia określonych w regulaminie Europejskiej Komisji Gospodarczej ONZ nr 48 zasięg oświetlanej drogi może zmieniać się od 20 m do 200 m. Uwzględniając tolerancje eksploatacyjne ustawienia świateł przedział zmian jest jeszcze większy. Natomiast wartości parametrów fotometrycznych wiązki świetlnej w pobliżu drogi są pochodną tych wymagań oraz parametrów fotometrycznych rzeczywistych reflektorów zainstalowanych na pojeździe oraz rzeczywistego ustawienia świateł. W przypadku eksploatacji samochodu ważny jest rzeczywisty zasięg oświetlenia drogi ze względu na bezpieczeństwo ruchu drogowego. Jest on także istotny w przypadku potrzeby rekonstrukcji wypadków. W artykule przeanalizowano czynniki wpływające na zasięg oświetlenia drogi jako podstawowy czynnik zauważenia przeszkód z uwzględnieniem pomiarów i obliczeń dla rzeczywistych reflektorów spotykanych na pojazdach oraz możliwych wartości pochylenia i odchylenia wiązki świetlnej. Przedstawiono także wnioski wynikające z oceny obecnego stanu przepisów i stosowanych technologii.

6

Spatial and seasonal variations of large tintinnid ciliates in Shenhu Bay of China

Wang Y., Zhang W., Lin Y., Zheng L., Cao W., Yang J.

Oceanological and Hydrobiological Studies

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2014

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Vol. 43, No. 3

292--302

EN

In this study, the spatial distribution and seasonal variation of large tintinnids (>76 μm) were investigated in Shenhu Bay during three seasons of 2012. Of the 36 species identified, 9 were dominant (i.e. Tintinnopsis radix, Leprotintinnus simplex, Tintinnopsis japonica, Tintinnopsis tubulosoides, Leprotintinnus nordqvisti, Tintinnopsis beroidea, Stenosemella parvicollis, Tintinnidium primitivum, Tintinnopsis nana). A clear seasonal shift of the taxonomic composition as well as the lorica size of the dominant species was observed. The highest numbers of tintinnid species occurred in spring, while the highest abundance and biomass occurred in summer. Clustering indicated that the seasonal variations of the community structure were more obvious than spatial variations. Spearman correlation analysis revealed that density of phytoplankton prey had a significant impact on the tintinnid abundance. Redundancy analysis (RDA) illustrated that temperature, salinity and the nutrient level were the most important abiotic factors affecting the spatial and seasonal pattern of tintinnid communities in Shenhu Bay.

7

Minimizing total completion time for preemptive scheduling with release dates and deadline constraints

He C., Lin H., Lin Y., Dou J.

Foundations of Computing and Decision Sciences

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2014

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Vol. 39, No. 1

17--26

EN

It is known that the single machine preemptive scheduling problem of minimizing total completion time with release date and deadline constraints is NP-hard. Du and Leung solved some special cases by the generalized Baker's algorithm and the generalized Smith's algorithm in O(n2) time. In this paper we give an O(n2) algorithm for the special case where the processing times and deadlines are agreeable. Moreover, for the case where the processing times and deadlines are disagreeable, we present two properties which could enable us to reduce the range of the enumeration algorithm.

8

Effect of solution treatment on microstructures and mechanical properties of 2099 Al–Li alloy

Lin Y., Zheng Z. Q., Li S. C.

Archives of Civil and Mechanical Engineering

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2014

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Vol. 14, no. 1

61--71

EN

The influence of the solution treatment on microstructures and mechanical properties of 2099 Al–Li alloy was investigated by means of optical microscopy, scanning electron microscopy, transmission electron microscopy and tensile properties measurement. With increasing solution temperature, the quantity of primary particles in the alloy decreased, and the degree of recrystallization gradually increased, leading to softening of solution treated alloy. Dissolution of primary particles in the solution treatment process promoted δ′ and T1 phases to precipitate during sequent aging treatment resulting in increase of strength. The number of T1 phases increased to peak value when the alloy was solution treated at 540 °C because almost no further dissolution of Cu-containing particles occurred at higher temperature. However, exorbitant solution temperature caused the drastic increase in the size and quantity of recrystallized grains that softened the alloy. Thus, mechanical properties of aged alloy were determined by two mechanisms: precipitation strengthening and solution softening. Compared with solution temperature, solution time had less effect on microstructures and mechanical properties of alloy. The suitable solution treatment for 2099 Al–Li alloy was 540 °C for 1 h, treated by which the yield strength of the aged alloy was 604 MPa with the elongation of 7.9%.

9

Spatial pattern of the planktonic ciliate community and its relationship with the environment in spring in the northern Beibu Gulf, South China Sea

Wang Y., Zhang W., Lin Y., Zheng L., Cao W., Yang J.

Oceanological and Hydrobiological Studies

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2013

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Vol. 42, No. 4

470--479

EN

Surface water samples were collected from 19 sites in the northern Beibu Gulf in April 2011. Species composition and abundance of planktonic ciliates were investigated. They were combined with environmental data to obtain the spatial pattern of the ciliate community and its relationship with the environment. A total of 36 species belonging to 13 genera and 3 orders (Oligotrichida, Haptorida and Tintinnida) were identified, including 10 dominant species. All 19 samples were divided into three groups using cluster analysis and multidimensional scaling (MDS) on the basis of the ciliate species composition and abundance. Group 1 was the least abundant. The species of the order Oligotrichida dominated in Group 2. In contrast, Mesodinium species were of increased importance in Group 3. Redundancy analysis (RDA) revealed that ciliate communities were more closely related to the level of nitrogen (total nitrogen, nitrate nitrogen, nitrite nitrogen) and phosphorus (total phosphorus, active phosphorus) rather than other variables. As the levels of nitrogen and phosphorus increased, communities dominated by species from the order Oligotrichida were replaced by those dominated by Mesodinium species.

10

Development of wide range displacement sensors based on polarized light detecting technology

Lu X., Li W., Lin Y.

Optica Applicata

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2011

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Vol. 41, nr 1

97--108

EN

A series of novel wide range displacement sensors based on polarized light detecting technology is presented. The sensors include a displacement-current comparator and a servo comparison displacement sensor. Special structures and technologies are introduced to the sensor systems to solve the optical problems, such as the nonlinearity, the light source drift etc., and realize wide range measurement. The designing, assembling, and testing results of the prototypes of sensors are described. The testing results of the prototypes show that the novel sensors based on polarized light detecting technology have good linearity, and wide range measuring ability.

11

Bicriteria scheduling of minimizing maximum lateness and makespan on a serial-batching machine

He C., Lin Y., Yuan J.

Foundations of Computing and Decision Sciences

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2008

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Vol. 33, No. 4

369-376

EN

This paper studies the bicriteria problem of scheduling n jobs on a serial-batching machine to minimize maximum lateness and makespan simultaneously. A serial-batching machine is a machine that can handle up to b jobs in a batch and jobs in a batch start and complete respectively at the same time and the processing time of a batch is equal to the sum of the processing times of jobs in the batch. When a new batch starts, a constant setup time s occurs. We concentrate on the unbounded model, where 6 > n. We present an O(n2) algorithm for finding all Pareto optimal solutions of this bicriteria scheduling problem.

12

Effect of eddy diffusivity on turbulent film condensation outside a horizontal tube

Yang S., Lin Y.

Archives of Thermodynamics

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2006

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Vol. 27, no. 1

75--87

EN

The effect of eddy diffusivity upon the turbulent film condensation of saturated vapour flowing downward onto a horizontal isothermal circular tube is performed theoretically by employing the Hilpert semi-empirical model. The interfacial shear of the vapour from laminar flow to turbulent flow is evaluated with help of potential flow theory. The transition region or the separation point of condensate film is also studied for the following different dominant parameters including Prandtl number, Reynolds number, sub-cooling parameters and system pressure parameter. The condensate film flow and the heat transfer characteristics under the effects of eddy diffusivity and the above mentioned parameters are investigated. The present result shows in better agreement with the experimental data than the previous theoretical modes do.

13

DSD : Maintain Data Cubes More Efficiently

Li H., Huang H., Lin Y.

Fundamenta Informaticae

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2004

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Vol. 59, nr 2,3

173--190

EN

A well-known challenge in data warehousing is the efficient incremental maintenance of data cube in the presence of source data updates. In this paper, we present a new incremental maintenance algorithm, DSD, developed from Mumick's algorithm. Instead of using one auxiliary delta table, we use two tables to improve efficiency of data update. Moreover, when a materialized view has to be recomputed, we use its smallest ancestral view's data, while Mumick uses the fact table which is usually much lager than its smallest ancestor. We have implemented DSD algorithm and found that its performance shows a significant improvement.

14

Differential and integral calculus on discrete time series data.

Lin Y.

Systems Science

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2001

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Vol. 27, nr 3

49-58

EN

It has been found that discontinuity plays a crucial role in natural evolutions (Lin 1998). In this presentation, we will generalize the idea of integration and differentiation, we developed in calculus, to the study of time series in the hope that the problem of outliers and discontinuities can be resolved more successfully than simply deleting the outliers and avoiding discontinuities from the overall data analysis. In general, appearances of outliers tend to mean existence of discontinuities, explosive growth or decline in the evolution. At the same time, our approach can be employed to partially overcome the problem of not having enough data values in any available time series. At the end, we will look at some real-life problems of prediction in order to see the power of this new approach.

15

Predictability of atmospheric eddy motions and reversal changes in systems evolutions.

Xiao T., Lin Y., Ouyang S.

Systems Science

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1999

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Vol. 25, nr 2

111-124

EN

This paper contains our study on the importance and universality of eddy motions in atmospherical motions. By using the theory of blow-ups of physical evolutions and the method of fractal dimensions, we study the predictability of eddy motions. Our results indicate that these methods basically provide predictions with roughly the same amount of time before the arrivals of atmospherical motions. Also, it is found that the time scale of the predicted arrival of an atmospherical motion is dependent on the special scale of the eddy system and external parameters, such as geographical locations, changes of seasons, etc. If seen from the point of view of the whole evolutionary chains of systems, the predicable time period before the arrival of an eddy system essentially reflects the time period before a reversal change occurs in the system so that predictability should not be considered as continuity of the initial values.