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1

Sensitivity analysis study of the source parameter uncertainty factors for predicting near-field strong ground motion

Li Z., Gao M., Jiang H., Chen X., Li T., Zhao X.

Acta Geophysica

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2018

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Vol. 66, no. 4

523--540

EN

Uncertainty factors have substantial influences on the numerical simulations of earthquakes. However, most simulation methods are deterministic and do not sufficiently consider those uncertainty factors. A good approach for predicting future destructive earthquakes that is also applied to probabilistic hazard analysis is studying those uncertainty factors, which is very significant for improving the reliability and accuracy of ground-motion predictions. In this paper, we investigated several uncertainty factors, namely the initial rupture point, stress drop, and number of sub-faults, all of which display substantial influences on ground-motion predictions, via sensitivity analysis. The associated uncertainties are derived by considering the uncertainties in the parameter values, as those uncertainties are associated with the ground motion itself. A sensitivity analysis confirms which uncertainty factors have large influences on ground motion predictions, based upon which we can allocate appropriate weights to those uncertainty factors during the prediction process. We employ the empirical Green function method as a numerical simulation tool. The effectiveness of this method has been previously validated, especially in areas with sufficient earthquake record data such as Japan, Southwest China, and Taiwan, China. Accordingly, we analyse the sensitivities of the uncertainty factors during a prediction of strong ground motion using the empirical Green function method. We consequently draw the following conclusions. (1) The stress drop has the largest influence on ground-motion predictions. The discrepancy between the maximum and minimum PGA among three different stations is very large. In addition, the PGV and PGD also change drastically. The Arias intensity increases exponentially with an increase in the stress drop ratio of two earthquakes. (2) The number of sub-faults also has a large influence on various ground-motion parameters but a small influence on the Fourier spectrum and response spectrum. (3) The initial rupture point largely influences the PGA and Arias intensity. We will accordingly pay additional attention to these uncertainty factors when we conduct ground-motion predictions in the future.

2

Summary of the port shoreline resource evaluation based on triangular fuzzy analytic hierarchy process

Jiang L., Tao T., Zhang C., Jiang H., Wang J.

Polish Maritime Research

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2017

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S 3

16--22

EN

Port shoreline resources are the basis of port and shipping development, and its assessment method has become one of the hot issues in port research. On the basis of constructing a reasonable index evaluation system, this paper constructs the fuzzy evaluation matrix based on the triangular fuzzy analytic hierarchy process and constructs the fuzzy evaluation matrix by using the fuzzy comprehensive evaluation method, and obtains the maximum membership degree of the port shoreline resources. Compared with the traditional port shoreline Resource evaluation methods, the new one got more advantages in objective and quantitative. Finally, Combined with the Nanjing section of the Yangtze River as a case for verification, the results show that the model can accurately solve the problem of resource evaluation of port shoreline.

3

Theoretical derivation of basic mechanical property required for triggering mine-pillar rockburst

Huang H., Lli J., Jiang H.

Acta Geophysica

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2017

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Vol. 65, no. 5

945--955

EN

Rockburst is divided into two types, one is strain-type resulting from rock damage and another is sliding-type resulting from fault slip events. Triggering mine pillar rockburst mainly consists of two steps: the occurrence of shear-band and the application of disturbance. In this paper, mechanical model of mine pillar subjected to uniaxial compression is established. By simplifying the complete stress-strain curve and the crack propagation behaviour, based on the derived energy expressions corresponding to different crack propagation stages, the type of rockburst that the disturbance-induced pillar instability belongs to is defined. Next, by establishing the model of mine pillar with one inclined shear-band and by simplifying the stress evolution on the band, based on the necessary physical characteristics for triggering dynamic events, the basic mechanical property of mine pillar required for triggering instability is derived. It shows that the post-peak modulus greater than or equal to the pre-peak modulus is the basic mechanical property required for triggering mine pillar instability. Finally, by conducting laboratory experiments, the proposed model is verified. The requirement that the post-peak modulus is greater than or equal to the pre-peak modulus may be the rea-son why triggered mine pillar rockburst is not often observed.

4

Probability of Secrecy Outage in Cognitive Radio Networks over Rician-Fading Channels

Zhang J., Jiang H., Pan G.

International Journal of Electronics and Telecommunications

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2016

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Vol. 62, No. 2

153--158

EN

In Rician-fading scenario, cognitive radio networks (CRNs) with a source in a secondary system transmitting its confidential information to a legitimate destination in the presence of an eavesdropper, are considered in this paper. Under CRNs, the interference power reaching at primary user (PU) is limited by some pre-defined threshold. Secrecy outage not only occurs when the achievable secrecy capacity for source-destination link is smaller than a target rate, but also occurs in the case that the interference power at PU is greater than that threshold. Analytical expression for secrecy outage probability has been derived and verified with simulation results. In addition, we have also derived the analytical expression for probability of non-zero secrecy capacity.

5

Objective assessment for characterising the flatness of garment sewing stitches

Jiang H., Liu J., Chai Z., Wang C., Zhang M.

Autex Research Journal

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2013

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Vol. 13, no. 4

110--117

EN

In this paper, a novel classification method of assessing garment sewing stitch based on amended bi-dimensional empirical mode decomposition (ABEMD) has been introduced. Two parameters that characterise garment sewing stitch, average area and standard deviation, have been defined based on the grey value of pixels. Experimental results showed that when the window size is 512×128 pixels with regard to average area, the threshold can be decided as 6.00, 5.50, 5.30 and 4.00 for five different grades , respectively. Meanwhile, with regard to standard deviation, the threshold can be decided as 48.00, 40.00, 30.00 and 20.00, respectively. It is demonstrated that the parameters are effective in discriminating sewing stitch images in terms of the grades when used as inputs for the ABEMD. The performance of the algorithm on different garment status is significantly reliable.

6

Multiple Support Vector-based approach to Breast tumor recognition

Jiang H., Chen X., Liu B.

Przegląd Elektrotechniczny

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2012

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R. 88, nr 5b

105-107

EN

Based on Multi-Support Vector Machine (MSVM),this paper provides a method of MSVM for breast tumor recognition to solve unfixed size and individual difference with the breast tumor. Support Vector Machine (SVM) on the eight direction of bump area is taken to generate vector classifier and to select Gauss kernel function as kernel function. The system application and test shows that the MSVM in breast tumor recognition achieved good result, and provide the reliable basis for further medical diagnosis. The breast tumor recognition accuracy achieved 97.3%.

PL

Opisano wykorzystanie metody MSVM (multi-support vector machine) do wykrywania guza piersi. Metoda generuje klasyfikator wektorowy w ośmiu kierunkach a selekcję cech przeprowadza się wykorzystując funkcje Gaussa jako kernel.

7

An Application of Canonical Decomposition to TDOA Estimation for 3D Wireless Sensor Network Node Localization

Jiang H., Liu C., Sun X.

Przegląd Elektrotechniczny

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2012

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R. 88, nr 9b

92-95

EN

In this paper, a time difference of arrival (TDOA) estimation algorithm is proposed by extending canonical correlation decomposition (CCD) to measure multipath delays for determining node positions in Ultra-wideband wireless sensor networks (WSNs). Multilateral localization based on 3D Chan algorithm is employed to solve the non-linear problems for performance improvement. The method can perform well in the environment with unknown noise. The effectiveness is validated by simulations and the effects of noise and the number of anchor nodes are analyzed.

PL

Przedstawiono algorytm TDOA (time difference of arrival) do określania wielościeżkowych opóźnień w szerokopasmowej bezprzewodowej sieci czujników. Metoda jest przydatna w środowisku o nieznanych szumach.

8

Leaf litter decomposition along the temperate - tropical transect (East China) : the influence of stand succession, litter quality and climate

Song X., Jiang H., Peng C., Zhou G., Chang S., Yu S., Ma Y., Peng S., Wei X.

Polish Journal of Ecology

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2012

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Vol. 60, nr 2

265-276

EN

The relationship between litter decomposition and forest succession in addition to the influence of climate variables on the rate of litter decomposition in forest ecosystems are poorly understood. In this study, the effects of forest successional stages, climate, and litter quality on litter decomposition rates were investigated in five sites located in China. The selected sites cover 29 degrees of latitude from 18[degrees]N to 47[degrees]N and spans more than 5,000 km in length along a temperature gradient that transverses across eastern China. This zonal gradient includes five climate zones from temperate to subtropical to tropical zones. Forest types include broad-leaved Korean pine, deciduous broad-leaved, evergreen broad-leaved, monsoon evergreen broad-leaved, and tropical rain forests. The North-South Transect of Eastern China (NSTEC) is one of fifteen international standard transects setup by Global Change and Terrestrial Ecosystems (GCTE). NSTEC is a key component of the International Geosphere-Biosphere Programme (IGBP). The litterbag method was used in this study to determine mass loss and annual decomposition rates of eight tree species (Pinus massoniana Lamb., Cunninghamia lanceolata (Lamb.) Hook., Schima superba Gardn. et Champ., Cinnamomum camphora (L.) Presl., Cyclobalanopsis glauca (Thunb.) Oerst., C. gracilis (Rehd. et Wils.) Cheng et T. Hong, Michelia chapensis Dandy, and Castanopsis eyeri (Champ.) Tutch. through a timeframe starting in May, 2006, and ending in May, 2008. Litterbags 15 x 15 cm and 0.5 x 1.0 mm mesh were filled with 10 g of leaf litter collected from the subtropical forest region and then placed onto the forest floor in triplicate samples for each eight species in all five sites. Three litterbags per species were retrieved from each of the five sites at two month intervals during the two year experimental period. Results suggest that species litter in the climax stage (C. glauca, C. gracilis, and M. chapensis) tended to decompose faster than those in the pioneer stage (P. massoniana and C. lanceolata). Initial phosphorous (P) and nitrogen (N) concentrations of leaf litter were the most critical variables of litter quality in relation to the impact on the rate of litter decomposition. Litter decomposition at different successional stages was found to be directly related to climatic variables such as mean annual precipitation (MAP) and mean annual temperature (MAT). MAP and initial P and N concentrations could therefore be considered good indicators of rates of decomposition.

9

Evaluating the habitat quality of giant panda (Ailuropoda Melanoleuca) using Habitat Suitability Index (HSI)

Jian J., Jiang H., Jiang Z., Zhou G., Yu S., Peng S., Liu S., Liu S., Wang J.

Polish Journal of Ecology

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2012

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Vol. 60, nr 4

827--837

EN

Habitat quality for many wildlife populations has a spatial component related to the arrangement of habitat elements across large geographic areas. With remote sensing and GIS technology, this paper presents an approach to calculate Habitat Suitability Index (HSI) for Giant Pandas to evaluate the habitat quality. In this paper, a buffer of a given distance (30 km or more) to the Giant Panda distribution area estimated in three national surveys (1974, 1989 and 2002), which is located in Sichuan, Gansu and Shanxi provinces in western China, was used as the study area. In order to study different species group’s habitat quality, the study area is divided into five parts: the Qinling mountain systems, located in the southeast in Shanxi province, the Minshan mountain systems, located in the south in Gansu province and northwest in Sichuan province, the Qionglai mountain systems, the Xiangling mountain systems and the Liangshan mountain systems, located in the west of Sichuan province, conforming to the five big Giant Panda species groups. Three physical environmental factors (elevation, slope and aspect), one ecological factor (vegetation distribution) and several human-influence factors (distances to highways, general roads, inhabitants and rural areas) are selected as the influence factors to calculate HSI. Each factor was reclassified by grid-cell (30 × 30 m per cell) to the suitability index scale from 0 to 1 based on habitat affinities before final calculation. After analyzing the HSI values on the most Giant Panda distribution area, 0.0144 was considered as the threshold habitat quality. Then, HSI was calculated for five mountain systems for three periods conforming to three national surveys (1974, 1989 and 2002). Several benefits to the approach can be highlighted. Firstly, HSI can be used as the standard to evaluate the quality of Giant Panda habitat. Secondly, by using HSI maps from 1974, 1989 and 2002, we can see that the Giant Panda habitat was the largest in 1974, and was then reduced much before 1989. However, by 2002, it had recovered to some extent, which conforms to the habitat data from the three national surveys. Thirdly, the habitat changes in the five mountain systems examined in the study are different. Finally, nature reserves play an important role in the protection of Giant Panda habitat; there are more suitable habitats in nature reserves than non-protected areas.

10

Forecasting carbon budget under climate change and CO2 fertilization for subtropical region in China using Integrated Biosphere Simulator (IBIS) model

Zhu Q., Jiang H., Liu J., Peng C., Fang X., Yu S., Zhou G., Wei X., Ju W.

Polish Journal of Ecology

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2011

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Vol. 59, nr 1

3-23

EN

The regional carbon budget of the climatic transition zone may be very sensitive to climate change and increasing atmospheric CO2 concentrations. This study simulated the carbon cycles under these changes using process-based ecosystem models. The Integrated Biosphere Simulator (IBIS), a Dynamic Global Vegetation Model (DGVM), was used to evaluate the impacts of climate change and CO2 fertilization on net primary production (NPP), net ecosystem production (NEP), and the vegetation structure of terrestrial ecosystems in Zhejiang province (area 101,800 km2, mainly covered by subtropical evergreen forest and warm-temperate evergreen broadleaf forest) which is located in the subtropical climate area of China. Two general circulation models (HADCM3 and CGCM3) representing four IPCC climate change scenarios (HC3AA, HC3GG, CGCM-sresa2, and CGCM-sresb1) were used as climate inputs for IBIS. Results show that simulated historical biomass and NPP are consistent with field and other modelled data, which makes the analysis of future carbon budget reliable. The results indicate that NPP over the entire Zhejiang province was about 55 Mt C yr[^-1] during the last half of the 21st century. An NPP increase of about 24 Mt C by the end of the 21st century was estimated with the combined effects of increasing CO2 and climate change. A slight NPP increase of about 5 Mt C was estimated under the climate change alone scenario. Forests in Zhejiang are currently acting as a carbon sink with an average NEP of about 2.5 Mt C yr[^-1]. NEP will increase to about 5 Mt C yr[^-1] by the end of the 21st century with the increasing atmospheric CO2concentration and climate change. However, climate change alone will reduce the forest carbon sequestration of Zhejiang.s forests. Future climate warming will substantially change the vegetation cover types; warm-temperate evergreen broadleaf forest will be gradually substituted by subtropical evergreen forest. An increasing CO2 concentration willhave little contribution to vegetation changes. Simulated NPP shows geographic patterns consistent with temperature to a certain extent, and precipitation is not the limiting factor for forest NPP in the subtropical climate conditions. There is no close relationship between the spatial pattern of NEP and climate condition.

11

Visualization and determination of the geometrical parameters of slub yarn

Liu J., Li Z., Lu Y., Jiang H.

Fibres & Textiles in Eastern Europe

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2010

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Vol. 18, no. 1 (78)

31--35

EN

This paper presents an analytical method of determining slub yarn geometrical parameters based on a 2D visualization image of a slub yarn. The method can be used to adjust the slub yarn mechanism by comparing experimental results with the setting used. Geometrical size data of slub yarn are acquired by DAQ (Data Acquisition Card), and expressed as voltage signals. The dynamic threshold method is used to separate the base and slub parts, and the geometrical parameters of each part can be acquired through analysis of the new curve. The slub length can be plotted against the distance between slubs to give a 2D visualization of any pattern in the periodicity. Characteristic lengths and spacing can be estimated from the plot. According to the experimental results, the slub length is longer and the slub distance shorter than the values set for the mechanism of the spinning frame.

PL

Przedstawiono analityczną metodę określenia parametrów geometrycznych przędz fantazyjnych płomienistych wykorzystującą wizualizację obrazów 2D badanych przędz. Metoda może być stosowana dla dopasowania struktury otrzymywanej przędzy do nastawień parametrów przędzarki. Geometryczne wymiary poszczególnych segmentów przędzy są magazynowane i przetwarzane komputerowo na sygnały elektryczne. Zastosowano metodę dynamicznego progowania dla rozdzielenia sygnałów pochodzących z przędzy podstawowej oraz sygnałów z elementów fantazyjnych, a parametry geometryczne każdego z elementów mogą być zapisane i analizowane. Długość elementów fantazyjnych może być analizowana w stosunku do odległości między elementami a następnie można uzyskać wizualizację typu 2D. Zgodnie z uzyskanymi wynikami doświadczalnymi stwierdzono, że długość elementów fantazyjnych jest większa a odległość między nimi mniejsza w stosunku do wartości nastawionych na przędzarce.

12

Carbon storage of cycad and other gymnosperm ecosystems in China: implications to evolutionary trends

Ma Y., Jiang H., Wang B., Zhou G., Yu S., Peng S., Hao Y., Wei X., Liu J., Yu Z.

Polish Journal of Ecology

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2009

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Vol. 57, nr 4 (2

635-646

EN

Cycads are an ancient lineage of plants that originated in the Permian, which are vital to the interpretation of plant ecology. The evidence in the fossil records indicates that the morphological and anatomical features of cycads are remarkably similar to the extant taxa, which has been instrumental in our understanding the connections between the early origins of seed plants and their present-day counterparts. The cycad ecosystem is an important vegetation type throughout geological time. Research on the ecological function of the cycad plays a significant role in the study of evolutionary ecology. In this study, we investigated the biomass, productivity and total carbon storage (total of vegetation, litter, and soil carbon) of cycad (Cycas panzhihuaensis L. Zhou et S.Y. Yang) ecosystems in the National C. panzhihuaensis Reserve of China (latitude 26[degrees]37', longitude 101[degrees]35', at 1635 m altitude) by applying the site-standard tree sampling harvest. Cycads are considered to be rare and endangered species, and are in the list of key protected wild plants in the world. The National C. panzhihuaensis Reserve is in Southwestern China, which area approximately 1358 ha, growing approximately 20 000 C. panzhihuaensis individuals. 20 sample plots, each 5 x 5 m were established in the spring of 2006. The mean height of cycads within the stand was 0.44 m and the mean basal diameter was 23.2 cm. The biomass and productivity data for other communities was compiled from references published over the past 20 years throughout China. The biomass and productivity of cycad ecosystems (8.102 [plus or minus] 6.880 t C ha[^-1] and 1.183 [plus or minus] 0.975 t C ha[^-1] yr[^-1], respectively) are smaller than tree fern (Alsophila spinulosa (Wall. ex Hook.) R. M. Tryon) or gymnosperm (Pinaceae, Cupressaceae or Taxodiaceae for representative) ecosystems. The community biomass of Pinaceae-, Cupressaceae- or Taxodiaceae-dominated ecosystems are 6.8, 5.4, and 5.3 times larger than the cycad ecosystem, respectively. The productivity of each is 2.3, 2.8 and 3.8 times larger than the cycad ecosystem. Cycad is an ancient dioecious plant. However, the results show that the differences between the biomass of male and female cycads, as well as the productivity, are not significant.

13

Sinusoidal phase modulating interferometer for real-time surface profile measurement

He G., Jiang H., Tan X.

Optica Applicata

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2008

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Vol. 38, nr 2

413-420

EN

The optical interferometry for the surface profile measurement is high accuracy, non-contact, and has a wide application in industry and scientific research. In this paper, a sinusoidal phase modulating (SPM) interferometer to realize real-time surface profile measurement is proposed, and its measuring principle is analyzed theoretically. In the SPM interferometer, the interferencje signal is detected by a high speed image sensor based on a low-speed CCD and a signal processing circuit is used to obtain the phase of each point on the surface. Therefore, the surface profile can be measured real time. The experiments measuring the surface profile of a wedge-shaped optical flat show that the measurement time of the SPM interferometer is less than 10 ms, the repetitive measurement accuracy is 5.2 nm. The experimental results confirm the validity of the SPM interferometer, and the merits of the interferometer is simple structure, high measurement accuracy.

14

Fabrication and dielectric properties of Si3N4-MgO-Al2O3 by spark plasma sintering technique

Li J., Chen F., Shen Q., Jiang H., Zhang L.

Materials Science Poland

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2007

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Vol. 25, No. 3

699--707

EN

In the present study, alfa-Si3N4 was prepared using MgO and Al2O3 as the sintering additives and spark plasma sintering (SPS) technique. The SPS sintering behaviour and mechanism have been discussed. The relationship between the content of sintering additives, sintering temperature, and relative densities of the samples have been analyzed. The phase composition was determined by XRD, the microstructures of the fracture surfaces were observed by SEM and the dielectric properties have been tested. The results suggest that when the sintering temperature is 1300-1500 oC, the content of sintering additives - 6-10%, the relative density of the sintered samples is 64-96%. When the sintering temperature reaches 1400 oC, the content of sintering additives 10%, the samples could be fully dense sintered (the relative density up to 95%) The sintering mechanism is liquid phase sintering. The electric permittivity of the sintered samples is 5-8 being in a close relationship with the relative density. The dielectric loss, influenced by the liquid phase, is less than 1×10-2.