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1

Multi-Objective Optimization of Traffic Signal Timing Using Non-Dominated Sorting Artificial Bee Colony Algorithm for Unsaturated Intersections

Zhao H., He R., Su J.

Archives of Transport

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2018

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Vol. 46, iss. 2

85--96

EN

Vehicle delay and stops at intersections are considered targets for optimizing signal timing for an isolated intersection to overcome the limitations of the linear combination and single objective optimization method. A multi-objective optimization model of a fixed-time signal control parameter of unsaturated intersections is proposed under the constraint of the saturation level of approach and signal time range. The signal cycle and green time length of each phase were considered decision variables, and a non-dominated sorting artificial bee colony (ABC) algorithm was used to solve the multi-objective optimization model. A typical intersection in Lanzhou City was used for the case study. Experimental results showed that a single-objective optimization method degrades other objectives when the optimized objective reaches an optimal value. Moreover, a reasonable balance of vehicle delay and stops must be achieved to flexibly adjust the signal cycle in a reasonable range. The convergence is better in the non-dominated sorting ABC algorithm than in non-dominated sorting genetic algorithm II, Webster timing, and weighted combination methods. The proposed algorithm can solve the Pareto front of a multi-objective problem, thereby improving the vehicle delay and stops simultaneously.

2

Microstructure and Mechanical Properties of Duplex Structured Mg-Li-Zn-Y Alloys

Su J., Yang Y., Fu X., Ma Q., Ren F., Peng X.

Archives of Foundry Engineering

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2018

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Vol. 18, iss. 1

181--185

EN

As-cast Mg-6Li-0.3Zn-0.6Y and Mg-6Li-1.2Zn-1.2Y (wt%) alloys were prepared and extruded at 260 ºC with an extrusion ratio of 25. The microstructure and mechanical behavior of as-cast and extruded alloys are reported and discussed. The results show that Mg-6Li-1.2Zn- 1.2Y alloy is composed of α-Mg, β-Li, and W-Mg3Zn3Y2 phases while Mg-6Li-0.3Zn-0.6Y alloy contains α-Mg, β-Li, W-Mg3Zn3Y2 phase and X-Mg12ZnY. After hot extrusion, the microstructure of specimens is refined and the average grains size of extruded alloys is 15 μm. Dynamic recrystallization occurs during the extrusion, leading to grain refinement of test alloys. Both the strength and elongation of test alloys are improved by extrusion. The extruded Mg-6Li-0.3Zn-0.6Y alloy possesses an ultimate strength of 225 MPa with an elongation of 18% while the strength and elongation of Mg-6Li-1.2Zn-1.2Y alloy are 206 MPa and 28%, respectively. The X-phase in Mg-6Li-0.3Zn- 0.6Y is beneficial to the improvement of strength, but will lead to the decrease of ductility.

3

Numerical simulation study on exposed reinforced anti-corrosion layer damage of the cross-sea bridge under the marine environment

Qu H., Su J., Huang P., Ren X.

Polish Maritime Research

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2017

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S 3

207--212

EN

To solve the problem of low precision of numerical simulation of the exposed reinforced anti-corrosion layer damage of the cross-sea bridge, we use the stress ratio between the double slash and the reinforced anti-corrosion layer to analyze the parameters and the damage rate in different qualities of reinforced anti-corrosion layers, use Ansys software to build reinforced finite element model, and analyze the damage degree when the inclination angle was 15 °, 45 ° and 60 °, respectively. The experimental results showed that the proposed method can improve the numerical simulation efficiency, the numerical simulation results, the experimental results, and the theoretical analysis results have good consistency and stability.

4

Response patterns of phytoplankton growth to variations in resuspension in the German Bight revealed by daily MERIS data in 2003 and 2004

Su J., Tian T., Krasemann H., Schartau M., Wirtz K.

Oceanologia

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2015

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No. 57 (4)

328--341

EN

Chlorophyll (chl a) concentration in coastal seas exhibits variability on various spatial and temporal scales. Resuspension of particulate matter can somewhat limit algal growth, but can also enhance productivity because of the intrusion of nutrient-rich pore water from sediments or bottom water layers into the whole water column. This study investigates whether characteristic changes in net phytoplankton growth can be directly linked to resuspension events within the German Bight. Satellite-derived chl a were used to derive spatial patterns of net rates of chl a increase/decrease (NR) in 2003 and 2004. Spatial correlations between NR and mean water column irradiance were analysed. High correlations in space and time were found in most areas of the German Bight (R2 > 0.4), suggesting a tight coupling between light availability and algal growth during spring. These correlations were reduced within a distinct zone in the transition between shallow coastal areas and deeper offshore waters. In summer and autumn, a mismatch was found between phytoplankton blooms (chl a > 6 mg m−3) and spring-tidal induced resuspension events as indicated by bottom velocity, suggesting that there is no phytoplankton resuspension during spring tides. It is instead proposed here that frequent and recurrent spring-tidal resuspension events enhance algal growth by supplying remineralized nutrients. This hypothesis is corroborated by a lag correlation analysis between resuspension events and in-situ measured nutrient concentrations. This study outlines seasonally different patterns in phytoplankton productivity in response to variations in resuspension, which can serve as a reference for modelling coastal ecosystem dynamics.

5

Electronic structures of Hg-doped anatase TiO2 with different O vacancy concentrations

Zheng S K, Wu G., Zhang S., Su J., Liu L.

Materials Science Poland

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2014

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Vol. 32, No. 1

93--97

EN

The electronic structures of Hg-doped anatase TiO2 with different O vacancy concentrations were calculated using the first-principles based on the density functional theory. The calculated results show that the forbidden band widths of Hgdoped anatase TiO2 widened along with the increase of O vacancy concentration, which is responsible for the blue shift in the absorption edges. It can be deduced from the present study that the Hg-doped TiO2 samples prepared in the experimental research contain a certain quantity of O vacancies.

6

Wear Measurement of the Vehicle Brake Shoe and Determination Method of the Optimal

Xu G., Li X., Su J., Chen R., Wang X.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 2a

175--178

EN

Position for Inspection Wear measurement of a vehicle brake shoe is an effective way to enhance the vehicle safety. The continuous measurement problem of the abrasion loss of a brake shoe is solved by employing an electronic chip with series circuit. The quasi-linear solution is achieved by simulating the constructed model of the resistances distribution. Furthermore, the optimal location for the inspection is formulated by analyzing the brake kinematics. Simulations are performed on the representative conditions and agree to the experiments with an acceptable 0.1 V error.

PL

Pomiar zużycia szczęk hamulcowych ma istotne znaczenie dla bezpieczeństwa. Problem ciągłego pomiaru zużycia szczęk rozwiązano stosując odpowiedni czujnik. W artykule analizuje się tez optymalne położenie czujnika.

7

A vacuum sensor of large measurement scale based on rubbing-processed carbon nanotube films

Su J., He K.-X., Guo D.-Z., Xing Y.-J., Zhang G.-M.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 1b

134--137

EN

A miniature vacuum sensor with the widest vacuum measurement scale from 5×10-6 to 1×105 Pa by using carbon nanotube (CNT) films as the sensing material is presented. The CNT-films were mechanically rubbed onto quartz-glass substrates, with two electrodes evaporated at the two ends. It is found that the resistance of the CNT-films responses sensitively to the change of vacuum pressure. The mechanism of the sensors relates to the adsorption of water molecules which influences the electron transfer in CNTs and increases the CNT-junction resistivity.

PL

Zaproponowano miniaturowy czujnik próżniowy z szerokim zakresem pomiaru, od 5x10-6 do 1x105Pa, wykorzystujący, jako materiału czułego, błony z nanorurek węglowych (CNT). Błony przetarte są mechanicznie na podłożach ze szkła kwarcowego, na końcach których napylono dwie elektrody. Stwierdzono, że oporność CNT silnie zależy od ciśnienia próżni. Za mechanizm wrażliwości odpowiada adsorpcja cząsteczek wody, co wpływa na przepływ elektronów w CNT i powoduje wzrost oporności złącza CNT.

8

Variation and correlations of leaf traits of two Taxus species with different shade tolerance along the light gradient

Liu W., Li S., Su L., Su J.

Polish Journal of Ecology

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2013

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Vol. 61, nr 2

329--339

EN

The variations in leaf traits of Taxus species in different light conditions are still poorly understood. We sampled leaves of Taxus yunnanensis W. C. Chang L. K. Fu and Taxus chinensis var. mairei (Lemée and Lév.) W. C. Cheng and L. K. Fu along an illumination gradient (full daylight, 40–60% full daylight, <10% full daylight), and analyzed how seven leaf traits and their correlations changed under different light conditions. The leaf trait that showed the greatest variation was specific leaf area (SLA) for T. yunnanensis, followed by leaf dry mass (LM) for both taxa. The smallest variation was in leaf width (LW) for both taxa. Plasticities of all leaf traits in both taxa were higher than 50%, and those of leaf area (LA), LM and SLA were greater than 80%. The light gradient was positively correlated with leaf length (LL), LM, leaf dry matter content (LDMC), and leaf length to width ratio (LWR). LW and SLA were negatively correlated with the light gradient. Analyses of relationships among leaf traits showed that LM of T. yunnanensis, T. chinensis var. mairei and both taxa was positively correlated with LL, LW, LA, LDMC, and LWR, and negatively correlated with SLA under all light conditions. We concluded that leaf traits and their relationships were affected by light conditions.

9

Determination of interfacial parameters of horizontal two-phase plug flow using a high speed pulse-echo ultrasonic technique

Masala T., Harvel G., Su J., Chang J.

Transactions of the Institute of Fluid-Flow Machinery

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2010

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nr 122

61-76

EN

This paper presents a high-speed, multiple-transducers, pulse-echo ultrasonic technique for the measurement of interfacial parameters of horizontal two-phase intermittent flow regimes. The ultrasonic system consisted of an ultrasonic driver, a multiplexer with 4 transducers, and a microcomputer equipped with a data acquisition card, a motion controller card and the Winspect Data Acquisition software. Two transducers were mounted on the top of a 2.1 cm inner diameter circular pipe, while the other two transducers were mounted on the bottom of the pipe. Using instantaneous liquid level measurements from multiple transducers, two-phase flow interfacial parameters in plug were determined, such as the lengths and the velocities of liquid plugs and bubbles, the shape of the gas-liquid interface, and hence instantaneous and cross sectional averaged void fraction and interfacial area. The results showed that the liquid plug velocities as well as the elongated bubble velocity increases with increasing superficial liquid and gas velocities. An experimental correlation for liquid plug velocity was proposed based on the present results. The results also showed that the time and cross-sectional averaged void fraction in the plug flow regime was only slightly influenced by the superficial gas velocity but was not influenced by the superficial liquid velocity.

10

Phylogenetic discontinuity of plateau zokor (myospalax baileyi thomas) populations in qinghai-tibetan plateau

Tang L., Zhang T., Lin G., Su J.

Polish Journal of Ecology

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2010

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Vol. 58, nr 1

167-176

EN

Mitochondrial cytochrome b gene sequences and morphological data (body length, hind foot length, etc.) for twelve populations with pairwise distances 27-600 km in Qinghai-Tibetan Plateau (distributed in Qinghai, Gansu and Sichuan Province, and at the altitude 3020-4550 m) in Western China were used to investigate the phylogeographical pattern of Plateau zokor (Myospalax baileyi Thomas). There was a little disparity between mtDNA genetic distance and morphological Euclidean distance on population relationships. However, there is a significant correlation (P <0.001) calculated by Mantel's tests was validated between mtDNA and morphology distances. Analysis of Molecular Variance showed that most of the observed genetic variations occurred between populations, indicating little maternal gene flow between them, as a result of geographical restrictions. Phylogenetic analysis coupled with cluster analysis together showed that the substantial population structuring and phylogenetic discontinuities existed within this species. The evident allopatric population structuring of this subterranean rodent may mostly result from its specialized subterranean excavating behavior with high energy costs, predation from grassland raptors and also the influences of perennial tundra and environmental desiccation in the Qinghai-Tibetan Plateau.

11

Genetic variation and molecular evolution of endangered Kozlov.s pika (Ochotona koslowi Buchner) based on mitochondrial cytochrome b gene

Lin G., Ci H., Thirgood S., Zhang T., Su J.

Polish Journal of Ecology

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2010

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Vol. 58, nr 3

563-568

EN

Kozlov's pika is a rare and endangered lagomorph species with a limited distribution in the southern Kunlun Mountains in western China. Because of its endangered status, Kozlov's pika is considered a priority species for research and conservation action. Genetic variation and molecular evolution of the Kozlov's pika were studied based on a total of 14 individuals from four locations along the eastern boundary between Xinjiang and Tibet province (35.20-36.48[degrees]N, 86.08-83.04[degrees]E) on extremely high elevation (usually over 4800 m a.s.l.). The density of local populations was about 3-4 per ha, living in a typical alpine desert grassland habitat. The complete mitochondrial cytochrome b (cytb) gene was amplified and sequenced. Based on the cytb gene sequences the genetic variation and molecular evolution were analyzed. Unexpected high haplotype diversity (0.956 [plus or minus] 0.045) but low nucleotide diversity (0.00537 [plus or minus] 0.00126) was found, indicating past demographic expansion. Significant partitioning of variance (P <0.01) among populations (46.7%), and within populations (53.3%), indicating low level of genetic differentiations among local populations. Our results gave an optimistic survival status of Kozlov's pika at the genetic level. Bayes Empirical Bayes analysis with model M2a and M8 detected three positively selected amino acid sites at the significance level of 0.05. The mutant types with either or both of the mutations aspartic acid to asparagine and glutamic acid to lysine had higher isoelectric point values. We suggested these mutant types might have biological significance to help individuals to adapt to the extremely high elevation habitats.

12

Summer diet of two sympatric species of raptors Upland Buzzard (Buteo hemiliasius) and Eurasian Eagle Owl (Bubo bubo) in alpine meadow : problem of coexistence

Cui Q., Su J., Jiang Z.

Polish Journal of Ecology

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2008

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Vol. 56, nr 1

173-179

EN

Summer diets of two sympatric raptors Upland Buzzards (Buteo hemilasius Temminck et Schlegel) and Eurasian Eagle Owls (Bubo bubo L. subsp. Hemachalana Hume) were studied in an alpine meadow (3250 m a.s.l.) on Qinghai-Tibet Plateau, China. Root voles Microtus oeconomus Pallas, plateau pikas Ochotona curzoniae Hodgson, Gansu pikas O. cansus Lyon and plateau zokors Myospalax baileyi Thomas were the main diet components of Upland Buzzards as identified through the pellets analysis with the frequency of 57, 20, 19 and 4%, respectively The four rodent species also were the main diet components of Eurasian Eagle Owls basing on the pellets and prey leftovers analysis with the frequency of 53, 26, 13 and 5%, respectively. The food niche breadth indexes of Upland Buzzards and Eurasian Eagle Owls were 1.60 and 1.77 respectively (higher value of the index means the food niche of the raptor is broader), and the diet overlap index of the two raptors was larger (C[ue] = 0.90) (the index range from 0 - no overlap - to 1 - complete overlap). It means that the diets of Upland Buzzards and Eurasian Eagle Owls were similar (Two Related Samples Test, Z = -0.752, P = 0.452). The classical resource partitioning theory can not explain the coexistence of Upland Buzzards and Eurasian Eagle Owls in alpine meadows of Qinghai-Tibet Plateau. However, differences in body size, predation mode and activity rhythm between Upland Buzzards and Eurasian Eagle Owls may explain the coexistence of these two sympatric raptors.

13

Host sex and ectoparasite infections of plateau pika (Ochotona curzoniae, Hudson) on the Qinghai-Tibetan Plateau

Ci H., Lin G., Su J., Cao Y.

Polish Journal of Ecology

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2008

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Vol. 56, nr 3

535-539

EN

A total of 449 plateau pika (Ochotona curzoniae Hudgson) individuals were sampled with rattraps from 21 plots (size 1 ha) randomly scattered over the area of the species distribution at the altitude 3275-4807 m a.s.l. in the Qinghai-Tibetan Plateau (West China). Two main ectoparasite species Hypoderma satyrus Brauer and Ixodes crenulatus Neumann of plateau pika were surveyed, and the relations between host sex and parasitism were analyzed. The results were: (i) although not significantly, the infection rate of female young was close to zero and lower than that of male young (6%), while the infection rate of female sub-adults (19%) was contrarily - higher than that of male sub-adults (11%); adult females had significantly higher (41%) infection rate than that of males (18%) (P <0.001); (ii) the parasite infection rates for both males and females increased with increasing age, but female age-groups had obviously steeper slope. We suggested that the differences of body mass, growth rate and home range between males and females had mainly caused the sex-biased parasitism (SBP) of plateau pika at each age stage. Also, due to the higher increases of body mass and maybe as well as of the home range differences between consecutive age-groups, the parasite infections of females became more sensitive to the influences of age than that of males.