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Experimental research on mechanical features model of prestressed mutual-anchored retaining wall Jianhong JIANG,Zhenyu YANG,Qi CHEN,Qingyu MENG,Hongbo ZHANG Journal of Shandong University(Engineering Science)    2019, 49 (4): 61-69.   DOI: 10.6040/j.issn.1672-3961.0.2018.165 Abstract （1215）   HTML （4）    PDF（pc） （3546KB）（10071）       Knowledge map    Save To study the mechanical behaviors of the prestressed mutual anchoring retaining walls under different structural parameters, an indoor model test device was designed considering the mechanical mechanism and different prestress levels and different anchor placement positions. The results showed that due to the lateral restraint effect of the anchor (cable) on the wall and under the lateral prestress, the wall moved towards the direction of the filler, and gradually increased with the prestressing of the anchor. It evolved from T-model into the T+RB model. The earth pressure behind the wall gradually increased and it had a parabolic distribution with the peak at the anchor. According to the test results, the optimal anchoring position was recommended, and the range of anchored prestressing and optimal prestressing. The research results could be used to guide the design calculation of the prestressed mutual anchoring retaining walls. Table and Figures | Reference | Related Articles | Metrics

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Biomimetic fabrication of 2D photonic Y2O3:Eu3+ phosphor templated from butterfly wing scales YU Kui-long, FAN Tong-xiang* JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2012, 42 (1): 121-126.   Abstract （555）      PDF（pc） （2536KB）（2700）       Knowledge map    Save Using the natural intricate and delicate structures in biology as templates, i.e. biotemplation, the artificial analogue could be fabricated for improving the properties of novel materials. The green wing scales of the butterfly Papilio epiphorbas with intricate two dimensional photonic crystal (2D PhC) structure were adopted as templates to fabricate the 2D PhC Y2O3:Eu3+ phosphor through the aqueous sol-gel method. Field emission scanning electron microscopy (FESEM) demonstrated that the biomimetic Y2O3:Eu3+ could well duplicate the 2D PhC structure of butterfly scales. Emission spectra of the biomimetic Y2O3:Eu3+ tested via Laser-focused Raman microspectrometer confirmed that Eu3+ was efficiently dopped into the Y2O3 matrix and the target biomimetic material was obtained. The experimental contrast of fabrication routes with aqueous solgel precursor and water solution precursor indicated the advantages of the aqueous sol-gel method in fabricating delicate materials through biotemplation and thus could provide significant reference. Related Articles | Metrics

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Review and prospect of the development of heat exchanger structure Wenjing DU,Junzhe ZHAO,Lixin ZHANG,Zhan WANG,Wanxiang JI Journal of Shandong University(Engineering Science)    2021, 51 (5): 76-83.   DOI: 10.6040/j.issn.1672-3961.0.2020.423 Abstract （2392）   HTML （159）    PDF（pc） （4892KB）（1435）       Knowledge map    Save The development of heat exchanger for more than 200 years was introduced. The generation and typical applications of heat exchangers with different structures were reviewed. Four heat exchangers with different structures including shell-and-tube heat exchanger, plate heat exchanger, microstructure heat exchanger, and printed circuit heat exchanger were described emphatically, and the development work of related geometric parameter optimization and structure improvement was carried out to realize heat transfer enhancement. The existing problems and limitations in the structure design of the heat exchanger were analyzed, and the specific suggestions and development trends for the structure improvement of the heat exchanger in the future were proposed. Table and Figures | Reference | Related Articles | Metrics

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Review and prospect of research on power system inertia with high penetration of renewable energy source Hengxu ZHANG,Zhimin GAO,Yongji CAO,Hao QIN,Dong YANG,Huan MA Journal of Shandong University(Engineering Science)    2022, 52 (5): 1-13.   DOI: 10.6040/j.issn.1672-3961.0.2022.237 Abstract （1436）   HTML （88）    PDF（pc） （4575KB）（1206）       Knowledge map    Save With the aim of carbon peak and carbon neutrality, the integration of high-proportion renewable energy sources (RESs) makes the low-inertia characteristic of the new power system more obvious. In order to ensure power system security and stability, and support the integration of RESs, the research on the power system inertia was reviewed and prospected. The essence of the power system inertia was introduced, and the correlation among the conventional inertia, virtual inertia and equivalent inertia was discussed, on which the physical significance of the virtual inertia was revealed. From the viewpoints of the sources of inertia, the research on the virtual inertia control of the wind machine, photovoltaic generation, and energy storage system was summarized. Additionally, the assessment methods of power system inertia were reviewed. The important issues to be focused in the research area of power system inertia were summarized, and the suggestions for further studies were provided. Table and Figures | Reference | Related Articles | Metrics

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Review on development of simultaneous localization and mapping technology Jianqing WU,Xiuguang SONG Journal of Shandong University(Engineering Science)    2021, 51 (5): 16-31.   DOI: 10.6040/j.issn.1672-3961.0.2021.168 Abstract （1928）   HTML （254）    PDF（pc） （2986KB）（1190）       Knowledge map    Save As a hot spot in the field of intelligent transportation, simultaneous localization and mapping (SLAM) technology is the key to autonomous path planning for self-driving vehicles. This review focused on four parts with introduction of sensors related to SLAM technology, localization, mapping, and multi-sensor integration. Each step of realization for SLAM technology was introduced from advantages and disadvantages, range of application, probability algorithm, types of map, and integration methods. Based on the investigation of relevant researches about multi-sensor integration, common problems of SLAM technology were analyzed, future development trend and practical engineering application of SLAM technology were prospected. Table and Figures | Reference | Related Articles | Metrics

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Review on smart highways critical technology Jianqing WU,Xiuguang SONG Journal of Shandong University(Engineering Science)    2020, 50 (4): 52-69.   DOI: 10.6040/j.issn.1672-3961.0.2020.149 Abstract （2832）   HTML （587）    PDF（pc） （2579KB）（2121）       Knowledge map    Save Giving highway engineering "wisdom" and establishing new generation five-in-one system of "Internet+" design, construction, management, monitoring and operation, namely, the smart highway, was the hot issue of the interdisciplinary study of civil engineering, control engineering, mechanical engineering, transportation engineering, and computer science. To comprehensively understand the smart highway, this review focused on the critical technology in the integrated system in full life-cycle of the smart highway as well as systematically investigated the relevant previous efforts, critical common technologies, and future scopes on multi-function pavement material, smart construction, smart detection, autonomous vehicles, connected vehicles, and internet of things technology. Table and Figures | Reference | Related Articles | Metrics

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Simulation for separation of ethyl acetate and ethanol by heat-integrated pressure swing distillation YANG Jin-bei1, 3, YU Mei-qiong1, ZHENG Zhi-gong2, QIU Ting3* JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2013, 43 (1): 109-114.   Abstract （597）      PDF（pc） （2044KB）（1933）       Knowledge map    Save Heat-integrated pressure swing distillation for separation of ethyl acetate and ethanol was investigated based on the pressure-sensitivity of the azeotropic composition, and the separation sequence was formed by two columns operating at different pressures. The simulation of separation process was carried out satisfactorily by means of a package of commercial software Aspen Plus and using the thermodynamic model NRTL (non random two liquids) with binary parameters between ethyl acetate and ethanol obtained by experimental data of vapor liquid equilibrium (VLE). The factors affecting the separation efficiency and energy consumption including the number of theoretical plates, feed location and reflux ratio of two columns were analyzed. The results showed that ethyl acetate and ethanol could be efficiently separated by heat-integrated pressure swing distillation, and the optimal conditions were obtained. The heat-integrated pressure swing distillation could save heating steam by 34.7％ compared with conventional pressure swing distillation, which could provide an effective method for the design and energy-saving of azeotropic system separation. Related Articles | Metrics

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On comparison and selection of the wave spectrum in realtime rendering of the irregular ocean wave CHEN Li-ning, JIN Yi-cheng, REN Hong-xiang, YIN Yong JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2013, 43 (6): 47-52.   Abstract （1707）      PDF（pc） （1289KB）（2043）       Knowledge map    Save The Phillips spectrum was widely applied in real-time rendering of the irregular ocean wave. The structure of the Phillips spectrum was analyzed, and the frequency spectrum and directional distribution function of the Phillips spectrum were calculated. The frequency spectrum was similar with the P-M spectrum, so the constant A of the Phillips spectrum was computed by reference to the P-M spectrum, and the spectral wind speed was clarified. In addition to the Phillips spectrum, other spectra were tried. The P-M spectrum and the directional distribution function of the cos(-2s) form were used to construct the PM-cos2s spectrum, and the JONSWAP spectrum and the direction distribution function of the Poisson form were applied for constructing the J-Po spectrum. The three spectra mentioned above were used for rendering ocean wave, and the rendering results were compared. The waves rendered by the Phillips spectrum or PM-cos2s spectrum reflected the wind speed effect, and the wave generated by the J-Po spectrum showed the wind speed effect along with the fetch length effect. The frame rate of the three spectra shared the same value. Because the wave produced by the J-Po spectrum reflected the wind speed and fetch length influence, and the generated wave distributed in (-π,π］ of the wind direction, the J-Po spectrum was more suitable for the maritime simulator. Related Articles | Metrics

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Research progress of ocean wave energy converters Yanjun LIU,Shuang WU,Dengshuai WANG,Ruohong WANG Journal of Shandong University(Engineering Science)    2021, 51 (5): 63-75.   DOI: 10.6040/j.issn.1672-3961.0.2021.234 Abstract （2495）   HTML （143）    PDF（pc） （13090KB）（1009）       Knowledge map    Save In order to accurately keeping the developments of ocean wave energy utilization technology, the important research progress of wave energy converters was reviewed. The forms of wave energy converters had not yet converged. According to the classification principle of different energy capture methods, the working principle and the energy conversion system of three main types of devices, namely, oscillating water column, overtopping and oscillating bodies were introduced. The advantages and disadvantages of each type of converter were analyzed. Typical engineering devices were selected for detailed introduction. The engineering devices which had been completed sea trial in China were summarized. It has been found that the oscillation type was the most popular type of converter in China. The research progress related to the performance evaluation of wave energy converters were summarized, but there was no unified evaluation standard yet. The difficulties and the main breakthrough directions of the developments of wave energy converters were discussed from three aspects of high efficiency and stability, reliability and cost, and the construction of diversified integrated platforms. Table and Figures | Reference | Related Articles | Metrics

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Fault diagnosis and fault-tolerant control methods of X-tail UAV DENG Junwu, ZHANG Yumin, ZHANG Hongdi, DU Xiaokun JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2017, 47 (5): 166-172.   DOI: 10.6040/j.issn.1672-3961.0.2017.195 Abstract （1434）      PDF（pc） （4281KB）（1097）       Knowledge map    Save Actuators are the key agency of the UAV. For fault detection and fault diagnosis purpose of problems such as the dead, gain loss and deviation of the actuator, the fault detection filter and Kalman filter were presented in this contribution. The residual vector with actuator fault information was output by using the detection filter, then the threshold detection and residual direction characteristics were used to detect and isolate the fault. After the fault alarm, the Kalman filter was used to estimate the fault parameters, and the nature and extent of the fault were obtained. According to the different forms of fault, the method of control command compensation or reconstruction was finally used for fault-tolerant control purpose. Based on the turning rate model of the X-tails UAV, simulation test showed that the fault diagnosis method was effective and feasible, which could rapidly obtain the fault information, and the fault-tolerant strategy could well restore the system performance. Reference | Related Articles | Metrics

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High precision algorithm of metal detector based on balance coil BAI Shuzhong, DONG Chunyang JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2017, 47 (4): 83-88.   DOI: 10.6040/j.issn.1672-3961.0.2016.112 Abstract （1623）      PDF（pc） （1807KB）（1284）       Knowledge map    Save Metal detector is widely used in food security and industrial manufacture. In order to solve the product effect problem which used only amplitude feature, the dual channel digital detecting algorithm was put forward based on amplitude and phase information, also the balance coil mathematical model was built, and the metal signal feature was deeply analyzed. Through the coordinate orientating,the amplitude and phase information of metal could be exactly extracted, product learning and clustering algorithm could efficiently separate the metal signal and product effect signal. The experiment results showed that the phase information could separate different material metal effectively, cooperated with the amplitude information, the dual channel digital detecting algorithm could extract the metal information accurately and detect the metal with strong product effect. Reference | Related Articles | Metrics

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The influence of shape parameters of wave energy device floating body on energy capture characteristics Yanjun LIU, Wei WANG, Zhi CHEN, Donghai WANG, Dengshuai WANG, Gang XUE Journal of Shandong University(Engineering Science)    2020, 50 (6): 1-8.   DOI: 10.6040/j.issn.1672-3961.0.2020.160 Abstract （1092）   HTML （157）    PDF（pc） （6369KB）（1432）       Knowledge map    Save To clarify the effect of the floating body′s shape parameters on the energy capture performance and working stability, an oscillating float type wave energy converter (WEC) model with linear power take-off system was established. Frequency domain calculation theory was used to deduce the formulas of energy capture power and energy capture width ratio. After introducing the numerical simulation steps of floating body in frequency domain, ANSYS-AQWA software was used to investigate the floater's energy capture power and energy capture width ratio with different bottom shapes and half vertex angles. Influence of shape parameters on the energy capture performance was drawn to provide a theoretical basis for the shape optimization of the floating body applied to the wave power supply device and floating platform. The results showed that the practical fabrication feasibility of circular truncated cone bottom was higher than that of cone and sphere. The energy capture characteristics and stability of circular truncated cone bottom were better than that of general cylindrical floating body in the intermediate wave frequency band. The energy capture performance and working stability of circular truncated cone floating body with big top and small bottom were better. The energy capture performance under intermediate frequency waves could be improved with the increase of the half vertex angle. The optimal power capture performance and working stability could be achieved with a proper apex angle. Table and Figures | Reference | Related Articles | Metrics

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Design of triple-cables limiting-location anti-swing device for shipboard crane Zhaopeng REN, Rui XI, Shenghai WANG, Zhijiang ZHANG, Haiquan CHEN Journal of Shandong University(Engineering Science)    2020, 50 (3): 125-132.   DOI: 10.6040/j.issn.1672-3961.0.2019.004 Abstract （1211）   HTML （6）    PDF（pc） （4845KB）（1119）       Knowledge map    Save To reduce the payload pendulation of shipboard cranes, a mechanical anti-swing device based on triple-cables limiting-location was proposed. Three cables were used to pull the hook, which limited the spatial position of the payload to prevent the payload pendulation. According to the established kinematic model of the shipboard crane, the effect of length on the anti-swing was analyzed. The dynamic model of the payload system was established, and the effect of tension value on the anti-swing was analyzed. The models were verified by physical experiment based on a self-built test platform. The experimental results proved that the proposed mechanical anti-swing device based on triple-cables limiting-location had good anti-swing effect in practical applications. The overall anti-swing effect could reach more than 61%. Table and Figures | Reference | Related Articles | Metrics

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Experimental of the effects of static magnetic field on carp frozen process LOU Yao-jia, ZHAO Hong-xia*, LI Wen-bo, HAN Ji-tian JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2013, 43 (6): 89-95.   Abstract （1057）      PDF（pc） （1263KB）（2144）       Knowledge map    Save Carp frozen process in static magnetic field was experimentally investigated. The test samples were between 600～800g and the maximum thicknesses were between 46～52mm. All frozen processes were performed in an airblast quickfreezer, where the temperature was set -35℃. Magnetic field intensity was respectively 0G／3.6G／7.2G／10.8G. The surface and thermal centre temperatures were measured and recorded continuously in the whole frozen processes. The results indicated that the rule magnetic influencing frozen rate varied at different frozen stages. Magnetic field had little influence on cooling period, while, it held obvious promotion at phase change stage and delayed the freezing period. Related Articles | Metrics

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Fitting heat transfer coefficient correlation on flow boiling and error analysis for the helically coiled tube JI Cuilian, HAN Jitian, YIN Jing, CHEN Changnian, REN Libo, KONG Lingjian JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2014, 44 (5): 83-87.   DOI: 10.6040/j.issn.1672-3961.0.2014.020 Abstract （1762）      PDF（pc） （1407KB）（1102）       Knowledge map    Save In order to develop flow boiling heat transfer coefficient correlations for helically coiled tube, based on the mechanism of flow boiling heat transfer. The Dn factor was introduced to consider complex pipeline effects on flow boiling heat transfer. The index of the Dn factor was gained by using the regression method. And relation of the ratio of the experimental and predicted values with the mass flow rate and vapor quality was further analyzed. A new heat transfer coefficient correlation of flow boiling in helically coiled tube was developed. The applicability for the heat transfer coefficient correlation was validated by experimental data of flow boiling heat transfer in helically coiled tube with R134a. The MRE and the RMSE were used to measure the accuracy of regression results, with MRE and RMSE being 8.23% and 0.532, respectively. The MRE and the RMSE were small, the regression results conformed to the requirements. Therefore, the method is very applicable, and is worthy of popularization. Reference | Related Articles | Metrics

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The analysis and testing of thermal performance on solar evacuated tube ZHANG Tao, HAN Jitian, YAN Suying, YU Zeting, ZHOU Ran JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2014, 44 (4): 76-83.   DOI: 10.6040/j.issn.1672-3961.0.2014.006 Abstract （1615）      PDF（pc） （3832KB）（1123）       Knowledge map    Save The joint application test bench for solar-thermal photovoltaic was set up to study solar Kalina cycle. The analysis and testing of thermal performance on solar evacuated tube was carried out with methods of experimental and numerical simulation through the experiment platform of single tube solar water heater. The temperature and velocity field of single tube solar water heater were visible analyzed with field synergy principle. The study showed that the two dimensional numerical calculation model could accurately reflect the trend of all-glass evacuated tube solar water heater in the same conditions and the coefficient of field synergy on evacuated tube which was equipped with guide plate was superior to other structures. It was finally confirmed that the Φ58 mm×1 800 mm of solar evacuated tube equipped with reflector and guide plate was the best choice. Reference | Related Articles | Metrics

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Discussion on emergency control of central air conditioner at large receiving-end grid to cope with HVDC blocking fault Meng LIU,Dingyi CHENG,Wen ZHANG,Hengxu ZHANG,Kuan LI,Guohui ZHANG,Jianjun SU Journal of Shandong University(Engineering Science)    2020, 50 (1): 72-81.   DOI: 10.6040/j.issn.1672-3961.0.2019.201 Abstract （1121）   HTML （6）    PDF（pc） （5590KB）（1281）       Knowledge map    Save The central air conditioner had the potential to cope with the DC blocking fault through emergency control, ensure the safe and stable operation of the receiving-end grid after suffering from large power shortage. The basic principle of the central air conditioner was introduced. On this basis, the physical model of the central air conditioner which included central air conditioning unit, temperature change of frozen inflow and outflow water, heat exchange between the cooling water of the fan coil and the room, indoor average temperature change as well as the proportion of the room in the open state were established. An emergency control strategy for direct power cut and flexible recovery of central air conditioning was proposed. The feasibility of the emergency control of the central air conditioning system in response to stability control and under frequency/voltage load shedding were discussed respectively. The characteristics of the central air conditioning emergency control were simulated. The emergency control of central air conditioner was simulated after HVDC blocking fault occurs in Shandong power grid, verifying that the power grid frequency could be increased by 0.04 Hz when central air conditioners accounted for 1% of the total load in Shandong power grid. Table and Figures | Reference | Related Articles | Metrics

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Global and local multi-view multi-label learning with active three-way clustering ZHU Changming, YUE Wen, WANG Panhong, SHEN Zhenyu, ZHOU Rigui Journal of Shandong University(Engineering Science)    2021, 51 (2): 34-46.   DOI: 10.6040/j.issn.1672-3961.0.2020.234 Abstract （696）      PDF（pc） （1030KB）（709）       Knowledge map    Save In order to consider the uncertain belongingness relationship between instances and clusters and then extend the application scopes of global and local multi-view multi-label learning, an algorithm of global and local multi-view multi-label learning machine with active three-way clustering(GLMVML-ATC)was proposed. With the usage of active three-way clustering strategy, the belongingness of instances to a cluster depended on the probabilities of uncertain instances belonging to core regions. This made local label correlations more authentic, which enhanced the performances of multi-view multi-label learning machines further and accelerated their development. Experimental results validated that GLMVML-ATC improved the classification performances with 3% at least, while the added training time less than 7%. It was superior to the classical multi-view learning machines and multi-label learning machines. Reference | Related Articles | Metrics

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Multi-infeed HVDC simultaneous commutation failure risk evaluation method considering synchronous condenser reactive power Changhui MA,Liang WANG,Shaoqing TAN,Yi LU,Huan MA,Kang ZHAO Journal of Shandong University(Engineering Science)    2020, 50 (3): 98-103.   DOI: 10.6040/j.issn.1672-3961.0.2019.575 Abstract （1140）   HTML （5）    PDF（pc） （1571KB）（713）       Knowledge map    Save In order to improve the "Strong alternating current and weak direct current" characteristics of multi-infeed high voltage direct current systems, the synchronous condenser gradually gained attention.For the problem of multi-infeed high voltage direct current with synchronous condenser simultaneous commutation failure, a risk evaluation method considering the synchronous condenser reactive voltage characteristics was proposed. Firstly, the reactive voltage characteristics of the synchronous condenser were analyzed, and the multi-infeed interaction factor was calculated by reactive voltage sensitivity of the synchronous condenser, high voltage direct current system and static reactive power compensation device. Then, based on the nature of the commutation failure, the commutation failure evaluation factor was defined, and the simultaneous commutation failure risk of the multi-infeed high voltage direct current system with synchronous condenser was evaluated. Finally, the Shandong power grid was taken as an example to verify the results that the proposed method could effectively evaluate the multi-infeed high voltage direct current simultaneous commutation failure, and it was important in the early planning of the high voltage direct current transmission system and ensuring the stability and security of the power system. Table and Figures | Reference | Related Articles | Metrics

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Preparation of SiO2-ZrO2 compound high temperature adhesive HE Zhao-pin, SHI Yuan-chang*, SUN Li-bo, LI Bo, YUAN Ye, LIU Jiu-rong JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2013, 43 (1): 104-108.   Abstract （684）      PDF（pc） （1766KB）（2460）       Knowledge map    Save In order to improve the high temperature resistant performance of traditional silicate inorganic adhesive, the new-type compound high temperature adhesive was prepared by sol-gel method with tetraethyl orthosilicate and zirconium oxychloride. Its thermal stability and bonding performance were studied by characterizing the structure, phase composition, heat change and appearance. The results showed that pH was of great influence on the sol-gel reaction process, and the optimal pH was 3. The preparation methods had obvious influence on the microstructure of SiO2-ZrO2 compound adhesive. Dispersion method was better than the in situ synthesis method for preparing the compound adhesive. The molar ratio of raw materials was an important influencing factor on the performance of the compound adhesive. The SiO2-ZrO2 compound adhesive could provide good bonding performance and good thermal stability when the Si-Zr molar ratio was 1∶3. Related Articles | Metrics

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Comparison and analysis on measure indexes for structural hole nodes in social network HAN Zhongming, WU Yang, TAN Xusheng, LIU Wen, YANG Weijie JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2015, 45 (1): 1-8.   DOI: 10.6040/j.issn.1672-3961.1.2014.120 Abstract （2507）      PDF（pc） （2601KB）（2738）       Knowledge map    Save In order to analyze different factors that affected structural holes measurement in social networks, seven existing methods to measure structural hole nodes were analyzed. Four groups of 12 simulated networks were built. Measure indexes for structural hole nodes were deeply and overall analyzed and compared in the simulated network, which were testified and analyzed in social network of Renren websites. The experimental results showed that seven existing methods perform poorly on identifying the structural hole nodes and some methods were highly correlated. Among these seven methods, betweenness centrality was relatively more effective. Reference | Related Articles | Metrics

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Exergy analysis of the R404A／CO2cascade refrigeration system LAI Yan-hua1, WANG Qing-wei1, L Ming-xin1, SHAO Chang-bo2, KONG De-min1 JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2011, 41 (6): 115-121.   Abstract （664）      PDF（pc） （2573KB）（1500）       Knowledge map    Save In order to decrease the energy consumption of the R404A／CO2 cascade refrigeration system, exergy analysis was applied to this system. An exergy analysis method was adopted to obtain  the influence of the design and operating parameters on the coefficient of performance ε, the exergy destruction X and the exergetic efficiency ηe of this system. The design and operating parameters include the evaporating temperature Te, the condensing temperature Tk and the temperature difference ΔT in the cascade-condenser. The results indicate that there were a maximum ε, ηe and a minimum Xtot at the same optimal condensing temperature of the cascade-condenser T4opt when Te, Tk and ΔT were constant in the system. It is helpful to reduce X and improve ηe  and ε through increasing Te, decreasing Tk and ΔT. The total exergy destructions of the throttling device and the compressor of the R404A circuit, the cascade-condenser and the compressor of the CO2 circuit were  80％ of the total exergy destruction of the system. A Multiple linear regression analysis was employed in term of  Te, Tk and ΔT to develop mathematics expressions for t4opt, εmaxand ηe,max. Related Articles | Metrics

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Calibration of micro-parameters of parallel bonded model for rocks JIANG Mingjing, FANG Wei, SIMA Jun JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2015, 45 (4): 50-56.   DOI: 10.6040/j.issn.1672-3961.0.2014.183 Abstract （1817）      PDF（pc） （2117KB）（2162）       Knowledge map    Save The micro-parameters of parallel bond model could not satisfy the compressive strength and tensile strength simultaneously, this was a problem in the simulation of rocks. A set of uniaxial tension tests and uniaxial compression tests of rocks were simulated to investigate this problem. First, DEM specimens with different porosity ratio and different nonuniform coefficient were calibrated according to the laboratory test results of Lac du Bonnet granite. Second, the deficiency of the parallel bond model was pointed out and the improved methods were proposed from the perspective of microscopic failure mechanism. The simulation results showed that the microscopic parameters satisfied tension strength was one order of magnitude deviated from the microscopic parameters, which could also satisfy compression strength. Tensile characteristics and shear characteristics were considered in the parallel bond model, while the influence of normal stress on the bond was ignored. This was the reason that the tension-compression strength ratio of rock was different from the experimental result. It was advised to use clumped particle model which could simulate particle breakage or cementation model based on laboratory tests. Reference | Related Articles | Metrics

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Automatic detection research of arrhythmia based on CNN-LSTM hybrid model TAO Liang, LIU Baoning, LIANG Wei Journal of Shandong University(Engineering Science)    2021, 51 (3): 30-36.   DOI: 10.6040/j.issn.1672-3961.0.2020.445 Abstract （1475）      PDF（pc） （3912KB）（817）       Knowledge map    Save A hybrid algorithm of convolutional neural network and long short-term memory network was proposed for automatic detection of arrhythmias. The model structure was composed of 5 convolutional layers, 5 pooled layers, 1 LSTM layer and 1 fully connected layer. By taking advantage of CNN's ability to automatically extract features and LSTM's ability to capture dependencies before and after time series, the simple preprocessed ECG signal data were directly input into the hybrid model. The whole model combined the two steps of feature extraction and classifier classification, so as to identify five different arrhythmias more efficiently and accurately. The accuracy, sensitivity and specificity of the test set were 99.48%, 99.47% and 99.86% respectively. The experimental results showed that the proposed method could efficiently and accurately identify different types of arrhythmias. Reference | Related Articles | Metrics

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Comprehensive protection scheme for grounding fault in low resistance grounding system HUANG Fuquan, WANG Tinghuang, ZHANG Haitai, LIU Zijun, LI Guodong Journal of Shandong University(Engineering Science)    2021, 51 (3): 113-118.   DOI: 10.6040/j.issn.1672-3961.0.2020.159 Abstract （1571）      PDF（pc） （2199KB）（702）       Knowledge map    Save Because the existing grounding protection in low resistance grounding system had imcomplete protection configuration, poor selectivity, low sensitivity and insufficient ability to detect high-imedance grounding fault, the characteristics of zero sequence current while single-phase grounding fault occured in low resistance grounding system was analyzied. With the help of longitudinal cooperation between the upper and lower protections, the multistage grounding protection based on zero sequence current and the high sensitivity grounding protection based on low setting and time delay were proposed, and also the grounding protection configuration scheme and the setting principles at all levels were discussed. Fault line selection method was proposed for the high-impedance grounding fault using the lateral comparasion of the amplitudes of zero sequence currents between the outlet of each feeder and the neutral line. The feasibility and reliability of the proposed comprehensive protection scheme for grounding fault were verified by the simulation in a typical small resistance grounding distribution network. Reference | Related Articles | Metrics

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Bound gait controlling method of quadruped robot MENG Jian, LI Yibin, LI Bin JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2015, 45 (3): 28-34.   DOI: 10.6040/j.issn.1672-3961.0.2014.328 Abstract （2234）      PDF（pc） （3687KB）（1536）       Knowledge map    Save Aiming at the problem of running control of quadruped robot, a running control method based on bound gait was proposed. The bound gait of the quadruped robot was implemented by fast and small range swing motion of the legs. A finite state machine was used to separate one complete cycle of motion into six stages, three stages for fore legs and three for hind legs respectively. In contact and buffering stage, vertical spring-damper model was used; in thrust stage, virtual model was used to adjust the thrust direction of the legs; and in swing stage, Bezier curve was used to plan the trajectory of the toes. By constructing a virtual model with the same size and mass with the hydraulic driven quadruped robot SCalf-II in the dynamics simulation software, the control method was verified and tested, simulation results showed that the robot came into a cyclic bounding motion with strong periodicity after five periods, the speed vibration in forward direction was small, the joint range of motion, speed and torque were all within the range of the design objective of SCalf-II, which verified the correctness and effectiveness of the proposed method. Reference | Related Articles | Metrics

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A study of the stability of complexes formed by cytosine and metal ions (Cu+／2+, Zn2+) LIU Jing-jing, AI Hong-qi*, ZHAO Lei, SHI Hu JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2012, 42 (3): 110-114.   Abstract （704）      PDF（pc） （1724KB）（1574）       Knowledge map    Save Related Articles | Metrics

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Identification of inertia and state estimation for PMSM DING Xin-zhong1, ZHANG Cheng-rui1*, LI Hu-xiu1, YU Le-hua2 JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2012, 42 (2): 70-76.   Abstract （780）      PDF（pc） （3010KB）（2573）       Knowledge map    Save  Based on theories of the model reference adaptive system (MRAS) and the Kalman filter, the online inertia identification and state estimation of permanent magnet synchronous motor (PMSM) servo system were  respectively studied for improving the dynamic performance and robustness. In the proposed algorithm, an optimal state estimator based on the Kalman filter was used to provide exact estimation for the rotor speed, rotor position and disturbance torque in a random noisy environment. Also, the MRAS was incorporated to identify the variations of inertia moment real time, and the identified inertia was used to adapt the EKF for better dynamic performance. In addition, the disturbancerejection ability to variations of the mechanical parameters was discussed, and it was verified that the system was robust to the modeling error and system noise. Simulation and experimental results showed that, compared with the M／T method, the proposed technique had better performance in speed resolution, real-time and anti-interference ability. Related Articles | Metrics

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Fast 4-points congruent sets for coarse registration of 3D point cloud Shiguang LIU,Hairong WANG,Jin LIU Journal of Shandong University(Engineering Science)    2019, 49 (2): 1-7.   DOI: 10.6040/j.issn.1672-3961.0.2018.244 Abstract （2860）   HTML （148）    PDF（pc） （6934KB）（1254）       Knowledge map    Save In order to solve the problem that the 4-points congruent sets (4 PCS) method suffered from low computational efficiency and high registration errors when the overlap rate of two pieces of input point clouds was low, fast 4-points congruent sets (F-4PCS) was put forward. A new method for selecting four-point basis was presented. The source point cloud and target point cloud were given, their boundaries were separately extracted and extended as the boundary feature bands, and then a consistent four-point basis set was chosen from the boundary feature bands. This method could avoid some unnecessary iterations. By limiting the characteristics of the four-point basis, the invalid four-point basis was removed, it could reduce the verification time of the algorithm and improve the computational efficiency. Experiments results carried out on the relevant data sets showed that the F-4PCS method was more efficient than conventional 4PCS method in the case of low overlap rate of input point clouds and the registration success rate was higher than state-of-the-arts. Table and Figures | Reference | Related Articles | Metrics

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Analysis of transmission spectra of 6H—SiC crystal in the visible and near infrared range YU Yuanxun1, LIAN Jie2*, GUAN Wenli1, WANG Gongtang3, LI Juan4, XU Xiangang4 JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2011, 41 (2): 126-129.   Abstract （1429）      PDF（pc） （819KB）（3896）       Knowledge map    Save Transmission spectra of instinct and N doped 6H—SiC crystals in the visible and near infrared range were measured by using the UVVis spectrophotometer and infrared spectrum measurement system. Optical transmission spectra demonstrated that the 6H—SiC single crystal was transparent for visible and near infrared radiation. Compared with the 6H—SiC single crystal, it was also observed that  nitrogen doping could make the bandgap narrower, and the optical absorption of N doped SiC appeared in the visible and near infrared range. Also,  dispersion curves were obtained by the transmission spectra, and the refractive indices were analyzed using the dispersion equation in the transparent region. In addition,  spectra analysis showed that the absorption at 625nm corresponded to the free electron transition from the low energy level of band tailing induced by N doping to the high energy level in the conduction band, and the absorption of free carrier resulted in low transmission around 2500nm for nitrogen doped crystal. Related Articles | Metrics

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Unit commitment considering alternating current power flow constraints PAN Zhi-yuan1, HAN Xue-shan1*, LIU Chao-nan2 JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2012, 42 (2): 130-137.   Abstract （578）      PDF（pc） （1230KB）（2006）       Knowledge map    Save With the parallel development of  distributed generation technology and  large power grid technology, a great amount of renewable energy generation was introduced to the electrical power grid. Under this circumstance, a unit commitment model was established by considering the constraints of transmission safety using AC(alternating current) power flow.  This model also involved reactive and voltage constraints, as well as safe operation limits of generators. According to the Benders decomposition, the model was decomposed into a master problem and a sub-problem. The master problem could solve the unit commitment without AC constraints, and then the sub-problem could check the AC constraints according to the result of the master problem. Benders cuts might develop from the sub problem, and the cuts would form additional associated constraints, which could connect the master problem and the sub problem. Simulation results of modified IEEE-14 buses case proved that the proposed method could effectively solve unit commitment problems with constraints of AC power flow. Related Articles | Metrics

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Eigenvector selection in spectral clustering based on Bagging WANG Xing-liang, WANG Li-hong*, LI Hai-jun JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2013, 43 (2): 35-41.   Abstract （803）      PDF（pc） （1485KB）（2023）       Knowledge map    Save For the spectral clustering algorithm, the largest k eigenvectors of the affinity matrix derived from the dataset were not always able to find the structure of dataset effectively. An eigenvector selection algorithm in spectral clustering based on Bagging was proposed in order to select better eigenvectors. The  eigenvectors were evaluated by pairwise constraints score. First, some eigenvectors were ranked according to their constraint scores, and then the suitable eigenvectors were selected from the ranking list, finally the optimal combination of k eigenvectors was obtained by Baggingbased ensemble algorithm. The better eigenvectors could be achieved. Experimental results on UCI benchmark datasets showed that this algorithm could gain satisfactory prediction results. Related Articles | Metrics

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Review of risk conflict identification and early warning for interchange Jianqing WU,Qifeng WANG,Zhouyuan LI,Yuan TIAN Journal of Shandong University(Engineering Science)    2022, 52 (6): 1-13.   DOI: 10.6040/j.issn.1672-3961.0.2022.172 Abstract （856）   HTML （28）    PDF（pc） （2835KB）（446）       Knowledge map    Save This review focused on three parts with data collection method, related indexes of traffic conflict and conflict risk early warning method. Each step of the technology was introduced from range of application, working principle, advantages and disadvantages.Based on the real-time multi-sensor data fusion and roadside early warning method, the future development trend and practical application of risk conflict identification and early warning technology for urban interchanges were prospected. Table and Figures | Reference | Related Articles | Metrics

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Barbalat Lemma and its application in analysis of system stability MIN Ying-ying,LIU Yun-gang JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    Abstract （1299）      PDF（pc） （269KB）（8480）       Knowledge map    Save A set of primary formulations of Barbalat Lemma and its simple alternatives are summarized. The relationships among those formulations and their applicable scopes are investigated. The applications of Barbalat Lemma in analyzing asymptotically convergence of the system, adaptive control design and Lp stability are discussed via three examples. Related Articles | Metrics

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Numerical study on the air motion of H-type finned tubes and heat transfer characteristics WU Yanyan, SUN Fengzhong, LI Fei, CHEN Changxian JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2014, 44 (6): 90-94.   DOI: 10.6040/j.issn.1672-3961.0.2014.125 Abstract （1391）      PDF（pc） （2141KB）（1190）       Knowledge map    Save In order to analyze H-type finned tubes in different arrangement modes numerically, flow and heat transfer numerical models of H-type finned tubes in different arrangement forms were established. The change rules of flow and heat transfer characteristics of two typical arrangements has been obtained. The result showed that the special groove structure of H-type finned tubes turned leeward side into vertical flushing flow field with obvious three-dimensional flow characteristics which had the functions of automatic cleaning and nearly gathering no dust. The heat transfer coefficient of staggered finned parent tubes was higher than that of the parent tubes arranged in equal interval. Additionally, the difference of heat transfer effect was increasingly obvious with the increase of speed. The influence of array pitch of tubes on the heat transfer coefficient of finned tubes was remarkably greater than that of row pitch. The increase of the array pitch of tubes lowered the average speed of air in flow channel, heat transfer coefficient and the loss of flow channel. Reference | Related Articles | Metrics

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Mechanical design and gait planning of a hydraulically actuated quadruped bionic robot LI Yi-bin1, LI Bin1,2, RONG Xue-wen1, MENG Jian1 JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2011, 41 (5): 32-36.   Abstract （1250）      PDF（pc） （1531KB）（6711）       Knowledge map    Save A hydraulically actuated quadruped bionic robot has been developed by Center for Robotics at Shandong University is described in this paper. The objective is to design a highly dynamic and high load quadruped robot that enables the adaptation to complex terrain. Based on mule／horse creature bionics, the leg configuration with passive structure and hydraulic actuation are met the needs of stability control and high load capacity. And the stability dynamic trotting gait of the quadruped robot is planned based on the forward kinematics and inverse kinematics. Experiments of the developed quadruped bionic robot platform show the rationality of mechanical design and the effectiveness of gait planning. Related Articles | Metrics

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Web spam detection based on SMOTE and random forests FANG Xiao-nan1,2, ZHANG Hua-xiang1,2*, GAO Shuang1,2 JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2013, 43 (1): 22-27.   Abstract （855）      PDF（pc） （1009KB）（3420）       Knowledge map    Save Web spam refers to the actions intended to mislead search engines into ranking some pages higher than they deserved, which could significantly deteriorate the quality of searching results. Considering the serious imbalance of the Web spam dataset, it was proposed to use oversampling method SMOTE to balance the dataset, then to train the classifiers with random forests algorithm. The results showed that the SMOTE+RF method was more prominent by means of experimental comparison with the conventional single classifiers and the ensemble learning classifiers. The important parameters of this method were optimized based on experimental results, and the reasons for the improvement of the AUC value after using SMOTE were also analyzed. Experimental results on WEBSPAM UK2007 dataset showed that this method could markedly improve the performance of the classifiers, of which the AUC value could exceed the best result of Web Spam Challenge 2008. Related Articles | Metrics

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Experimental research and synergy analysis on characteristics of tube bundles LI Fei, SUN Fengzhong, SHI Yuetao, MA Lei JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2014, 44 (4): 70-75.   DOI: 10.6040/j.issn.1672-3961.0.2014.033 Abstract （1385）      PDF（pc） （1880KB）（926）       Knowledge map    Save Experimental studies, establishing a stable thermal state flow field with 4 tube rows and multiple columns (varied from 2 to 10) in staggered and in-line arrangement, were carried out to analyze the rules of the heat transfer and flow characteristics under different tube rows to obtain the influence rules of flowing around front tubes on the resistance of back rows. In order to obtain the influence rules of the number of tube rows on the resistance characteristics, bundle resistance correction coefficient was defined and values were given according to a series of experimental data. Rate of relative field synergy based on the field synergy principle was defined to characterize the ratio of the overall heat transfer efficiency relative to the actual maximum heat transfer with different numbers of tube rows. The results showed that the flow disturbance around the tail was the major factor in the deterioration of the resistance and the enhancement of the heat transfer, the flow fields up to 10 rows were well-distributed with the minimum influence of the flow disturbance around the tail and small synergy angles, the flow fields within 10 rows should be corrected with tube row correction factor. Reference | Related Articles | Metrics

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First-principles study of electronic and optical properties of Mn-doped cubic ZrO2 ZHANG Yufen, HOU Zhitao, REN Hao, ZHAO Shuai, WANG Cheng JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2014, 44 (4): 84-89.   DOI: 10.6040/j.issn.1672-3961.9.2014.001 Abstract （1042）      PDF（pc） （1553KB）（1035）       Knowledge map    Save First-principles calculations based on DFT+U were performed on electronic and optical properties of Mn-doped cubic ZrO2. When Zr was replaced by Mn in cubic ZrO2, the density of states spectra showed that a band gap reduction was observed and an obvious increase at the top of valence band could make the width of valence band broader by about ～5%. In the majority spin, the states near the Fermi level were attributed to Mn 3 d states with a strong admixture of O 2p states, which resulted in a half-metallic ferromagnetism behavior of the system and may be the reason to cause the band gap reduction. By Mn doping, it found that there was an obvious increase of refractive index, and there was also a new steep absorption peak at lower energy region around 2.8 eV, which could be used for photo absorption applications. The ferromagnetism in Mn-doped system was explained by Zener's double exchange mechanism for ferromagnetism as in other compounds, and the probable relations between electronic structure and optical properties were also found out. Reference | Related Articles | Metrics

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Research review of highway differentiated toll collection Jianqing WU,Yanqiang HUO,Jianzhu WANG,Hongyu GUO Journal of Shandong University(Engineering Science)    2023, 53 (4): 18-29.   DOI: 10.6040/j.issn.1672-3961.0.2023.063 Abstract （442）   HTML （6）    PDF（pc） （1386KB）（343）       Knowledge map    Save In order to formulate a scientific and reasonable scheme for highway differentiated toll collection, the background, realization manners, related theories and key technologies are systematically described, and the cases upgraded in Guangxi, Tianjin and Hebei are briefly introduced with design essentials and application effects, and outlooks on the research trend of highway differentiated toll collection are given. Table and Figures | Reference | Related Articles | Metrics

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Transfer function modeling algorithm  for digital background calibration in Pipeline ADC GONG Yuehong, LUO Min*, YU Mingyan, JIN Jie JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    DOI: 10.6040/j.issn.1672-3961.0.2013.113

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Transverse anti-cracking of bottom slab and layout of transverse pre-stressed tendon of rail transit U-shaped girder Xu DONG,Jian GUO,Haican ZHOU,Zhenquan DENG,Shuchen LI Journal of Shandong University(Engineering Science)    2019, 49 (4): 44-50.   DOI: 10.6040/j.issn.1672-3961.0.2017.550 Abstract （1205）   HTML （4）    PDF（pc） （3093KB）（615）       Knowledge map    Save Rail transit U-shaped girder had the structural characteristic of only arranging ordinary regular reinforcements in transverse direction of bottom slab. Based on a rail transit U-shaped girder project in Qingdao, in order to improve its safety and transverse anti-cracking performance, finite element analysis method was used to study the transverse anti-cracking and stress distribution of bottom slab of U-shaped girder. An arrangement method of U-shaped girder transverse pre-stressed tendons was put forward. The results showed that, the transverse tensile stress of bottom slab of midspan was mainly caused by self-weight and design load, while transverse tensile stress of girder ends was influenced by many factors. Under design load, maximum transverse stress of structure was 1.71 MPa, while applying 1.3 times overloading, maximum transverse stress reached 2.04 MPa, which was beyond code requirements. Safety margin of U-shaped girder was low and transverse crack resistance was weak. The proposed layout of transverse pre-stressed tendons effectively decreased transverse tensile stress in bottom slab of girder midspan to -0.117 MPa. The distribution of tensile stress became more uniform and structural safety was significantly improved. The research could provide a reference for transverse reinforcement design of U-shaped girder bottom slab. Table and Figures | Reference | Related Articles | Metrics

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Experimental research on the manufacture of chlorine dioxide by sodium chlorite and hydrochloric acid at low concentration MO Zhengbo, HU Songtao, HU Dedong JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2017, 47 (2): 100-105.   DOI: 10.6040/j.issn.1672-3961.0.2016.050 Abstract （1756）      PDF（pc） （1610KB）（1295）       Knowledge map    Save The reaction rate of sodium chlorite was studied at various temperatures and molar concentrations of chlorite and hydrochloric acid at low concentrations. The reaction rate law was established, and macro kinetics formula was obtained. Reaction rates had been found as 1 and 1.39 apparent reaction order with respect to NaClO2 and hydrochloric acid respectively when the chloride dioxide was prepared at low concentrations of sodium chlorite and hydrochloric acid. The temperature dependence of the reaction was also investigated and pre-exponential Arrhenius parameter as well as activation energy were determined. The theoretical basis was laid for the reactor design and further development and application of the new technique. This study provides a theoretical basis for the design of chlorine dioxide generator. Reference | Related Articles | Metrics

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Design of self-adaptive sliding mode controller with finite time convergence ZHAO Zhan-shan1,2, ZHANG Jing3, SUN Lian-kun, DING Gang1 JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2012, 42 (4): 74-78.   Abstract （684）      PDF（pc） （1345KB）（2282）       Knowledge map    Save A new self-adaptive sliding mode controller algorithm was proposed for a class of uncertain nonlinear systems with unknown but bounded uncertainties. The proposed solution  could stabilize the status of these systems in finite time by using geometric homogeneity and integral sliding mode control. In order to solve system uncertainties with unknown but bounded, the corresponding adaptation law was developed to evaluate the gain of the controller. The theoretic analysis based on Lyapunov theory proved that the systems with the proposed controller could be stabilized in finite time. Simulation results showed that the proposed adaptive sliding mode controller could achieve better robustness and adaptation against uncertainties. Related Articles | Metrics

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Quadratic filtering of stochastic systems with multiplicative noise and delayed measurements XING Guo-jing, ZANG Cheng-hui*, ZHAO Hui-hong JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2011, 41 (6): 50-58.   Abstract （598）      PDF（pc） （1254KB）（1526）       Knowledge map    Save The problem of quadratic filtering for a bilinear stochastic system with state-dependent multiplicative noise  and single delayed measurements was studied. Due to the presence of multiplicative noises, the system parameter matrices  were random. So, the classical Kalman approach could not be  directly  used in the presence of multiplicative noises and would delay the measurements. Based on Kronecker algebra, the original system was changed into a linear augmented system, whose states and observations included the original states, observations and their second order Kronecker product. Then, the augmented system was transformed into a delay free system via the reorganized innovation approach, and the linear optimal filter for the augmented system was designed through projection theorem. Finally, the quadratic filter of the original system was derived by extracting the first n elements of the augmented state estimation. Compared with the widely used linear optimal filter, estimation accuracy of the quadratic filter increased 27％, and the overall performance was improved. Related Articles | Metrics

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Experiment research on unconfined compressive strength of cement soil under small age ZHOU Hai-long, SHEN Xiang-dong, XUE Hui-jun JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2014, 44 (1): 75-79.   DOI: 10.6040/j.issn.1672-3961.0.2013.276 Abstract （1259）      PDF（pc） （1137KB）（1799）       Knowledge map    Save  The cement mixing ratio  was respectively selected as 5％, 10％, 15％, 20％, and the curing age was respectively selected as 7, 14, 21, 28d to put forth the uniaxial compression test. The value of unconfined compressive strength and the change law of stressstrain curve for cement soil was obtained. Finally, the influence of cement mixing ratio and small age on mechanical behavior of cement soil were quantitatively analyzed, and the mathematical expression of stressstrain relation curve was granted, which could  provide science foundation for applying cement soil into irrigation channel liner impervious engineering and civil construction engineering in the middle area of Inner Mongolian Autonomous Region. Related Articles | Metrics

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A fault detection method based on modified canonical correlation analysis CHEN Zhiwen, PENG Tao, YANG Chunhua , HE Zhangming, YANG Chao, YANG Xiaoyue JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2017, 47 (5): 44-50.   DOI: 10.6040/j.issn.1672-3961.0.2017.171 Abstract （1564）      PDF（pc） （1953KB）（816）       Knowledge map    Save In order to improve the effectiveness of the fault detection(FD)method based on standard canonical correlation analysis(CCA), the original residual generation was modified. By analyzing the statistical characteristics of the residual signal and changing the residual generation mode, the improved residual generation method did not depend on the selection of the number of principal components, so that the fault detection performance would be free of such a selection. The proposed method was further applied to the Tennessee Eastman benchmark process, in which four typical faults were simulated. The achieved results showed that the proposed method could successfully detect the faults. Due to the different fault sensitivity of the two test statistics, it could be found that the fault detectability of the two test statistics were different. Reference | Related Articles | Metrics

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Arc modeling and practical simulation application based on ATP-EMTP DOU Tingting, YAO Yuanxi, CHEN Peng, LU Deng JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2018, 48 (4): 102-108.   DOI: 10.6040/j.issn.1672-3961.0.2018.129 Abstract （4070）   HTML    PDF（pc） （1438KB）（684）       Knowledge map    Save The HVDC line and earth electrode line might be constructed using common tower, but there was lack of research on the back flashover performance of HVDC line, whats more, the earth electrode line arcing horn discharge characteristics was also scanty, in the case of tower struck by lightning. The frequency characteristic simulation transmission line, multi-impedance tower model and air gap breakdown model were established by ATP-EMTP, the influence of electrode line on back flashover level for HVDC line was studied, and the arcing horn discharge characteristics was researched. The results showed that, back flashover performance of HVDC line could obviously be improved by earth electrode line, and lasting arc could be established by DC current in the single pole operation mode. Reference | Related Articles | Metrics

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Field test and research on vehicle load induced dynamic pore pressure in asphalt pavement TANG Weize, OU Jinqiu, CUI Xinzhuang, LOU Junjie, XIAO Ming, ZHANG Jiong, HUANG Dan, HOU Fei JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2015, 45 (6): 84-90.   DOI: 10.6040/j.issn.1672-3961.0.2015.098 Abstract （1436）      PDF（pc） （3648KB）（1160）       Knowledge map    Save In order to study the influence on moisture damage of asphalt pavement caused by dynamic pore pressure due to moving vehicle loads, and explore the time histories of dynamic stress and dynamic pore pressure in the pavement surface layers, the heat-resistant dynamic stress and pore pressure sensors were developed and used to measure the dynamic stresses and pore pressures in the field, and the field measured data of dynamic pore pressure was acquired. Based on the Biot's consolidation theory, a numerical fluid-solid coupling simulation method reflecting mobile effect of wheel load was used to analyze the response of pavement under the actual condition. The time history of dynamic pore pressure in pavement was quantitatively analyzed. Numerical simulation results matched well with in situ test data. The pump-suction effect of dynamic pore pressure that continuously generated in pavement void under cyclical vehicle loads led to the reduce of the asphalt-aggregate bond strength and further triggered the moisture damage. This study verified the hydraulic drive mechanism of moisture damage, and provided a theoretical guild for the moisture damage research and pavement design. Reference | Related Articles | Metrics

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A method of multi-sensor data fusion under the complicated environment Mingming TIAN,Jihua YE,Shimin WANG,Yejing WAN Journal of Shandong University(Engineering Science)    2019, 49 (3): 32-38.   DOI: 10.6040/j.issn.1672-3961.0.2017.426 Abstract （1488）   HTML （88）    PDF（pc） （1038KB）（590）       Knowledge map    Save The existing methods do not use the reliability information of the source of evidence data collection, a multi-sensor data fusion algorithm based on the temperature data in complex environment was proposed. It proceeded from the sensor data source, analyzed the evidence source information, evaluated the confidence measure, and revised the conflict evidence with the confidence measure. In the evidence fusion moment, we used iterative fusion method to revise and fusion evidence until the fusion result convergence. Compared with other fusion methods, this method was effective and had better results in the question of evidence conflict. Table and Figures | Reference | Related Articles | Metrics