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    Perchlorate removal in water by bacteria associated with Fe0
    SHI Qiong, LIANG Shuang, WANG Shu-guang*
    JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2012, 42 (6): 107-114.  
    Abstract408)      PDF(pc) (2345KB)(5446)       Save
    According to the variation of perchlorate mass concentration as a function of time in a series of batch tests, the influence on perchlorate removal by perchlorate reducing microbes (PRMs) associated with Fe0 as electron donor was investigated, which was caused by some relative factors, such as Fe0 adding amount, bacteria concentration, perchlorate load, and initial pH. The results showed that unlike some research before, the Fe0 adding amount was not as much as better. The optimum Fe0 adding amount (mass concentration) with perchlorate mass concentration at 10000 μg/L was about 40g/L. In this case, enough electrons could be produced, while the pH increased not too fast. The perchlorate load for PRMs used in this research was about 603μg/(L?hr?gPRMs), which could take the place of pure microbes to undertake perchlorate removal in the environmental water. The optimum pH for PRMs was around 7.0. The PRMs were more sensitive to the variation of initial pH, but they could survive in a wider range of pH during the reaction. In addition, the changes of the main PRMs species were analyzed through building phylogenetic tree. Compared with the microbes after incubation, the bacteria species partly changed after the experiments. This research may provide a theoretical support for the application of perchlorate removal by PRMs associated with Fe0 to a certain degree.
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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
    Abstract690)   HTML3)    PDF(pc) (3546KB)(678)       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.

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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
    Abstract584)   HTML6)    PDF(pc) (5590KB)(457)       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.

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    Nuclei detection of breast histopathology based on HOG feature and sliding window
    XIANG Lei, XU Jun
    JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2015, 45 (1): 37-44.   DOI: 10.6040/j.issn.1672-3961.2.2014.048
    Abstract982)      PDF(pc) (5610KB)(1590)       Save
    A new method was presented which integrated histograms of oriented gradient (HOG) feature and sliding window for rapid, efficient and accurate detection of nuclei from high resolution pathological images. HOG feature was extracted from the training samples which include both nuclei and non-nuclei patches. The supervised classifier were trained with HOG features. The trained classifier was employed for automated nuclei detection from input patches that selected from histopathological images. During the detection, sliding window was used to select patches. In order to verify the effectiveness of the method on detecting nuclei from histopathological images, this article compared the proposed method with softmax (SM) classifier, sparse autoencoder(SAE)+SM, local binary pattern (LBP)+SM, support vector machine(SVM), HOG+SM, and HOG+SVM models. The experiments on 37 pieces of H&E staining histopathological images showed that the proposed method achieved highest precision, recall and F1-measure values, which were 71.5%, 82.3% and 76.5% respectively.
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    Biomechanical model of seated human body exposed to vertical vibration
    LIU Fei-fei, LI Jian-ping, CHEN Guo-qiang, LUO Si-te, LI Zeng-yong*
    JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2012, 42 (4): 103-107.  
    Abstract372)      PDF(pc) (1380KB)(1387)       Save

    A 7 DOF (degree-of-freedom) biomechanical model of human on a seat without backrest based on multi-body dynamics theory was developed to predict the biodynamic responses of the seated human body in vertical vibration conditions. The parameters of the model were estimated to satisfy the STH (seat-to-head transmissibility) characteristic defined by a synthesis of published data for seated subjects without backrest support. The parameter identification technique involves the solution of a multivariable optimization function and comprises the sum of squared magnitude and phase errors associated with the seattohead transmissibility target values. The cerebral oxygenation was detected by NIRS to verify the accuracy of the studied model. The results showed that the proposed model could improve the vehicle seating system designs.

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    Mechanical responses of asphalt pavement structure with a crack under wheel load
    ZHU Deng-yuan1, 2, YAO Zhan-yong2*
    JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2013, 43 (4): 74-79.  
    Abstract212)      PDF(pc) (1923KB)(1386)       Save

    The mechanical responses of pavement with a crack under standard wheel load were discussed. The three-dimensional model of pavement structure with a crack was built with Abaqus6.10 program. The Coulomb friction model was used to simulate the behavior of the pavement crack under load. Surface deflections of the pavement, tension stress to the layer bottom of the base and asphalt pavement, were calculated. The result demonstrated that the tension and compression stress parallel to the crack direction along the depth of the pavement structure with crack were both increased under wheel load, and the peak tension stress of cement stabilized base appeared at the wheel load near to the crack. The pavement structure would be destroyed due to the tension stress parallel to crack first, and the capacity to transfer load and integrity of the pavement would be reduced with the crack. The impact of the crack should be taken into account in pavement structure design.

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    Pollution characteristics and atmospheric transmission of PM2.5 and PM1.0 in Jinan city
    Qi HUANG,Lingxiao YANG,Yanyan LI,Pan JIANG,Ying GAO,Wenxing WANG
    Journal of Shandong University(Engineering Science)    2020, 50 (1): 95-100, 108.   DOI: 10.6040/j.issn.1672-3961.0.2019.001
    Abstract643)   HTML5)    PDF(pc) (3561KB)(313)       Save

    To study the characteristics of PM2.5 and PM1.0 in the North China Plain, atmospheric particulate samples were collected from October, 2014 to June, 2016 in Jinan urban area by using mid-volume samplers. Then we determined iron composition of Water-soluble inorganic ions with ion chromatography(IC)and carbonaceous component with thermal-optical transmittance (TOT) carbon aerosol analyzer. It was shown that the fine particle pollution of the atmosphere was serious in winter. The secondary ions SO42-, NO3- and NH4+ were the major water-soluble ions of PM2.5 and PM1.0, especially easily enriched in PM1.0. Compared with autumn and winter, concentrations of organic carbon(OC) and elemental carbon (EC) were much lower in spring and summer. The mass concentration of SOC, most of which was distributed in particles with particle size >1 μm, increased obviously in winter. Indicated by the 72 h backward trajectories, long-distance transmission from Hebei and Inner Mongolia, as well as local transmission from Shan- dong had an important influence on the ion mass concentration of PM2.5 and PM1.0 in the atmosphere of Jinan. The extinction coefficient of Jinan was up to 789.13 Mm-1 in winter. The extinction coefficient had a high correlation with secondary particles NH4+, SO42- and NO3- in PM2.5, which was the chief reason of the reduction in the visibility of the atmosphere.

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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
    Abstract1169)      PDF(pc) (1407KB)(568)       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.
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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
    Abstract1547)      PDF(pc) (3687KB)(997)       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.
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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
    Abstract493)      PDF(pc) (3912KB)(241)       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.
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    Multi-node human behavior recognition based on linear acceleration
    Xing LI,Zhenjie HOU,Jiuzhen LIANG,Xingzhi CHANG
    Journal of Shandong University(Engineering Science)    2018, 48 (6): 56-66.   DOI: 10.6040/j.issn.1672-3961.0.2018.202
    Abstract707)   HTML6)    PDF(pc) (4138KB)(281)       Save

    Focused on the issue that the behavior data in the current acceleration-based human behavior recognition method was affected by the gravitational acceleration and the lack of spatial information, a multi-node human behavior recognition algorithm based on linear acceleration was proposed. The linear acceleration was obtained by removing gravitational acceleration using segmented bi-directionally removal of gravitational acceleration algorithm. The tremor motion signal was filtered by a sliding averaging filter for linear acceleration and sensor acceleration, and the redundant actions in the two accelerations were cropped. The dynamic time warping (DTW) distance features between different joint points and seven conventional time domain features were extracted from two accelerations. The support vector machine was employed to recognize the human behavior. Experimental results showed that this method could effectively improve the accuracy of human behavior recognition.

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    Active learning of pairwise constraints in block diagonal subspace clustering
    XIE Ziqi, WANG Lihong, LI Man
    Journal of Shandong University(Engineering Science)    2021, 51 (2): 65-73.   DOI: 10.6040/j.issn.1672-3961.0.2020.182
    Abstract399)      PDF(pc) (2258KB)(191)       Save
    Focusing on the poor performance of subspace clustering by block diagonal representation(BDR)on high-dimensional data with overlapped subspaces, an active learning strategy was designed to obtain partial pairwise information among a few data points. A pairwise constrained block diagonal representation algorithm(CBDR)was proposed to improve the performance of the BDR algorithm. The objective function and solution process of the CBDR were given. The experimental results on the test datasets showed that the CBDR algorithm reduced the clustering error by more than 5% with less than 5‰ constraint information in terms of clustering error and normalized mutual information, which significantly outperformed the compared algorithms, i.e., BDR, SBDR(structured block diagonal representation)with random selection of pairwise constraints.
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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
    Abstract1170)   HTML484)    PDF(pc) (2579KB)(1076)       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.

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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
    Abstract1613)      PDF(pc) (2601KB)(2214)       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.
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    Remote testing on low voltage ride through of offshore wind turbines
    XIE Caike, JIANG Ziming, LIU Yutian, WANG Chunyi
    JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2017, 47 (4): 110-116.   DOI: 10.6040/j.issn.1672-3961.0.2016.218
    Abstract776)      PDF(pc) (3760KB)(573)       Save
    In order to cope with the long-distance submarine cable effects on low voltage ride through(LVRT)remote testing for offshore wind turbines(WTs), the LVRT testing model was built and the method for remote testing on LVRT of offshore WTs was proposed according to the existing LVRT testing technique and standards based on the outlet of WTs. The difference between near and remote testing in both steady and transient situations was analyzed according to the existing devices and method, which concluded that the mutual influence of current limiting reactance and cable heightened the voltage of the outlet, prolonged the transient process and increased harmonic component. The circuit breaker of original device was replaced with electronic switches in order to control the operation of reactance accurately. The operation sequence of the reactance was improved to make the action intervals of time between the current-limiting reactance and short-circuit reactance trended to 0. By doing this, the mutual influence of current-limiting reactance and cable could be avoided. A simulation was put forth to verify the effectiveness of the improved process and to provide supports for development of remote LVRT testing equipment at the same time.
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    Cross-domain text sentiment classification based on domain-adversarialnetwork and BERT
    Guoyong CAI,Qiang LIN,Kaiqi REN
    Journal of Shandong University(Engineering Science)    2020, 50 (1): 1-7,20.   DOI: 10.6040/j.issn.1672-3961.0.2019.293
    Abstract1192)   HTML47)    PDF(pc) (1549KB)(711)       Save

    In order to capture more sentence semantic information from the extracted shared sentiment features for cross-domain sentiment analysis, a deep network model based on domain adversarial mechanism and BERT (bidirectional encoder representations from transformers) was proposed. The model firstly used BERT to obtain the semantic representation vectors of sentences, and then extracted the local features of sentences with a convolutional neural network. A domain adversarial neural network was designed to make the representations of features extracted from different domains to be as indistinguishable as possible, that was, the features extracted from source domain and target domain had much more similarities; and a sentiment classifier was trained on the source domain dataset with sentiment labels, and it was expected that the trained sentiment classifier would have good classification performance in the source domain, and in the target domain. The experimental results on Amazon product reviews dataset showed that the proposed method achieved the expectation and was competent for achieving cross-domain text sentiment classification.

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    Independent component analysis and co-training based Web spam detection
    GAO Shuang1,2, ZHANG Hua-xiang1,2*, FANG Xiao-nan1,2
    JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2013, 43 (2): 29-34.  
    Abstract470)      PDF(pc) (1728KB)(1742)       Save

    Web spam detection is of great significance, and there only exists a small number of labeled pages. Thus, the semi-supervised co-training was used to detect the Web spam pages. The page features were divided into two views, the content view and the link view. First, the independent components of each view were extracted by  the independent component analysis, and then the co-training was used to detect the label of each Web page. Experimental results showed that this method could effectively improve the recognition accuracy of Web spam. The results also verified that two respective independent component analyses of each view were more effective than the other methods.

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    Difference calculation of grounding grid performance under different soil layered structures
    TAO Yaguang, LI Tianjiao, TIAN Ye, WANG Zhaojun, CHENG Famin, LI Qingquan
    JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2017, 47 (4): 103-109.   DOI: 10.6040/j.issn.1672-3961.0.2017.100
    Abstract703)      PDF(pc) (4293KB)(561)       Save
    In order to quantify the difference in safety performance of the substation grounding network under different soil structures as much as possible, based on the measured soil resistivity data, the substation ground network safety indicators, such as step voltage and touch voltage of the mountains, coastal and hilly areas under the vertical layered soil structure and the level layered soil structure were analysed, and the differences between regions in percentage were evaluated. The results showed that the soil vertical layered structure and horizontal layered structure could be accurately calculated by using current distribution, electromagnetic field and soil analysis(CDEGS)software,the necessity of considering vertical layered soil was explained by the contrast of step voltage and touch voltage under two kinds of soil structure in different regions,deviation percentage of touch voltage and step voltage near the soil interface part under vertical stratification structure were higher at the same area, and the calculation results of maximum deviation percentage showed that the difference caused by different soil layers structure was more obvious in the bigger resistivity region
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    Thermal calculation method for quad-sectional regenerative air preheater
    CHEN Changxian, SUN Fengzhong, LI Fei, WU Yanyan
    JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2014, 44 (4): 58-63.   DOI: 10.6040/j.issn.1672-3961.0.2013.360
    Abstract1222)      PDF(pc) (1710KB)(1267)       Save
    A new thermal calculation model for quad-sectional regenerative air preheater was investigated based on the analysis of operating mode and heat transfer characteristics of quad-sectional air preheaters. The model included two calculating steps: the average outlet flue gas temperature and the weighted average outlet air temperature were obtained through the first step calculation; and based on the first step calculation results, the average outlet air temperatures were obtained in right-secondary airside, primary air side and left-secondary airside respectively by the second step calculation. The results showed that the maximum and minimum relative deviations between calculated values and design values were 2.27% and 0.21% respectively. For a 300 MW circulating fluidized bed boiler unit with quad-sectional air preheater, the maximum and average relative deviations between calculated values and actual operation data were 4% and 1.8% respectively, the accuracy and reliability of this thermal calculation model were verified.
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    Power demand forecasting in Shandong province with system dynamics
    YU Songqing, HOU Chenghao, SUN Yingtao
    JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2015, 45 (6): 91-98.   DOI: 10.6040/j.issn.1672-3961.0.2015.084
    Abstract817)      PDF(pc) (2765KB)(682)       Save
    To enhance the depth and breadth of choice about the influence factors of power demand, a systematic analysis was made to the society power demand based on system dynamics, and the system dynamics model of power demand forecast were established, which reflects the multiple factors. The accuracy of system dynamics model was verified by historical data, and then was used to simulate and predict the power consumption in Shandong Province. Final, the relevant policy was analyzed for saving technology and urbanization process variable, and some policy suggestion was put forward.
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    Application of the horizontal jet grouting pile in water-bearing sandy layer of shallow excavating tunnel
    ZHOU Qian, ZHAO Degang
    JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2014, 44 (4): 52-57.   DOI: 10.6040/j.issn.1672-3961.0.2014.142
    Abstract993)      PDF(pc) (2788KB)(1107)       Save
    The construction process of a shallow buried tunnel crossing the water rich sand layer was analyzed in Shenzhen by 3-D numerical simulation, the deformation and the stress of the surrounding rock were discussed under the circumstances of using horizontal jet grouting pile or not in the process of excavating. Based on the numerical simulation and the measurement results, a conclusion could be drawn that the application of the horizontal jet grouting pile had significant effect in controlling the deformation, the subsidence of support and the stress of support. Furthermore, some solutions were put forth to some problems in the construction of horizontal jet grouting pile and the direction of the development. The obtained conclusions could provide experience and numerical support for the design and construction of the similar situation.
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    Improved bird swarm algorithms based on mixed decision making
    Wei YAN,Damin ZHANG,Huijuan ZHANG,Ziyun XI,Zhongyun CHEN
    Journal of Shandong University(Engineering Science)    2020, 50 (2): 34-43.   DOI: 10.6040/j.issn.1672-3961.0.2019.294
    Abstract807)   HTML9)    PDF(pc) (1356KB)(541)       Save

    Aiming at the problems of low precision and easy to fall into local optimum in solving complex function problems of traditional bird swarm algorithm (BSA), an improved bird swarm algorithm based on mixed decision-making was proposed while retaining the simplicity of BSA. The centroid opposition-based learning was used to initialize the bird population and maintain the better spatial solution distribution of the bird flock. In order to balance the global search ability and local detection ability of the algorithm in the optimization process, the period time of the birds flying to another area was dynamically adjusted. The weighting strategy of adaptive cosine function and weighted averaging idea were introduced to improve the producer's foraging formula, so as to increase the ability of the algorithm to get rid of difficulties after falling into local optimum. The performance of improved bird swarm algorithm based on mixed decision-making, bird swarm algorithm and particle swarm optimization were compared on the basis of nine test functions. The results showed that the accuracy and speed of the improved algorithm were greatly improved in the test of single-peak and multi-peak functions.

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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
    Abstract998)      PDF(pc) (1807KB)(664)       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.
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    Location and algorithm of multi-level electric vehicle charging stations
    ZHANG Guo-liang, LI Bo*, WANG Yun-fa
    JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2011, 41 (6): 136-142.  
    Abstract515)      PDF(pc) (1538KB)(2184)       Save

    The charging station is  part  of the crucial infrastructure of  the electric vehicle, and the location and scale of the charging stations are  significant for the development of the electric vehicle industry. A location and solving algorithm of multi-level electric vehicle charging stations was proposed. Concerning  the user’ distributions,based on the objective program thought, the multi-level electric site model was developed to minimize the initial construction cost and the total users’ charging service cost. An improved tabu search algorithm was presented to solve the model. The new combination of tabu coding and the generating of initial solutions were  designed to characterize the two decision variables of the multi-level sites and the allocation to the users, using the strategy of 2-opt search neighbor,  locating sites,   station levels and the allocation of the demand points to the stations were simultaneously determined. Finally, a numerical example demonstrated that the algorithm had better global searching performance and convergence property and the proposed model was also effective.

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    Performance of W6Mo5Cr4V2 laser cladding on 40Cr curved substrate
    XU Mingsan, WANG Tao, LI Jianfeng, DAI Tengyun
    JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2018, 48 (1): 57-64.   DOI: 10.6040/j.issn.1672-3961.0.2017.504
    Abstract927)   HTML    PDF(pc) (5813KB)(365)       Save
    In order to realize the additive manufactured on the blade edges of die-cutting machines by using laser cladding technology,orthogonal tests of multi-pass laser cladding with high-speed steel powder W6Mo5Cr4V2 on the curved substrate 40 Cr were carried out. Process parameters which included the radius of curvature,cladding trajectory and the lap-over ratio, etc. were taken as the influencing factors. The residual stress, micro-hardness and microstructure of the cladding layer were analyzed. The results showed that the flow of protective gas had a significant effect on the residual stress. The minimum residual stresses were obtained under the laser power of 1 800 W,the scanning velocity of 10 m/s,the protective gas flow of 400 g/min,the curvature radius of 60 mm and the lap-over ratio of 30% with a circumferential cladding direction. The crystal morphology from the top of the cladding layer to the bonding zone was developed from the plane crystal to the dendrite. Besides, no defects in the cladding layer were observed and a metallurgical bonding between powders and substrate was achieved. In addition, the micro-hardness value experienced a stair-step increase from the substrate to the top of cladding layer. The average micro-hardness was more than 60 HRC, which could meet the hardness requirements of blade edges on die-cutting machines.
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    Payload pendulation dynamic analysis of ship-mounted crane
    HAN Guangdong, ZHANG Tong, CHEN Haiquan, WANG Shenghai, ZHANG Jinnan
    JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2017, 47 (1): 112-118.   DOI: 10.6040/j.issn.1672-3961.0.2016.326
    Abstract859)      PDF(pc) (6642KB)(512)       Save
    The pendulation of payload was caused by the motion of ship which induced by wave. The motion equation was obtained by means of the relative position of the payload, The kinematics model of ship-mounted crane payload system was established using Lagrange equation, the dynamic was carried out in Matlab/Simulink simulation environment, the influence of rope length, excitation frequency and lifting speed on payload pendulation was analyzed in a comparative manner. The simulation results showed that the payload swing angle increased first and then decreased with the increasing of the rope length; meanwhile, the swing angle increased with the excitation frequency approaching the natural frequency of the system; finally, the swing angle tended to increase with the increasing of the lifting speed, however, the swing angle decreased with the increasing of the lowering speed. Experiment was carried out, and the accuracy of the simulation results was verified.
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    Joint dispatch control of electrical water heater and inverter air conditioner load group
    LIANG Zhiyuan, GONG Qingwu, CHEN Yuanfeng
    JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2018, 48 (2): 100-106.   DOI: 10.6040/j.issn.1672-3961.0.2017.237
    Abstract1103)   HTML    PDF(pc) (2620KB)(240)       Save
    For the demand response requirements of the energy internet, a joint dispatch control strategy based on the electric water heater and the inverter air conditioner load group were proposed in order to make the household load response to grid power fluctuation. The advantages of electric water heater and inverter air conditioner as power dispatch backup were explained and the response aggregation model was established. Combining the load characteristics, a joint dispatch control strategy which adjusted the electric water heater firstly and the inverter air conditioner secondly was proposed based on the consideration of the diversity of inverter air conditioner load group. The scheduling dead zone was set based on load dispatch curve to simulate the proposed dispatch control strategy, the effectiveness of the proposed control strategy in power dispatch was verified, which showed that increasing the number of loads could significantly improve the load response of power scheduling ability.
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    MR image classification and recognition model of breast cancer based onGabor feature
    Gaoteng YUAN,Yihui LIU,Wei HUANG,Bing HU
    Journal of Shandong University(Engineering Science)    2020, 50 (3): 15-23.   DOI: 10.6040/j.issn.1672-3961.0.2019.305
    Abstract678)   HTML12)    PDF(pc) (7621KB)(310)       Save

    To investigate the clinical value of breast tumor magnetic resonance (MR) images in differentiating fibroadenoma of breast (FB), invasive ductal carcinoma (IDC) and invasive lobular carcinoma (ILC), the region of interest of MR image was selected and the MR image was decomposed by wavelet transform, and the region of tumor was segmented by K-means algorithm. Gabor wavelet was used to filter the region of interest from 8 directions and 5 scales, and the mean value of the tumor location was taken as the feature. The extracted features were analyzed and the key features were obtained. Different classification algorithms were compared in machine learning, such as support vector machine, Bayesian, and neural network, to classify and predict the key features, and calculate the accuracy, sensitivity and specificity of classification, so as to get the most suitable parameter settings for classification model. Texture analysis of breast MR images could distinguish three kinds of common breast tumors, and the prediction accuracy was 77.36%, which showed that MR image had important clinical value in differentiating FB, IDC and ILC.

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    Entity alignment method based on adaptive attribute selection
    Jialin SU,Yuanzhuo WANG,Xiaolong JIN,Xueqi CHENG
    Journal of Shandong University(Engineering Science)    2020, 50 (1): 14-20.   DOI: 10.6040/j.issn.1672-3961.0.2019.415
    Abstract1119)   HTML21)    PDF(pc) (1167KB)(571)       Save

    Most existing entity alignment methods typically relied on external information and required expensive manual feature construction to complete alignment. Knowledge graph-based methods used only semantic information and failed to use structural information. Therefore, this paper proposed a new entity alignment method based on adaptive attribute selection, training an entity alignment model based on the joint embedding of the two knowledge graphs, which combined the semantic and structural information. Also, this paper proposed the use of strong attribute constraint based on adaptive attribute selection, which could adaptively generate the most effective attribute category and weight, to improve the performance of entity alignment. Experiments on two realistic datasets showed that, compared with traditional methods, the precision of the proposed method was improved by 11%.

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    Design of pre-amplifier circuit on blood alcohol detection  based on NIR
    LU Liqian, LI Zengyong*, CUI Ruofei, ZHOU Weiwei
    JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    DOI: 10.6040/j.issn.1672-3961.0.2013.168
    Location optimization of median BRT station at intersection
    GUO Rongrong, ZHANG Ruhua, MA Xinhui, GUO Senyao
    Journal of Shandong University(Engineering Science)    2021, 51 (3): 61-67.   DOI: 10.6040/j.issn.1672-3961.0.2020.345
    Abstract328)      PDF(pc) (1618KB)(98)       Save
    Based on the optimal comprehensive time efficiency of BRT vehicles and arriving passengers, a station selection optimization method was proposed. The time efficiency model was established and calculated by fuzzy analytic hierarchy process and genetic algorithm. Huanggang Road Station in Jinan was selected for case analysis. The results showed that the larger the weight of BRT operation time in a measurement unit was, the smaller the weight of arrival passenger travel time was, and the greater the buffer distance when the time efficiency was optimal. When the case station was set up at 25 meters downstream of the intersection, the efficiency of comprehensive time was the most optimal, which was 20% higher than the current situation.
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    Design of vehicle hydraulic active stabilizer bar and its control algorithm
    KONG Zhenxing, PI Dawei, WANG Xianhui, WANG Hongliang, CHEN Shan
    JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2017, 47 (1): 104-111.   DOI: 10.6040/j.issn.1672-3961.0.2016.108
    Abstract759)      PDF(pc) (3053KB)(519)       Save
    According to vehicles active roll control, a design solution to hydraulic active stabilizer bar(ASB)system was put forward based on the analysis of vehicles roll and yaw response characteristics. The structure and principle of hydraulic ASB system was introduced, and its sliding mode control algorithm was designed to improve the vehicles roll stability. The anti-roll torque of ASB system on the front and rear axles were distributed dynamically to improve vehicles steering characteristics. Based on MATLAB/Simulink, 14 degree-of-freedom vehicle, hydraulic actuators model, road input model and so on were established. The simulation of PID+feedforward control and sliding mode control system was carried out under typical maneuvers. Simulation results showed that the hydraulic ASB system using sliding mode control algorithm had obvious advantage in the robustness and adaptability compared with PID+feedforward control, which could enhance vehicle roll and yaw response effectively, and improve roll stability, ride comfort and handling stability further.
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    Model of contact angle of hydrophobic surface based on minimum Gibbs free energy
    SONG Hao, LIU Zhanqiang, SHI Zhenyu, CAI Yukui
    JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2015, 45 (2): 56-61.   DOI: 10.6040/j.issn.1672-3961.0.2014.272
    Abstract1067)      PDF(pc) (1432KB)(1301)       Save
    Based on the function of Young used for smooth surface and the model of Cassie-Baxter used for rough surface, the prediction model for contact angle of hydrophobic surface based on minimum Gibbs free energy was proposed. The model for contact angle prediction was then modified by considering the influence of skew walls on the contact line between gas-liquid. The effects of hydrophobic surface material properties and geometric parameters on contact angle were analyzed based on the modified model. The results showed that, under the same condition of machined micro-surface, the contract angle on the hydrophobic surface root was larger than that on the hydrophilic one. Besides, for the Cassie-Baxter model, the larger radio between the width of groove and the width of convex was, the larger contract angle was.
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    Gait planning and control of a biped robot walking up and down stairs
    WANG Hai-yan, LI Yi-bin*
    JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2014, 44 (1): 57-62.   DOI: 10.6040/j.issn.1672-3961.0.2013.147
    Abstract973)      PDF(pc) (2649KB)(1373)       Save

    Focusing on the walking stability of humanoid robot going up and down stairs, according to the restrains condition of the stairs, the gait for the biped robot climbing up and down stairs dynamically and the corresponding control policy for the biped robot walking stably were proposed. The gait planning method which kept the COM (Center of Mass) of the biped robot in the dynamic balance was proposed and the maximum displacement of the trunk was used to realize the stability of the biped robot in the lateral plane. Cubic polynomial fitting was used in the gait generation of the forward motion and gravity directions. In order to keep the motion stability of the biped robot in the frontal plane, the stairs information combining with the trunk posture angles and the corresponding angular velocity which were obtained from VG (Vertical Gyro), were used to adjust the COM position in the forward motion and the gravity directions. The validity of the proposed methods was verified by the simulations of the biped robot climbing up and down stairs dynamically.

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    Optimization of ventilation system of TBM tunnel construction and evaluation of dust suppression effect
    WANG Chunguo
    Journal of Shandong University(Engineering Science)    2021, 51 (3): 52-60.   DOI: 10.6040/j.issn.1672-3961.0.2020.468
    Abstract376)      PDF(pc) (5863KB)(145)       Save
    Hard rock tunneling boring machine(TBM)produces a large amount of dust during construction, which is an important factor affecting the operating environment and the health of workers. To further optimize the construction ventilation and dust removal effect, combined with the actual working conditions of Qingdao Metro Line 1 double shield TBM, Ansys-Fluent software was used to carry out numerical analysis of the tunnel excavation process. The wind speed and dust mass concentration at each location of the tunnel were detected and compared with the numerical simulation results to verify the effectiveness of the model. In view of whether it is necessary to open the dust removal system in the process of TBM tunnel construction, as well as the location of dust removal tuyere and the selection of optimal suction flow, numerical simulation was carried out. When the dust removal system was turned off or the dust removal system was turned on but the suction flow was below 4 m3/s, and the dust diffuses to most areas of the TBM tunneling area. When the dust duct was 15 m away from the hand surface and the suction airflow was 12 m3/s, the dust removal effect reached the best, and the dust diffusion distance was reduced to 45 m, which could effectively remove dust. The research results could provide a scientific basis for the design and construction of tunnel ventilation and dust removal.
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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.  
    Abstract306)      PDF(pc) (1766KB)(1861)       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.

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    Failure prognosis method based on evidential reasoning for aerospace relay
    ZHOU Zhijie, ZHAO Fujun, HU Changhua, WANG Li, FENG Zhichao, LIU Taoyuan
    JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2017, 47 (5): 22-29.   DOI: 10.6040/j.issn.1672-3961.0.2017.211
    Abstract901)      PDF(pc) (2811KB)(535)       Save
    To solve the high failure ratio problem of aerospace relay and strong uncertainty in its failure prognosis, a failure prognosis method based on evidential reasoning(ER)by fusing multiple fault characteristics information was proposed. The JRC-7M aerospace relay was chosen as the research object and its characteristic parameters, super-path time and pick-up time, were chosen as the main fault characteristics. In the proposed method, a forecasting model based on the third-order Volterra filter was proposed to online predict the fault characteristics' information, then an adaptive weighting model based on coefficient of variation-based weighting was adopted to calculate the relative weight. To obtain a comprehensive failure prognosis result of the aerospace relay, an safety assessment aggregation scheme based on the ER approach was developed to fuse multiple fault characteristics, and the “history”, “current” and “future” fault state information were synthetically fused. The validity of the proposed method was verified by the testing data collected by the STS2104A electromagnetic relay test system.
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    Toxic effects and mechanisms of oxidative stress induced by modified ultrafine carbon black
    Chenhao JIA,Rutao LIU
    Journal of Shandong University(Engineering Science)    2019, 49 (3): 120-128.   DOI: 10.6040/j.issn.1672-3961.0.2018.443
    Abstract628)   HTML8)    PDF(pc) (6678KB)(207)       Save

    To study the toxic effects and mechanisms of oxidative stress induced by modified ultrafine carbon black (MCB), mouse hepatocytes and catalase (CAT) were exposed to MCB solutions. The cytotoxicity of MCB was assessed by CCK-8 kit, malondialdehyde (MDA) kit and CAT activity assay. The effects on CAT structure and function of MCB were investigated by utilizing fluorescence, UV—vis absorption and circular dichroism spectroscopy. The experiment results demonstrated that the hepatocyte viability decreased with the increase of MCB concentration. Low MCB doses (< 30 mg/L) increased CAT activity to protectcells from oxidative damage while high doses of MCB (> 30 mg/L) caused accumulation of MDA and redox imbalance in the cells, which induced oxidative damage in the liver. Spectroscopy studies found that MCB destroyed the secondary and tertiary structure of CAT and changed the microenvironment of amino acids, which made denaturation of the peptide chain. As a result, changes of skeleton structure reduced the activity of CAT. This study clarified the oxidative mechanism of MCB causing oxidative stress effects and provided a reference for the toxicity mechanism of nanomaterials.

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    Prediction method of wind power and PV ramp event based on deep learning
    Zhixiang LIANG,Xiaoming LIU,Ying MU,Yutian LIU
    Journal of Shandong University(Engineering Science)    2019, 49 (5): 24-28.   DOI: 10.6040/j.issn.1672-3961.0.2019.132
    Abstract979)   HTML17)    PDF(pc) (1178KB)(500)       Save

    With the gradual increase of the renewable energy penetration rate, the ramp event that caused the unbalanced active power occured sometimes, and even a large load loss. Due to the insufficient accuracy of wind power and photovoltaic prediction, there were many operational scenarios to be considered. The time domain simulation could not meet the online assessment requirements. A method based on deep learning was proposed in this paper. Considering the generation unit and tie line adjustment ability, the stacked denoising autoencoder was used to extract each layer feature to train support vector machine. The wind power, photovoltaic and load forecast data, and the power of the tie line at the previous moment were taken as inputs, and whether the ramp event occured as an output. The vector machine was used to quickly predict whether a ramp event occured. The simulation results of practical power grid showed that the proposed method was fast and accurate. It could effectively identify ramp events.

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    Flow characteristics of rough rock fractures under wide range of Reynolds numbers
    Jie LIU,Zhechao WANG,Yupeng ZHANG,Huayang SUN
    Journal of Shandong University(Engineering Science)    2019, 49 (4): 70-77, 85.   DOI: 10.6040/j.issn.1672-3961.0.2018.533
    Abstract843)   HTML11)    PDF(pc) (6754KB)(404)       Save

    Through experiments and theoretical analysis, the flow characteristics of rock rough fractures with different geometric parameters were studied, including non-Darcy coefficient β, critical Reynolds number Rec and non-Darcy effect factor E. Testing equipment for fluid flow in fractures was developed and 9 rough single fracture models with different apertures and Joint Roughness Coefficients (JRC) were prepared. Laboratory tests on flow in rough fractures with Reynolds numbers, i.e., from 2 to 5000 were performed. The characteristics of flow in single fractures with different roughness (JRC=2-20) under wide range of Reynolds numbers were obtained. It was shown that fracture roughness had a significant impact on the nonlinear flow characteristics of the fracture. Based on the Forchheimer equation, the effects of fracture roughness on equation parameters were quantitatively studied. The larger fracture roughness was, the more likely it was to cause the nonlinearity of the fracture flow, the smaller critical Reynolds number was, and the stronger non-linear effect would be.

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    Research status and development trend of autonomous cognition and learning of robot manipulation skills
    Wei WANG,Feng WU,Fengyu ZHOU
    Journal of Shandong University(Engineering Science)    2019, 49 (6): 11-24.   DOI: 10.6040/j.issn.1672-3961.0.2019.229
    Abstract982)   HTML24)    PDF(pc) (2077KB)(468)       Save

    Autonomous cognition and learning of manipulation skills, being one of the most important skills for robots, has been one of the hot issues in the field of robotics research. Combining with the authors' work in the field of robotics, this paper's focus is placed on giving a comprehensive overview of the mainstream modes, methods, algorithms, as well as advantages and disadvantages of different methods in terms of robots' manipulation skill learning. It concludes the challenges faced by autonomous learning and the key issues that need to be addressed for the individual cloud robots learning manipulation skills in the knowledge sharing mode. At the end, a potential solution for the above issues is given, and that is to integrate individual learning mode and shared learning model for the purpose of enhancing autonomous cognition and learning ability for robots.

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    Classification and analysis of epileptic EEG based on complex networks
    HAO Chongqing, WANG Zhihong
    JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2017, 47 (3): 8-15.   DOI: 10.6040/j.issn.1672-3961.0.2016.279
    Abstract795)      PDF(pc) (5850KB)(417)       Save
    To extract epileptic EEG features in the ictal and interictal period, a method of depicting epileptic EEG was proposed by transforming epileptic EEG time series to epileptic networks. Chaotic multi-dimensional time series coming from the Lorenz system and Rössler system were used to construct a complex network,in which all the variables could be measured. It was found that there was morphological similarity between topology of the complex networks and the attractor of chaotic system. This indicated that complex networks constructed from time series could depict the characteristics of the original signals. For only one measureable variable, multi-dimensional time series were obtained by reconstruction of the phase space. Therefore, the epileptic EEG network was constructed and analyzed in the ictal and interictal period. The results showed that epileptic EEG network topologies in the ictal period were significantly different from that in the interictal period. Meanwhile, the average path length of the network increased significantly and recurrence rates decreased significantly in the ictal period comparing to in the interictal period. These network features could be used to depict the characteristics of EEG time series and could provide the basis for epilepsy automatic identification and prediction.
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    Intelligent interaction method for power distribution robot based on Kinect
    Mian ZHANG,Ying HUANG,Haiyi MEI,Yu GUO
    Journal of Shandong University(Engineering Science)    2018, 48 (5): 103-108.   DOI: 10.6040/j.issn.1672-3961.0.2018.228
    Abstract1046)   HTML6)    PDF(pc) (3940KB)(335)       Save

    In order to realize natural interaction between the operator and the live-line working robot, an intelligent man-machine interaction method based on the Kinect gesture recognition was proposed. Based on the Kinect's depth information and skeleton information, the operator's gesture was segmented, the geometric moment Hu moment was selected as the gesture feature, and the machine learning method of SVM was used to classify and identify the operator's gesture. The gestures were mapped to the motion of the robot, and the motion control of the robot was realized by the gesture. The experimental results verified the feasibility of the intelligent human-computer interaction method of the power distribution robot.

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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
    Abstract416)   HTML36)    PDF(pc) (4892KB)(134)       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.

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    Algorithm of scale change objects tracking with adaptive bandwidth
    LI Wu, HOU Zhiqiang*, WEI Guojian, YU Wangsheng
    JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    DOI: 10.6040/j.issn.1672-3961.0.2013.214
    Facial expression recognition based on adaptive dictionary learning and sparse representation
    XIA Hai-ying1, DU Hai-ming2,XU Lu-hui1, YAN Yuan-hui1
    JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2014, 44 (1): 45-48.   DOI: 10.6040/j.issn.1672-3961.1.2013.009
    Abstract813)      PDF(pc) (1496KB)(1281)       Save

    A facial expression recognition method based on adaptive dictionary learning and sparse representation was proposed. Eyes and mouth were located by Haar-like features and the geometric structure of face. For learning dictionaries, random blocks near facial salient points were extracted, and those blocks were trained from the same kind of expression to form one expression dictionary. Then, all expression dictionaries were arranged into a learned dictionary. The test expressions were classified by sparse decomposition. The good performance was verified by the experiments on standard JAFFE and Cohn-kanade expression database. Good robustness was obtained even if the image had noise corruption or under occlusion.

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    Real-time traffic prediction based on MGU for large-scale IP backbone networks
    Fang GUO,Lei CHEN,Ziwen YANG
    Journal of Shandong University(Engineering Science)    2019, 49 (2): 88-95.   DOI: 10.6040/j.issn.1672-3961.0.2018.342
    Abstract838)   HTML11)    PDF(pc) (4768KB)(319)       Save

    In order to overcome the shortcomings of long short-term memory (LSTM) computing cost, a real-time traffic prediction method based on minimum gated unit (MGU) for large-scale IP backbone networks was proposed. The experimental results showed that compared with the LSTM-based traffic prediction method, the proposed method achieved fairly or even better traffic prediction performance with less model training time, meanwhile it outperformed the most advanced feed forward neural network (FFNN), LSTM and gated recurrent unit(GRU) in terms of prediction accuracy and real-time performance.

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    Heat transfer performance analysis of phase change energy storage heat exchanger based on entransy theory
    Xinchen ZHOU,Xuelai ZHANG,Yue CHEN,Lu LIU
    Journal of Shandong University(Engineering Science)    2019, 49 (5): 72-84.   DOI: 10.6040/j.issn.1672-3961.0.2019.151
    Abstract623)   HTML9)    PDF(pc) (4434KB)(385)       Save

    Entransy transfer efficiency, entransy dissipation number and thermal resistance of heat exchanger based on entransy dissipation were applied to heat transfer performance analysis of phase change energy storage heat exchanger on the basis of successful application of entransy theory on conventional heat exchanger. The generalized entransy dissipation rate was defined to derive (instantaneous) entransy transfer efficiency of phase change energy storage heat exchanger in heat storage, heat release and total process, and heat transfer rate was determined to calculate entransy dissipation number and thermal resistance of heat exchanger based on entransy dissipation. A kind of phase change energy storage heat exchanger was selected as the object, and the temperature variation of main parts were described by theoretical analyses. The temperature variation of outlet of silicon oil and water were further simplified to derive their expression, as the basis of calculation and analyses. The results showed that the application range of entransy transfer efficiency was the widest, which was used to calculate the (instantaneous) irreversible heat loss of phase change energy storage heat exchanger in heat storage, heat release and total process. The evaluation results of entransy transfer efficiency were consistent with heat transfer performance and its instantaneous values were increased first, then unchanged, finally increased, with increasing heat storage time, and were decreased first, then unchanged, finally decreased, with increasing heat release time. The evaluation results of entransy dissipation number in heat storage and total process were consistent with that of entransy transfer efficiency. With increasing heat storage time, its instantaneous values were decreased first, then unchanged, finally decreased, while its application was limited in heat release process. The application of thermal resistance of heat exchanger based on entransy dissipation was the most limited since parts of its evaluation results were inconsistent with actual state. In heat storage and total process, the entransy transfer efficiency, entransy dissipation number and thermal resistance of heat exchanger based on entransy dissipation were nearly unchangeable when the heat storage quantity, heat release quantity and stage time in the process of heat storage and release were synchronous. The entransy transfer efficiency was increased, while the entransy dissipation number and the thermal resistance of heat exchanger based on entransy dissipation were decreased when the heat transfer efficiency was improved. In the heat release process, entransy transfer efficiency was unchangeable since the heat transfer performance of system was not influenced by the change of parameters setted.

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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
    Abstract400)      PDF(pc) (2199KB)(117)       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.
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    A TOA estimation algorithm based on envelope extraction
    LIU Qian1, XIA Bin1*, PENG Rong-qun1, CHEN Nai-shu2
    JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2012, 42 (5): 24-29.  
    Abstract244)      PDF(pc) (2905KB)(1174)       Save
    The noise could affect the location precision in ultra wideband wireless sensor network. In order to solve this problem, a time of arrival (TOA) estimation algorithm based on envelope extraction was proposed. The noise component of signal could be effectively removed by the multiresolution analysis of wavelet transform. Then the envelope of denoising signal was extracted by Hilbert transform. Finally, the maximum value of the first envelope was used as the TOA estimation value. The simulation results showed that the algorithm could suppress the noise and improve estimation precision.
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