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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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    Unmanned vehicle path planning based on deep Q learning in real environment
    Hao XIAO,Zhuhua LIAO,Yizhi LIU,Silin LIU,Jianxun LIU
    Journal of Shandong University(Engineering Science)    2021, 51 (1): 100-107.   DOI: 10.6040/j.issn.1672-3961.0.2020.247
    Abstract481)   HTML22)    PDF(pc) (6074KB)(904)       Save

    It was an important problem for the intelligent navigation of unmanned vehicles that planning the optimal path in the actual traffic environment. At present, many researches about global path planning of unmanned vehicle mainly focused on the improvement of algorithm solution speed in the simulation environment. Most of them just only considered the optimal path distance or the current road conditions, also ignored other factors and future changes in the actual environment. In order to complete the complex task that competing global path planning of unmanned vehicle in dynamic road network, this research put forward a framework of unmanned vehicle driving system for practical environment based on the thought of planning after prediction, and put forward DP-DQN which was a fast global path planning method combined with deep Q learning and deep prediction network technology. This method used the road characteristic data such as time and space, weather et al to predict the future traffic situation, and then competed the global optimal path. Finally, experimental results based on open datasets showed that the proposed method reduced driving time 17.97% at most than Dijkstra, A*, algorithm et al.

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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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    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
    Abstract1073)      PDF(pc) (2117KB)(1617)       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.
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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): 125-132142.   DOI: 10.6040/j.issn.1672-3961.0.2019.004
    Abstract696)   HTML5)    PDF(pc) (4845KB)(548)       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%.

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    A method on building Chinese sentiment lexicon for text sentiment analysis
    ZHOU Yong-mei1, YANG Jia-neng2, YANG Ai-min1
    JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2013, 43 (6): 27-33.  
    Abstract1487)      PDF(pc) (1259KB)(5345)       Save

    A method on building Chinese sentiment lexicon based on HowNet and SentiWordNet was proposed,in which sentiment intensity of the word was automatically calculated by decomposing it into multiple semantic units and a lexicon proofreading technique was used to optimize the value of sentiment intensity of the word. The building lexicon was applied to the task of sentiment analysis, in which the support vector machine was used to build the sentiment classifier. The experiment results showed that the built sentiment lexicon was more effective than the general polar sentiment lexicon,and provided an effective dictionary resource for the research of sentiment analysis.

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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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    Air quality prediction approach based on integrating forecasting dataset
    Minghe GAO,Ying ZHANG,Rongrong ZHANG,Zihao HUANG,Linyan HUANG,Fanyu LI,Xin ZHANG,Yanhao WANG
    Journal of Shandong University(Engineering Science)    2020, 50 (2): 91-99.   DOI: 10.6040/j.issn.1672-3961.0.2019.404
    Abstract1078)   HTML19)    PDF(pc) (4733KB)(688)       Save

    Towarding the air quality prediction research problem, LightGBM was employed to propose and design a predictive feature-based air quality prediction approach, which could effectively predict the PM2.5 concentration, i.e., the key indicator reflecting air quality, in the upcoming 24-hour within Beijing. During constructing the prediction solution, the features of the training data set was analyzed to execute data cleansing, and the methods of random forest and linear interpolation were used to solve the problem of high data loss and noise interference. The predictive data features were integrated into the dataset, and meanwhile the corresponding statistical features were designed to imiprove the prediction accurancy. The sliding window mechanism was used to mine high-dimensional time features and increase the quantity of data features. The performance and result of the proposed approach were analyzed in details through comparing with the basedline models. The experimental results showed that compared with other model methods, the proposed LightGBM-based prediction approach with integrating forecasting data had higher prediction accuracy.

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    End force tracking control algorithm of grinding robot based on model predictive control
    LIU Zhe, SONG Rui, ZOU Tao
    JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2018, 48 (1): 42-49.   DOI: 10.6040/j.issn.1672-3961.0.2017.569
    Abstract975)   HTML    PDF(pc) (1280KB)(762)       Save
    A precise control algorithm using the model predictive control and surface prediction was proposed. The dynamic model and the prediction model of the manipulator were given. The surface coordinates of the next moment were obtained according to the surface prediction algorithm, and the desired rotation angle of each joint was obtained by the fast algorithm and the inverse kinematic algorithm. And in order to realize the overshoot tracking of the desired joint angle, the dynamic matrix control algorithm was used to solve the input torque of each joint motor. The end-point of manipulator was controlled to track the continuous surface by experimental and simulation. The results showed that the end force control algorithm using surface prediction and model prediction algorithm could effectively track the continuous surface in real time, which satisfied the ideal force control requirement.
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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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    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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    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
    Abstract499)   HTML39)    PDF(pc) (13090KB)(274)       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.

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    Review of capsule network
    Jucheng YANG,Shujie HAN,Lei MAO,Xiangzi DAI,Yarui CHEN
    Journal of Shandong University(Engineering Science)    2019, 49 (6): 1-10.   DOI: 10.6040/j.issn.1672-3961.0.2019.312
    Abstract1700)   HTML105)    PDF(pc) (4331KB)(998)       Save

    Recently capsule network with dynamic routing was the new neural network model which was considered a significant model in next generation. In recent years, much research evidenced capsule network exceptional ability to fit features. But the high computational overhead made it unable to fit complex and large datasets. Consequently, reducing computational became a research hotspot. There were two methods, including optimized capsule and optimized routing, to solve the issue. Optimized capsule was usually driven by application purpose which was designed as a model of specific classification tasks. And optimized routing was the way to improve the performance of the model from an algorithmic perspective.

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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
    Abstract607)   HTML232)    PDF(pc) (2986KB)(268)       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.

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    Construction of knowledge graph of relationship between LncRNA and diseases
    GONG Lejun, YANG Lu, GAO Zhihong, LI Huakang
    Journal of Shandong University(Engineering Science)    2021, 51 (2): 26-33.   DOI: 10.6040/j.issn.1672-3961.0.2020.212
    Abstract365)      PDF(pc) (4656KB)(302)       Save
    Based on the analysis of the relationship between LncRNA and diseases, the concept of knowledge modeling of LncRNA and diseases was proposed, and an effective method of knowledge mapping of the relationship between LncRNA and diseases was proposed. Protege was used to construct the ontology structure and the concept layer, integrate the structured and unstructured data from two different sources to the data layer, and describe the data and the corresponding relationship through RDF/OWL technology. The production rules based on forward reasoning were used to carry out the corresponding knowledge reasoning. The inference effect of knowledge query was demonstrated by SPARQL query language and visualization technology. This study provided further reference value for the study of the relationship between LncRNA and diseases. Moreover, it also promoted the development of this field.
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    Analysis of the influence of the underside baffle and deflector of the fume hood on the flow field
    Ruiyi YAN,Zhen DONG,Sen LU,Yanhua LAI,Mingxin LÜ
    Journal of Shandong University(Engineering Science)    2021, 51 (5): 122-130.   DOI: 10.6040/j.issn.1672-3961.0.2021.177
    Abstract319)   HTML23)    PDF(pc) (19825KB)(251)       Save

    For the phenomenon of vortex and gas escape in the flow field of the extant fume hood, the computational fluid dynamics method was used for simulation. This research changed the shape parameters of the underside structure of the fume hood window, used circular arc baffles with different radii, elliptical arc baffles with different lengths, and added deflectors with different radii. Then this research studied the influence of structural changes on the flow field in the fume hood by analyzing the size and location of the vortex to obtain the direction of structural optimization. The results showed that when the height of the underside baffle was low and the length was short, there was obvious large vortex in the center position of the fume hood and near the wall. A baffle with a height greater than 50 mm and a length greater than 90 mm could significantly reduce the vortex at the center of the fume hood and at the junction of the baffle and the side wall. Adding a deflector could optimize the flow field and make the center vortex disappear, and the radius of the deflector should not be greater than 70 mm, otherwise obvious vortices would be excited on the outside and end of the baffle, which provides a basis for the rational design of fume hoods.

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    A survey of image captioning methods based on deep learning
    Zhifu CHANG,Fengyu ZHOU,Yugang WANG,Dongdong SHEN,Yang ZHAO
    Journal of Shandong University(Engineering Science)    2019, 49 (6): 25-35.   DOI: 10.6040/j.issn.1672-3961.0.2019.244
    Abstract2298)   HTML63)    PDF(pc) (7881KB)(826)       Save

    Image captioning is the cross-research direction of computer vision and natural language processing. This paper aimsed to summarize the deep learning methods in the field of image captioning. Imgage captioning methods based on deep learning was summarized into five categories: multimodal space based method, multi-region based method, enconder-deconder based method, reinforcement learning based method, and generative adversarial networks based method.The datasets and evaluation metrics were demonstrated, and experimental result of different methods were compared. The three key problems and future research direction for image captioning were presented and summarized.

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    Phase change characteristics of paraffin in rectangular storage unit
    Huilin ZHOU,Yan QIU
    Journal of Shandong University(Engineering Science)    2019, 49 (4): 99-107.   DOI: 10.6040/j.issn.1672-3961.0.2019.018
    Abstract815)   HTML8)    PDF(pc) (3235KB)(834)       Save

    To study the heat transfer characteristics of phase change material (PCM) in a storage unit and improve the heat transfer efficiency of phase change heat exchanger, the enthalpy-porous media model and FLUENT program were used to carry out a numerical investigation on the heat transfer process of paraffin in a rectangular heat storage unit. The element liquid fraction β and dimensionless Fo, Ste and Ra were introduced to analyze the influences of different positions outside the tube and inlet temperatures of heat transfer fluid on the melting and solidification process of paraffin. The results showed that the paraffin outside the tube was melted in order from the upper to the left/right part, then the lower part. The total melting time of paraffin in upper part was shorten by at least 20% compared with other parts. Conversely, in the heat release process, the paraffin was solidified in order from the lower, the left/right part and the upper part. The heat transfer mechanism in the unit changed gradually from heat conduction to natural convection in the thermal storage process. The efficiency of heat storage and release could be improved significantly by increasing the temperature difference between heat transfer fluid and paraffin. The criterion of β was obtained by polynomial fitting.

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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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    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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    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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    Optimal calculation method of pavement shakedown limit based on genetic algorithm
    Xiuguang SONG,Yingchao ZHANG,Peizhi ZHUANG,He YANG,Haifeng ZHANG,Juan WANG
    Journal of Shandong University(Engineering Science)    2021, 51 (5): 1-7.   DOI: 10.6040/j.issn.1672-3961.0.2021.153
    Abstract436)   HTML299)    PDF(pc) (4005KB)(206)       Save

    To solve the problem that road structures are prone to elasto-plastic deformation under the action of long-term reciprocating vehicle loads, based on the static shakedown theorem, the shakedown behavior of the semi-infinite space Mohr-Coulomb structure under the Hertz load was studied, and the genetic algorithm was introduced to construct an efficient calculation method for the lower limit of the shakedown limit of the road structure under the reciprocating vehicle load. The accuracy and efficiency of the new method was verified by comparison with the existing solution method and parameter analysis.

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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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    Algorithm of adaptive slope adjustment of quadruped robot based on model predictive control and its application
    LIANG Qixing, LI Bin, LI Zhi, ZHANG Hui, RONG Xuewen, FAN Yong
    Journal of Shandong University(Engineering Science)    2021, 51 (3): 37-44.   DOI: 10.6040/j.issn.1672-3961.0.2020.320
    Abstract414)      PDF(pc) (6868KB)(230)       Save
    In order to realize the adaptive and stable walking of the quadruped robot on slope terrain, the adaptive adjustment strategies of both feet position and trunk posture of quadruped robot on slope were proposed based on the model predictive control. The posture determination parameters of the robot in locomotion were measured by the inertial measurement unit(IMU). By means of the derived foot end trajectory algorithm, the coordinate mapping of its toe position was obtained in order to adjust the center of gravity of the robot on the slope. Then the adaptive adjustment of the trunk posture of the robot in the process of climbing could be achieved through the trunk posture adjustment algorithm by means of designed “virtual slope”. With the help of the physical platform of quadruped robot and the actual slope terrain environment built in the laboratory, the feasibility and validity of the proposed algorithm are verified. Experimental result showed that the proposed slope adaptive control method had improved the stability margin of the robot on the slope and optimized the foot end motion space, thus leading to the realization of adaptive adjustment in climbing slope for the quadruped robot.
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    Survey of outlier detection technologies
    CHEN Bin, CHEN Song-Can, PAN Zhi-Song, LI Bin
    JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2009, 39 (6): 13-23.  
    Abstract1007)      PDF(pc) (1025KB)(3892)       Save

    Outlier detection aims to detect those data that significantly deviate from the expected behavior, and thus is widely applied in many fields, such as, machine fault detection, intrusion detection, fraud detection and data preprocessing. Hence, there exist many generic and special algorithms for outlier detection under the unsupervised and supervised learning framework. But up to now, there still has been no clear classification in this aspect. To provide a structural view, the review of the state-of-the-art statistics-based methods for outlier detection was focusedon, and a simple classification was given in this aspect. Moreover,the equivalence between some outlier detectors in depth is particularly discussed.

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    Abnormal sound detection of washing machines based on deep learning
    Chunyang LI,Nan LI,Tao FENG,Zhuhe WANG,Jingkai MA
    Journal of Shandong University(Engineering Science)    2020, 50 (2): 108-117.   DOI: 10.6040/j.issn.1672-3961.0.2019.419
    Abstract835)   HTML19)    PDF(pc) (5582KB)(672)       Save

    Based on the convolutional neural network (CNN) framework, a model for abnormal sounds recognition of washing machine was proposed. According to the remarkable feature extraction ability and translation invariance of convolutional neural network, the abnormal sound features of washing machines were learned, so as to achieve the purpose of the automatic intelligent recognition of abnormal sounds for washing machines in production line. This method provided a complete process to solve the problems of training datasets establishment and data imbalance. A network model for data augmentation called advanced deep convolution generated adversarial network (ADCGAN)was proposed to solve the problem of training data scarcity. The traditional deep convolution generated adversarial network (DCGAN) model was improved to better adapt to the generation of industrial sounds. This model could be used to extend the original data and generate the abnormal sound augmented datasets of washing machine. The augmented datasets was used to train the convolutional neural network, and the test accuracy reached 0.999. The generalization ability of abnormal sounds recognition model for washing machine network was tested by using the data set with background noise signal added. The correct recognition rate reached 0.902, which indicated that this network had good robustness in recognizing abnormal noises of washing machines.

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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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    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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    Laminar flow field characteristics in the stirred vessel equipped with an eccentric-shaft impeller
    Meiting LI,Wei LI,Xiaoguang LI,Fengling YANG
    Journal of Shandong University(Engineering Science)    2019, 49 (4): 93-98, 107.   DOI: 10.6040/j.issn.1672-3961.0.2018.530
    Abstract876)   HTML7)    PDF(pc) (2868KB)(627)       Save

    For the purpose of improving mixing efficiency of the stirred tank with high viscosity fluid laminar flow condition, an eccentric-shaft agitation method was proposed. With a purity of 99% glycerol as medium, and the traditional 2-flat-blade impeller as the research object, the laminar flow fields were numerically studied. The inner diameter of the stirred vessel was 0.3m and the agitated fluid was glycerol. The modeling reliability and simulation methods of the concentric agitation were validated by experimental results. In comparison with the concentric agitation, flow fields generated by eccentric and eccentric-shaft agitation were asymmetrical, and theoverall volume weitghted average velocity of the groove fluid generated by eccentric-shaft agitation could be raised by 68%. And furthermore, when operated under the same speed, the power consumption of eccentric-shaft agitation increased 15.3% than that of concentric agitation. However, the eccentric shaft agitation increased the speed in the tank and expanded the range of disturbance. Accordingly, the superiority of eccentric-shaft agitation of improving the mixing efficiency in the tank was apparent.

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    Design of robot cloud service platform based on microservice
    Lei YIN,Fengyu ZHOU,Ming LI,Yugang WANG,Yinbo GUO,Ke CHEN
    Journal of Shandong University(Engineering Science)    2019, 49 (6): 55-62, 80.   DOI: 10.6040/j.issn.1672-3961.0.2019.251
    Abstract1048)   HTML11)    PDF(pc) (4187KB)(568)       Save

    To improve the intelligent level of service robots, a cloud service design method for service robots based on micro-service was proposed in this paper. The framework of cloud service based on micro-service was designed based on virtual model of service robot. Kinematics model, sensor model and environment model were proposed to map the robot parameters to cloud center. The interactive interface for cloud services was proposed. The adaptive matching of heterogeneous protocols was realized by using the protocol response of robots. Cloud service development methods were proposed in detail. The experiment result were done to demonstrate the cloud service results, real time and fine-grained quality of service of the proposed cloud service design for service robots.

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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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    Fault diagnosis for industrial processes based on causal topological graph
    WANG Mengyuan, ZHANG Xiong, MA Liang, PENG Kaixiang
    JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2017, 47 (5): 187-194.   DOI: 10.6040/j.issn.1672-3961.0.2017.239
    Abstract1000)      PDF(pc) (2687KB)(487)       Save
    With the combination of the process knowledge and data driven methods, the fault diagnosis method based on causal topological graph could effectively deal with the fault location and fault propagation identification. A correlation index(CI)based on partial correlation coefficient was applied to the causal topological graph to analyze the correlation between variables quantitatively. The proposed CI was monitored via probabilistic principal component analysis method(PPCA)for fault detection. The concept of mean weighted value and causal topological graph were introduced in order to identify the optimal fault propagation path based on reconstruction-based contribution(RBC)after detecting a fault. The effectiveness of the method was verified by the application of hot strip mill process(HSMP). The results showed that the proposed method could effectively identify the fault roots and propagation paths.
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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
    Abstract2239)   HTML146)    PDF(pc) (6934KB)(710)       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.

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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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    Visual servo grasping of household objects for NAO robot
    YUAN Li, TIAN Guohui*, LI Guodong
    JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    DOI: 10.6040/j.issn.1672-3961.0.2013.359
    Multiple objective and attribute decision making based on the subjective and objective weighting
    SONG Dongmei, LIU Chunxiao, SHEN Chen, SHI Xuefa, ZANG Lin, FENG Wenqiang
    JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2015, 45 (4): 1-9.   DOI: 10.6040/j.issn.1672-3961.0.2014.306
    Abstract1104)      PDF(pc) (1455KB)(1323)       Save
    For main defects of traditional subjective weighing and objective weighing method in the process of multi-objective and multiple attribute decision, a new weight way combined subjective and objective weighting method was proposed. Subjective weigh method has advantages of considering three different attitudes (pessimistic, neutral, optimistic) of the policy makers. Objective weighting method was based on the CRITIC method and the Entropy value method, which fully considered the discrete, correlation and contrast intensity of the data. Finally, linear group legal and multiplication operator were used to combine subjective and objective weighting method. The feasibility and practicability of the proposed method was proved by the experiment of assessment on the anti-interference ability of the communication equipment.
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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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    Effects of multiplicative actuator faults on the fault diagnosis performance in open-loop and closed-loop systems
    LIU Yang
    JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2017, 47 (5): 38-43.   DOI: 10.6040/j.issn.1672-3961.0.2017.182
    Abstract1180)      PDF(pc) (1321KB)(693)       Save
    The effects of multiplicative actuator faults on the fault diagnosis performance in both open-loop and closed-loop systems were investigated. Practical systems were usually subject to control inputs owing to the stability and robustness requirements. When multiplicative actuator faults were encountered, control signals could not be completely decoupled from the residual signals and the faults would unavoidably influence the fault diagnosis performance. The actuator faults were modeled for linear discrete systems and the Luenburger observer was used to generate the residual signals. By studying the one-step state transfer equation and the triangle inequality, the dynamics of the estimation error and residual was discussed and the conditions under which the open-loop and closed-loop residuals were bounded were established which were dependent on the amplitudes of the possible faults. Some numerical examples were provided to show the effectiveness of the proposed analysis for actuator faults with different amplitudes.
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    Analysis of factors affecting heat transfer of double U-shaped buried tubes based on TRNSYS
    Tao LIU,Ye TIAN,Yongzhi MA
    Journal of Shandong University(Engineering Science)    2019, 49 (6): 113-118.   DOI: 10.6040/j.issn.1672-3961.0.2019.317
    Abstract705)   HTML6)    PDF(pc) (1908KB)(349)       Save

    Because the horizontal buried tubes covered a large area, the heat transfer effect was poor, and the initial investment of the vertical buried tubes was high, the construction was difficult. A transient real-time simulation model of double U-shaped buried tubes heat exchanger was established with TRNSYS software. The factors, which could affect the heat transfer capacity of double U-shaped buried tubes heat exchanger, including the number and the spaceing of holes, and the depth of the buried tubes were analyzed under the condition of unique variable. The simulation experiment results showed that the heat transfer effect of buried tubes could be improved by increasing the number of holes, deepening drilling depth and increasing the spacing of the holes. It provided an analytical basis for the balance between the heat transfer effect of the buried tubes and the construction difficulty.

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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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    The centrifugal model test of cable stress monitoring for rock slope
    GUO Yongjian, CAO Zhouyang, SHENG Lijuan
    JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2016, 46 (2): 101-107.   DOI: 10.6040/j.issn.1672-3961.0.2015.048
    Abstract889)   HTML    PDF(pc) (2379KB)(861)       Save
    The centrifugal model test was taken to study the stress monitoring for the three typical types rock slopes,with the similar material mass ratio of quartz sand, plaster, and water as 1.50∶1.00∶0.25∶0.50. Test results showed that stress curves of the three typical types rock slopes were more flatted before the slope failure, stress monitoring and early warning were easy to grasp, and with similar properties,stress curves were used in the form of logistic curves fitting. Stress monitoring site of stratified rock slope should be mainly located in lower part of sliding surface. Failure mode of rock slope controlled by structural plane was mainly in the form of tensile shear,and test stress monitoring site of rock slope should be mainly located in upper part of structure plane,stress monitoring site of cataclastic structure rock slopes should be mainly located in upper part of slope. Centrifuge model test results showed that it was feasible to apply stress monitoring method to evaluate the rock slope stability.
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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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    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): 1-8,16.   DOI: 10.6040/j.issn.1672-3961.0.2020.160
    Abstract527)   HTML147)    PDF(pc) (6369KB)(401)       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.

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    Object detection of 3D point clouds based on F-PointNet
    Peng WAN
    Journal of Shandong University(Engineering Science)    2019, 49 (5): 98-104.   DOI: 10.6040/j.issn.1672-3961.0.2018.348
    Abstract2241)   HTML40)    PDF(pc) (3128KB)(808)       Save

    Aiming at the problem of poor detection accuracy of the current 3D point cloud object detection model, the F-PointNet model, which directly processed point cloud data, was used to detect cars, pedestrians and cyclists, and the model was fine-tuned to further improve the object detection accuracy. The model was tested by different parameter initialization methods, $\ell $2 regularization and modifying convolution kernels. The experimental results showed that the Xavier parameter initialization method converged faster 0.09s than the truncated normal distribution method, and the vehicle detection accuracy and the cyclists detection accuracy was about 3% and 2% higher respectively. By adding $\ell $2 regularization, the detection accuracy of pedestrians and cyclists was increased by about 2% and 1% respectively. By reducing the number of convolution kernels in the first layer of T-Net (Transformer Networks) to 128, the detection accuracy of cars and cyclists was increased by about 1% and 2% respectively, which confirmed that the model could effectively improve object detection accuracy.

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    Anti-reflective property of Ni-P/cicada microstructure composites
    CHEN Ting, QIN Ji-ning, FAN Tong-xiang*
    JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2014, 44 (1): 80-84.   DOI: 10.6040/j.issn.1672-3961.0.2013.320
    Abstract728)      PDF(pc) (2926KB)(2085)       Save

    The Ni-P/cicada  wing composites with nano-array structure were prepared by utilizing Pomponia imperatoria wing as the substrates of electroless plating. The microstructures of the samples were characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM), and the component as well as the optical property was respectively tested by X-ray photoelectron spectrometer (XPS) and UV-VIS-NIR spectrophotometer. Moreover, in order to investigate the effect of the nano-array structure on the antireflection property of the Ni-P coating, the 3D finite difference time domain (3D-FDTD) method was used to calculate the reflectance spectra of the synthesized composites based on the experimental data. Result showed that the reflectance of Ni-P/cicada  wing composites with nano-array structure was 70% lower than that of the one without the surface structure, which was ascribed to the interaction between the nanoarray structure and the incident light. This work could provide inspirations for the  antireflective Ni-P surface structure design.

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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.  
    Abstract938)      PDF(pc) (1289KB)(1388)       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.

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    Integrated advanced geological prediction technology of tunnel and its engineering application
    ZHOU Lun, LI Shucai, XU Zhenhao, LI Liping, HUANG Xin, HE Shujiang, LI Guohao
    JOURNAL OF SHANDONG UNIVERSITY (ENGINEERING SCIENCE)    2017, 47 (2): 55-62.   DOI: 10.6040/j.issn.1672-3961.0.2016.254
    Abstract860)      PDF(pc) (2775KB)(1049)       Save
    According to the question that the results from the single advanced prediction method for karst tunnel prediction were different from the actual excavation, the integrated advanced geological prediction technology was proposed to improve the accuracy to unfavorable geologic bodies. Macroscopic geological analysis, TSP(tunnel seismic prediction)method, ground penetrating radar, observation of the tunnel face and the method of advance borehole drilling were combined in advanced geological prediction for tunnel. The integrated advanced geological prediction could give full play to the advantages of each prediction method and improve the accuracy. The research results were successfully applied on advanced geological prediction work in the Liwan highway Moudao Connecting Road Qiyueshan Tunnel. It avoided the casualties and property losses. The large karst cave filled with water and mud in front of the tunnel face of mileage GK0+708~GK0+720 was taken as an example. The process of the integrated advanced geological prediction was detailed and some effective measures were taken to avoid the collapse and the inrush of mud. The study can guide the advanced geological prediction of other similar karst regions.
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    Photovoltaic power prediction method based on NWP irradiance inclination conversion
    Wenling JIANG,Yanqing ZHAO,Bo WANG,Shuanglei FENG,Yan PEI,Fei ZHANG
    Journal of Shandong University(Engineering Science)    2021, 51 (5): 114-121.   DOI: 10.6040/j.issn.1672-3961.0.2020.104
    Abstract304)   HTML23)    PDF(pc) (2582KB)(178)       Save

    Short-term photovoltaic (PV) power predictions statistical methods generally used the horizontal irradiance in numerical weather prediction (NWP) directly, but not the inclined irradiance received by tilt PV panels, which led to the calculation results not accurate enough. This paper proposed a new method to convert horizontal irradiance to inclined one. The method distinguished scattering into molecular scattering and Mie scattering with different properties, and then converted them separately. Using the new method, the paper converted NWP horizontal irradiance to inclined one. Based on inclined one, PV power model and prediction were made. The result of an example showed that the new method, whose root mean square error was 10.25% and correlation coefficient was 0.914 0, was more accurate than the traditional method, which used NWP horizontal irradiance directly.

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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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    Lightweight face super-resolution network based on asymmetric U-pyramid reconstruction
    Tongyu JIANG,Fan CHEN,Hongjie HE
    Journal of Shandong University(Engineering Science)    2022, 52 (1): 1-8, 18.   DOI: 10.6040/j.issn.1672-3961.0.2021.312
    Abstract240)   HTML8)    PDF(pc) (9804KB)(174)       Save

    A lightweight face super-resolution network was proposed in order to solve the problem that the model of deep convolutional neural network was complicated and difficult to be applied in the face super-resolution task. The coder composed of rescoding blocks was used for feature extraction, and pyramid reconstruction was introduced into the decoder to achieve fast and accurate super-resolution. To reduce the parameter number of the up-sampling operation in the decoding block, a non-uniform channel widening strategy based on resolution selection was adopted. To avoid adding extra branches, the prior knowledge of the face was introduced through heatmap loss. Experimental results showed that the model proposed in this paper could achieve light and accurate super-resolution reconstruction of ultra-low resolution face images that achieved better visual quality than the state-of-the-art method with lower model complexity.

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