Proceedings of the 2019 International Conference on Modeling, Analysis, Simulation Technologies and Applications (MASTA 2019)最新文献

{"title":"Simulation Study on Directional Dispersion of Strong Noise","authors":"Xu-dan Dong","doi":"10.2991/MASTA-19.2019.27","DOIUrl":"https://doi.org/10.2991/MASTA-19.2019.27","url":null,"abstract":"In dealing with emergencies, strong noise can effectively disperse the unruly crowd gathered illegally. Matlab was used to select different ultrasonic frequencies and individual transducer diameters, respectively, to carry out directional simulation of noise propagation, comparative analysis, to determine the selection of ideal ultrasonic frequency and transducer size. The directional image simulations of noise dispersal were carried out by selecting different array spacing of the transducer planar array. The noise dispersing sound pressure level was calculated to verify the noise dispersing efficiency. The determined optimal combination is ultrasonic wave with frequency f=40kHz, and the directional dispersing module selects a 4×4 array with diameter D=51mm and spacing d1=d2=1.2D=61.2mm. Introduction When dealing with mass emergencies such as large-scale illegal assembly and violent disturbance, targeted attack with strong noise can disperse effective targets without excessive harm to human body, and at the same time, it can produce ideal dispersing effect. However, the sound wave emitted by traditional loudspeaker is omnidirectional propagation, so it is difficult to produce audible noise with high directivity propagation and cannot achieve directional dispersing. Therefore, how to concentrate omnidirectional propagation noise in a specific direction domain and make it better directional propagation becomes the key link for the effective realization of directional dispersing of strong noise. Principle of Noise Dissipation System [1] Based on the principle of directional audio system, noise signal is transmitted by digital signal processor (DSP) loaded on ultrasonic signal. Because the acoustic attenuation coefficient is proportional to the second power of frequency, the ultrasonic waves and harmonics of higher frequency will be quickly absorbed by the air. The attack noise in the audible range is controlled to continue directional propagation in a certain area of space, and so the directional dissipation of noise can be achieved. The directivity of strong noise propagation is mainly realized by transducer. The sound pressure level of a single transducer is relatively small, and the directional propagation ability of the modulated noise is limited, so it is difficult to achieve effective dispersal effect. So the transducer should be formed into a plane array to improve the sound pressure level and propagation directivity of dispersal noise. Therefore, the directional dispersion effect of strong noise on living targets, will be determined by the parameters of a single transducer and a planar array. How to determine the size and other parameters of the transducer, how to make the planar array of the transducers give full play to the dispersing efficiency, and to give consideration to the size and structure limitations of the equipment and its own economic requirements, These are the primary problems to be solved in the research and development of n","PeriodicalId":103896,"journal":{"name":"Proceedings of the 2019 International Conference on Modeling, Analysis, Simulation Technologies and Applications (MASTA 2019)","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127128746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The General Idea of Constructing Complex Electromagnetic Environment in Conventional Shooting Range","authors":"Hong-ju Gao, Xiao-dong Jiang, Lei Wang","doi":"10.2991/MASTA-19.2019.63","DOIUrl":"https://doi.org/10.2991/MASTA-19.2019.63","url":null,"abstract":"In order to assess and appraise the electromagnetic environment adaptability of informationized weapon, some ideas about the construction requirements of complex electromagnetic environment of shooting range are proposed in this paper. Starting from the two general standards in the field of electromagnetic environment and the common intentional interference signals, this paper analyses what kind of electromagnetic environment should be built in the shooting range.","PeriodicalId":103896,"journal":{"name":"Proceedings of the 2019 International Conference on Modeling, Analysis, Simulation Technologies and Applications (MASTA 2019)","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128336528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on Three-Dimensional Temperature Field Induced by Laser Irradiation with Different Intensity Distribution","authors":"Hua Ding, Yi-cheng Guo, Zong-cheng Wang","doi":"10.2991/MASTA-19.2019.11","DOIUrl":"https://doi.org/10.2991/MASTA-19.2019.11","url":null,"abstract":"In this paper, a three-dimensional temperature field simulation model of metal surface irradiated by laser is established to analyze the temperature field distribution of Q235 metal plate irradiated by laser beam. The difference of temperature history and temperature field between Gauss fundamental mode beam and uniform rectangular beam is compared. The results show that the rectangular beam can make the temperature field more uniform, which is more suitable for laserassisted heat treatment and lamination process. Introduction As a new processing method, laser processing technology is widely used in materials, machinery and other industries, involving advanced processing technologies such as laser remanufacturing[1], cutting[2] and quenching[3]. In laser-assisted thermal processing, laser is used as a heat source to irradiate the surface of materials with extremely high power density, which makes the temperature of materials rise rapidly to meet the technological requirements. Subsequently, the material exits the irradiation zone and enters the cooling stage. The heating rate, the maximum temperature and the duration of the processing temperature are the main processing parameters. The temperature field has a great influence on the properties of materials[4]. When laser irradiates materials, the energy flow is complex. Using thermal infrared camera to measure temperature field directly is easy to be disturbed. And when using thermal resistance to measure the internal temperature of materials, the placement of thermal resistance will affect the internal structure of materials, which will also produce errors. Therefore, it will be very difficult to study the temperature field by experimental methods[5]. Most scholars use numerical or simulation methods to study the temperature field of laser irradiation. Wang G[6] established a two-dimensional temperature field model of laser irradiated materials by numerical method. Kashani[7] used Green's function to obtain the analytical solution of the transient temperature field in a rotating cylinder subjected to local laser heat source. Wang Y[8] proposed a numerical simulation method for studying the temperature field of laser quenching process. In summary, the research on temperature field of laser irradiation is mainly focused on two-dimensional simulation, ignoring the temperature field distribution in X or Y asix. And there is little research on the influence of different beam distribution on the time-dependent temperature field history. In this paper, the three-dimensional temperature field of laser irradiation is studied by simulation model. The temperature history and temperature field distribution of the material are analyzed, and the spatio-temporal distribution differences of temperature field irradiated by Gauss fundamental mode beam and uniform rectangular heat source are discussed. Mathematical Model of Temperature Field When metal plate is irradiated by a vertical laser beam, most of the light","PeriodicalId":103896,"journal":{"name":"Proceedings of the 2019 International Conference on Modeling, Analysis, Simulation Technologies and Applications (MASTA 2019)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134285770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design of Ship Course Controller Based on Improved Adaptive Backstepping","authors":"Zhi-hui Qu, Xing-cheng Wang","doi":"10.2991/MASTA-19.2019.5","DOIUrl":"https://doi.org/10.2991/MASTA-19.2019.5","url":null,"abstract":"This paper presents an improved adaptive backstepping control method based on uncertain parameters of ship model to design the ship course controller. The K-class function is introduced into every step of the virtual function design to ensure the stability of the closed-loop system and accelerate the convergence speed of the system state variables. Simulation results show that IAB control method is more superior than the traditional adaptive backstepping control method. Introduction Course control is the key of ship movement. Aiming at the problem of ship heading control strategy, many scholars have done a lot of researches in this field. The design of autopilot based on PD and PID is simple and effective, but its effect is not ideal in the real environment [1]. In [2], a ship autopilot is designed by combining high-order sliding mode control with dynamical sliding mode control. In [3], the approximation of unknown and uncertain dynamics is achieved by T-S fuzzy system, which guarantees the boundedness of all the signals in the closed-loop system. In [4], an adaptive control algorithm based on Nussbaum gain is proposed for the course keeping system, which solves the uncertainty of the ship course keeping system and reduces the influence of external interference and simplifies the control law. The backstepping method has advantages especially in nonlinear problems and has attracted extensive attention in ship motion control. In [5], an improved brief backstepping controller that replaces heading errors with a nonlinear function is proposed, which has proven to be robust. In [6], an eigenvalue decomposition adaptive sliding mode controller (SMC) is proposed, which can effectively eliminate the steady-state error and improve the capability of ship course keeping. In [7], an advanced adaptive observer based ship dynamic positioning backstepping is proposed, and the bias term is used to represent slow-varying disturbances and unmodeled dynamic. In [8], the backstepping is proposed to design station-keeping controllers of unmanned surface vehicle, and favorable results are obtained in the actual marine control system. In [9], the backstepping method is also adopted to design controller for under-actuated ships with input saturation, achieving global stability tracking. This paper takes the model parameters in the ship heading control system will be affected by the environment into account, which results in uncertainty of the model parameters. A new ship course controller is designed by combining the K-class function and the adaptive backstepping method to accelerate the system convergence speed and accurately track the desired course. Finally, the simulation results show that the proposed method has better performance. Problem Descriptions The Norrbin nonlinear model is used to describe the relationship between ship’s rudder angle ( )  and the rate ( ) r of the course ( )  , which is as follows: International Conference on Modeling, Analysis, Simulat","PeriodicalId":103896,"journal":{"name":"Proceedings of the 2019 International Conference on Modeling, Analysis, Simulation Technologies and Applications (MASTA 2019)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129428097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Powder Liner’s Density Distribution on Perforation Performance","authors":"Feng-Yi Zhou, Jiaxing Liu, Liang Tu, Yu Wang, Bin Shu","doi":"10.2991/MASTA-19.2019.7","DOIUrl":"https://doi.org/10.2991/MASTA-19.2019.7","url":null,"abstract":"In order to study the influence of the density distribution of the liner on the jet velocity gradient and the penetration performance, two numerical models of the typical density distribution of the powder liner were established. One is the uneven distribution of the axial density of the powder liner, and the other is the uneven distribution of circumferential density of the powder liner. The LS-DYNA software was used to calculate the multi-condition numerical values, and the shape, velocity gradient distribution and penetration depth of the jet are obtained. The jet velocity and the depth of the perforation are calculated and analyzed in combination with the quasi-steady theory of fluid mechanics and the virtual origin concept. The results show that the axial density of the powder liner has a certain increase on the jet shape and penetration depth. The density of the powder liner is unevenly distributed in the circumferential direction, and the jet has a tendency to deflect toward high density. Introduction As the core component of the shaped charge warhead, the powder liner is of concern for the quality and end effect of the jet under the explosive load. For example, delaying the breaking time of the jet [1], the petroleum perforating bullet has no corpus callosum and high penetration depth [2], increasing the mass ratio of the jet-type mask and increasing the driving ability of the powder liner. [3]. The design of the powder liner is close to the bottleneck, and the potential for excavation is small. Therefore, researchers at home and abroad have turned their attention to the application of new materials and new processes in the formation of the powder liner. The powder metallurgy liner is widely concerned because of its flexible material ratio, simple processing technology, high jet penetration depth and large pore surface area [4], and largely avoiding the phenomenon of plugging. However, the powder liner prepared by the pressing process generally has a problem of uneven density distribution in the axial/circumferential direction. In this paper, based on the above background, the axial/circumferential density distribution of the powder liner is uneven. The LS-DYNA finite element analysis software was used to carry out numerical simulation research, in order to provide theoretical basis for the shape, velocity gradient and penetration performance of the jet caused by uneven density distribution of the powder liner, and to provide reference for other related research. Theoretical Analysis According to the Allison and Vitalit hypothesis [5], there is a virtual source as the starting point of all jets, the jet velocity is linearly distributed along the axis, and the velocity of the jet micro-element does not change during the motion [6]. Therefore, the calculation formula for the penetration depth of the jet is International Conference on Modeling, Analysis, Simulation Technologies and Applications (MASTA 2019) Copyright © 2019, the Authors. Pub","PeriodicalId":103896,"journal":{"name":"Proceedings of the 2019 International Conference on Modeling, Analysis, Simulation Technologies and Applications (MASTA 2019)","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130198962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Promotion Effect of LOESS Smoothing Technique in Short-term Traffic Volume Clustering","authors":"Jia-juan Chen, Yu-bang Liu, Zhi-Yuan Wang, Chuan-tao Wang","doi":"10.2991/MASTA-19.2019.65","DOIUrl":"https://doi.org/10.2991/MASTA-19.2019.65","url":null,"abstract":"In short-term traffic volume clustering, one important issue is the representation of traffic profiles. This article focuses on how the LOESS smoothing technique enhances the clustering effect and what the best value of parameter span of LOESS is. This article used K-Means clustering algorithm and compared the clustering effect using raw data and smoothed data. The experiment result shows when the traffic profiles are slight smoothed, the clustering effect enhances from 39.15% to 66.48%. And the best range of parameter span is 0.2~0.4 to keep the balance of clustering effect and profiles details. This article verifies the promotion effect of LOESS smoothing technique in shortterm traffic volume clustering and gives advice on the best value of LOESS parameter. Introduction With the rapid development of information techniques such as Internet of things, big data, cloud computing, Intelligent Transport System (ITS) is making great progress not only in laboratories but also in real traffic management systems in China. Short term traffic analysis is the essential component of ITS to identify specific traffic patterns and make forecasting of short-term traffic flow. Short term traffic clustering, which can identify similar traffic flow of different sections of road on different day, is enlightening to find similar traffic patterns and support traffic management. Some researchers used clustering to support data driven forecasting methods such as K Nearest Neighbor regression and used locally estimated scatterplot smoothing (LOESS) to smooth the noise in traffic flow profiles. However, the promotion effect of LOESS to identify similar traffic profiles was rarely been focused on. This research aims to fill up this gap to find whether LOESS can enhance the clustering effect of short term traffic profiles and what the best parameter of LOESS is to keep the balance of maintaining the profiles details and clustering effect. Short term traffic profile is one type of time series. Aghabozorgi (2015) [1] has reviewed the four main elements of time series clustering, including representation method, similarity degree, prototype definition, clustering algorithm. This article uses Euclidean distance as similarity measurement, average value as prototype definition and K-Means as clustering algorithm. Raw profiles and LOESS smoothing profiles as two kinds of representation methods will be conducted in clustering experiments and the clustering effects will be compared. Methodology K-Means Clustering Methods K-Means is one of the most popular clustering algorithms based on partition. K-Means produces k clusters from n unlabeled objects to make sure that there is at least one object in each cluster [1]. The clustering prototype of K-Means is the average of the objects. The principle of K-Means is to minimize the sum of the distances (generally expressed in Euclidean distance) between all objects in the cluster and their cluster center (i.e. prototype). So this article ch","PeriodicalId":103896,"journal":{"name":"Proceedings of the 2019 International Conference on Modeling, Analysis, Simulation Technologies and Applications (MASTA 2019)","volume":"107 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116373228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Predicting Pulverized Coal Plasma Ignition Performance by BP Neural Network","authors":"Lei Shi, Yi Zhang, Yu-bin Men, Jia Hua Cheng","doi":"10.2991/MASTA-19.2019.3","DOIUrl":"https://doi.org/10.2991/MASTA-19.2019.3","url":null,"abstract":"To make sure the major factors and their influence for pulverized coal plasma ignition(PCPI), the way predicting the PCPI was investigated in this paper. The back propagation(BP) neural network was used to established a prediction model which can study by itself for PCPI. Then the sample database was set up by simulating the PCPI in kinds of conditions. After that, the prediction model was trained by sample database to improve the prediction level. At last, the prediction model was used to predict the PCPI in new conditions and the prediction error is under 0.004. The research show that the BP neural network can predict the PCPI correctly. In this paper, the BP neural network was applied to predict the PCPI innovatively, and the prediction efficiency increase highly and the prediction accurancy does not deline. Introduction During the operation PCPI, plasma torch injects into the pulverized coal stream to form a stable flame, which is poured into the furnace of boiler. PCPI technology has attracted attentions worldwide because it can be used in the pulverized coal fired boilers to realize the startup or stable combustion in part load operation. It has been a promising way to reduce oil consumption in coal fired power plants. Up to now, PCPI systems have been used in about 550 boilers in China, which have a total capability of near 230 GW. The PCPI processes have been investigated. Among these, Masaya Sugimoto et al.[1] investigated the ignition processes with different coal in a drop tube, discussed the power demand to realize the success of ignition under differential excess air ratio. E.I. Karpenko et al. [2], focused on a 200 MW boiler, studied the plasma ignition processes with Reynolds Average Navier Stocks (RANS) simulation and experiments in this boiler. Zhang xiaoyong et al. [3], studied how to design the multistep plasma ignition burner with RANS and experiments. With the development of PCPI both in practical applications and theory investigations, how to predict the main parameters of the PCPI becomes a challengeing problem. Traditional simulation methods, such as RANS and LES, can not meet command in practice because of prediction efficiendy. The back propagation(BP) neural network is an proper approach to slove this problem. It has been used in both laminar and turbulent reactive flows, as an alternative to the conventional kinetics evaluation, which can reduce the CPU cost largely [4~7]. But the applicability of BP neural network in two phase flows, especially in the pulverized coal combustion processes, still remains to be demonstrated. How to predict the PCPI by BP neural network was investigated in this paper. Establish Prediction Model The back propagation(BP) neural network is the most popular network architecture now. The transfer function of the neurons in BP neural network is Sigmoid differentiable function, so it can deal with the nonlinear mapping problems. The momentum—adaptive learning rate method is used to improve the p","PeriodicalId":103896,"journal":{"name":"Proceedings of the 2019 International Conference on Modeling, Analysis, Simulation Technologies and Applications (MASTA 2019)","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133333389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Research and Implementation of Algorithm Based on Data Fusion Technology","authors":"Yuzi Dou, Xiafei Feng, Ruifeng Zhu, Tianzhu Gao, Yanbing Wu, Lei Ma","doi":"10.2991/MASTA-19.2019.60","DOIUrl":"https://doi.org/10.2991/MASTA-19.2019.60","url":null,"abstract":"As the growing amount of data stored on the Internet, the work of searching for information becomes complicated. The traditional collection method cannot achieve a certain effect, it is cumbersome and time-consuming. Using natural language processing technology and web crawler technology to collect and analyze data about student evaluation, the purpose is to obtain the key factors affecting teachers' comprehensive evaluation results and propose the methods to solve the problems. For the traditional Web crawler technology, there is a lack of certain intelligence, initiative, etc. the design of the best priority crawler framework has improved and optimized its structure. And the improved PageRank value, user demand correlation degree, and NDC algorithm denoising are added, it can effectively solve a series of problems such as long retrieval time, overlapping information, incomplete information, and improve the accuracy of information collection. Introduction The proposal of student evaluation system is to find a solution to the current situation according to the specific needs of students and teachers' teaching requirements. As an integrated data processing technology, data fusion technology is applied to many traditional disciplines and emerging fields, which can improve the accuracy and reliability of target rule mining and prediction. In [1] combined with the crawler technology, the acquisition and analysis of multi-source spatial data is demonstrated, which is beneficial to better assist the urban planning work; In [2], the design of the Internet public opinion analysis system based on the principle of data fusion, and the data fusion analysis processing is realized by combining the crawler technology with the natural language processing technology; In [3], it is proposed a personal credit scoring system based on multi-source data fusion, which combines the logistic regression model to improve the model estimation accuracy; In [4], the data is collected by adaptive weighted fusion method based on data fusion principle, and the Grubbs criterion is used to eliminate invalid data, so as to comprehensively deal with the problem of measuring the parameters of the inlet section of the test piece in the afterburner of an aero-engine. Overall System Structure Design This paper uses multi-source data fusion technology to search for keyword group information about student evaluation in the webpages. The first chapter introduces the overall chapter arrangement of this article. The second chapter introduces the proposed system architecture and optimization scheme. In the third chapter, Applied to the comprehensive analysis of students' evaluation. Chapter four gives a summary and suggestions. As shown in Figure 1. Figure 1. Overall architecture flow chart Start Optimizati on scheme Web page classificat ion Data processin g Word frequency statistics Similar word substituti on Keyword list (NLP) END International Conference on Modeling, Analysis, Simulation ","PeriodicalId":103896,"journal":{"name":"Proceedings of the 2019 International Conference on Modeling, Analysis, Simulation Technologies and Applications (MASTA 2019)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132445412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Active Appearance Model Based Contour Extraction for MRI Images of Human Tongue","authors":"Zhi-cheng Liu, Qilong Sun, J. Wei","doi":"10.2991/MASTA-19.2019.24","DOIUrl":"https://doi.org/10.2991/MASTA-19.2019.24","url":null,"abstract":"In this article, we present the results of automatic extraction of speech articulator contours from Magnetic Resonance Imaging movie by employing the Active Appearance Model. An Active Appearance Model based framework is proposed to deal with the high nonlinear property of articulatory deformation during articulation, which demonstrates the advantage for tracking articulators shape from noisy MRI images. The extraction of the vocal tract contour was carried on MRI movies from Chinese subjects. The performance of this framework was evaluated by comparing manually labeled contours with automatically extracted ones. The average error is around 2.1 pixels. Introduction Speech is one of the most important functions of human communication. However, the mechanism of speech production is far from being fully discovered. The morphological and dynamic aspects of speech organs are the essential for understanding the knowledge of speech dynamic. Advanced imaging and image processing technologies are important for this research field. Magnetic Resonance Imaging (MRI) is able to produce high-resolution images of human articulators. This function makes MRI currently one of the most promising means for speech research and hence has been widely used in study speech production [1-3]. A set of databases of MRI image of human speech organs have been available for various purposes. A necessary procedure to use such databases, however, is a successful extraction of the desired speech organs from these images. A large variety of algorithms have been developed over the last few decades trying to handle this issue [4-6]. They mainly can be categorized as data-driven approach such as snake-like methods and modeldriven approach that use the prior knowledge to complete the task. Both categories have their own pros and cons. For data-driven approach, each image has to be given an initial shape before extracting the shape, which could not be fully automatic. The model-based approach has to be trained by a training set, which has to be labeled manually beforehand. Active Appearance Models (AAM) is one of the model-based approaches, which has been shown that it has great promising for automatically tracking objects from images. As MRI database of speech has a large number of images for recording articulatory movements, it is worthy to label a small training set for automatically extracting the shape from remaining images. AAM was developed by Cootes et .al [7-10], which is a statistical point distribution model (PDM). AAM has demonstrated its capability for image segmentation [11]. It is able to automatically learn the parameters of the PDMs from sets of corresponding landmarks as well as incorporating the shape and boundary gray-level information. An AAM describes the image appearance and shape of object of interest by obtaining a statistical shape-appearance model from a training set. AAM minimize the difference between the synthesized image from the model and an unseen image","PeriodicalId":103896,"journal":{"name":"Proceedings of the 2019 International Conference on Modeling, Analysis, Simulation Technologies and Applications (MASTA 2019)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116550872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pulse Sequence Frequency Selection Method of High Frequency Shake-out Machine","authors":"Fangzhen Song, Zheng-tao Yuan, Bo Song","doi":"10.2991/MASTA-19.2019.44","DOIUrl":"https://doi.org/10.2991/MASTA-19.2019.44","url":null,"abstract":"The pulse sequence frequency is an important control parameter of shake-out machine. Traditionally, the selection is done by trial and error. This method is low in efficiency, wastes energy in repeated impact tests, and the selected pulse frequency reliability is low, so it often fails to get good shake-out effect. Aiming at the shortcomings of the trial and error method, the method of selecting the pulse frequency of air hammer by means of modal analysis and harmonic response analysis of castings is proposed. The value range of frequency is greatly reduced and the optimization efficiency of pulse frequency is improved by means of this method. Introduction The shake-out of complex casting has always been a complex and laborious part in the process of casting cleaning. In the process of shake-out, the choice of the shock pulse frequency is traditionally chosen by trial and error. According to the experience, the traditional method shocks the casting by trial and error method, and then cuts the casting to observe the shakeout effect. But this method is low-efficiency, repeated shock tests waste energy and the reliability of the selected pulse frequency is also low. The shakeout effect is not good. In view of the shortcomings of the above methods, a new method is proposed. The pulse frequency of air hammer is selected by modal analysis and harmonic response analysis. This method improves the efficiency of frequency selection, and the choice of the pulse frequency verified by the practice of the shakeout effect is better. The value range of frequency is greatly reduced and the optimization efficiency of pulse frequency is improved by means of this method. The Working Principle of Shake-out Machine The shake-out machine works by using air hammer to repeatedly shock the castings, at the same time, vibrating the casting by vibrating motor to achieve the purpose of shakeout. The air hammer repeatedly shocks the casting, which corresponds to the sequence of pulses acting on the casting[1]. The structure of the shake-out machine is shown in Fig. 1 (1-Lower machine base; 2-Isolator; 3-Upper machine base; 4-Vibrating motor; 5-Air hammer mounting seat; 6-Air hammer; 7-Clamping fixture; 8-Rubber gasket; 9-Casting placing platform; 10-Pneumatic clamping mechanism )[2]. Different castings require different pulse frequency, thus according to tests to select a different pulse frequency. Spectrum Analysis of Air Hammer Shock Pulse Sequence The air hammer repeatedly shocks the casting, which corresponds to the sequence of pulses acting on the casting. The periodic rectangular pulse sequence with equal intervals is represented by a rectangular pulse sequence function rec(t,T0,τ,A), as shown in Fig. 2. Based on Fourier transform theory[3,4], the spectrum analysis of pulse sequence of shakeout shock force is carried out. The relationship between the time domain parameters and the frequency domain parameters of the shock pulse sequence is obtained. International Confere","PeriodicalId":103896,"journal":{"name":"Proceedings of the 2019 International Conference on Modeling, Analysis, Simulation Technologies and Applications (MASTA 2019)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123882863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}