Browsing by Author "Lin, Jia-Hong"

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A High-Efficiency Method of Mobile Positioning Based on Commercial Vehicle Operation Data
(2016-06-01)
Chen, Chi-Hua
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Lin, Jia-Hong
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Kuan, Ta-Sheng
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Lo, Kuen-Rong
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資訊管理與財務金融系註：原資管所+財金所
Commercial vehicle operation (CVO) has been a popular application of intelligent transportation systems. Location determination and route tracing of an on-board unit (OBU) in a vehicle is an important capability for CVO. However, large location errors from global positioning system (GPS) receivers may occur in cities that shield GPS signals. Therefore, a highly efficient mobile positioning method is proposed based on the collection and analysis of the cellular network signals of CVO data. Parallel- and cloud-computing techniques are designed into the proposed method to quickly determine the location of an OBU for CVO. Furthermore, this study proposes analytical models to analyze the availability of the proposed mobile positioning method with various outlier filtering criteria. Experimentally, a CVO system was designed and implemented to collect CVO data from Chunghwa Telecom vehicles and to analyze the cellular network signals of CVO data for location determination. A case study found that the average errors of location determination using the proposed method vs. using the traditional cell-ID-based location method were 163.7 m and 521.2 m, respectively. Furthermore, the practical results show that the average location error and availability of using the proposed method are better than using GPS or the cell-ID-based location method for each road type, particularly urban roads. Therefore, this approach is feasible to determine OBU locations for improving CVO.
Acoustic camera
(2010-10-28)
Bai, Mingsian R.
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Lin, Jia-Hong
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Liu, Kuan-Liang
An acoustic camera comprises a first sound pick-up device, a second sound pick-up device, and a switch. The switch is respectively connected to the first sound pick-up device and the second pick-up device and used to select the first sound pick-up device or the second sound pick-up device to reconstruct the sound field of the sound source of a detected object. The first sound pick-up device has a first microphone array, and the first microphone array is a near-field uniform microphone array. The second sound pick-up device has a second microphone array, and the second microphone array is a far-field non-uniform microphone array.
Agent-Based Control Framework for Mass Customization Manufacturing With UHF RFID Technology
(2009-09-01)
Tu, Mengru (Arthur)
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Lin, Jia-Hong
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Chen, Ruey-Shun
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Chen, Kai-Ying
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Jwo, Jung-Sing
Radio frequency identification (RFID) technology adoption in business environments has seen strong growth in recent years. Adopting an appropriate RFID-based information system has become increasingly important for enterprises making complex and highly customized products. However, most firms still use conventional barcode and run-card systems to manage their manufacturing processes. These systems often require human intervention during the production process. As a result, traditional systems are not able to fulfill the growing demand for managing dynamic process flows and are not able to obtain real-time work-in-process (WIP) views in mass customization manufacturing. This paper proposes an agent-based distributed production control framework with UHF RFID technology to help firms adapt to such a dynamic and agile manufacturing environment. This paper reports the design and development of the framework and the application of UHF RFID technology in manufacturing and logistic control applications. The framework's RFID event processing agent model is implemented in a smart end-point (SEP) device. A SEP can manage RFID readers, wirelessly communicate with shop-floor machines, make local decisions, and coordinate with other SEPs. A case study of a bicycle manufacturing company demonstrates how the proposed framework could improve a firm's mass customization operations. Results of experiments show the decentralized multiagent coordination scheme among SEPs outperformed the current practice of the firm in terms of reducing work-in-process and parts inventory.
Agent-Based Control Framework for Mass Customization Manufacturing With UHF RFID Technology (vol 3, pg 343, 2009)
(2009-12-01)
Tu, Mengru (Arthur)
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Lin, Jia-Hong
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Chen, Ruey-Shun
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Chen, Kai-Ying
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Jwo, Jung-Sing
Implementation issues of the nearfield equivalent source imaging microphone array
(2011-01-31)
Bai, Mingsian R.
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Lin, Jia-Hong
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Tseng, Chih-Wen
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機械工程學系
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Department of Mechanical Engineering
This paper revisits a nearfield microphone array technique termed nearfield equivalent source imaging (NESI) proposed previously. In particular, various issues concerning the implementation of the NESI algorithm are examined. The NESI can be implemented in both the time domain and the frequency domain. Acoustical variables including sound pressure, particle velocity, active intensity and sound power are calculated by using multichannel inverse filters. Issues concerning sensor deployment are also investigated for the nearfield array. The uniform array outperformed a random array previously optimized for far-field imaging, which contradicts the conventional wisdom in far-field arrays. For applications in which only a patch array with scarce sensors is available, a virtual microphone approach is employed to ameliorate edge effects using extrapolation and to improve imaging resolution using interpolation. To enhance the processing efficiency of the time-domain NESI, an eigensystem realization algorithm (ERA) is developed. Several filtering methods are compared in terms of computational complexity. Significant saving on computations can be achieved using ERA and the frequency-domain NESI, as compared to the traditional method. The NESI technique was also experimentally validated using practical sources including a 125 cc scooter and a wooden box model with a loudspeaker fitted inside. The NESI technique proved effective in identifying broadband and non-stationary sources produced by the sources. (C) 2010 Elsevier Ltd. All rights reserved.
On optimal retreat distance of equivalent source method-based near-field acoustical holography
(2010)
Bai, Mingsian R.
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Lin, Jia-Hong
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Chen, Ching-Cheng
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機械工程學系
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Department of Mechanical Engineering
This paper presents two nearfield acoustical holography (NAH) approaches using Equivalent Source Methods (ESM). The indirect ESM is derived from discretizing the simple layer potential integral, while the direct ESM is derived from discretizing the Helmholtz Integral Equation (HIE). In the indirect ESM, sound field is represented by a distribution of monopoles. In the direct ESM, on the other hand, sound field is represented by monopoles and dipoles. In the ESM formulation, it is vital that the virtual sources "retreat" from the reconstruction surface to avoid singularity. However, the distance can not be increased without limit because of the ill-posedness inherent at large reconstruction distance. It is widely believed that the retreat distance of one to two lattice spacing is appropriate. This paper revisits this issue of retreat distance, with the aid of an optimization technique: the golden ratio search with parabolic interpolation. Simulations are conducted for baffled planar and spherical pistons. The simulation results reveal that, differing from the widely accepted value, the retreat distance appropriate for the ESM is half of lattice spacing.
Optimized microphone deployment for near-field acoustic holography: To be, or not to be random, that is the question
(2010-07-05)
Bai, Mingsian R.
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Lin, Jia-Hong
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Liu, Kwan-Liang
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機械工程學系
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Department of Mechanical Engineering
Arrays with sparse and random sensor deployment are known to be capable of delivering high quality far-field images without grating lobes. This raises the question of whether or not this idea can be applied to near-field imaging as well. To answer this question that has not yet been widely investigated in previous research, numerical simulations are undertaken in this paper to optimize the microphone deployment for both far-field and near-field arrays with the latter being the main focus. In the simulation, a recently introduced near-field equivalent source imaging (NESI) technique is employed for the near-field imaging. Global optimization techniques including the simulated annealing (SA) algorithm and the intra-block Monte Carlo (IBMC) algorithm are exploited to find the optimal microphone position efficiently. The combined use of the SA and the IBMC algorithms enables efficient search for satisfactory deployment with excellent beam pattern and relatively uniform distribution of microphones. In the near-field optimization, a special kind of beam pattern and cost function definition is used for the multiple-input-multiple-output (MIMO) imaging problem. As indicated by the simulation results, random deployment of microphones is necessary to avoid grating lobes in far-field imaging. In the near-field simulation, all results suggest that the optimal near-field array is the uniform rectangular array (URA) and the random deployment presents no particular benefit in near-field imaging. (C) 2010 Elsevier Ltd. All rights reserved.
System and method for visualizing sound source energy distribution
(2007-09-27)
Bai, Mingsian R.
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Lin, Jia-Hong
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Ning, Yu-Wei
The present invention discloses a system for visualizing sound source energy distribution and a method thereof, wherein a propagation matrix and a window matrix are obtained firstly; next, an inverse operation of the propagation matrix is performed; next, a multiplication operation of the result of the inverse operation and the window matrix is performed; next, the result of the multiplication operation is transformed from the time domain to the frequency domain; thus, a sound source energy distribution reconstructor is established; then, an array of microphones is used to receive the sound source signals; next, a multi-channel capture device transforms the received sound source signals into digital sound source signals; lastly, a convolution operation is performed on the digital sound source signals and the sound source energy distribution reconstructor to obtain a visualized sound source energy distribution. Therefore, the present invention can provide the energy distributions of nearfield/farfield stable-state/unstable-state sound sources.