1. Chwan-Hwa Wu, J.D. Irwin, "Multimedia and multimedia communication: a tutorial," Trans. on Industrial Electronics, vol. 45, no. 1, pp. 4-14, Feb 1998. Full Text Link
Abstract : This paper presents, in a tutorial fashion, the important features of multimedia technology. The specific areas addressed are multimedia and compression standards, computer networks, multimedia transport, and some specific applications employed by industry to date. Multimedia and the effective and efficient communication of multimedia using compression and networks are fused together in this tutorial in an attempt to demonstrate the tight coupling which exists between these two interrelated technologies. First, the techniques and properties inherent in both multimedia and compression standards are presented. Then, the important characteristics of the major local and wide area networks are summarized. Next, the communication techniques for the transport of video and video conferencing are discussed. The new strategies employed to connect homes through cable TV and the telephone companies, as well as the new Ethernet technologies, are also described. Finally, some modern applications of multimedia communication derived from the automotive industry are used to describe the use of this technology in design, manufacturing, and sales
2. R.R. Rao, Tsuhan Chen, R.M. Mersereau, "Audio-to-visual conversion for multimedia communication," Trans. on Industrial Electronics, vol. 45, no. 1, pp. 15-22, Feb 1998. Full Text Link
Abstract : Although humans rely primarily on hearing to process speech, they can also extract a great deal of information with their eyes through lipreading. This skill becomes extremely important when the acoustic signal is degraded by noise. It would, therefore, be beneficial to find methods to reinforce acoustic speech with a synthesized visual signal for high noise environments. This paper addresses the interaction between acoustic speech and visible speech. Algorithms for converting audible speech into visible speech are examined, and applications which can utilize this conversion process are presented. Our results demonstrate that it is possible to animate a natural-looking talking head using acoustic speech as an input
3. Qingwen Hu, S. Panchanathan, "Image/video spatial scalability in compressed domain," Trans. on Industrial Electronics, vol. 45, no. 1, pp. 23-31, Feb 1998. Full Text Link
Abstract : Image/video compression is widely used in various applications with the advent of the Joint Photographic Expert Group (JPEG), Motion Picture Expert Group (MPEG), and H.261 standards. Hence, most visual data are stored in the compressed format. Spatial scalable encoding of visual data has several applications, including browsing visual databases, querying multimedia databases, interactive multimedia communications, etc. We propose two novel techniques, namely, format compatible (FC) discrete cosine transform (DCT) and format modified (FM) DCT to implement image/video spatial scalability directly in the DCT compressed domain. The FC-DCT technique can be used to manipulate the standard bit streams, such as JPEG, MPEG, etc., while the FM-DCT technique can be employed in a variety of applications which require fast processing. In contrast to the traditional spatial-domain techniques, the compressed-domain techniques remove the unnecessary decompression and recompression procedures, thus, they have the advantages of reduced computational complexity and storage requirements. Simulation results demonstrate that the proposed DCT-domain techniques can achieve a comparable performance at a much lower computational complexity compared to the spatial-domain techniques
4. R.T. Harding, Chwan-Hwa Wu, "A method for quantization scale factor selection in MPEG2 video sequence encoding using a bilayer fuzzy expert system," Trans. on Industrial Electronics, vol. 45, no. 1, pp. 32-37, Feb 1998. Full Text Link
Abstract : This paper presents a method for intelligent selection of the quantization scale factor used for varying bit rate and quality in the MPEG2 video encoding standard. The goal is to select the quantization scale factor, above which noticeable quality degradation occurs. This method uses a bilayer fuzzy logic system to aggregate measurements taken on the block level. The rulebases are designed around the characteristics of the human visual system (HVS). A qualitatively sensitive quantization scale factor can be chosen by taking advantage of the HVS characteristics
5. M.S. Moellenhoff, M.W. Maier, "DCT transform coding of stereo images for multimedia applications ," Trans. on Industrial Electronics, vol. 45, no. 1, pp. 38-43, Feb 1998. Full Text Link
Abstract : One form of multimedia finding increasing utility in factory automation is stereo imaging. Its uses include remote operation, telepresence, and object positioning. Stereo imaging, with doubled frames, requires high data-rate collection and transmission. Image compression techniques can be utilized to reduce the transmission bandwidth and/or storage space requirements of the stereo pair. This paper develops image compression techniques specific to stereo imaging and compares the performance with nonstereo methods. Disparity compensated residual image coding exploits the redundancy between the two images in a stereo pair. Stereo residuals possess special features that can be exploited within a discrete cosine transform (DCT) image coding framework. Use of these features results in several decibels of performance enhancement across a range of scene types. This approach provides its best performance below 0.75 b/pixel bitrate for 8-b grayscale imagery and below 2 b/pixel for 24-b color imagery
6. M.Y.M. Chiu, K.-H.A. Yeung, "Partial video sequence caching scheme for <>VOD<> systems with heterogeneous clients," Trans. on Industrial Electronics, vol. 45, no. 1, pp. 44-51, Feb 1998. Full Text Link
Abstract : Video on demand (VOD) is one of the key applications in the information era. A hinge factor to its widespread use is the huge bandwidth required to transmit digitized video to a large group of clients with widely varying requirements. This paper addresses issues of heterogeneous clients by proposing a program caching scheme called the partial video sequence (PVS) caching scheme. The PVS caching scheme decomposes video sequences into a number of parts by using a scalable video compression algorithm. Video parts are selected to be cached in local video servers based on the amount of bandwidth that would be demanded from the distribution network and central video server if it was only kept in the central video server. We also show that the PVS caching scheme is suitable for handling vastly varying client requirements
7. Chung-Ju Chang, Chih-Hen Lin, Dah-Sheng Guan, Ray-Guang Cheng, "Design of a power-spectrum-based ATM connection admission controller for multimedia communications," Trans. on Industrial Electronics, vol. 45, no. 1, pp. 52-59, Feb 1998. Full Text Link
Abstract : This paper proposes a power-spectrum-based connection admission controller design in asynchronous transfer mode (ATM) switches for multimedia communications. The controller contains a power-spectrum-indexed table for managing multimedia call requests, where traffic characteristics of call requests are described by the power spectrum. The power-spectrum can be obtained from the claimed traffic parameters of peak rate, mean rate, and peak rate duration; the power-spectrum has been shown to have a dominant effect on system performance. The results show that the proposed power-spectrum-based connection admission control method achieves higher system utilization and lower call-blocking probability than the equivalent-capacity allocation method
8. P.C. Ting, M.C. Yuang, "Dynamic multithreshold rate control mechanisms for supporting <>ABR<> traffic in ATM networks," Trans. on Industrial Electronics, vol. 45, no. 1, pp. 60-68, Feb 1998. Full Text Link
Abstract : Existing feedback-based rate control schemes supporting the available bit rate (ABR) service in ATM networks mostly employ a single static buffer threshold at each switching node as the forewarning of congestion. We first propose a continuous-based adaptive rate control mechanism, which employs, logically, an infinite number of thresholds. Each node periodically determines the precise permitted rate of immediate upstream nodes based on a simple fluid model aimed at satisfying both loss-free and starvation-free criteria. The scheme achieves high utilization and low (zero) cell-loss probability under highly bursty (deterministic) traffic, but at the expense of a drastic increase in signalling overhead due to frequent adjustment of permitted rates. To reduce overhead, we further propose a so-called stepwise-based rate control mechanism adopting a limited number of movable thresholds, referred to as the threshold set. The threshold set shifts up (down) reflecting the increase (decrease) in departure rates. Compared to continuous-based control via simulation, stepwise-based control is shown to be efficient and accurate using a reasonably low number of thresholds. Moreover, we also display simulation results, which demonstrate that the stepwise-based mechanism outperforms existing single-static-threshold-based schemes in terms of cell-loss probability and link utilization
9. M.C. Yuang, J.C. Liu, "QTS: a QOS-guaranteed transport system for broad-band multimedia communications," Trans. on Industrial Electronics, vol. 45, no. 1, pp. 69-77, Feb 1998. Full Text Link
Abstract : We propose a quality-of-service (QOS)-guaranteed transport system (QTS), which offers various QOSs at the transport layer for broad-band multimedia communications. The QTS, composed of a bandwidth allocator and a transport protocol module, supports three classes of applications requiring different bit rates, delay sensitivity, and loss sensitivity. The bandwidth allocator intelligently manages the allocation of transport-layer bandwidth at the expense of imposing inevitable blocking of delay-sensitive application connections. The transport protocol module of the QTS performs rate-based flow control for delay-sensitive applications based on transfer rates predetermined by the bandwidth allocator. In addition, the module accomplishes error control only for loss-sensitive applications. As a result, by providing guaranteed rates and reducing the error control overhead, the QTS offers satisfactory bounded delays and jitter for delay-sensitive applications, while incurring minimal throughput degradation for loss-sensitive applications. Finally, we demonstrate the superiority of the QTS over transmission control protocol (TCP) via simulation results in terms of maximum and mean system delays and delay jitter
10. J.R. Espinoza, G. Joos, "State variable decoupling and power flow control in PWM current-source rectifiers," Trans. on Industrial Electronics, vol. 45, no. 1, pp. 78-87, Feb 1998. Full Text Link
Abstract : Pulsewidth modulated (PWM) current-source rectifiers (CSR), among other alternatives, offer marked improvements over thyristor line-commutated rectifiers as a source of variable DC power. Advantages include reduced line current harmonic distortion and complete displacement power factor control, including unity displacement power factor operation. However, due to nonlinearities of the PWM-CSR model, their control has usually been carried out using direct line current control in a three-phase stationary frame (abc). This paper proposes the application of a nonlinear control technique that introduces more flexibility in the control of the rectifier and results in a more straightforward approach to controller design. The proposed technique is based on a nonlinear state variable feedback approach in the rotating frame (dq). The approach allows the independent control of the two components of the line current (active and reactive) with the same dynamic performance, regardless of the operating point. The control strategy also eliminates the need for input damping resistors and rejects the effect of supply voltage variations. Furthermore, a space vector modulation (SVM) technique is used to maximize the supply voltage utilization. This paper includes a complete formulation of the system equations and a controller design procedure. Experimental results on a 2 kVA digital-signal-processor-controlled prototype confirm the validity of theoretical considerations
11. Tsai-Fu Wu, Yu-Kai Chen, "A systematic and unified approach to modeling PWM DC/DC converters based on the graft scheme," Trans. on Industrial Electronics, vol. 45, no. 1, pp. 88-98, Feb 1998. Full Text Link
Abstract : A systematic and unified approach to modeling pulsewidth modulated (PWM) DC/DC converters based on the graft scheme is presented in this paper. With the graft scheme, the typical PWM switch-mode converters, such as buck-boost, boost-buck (Cuk), Sepic, and dual Sepic, can be generated from the two basic converters, buck and boost. The small signal models of these converters can, therefore, be derived by properly combining those of the buck and boost. Using the proposed approach can help to yield highly related dynamic models of the converters in a family and, in addition, physical insights into the converters can be readily identified. This has made the proposed modeling method valuable and viable
12. Chihchiang Hua, Jongrong Lin, Chihming Shen, "Implementation of a DSP-controlled photovoltaic system with peak power tracking," Trans. on Industrial Electronics, vol. 45, no. 1, pp. 99-107, Feb 1998. Full Text Link
Abstract : Photovoltaic systems normally use a maximum power point tracking (MPPT) technique to continuously deliver the highest possible power to the load when variations in the insulation and temperature occur. It overcomes the problem of mismatch between the solar arrays and the given load. A simple method of tracking the maximum power points (MPPs) and forcing the system to operate close to these points is presented. The principle of energy conservation is used to derive the large- and small-signal model and transfer function. By using the proposed model, the drawbacks of the state-space-averaging method can be overcome. The TI320C25 digital signal processor (DSP) was used to implement the proposed MPPT controller, which controls the DC/DC converter in the photovoltaic system. Simulations and experimental results show excellent performance
13. S.N. Vukosavic, M.R. Stojic, "Suppression of torsional oscillations in a high-performance speed servo drive," Trans. on Industrial Electronics, vol. 45, no. 1, pp. 108-117, Feb 1998. Full Text Link
Abstract : This paper deals with the problem of mechanical resonance in modern servo drive systems having the speed control loop bandwidth and resonance frequency above 100 Hz. To enable the extension of the range of stable gains in the presence of flexible coupling, a simple and straightforward modification of the speed loop controller is proposed in order to augment the performance of present speed controllers and to make them accordant with mechanical structure suffering from the compliance problem. This paper is comprised of the analytical considerations, straightforward design guidelines, and results of experimental verification obtained by an experimental setup with the elastically coupled 7-N m synchronous servo motor and mechanical resonance frequency of 160 Hz
14. T. Noguchi, K. Yamada, S. Kondo, I. Takahashi, "Initial rotor position estimation method of sensorless PM synchronous motor with no sensitivity to armature resistance," Trans. on Industrial Electronics, vol. 45, no. 1, pp. 118-125, Feb 1998. Full Text Link
Abstract : This paper proposes a new initial rotor position estimation method of a sensorless permanent magnet (PM) synchronous motor at starting condition, which has no sensitivity to the armature resistance. The method is based on saliency of the rotor and employs the alternating magnetic field which is excited by a current controller. The phase differences between the magnetizing current references and the voltage references make it possible to estimate the rotor direction accurately without motor parameters, except the ratio of direct axis and quadrature axis inductance. Also, the magnetic pole is evidently identified by detecting the voltage reference oscillation phenomena caused by magnetic saturation, which can be performed without motor parameters. The experimental result has proven that the estimation error was within -4.5 to +2.5 mechanical degrees, even though the armature resistance varied to 125% of the nominal value
15. V. Santibanez, R. Kelly, F. Reyes, "A new set-point controller with bounded torques for robot manipulators," Trans. on Industrial Electronics, vol. 45, no. 1, pp. 126-133, Feb 1998. Full Text Link
Abstract : In this paper, we propose a simple controller for set-point control of robot manipulators. The structure of this controller is composed by a saturated proportional-saturated derivative feedback plus gravity compensation. Such a control scheme has two practical features. First, for all desired joint positions, this controller delivers torques inside prescribed limits according to the actuator capability and second, the steady-state position errors owing to static friction can be arbitrarily reduced. In the case of absence of friction, we show global asymptotic stability of the closed-loop system. The performance of the proposed controller is illustrated via experiments on a two-degrees-of-freedom (2-DOF) direct-drive robot system
16. S. Mehta, J. Chiasson, "Nonlinear control of a series DC motor: theory and experiment," Trans. on Industrial Electronics, vol. 45, no. 1, pp. 134-141, Feb 1998. Full Text Link
Abstract : The control problem for a series DC motor is considered. Based on a nonlinear mathematical model of a series-connected DC motor, it is shown that the combination of a nonlinear transformation and state feedback (feedback linearization) reduces the nonlinear control design to a linear control design. To demonstrate its effectiveness, an experimental study of this controller is presented. These experimental results are also compared with a simulation of the closed-loop system. Finally, it is shown that a nonlinear observer (with linear error dynamics) for speed and load torque can be constructed based only on measurements of the motor current. Experimental results of this speed and load-torque estimator are also presented
17. H. Potlapalli, R.C. Luo, "Fractal-based classification of natural textures," Trans. on Industrial Electronics, vol. 45, no. 1, pp. 142-150, Feb 1998. Full Text Link
Abstract : Texture classification is an important first step in image segmentation and image recognition. The classification algorithm must be able to overcome distortions, such as scale, aspect and rotation changes in the input texture. In this paper, a new fractal model for texture classification is presented. The model is based on fractional Brownian motion (FBM). It is also shown that this model is invariant to changes in incident light; empirical results are also given. The isotropic nature of Brownian motion is particularly useful for outdoor applications, where the viewing direction may change. Classification results of this model are presented; comparisons with other texture measurement models indicate that the incremental FBM (IFBM) model has better performance for the samples tested
18. T.W.S. Chow, Yong Fang, "A recurrent neural-network-based real-time learning control strategy applying to nonlinear systems with unknown dynamics," Trans. on Industrial Electronics, vol. 45, no. 1, pp. 151-161, Feb 1998. Full Text Link
Abstract : In this paper, the authors present a real-time learning control scheme for unknown nonlinear dynamical systems using recurrent neural networks (RNNs). Two RNNs, based on the same network architecture, are utilized in the learning control system. One is used to approximate the nonlinear system, and the other is used to mimic the desired system response output. The learning rule is achieved by combining the two RNNs to form the neural network control system. A generalized real-time iterative learning algorithm is developed and used to train the RNNs. The algorithm is derived by means of two-dimensional (2-D) system theory that is different from the conventional algorithms that employ the steepest optimization to minimize a cost function. This paper shows that an RNN using the real-time iterative learning algorithm can approximate any trajectory tracking to a very high degree of accuracy. The proposed learning control scheme is applied to numerical problems, and simulation results are included. The results are very promising, and this paper suggests that the 2-D system theory-based RNN learning algorithm provides a new dimension in real-time neural control systems
19. Kit-Sang Tang, Kim-Fung Man, Zhi-Feng Liu, Sam Kwong, "Minimal fuzzy memberships and rules using hierarchical genetic algorithms," Trans. on Industrial Electronics, vol. 45, no. 1, pp. 162-169, Feb 1998. Full Text Link
Abstract : A new scheme to obtain optimal fuzzy subsets and rules is proposed. The method is derived from the use of genetic algorithms, where the genes of the chromosome are classified into two different types. These genes can be arranged in a hierarchical form, where one type of gene controls the other. The effectiveness of this genetic formulation enables the fuzzy subsets and rules to be optimally reduced and, yet, the system performance is well maintained. In this paper, the details of formulation of the genetic structure are given. The required procedures for coding the fuzzy membership function and rules into the chromosome are also described. To justify this approach to fuzzy logic design, the proposed scheme is applied to control a constant water pressure pumping system. The obtained results, as well as the associated final fuzzy subsets, are included in this paper. Because of its simplicity, the method could lead to a potentially low-cost fuzzy logic implementation
20. J. Teeter, Mo-Yuen Chow, "Application of functional link neural network to HVAC thermal dynamic system identification," Trans. on Industrial Electronics, vol. 45, no. 1, pp. 170-176, Feb 1998. Full Text Link
Abstract : Recent efforts to incorporate aspects of artificial intelligence into the design and operation of automatic control systems have focused attention on techniques such as fuzzy logic, artificial neural networks and expert systems. The use of computers for direct digital control highlights the recent trend toward more effective and efficient heating, ventilating and air-conditioning (HVAC) control methodologies. Researchers in the HVAC field have stressed the importance of self-learning in building control systems and have encouraged further studies in the integration of optimal control and other advanced techniques into the formulation of such systems. Artificial neural networks can also be used to emulate the plant dynamics, in order to estimate future plant outputs and obtain plant input/output sensitivity information for online neural control adaptation. This paper describes a functional link neural network approach to performing the HVAC thermal dynamic system identification. Methodologies to reduce inputs of the functional link network to reduce the complexity and speed up the training speed are presented. Analysis and comparison between the functional link network approach and the conventional network approach for the HVAC thermal modeling are also presented
21. Young Ahn Kwon, "Computation of optimal excitation of a switched reluctance motor using variable voltage," Trans. on Industrial Electronics, vol. 45, no. 1, pp. 177-180, Feb 1998. Full Text Link
Abstract : This paper investigates the optimal excitation of a switched reluctance motor, such that overall drive efficiency is maximized under a variable supply voltage. The result presented in the paper exhibits the improved drive efficiency and the expanded range of operating torque and speed. Furthermore, the variable supply voltage may be utilized in reducing torque ripple
22. Kuo-Kai Shyu, Hsin-Jang Shieh, Sheng-Shang Fu, "Model reference adaptive speed control for induction motor drive using neural networks," Trans. on Industrial Electronics, vol. 45, no. 1, pp. 180-182, Feb 1998. Full Text Link
Abstract : A model reference adaptive speed control scheme using neural networks is presented. The robust observer-based model reference tracking control technique is used to establish the training patterns. Then, the trained neural networks are used as an adaptive speed controller to robustly track a reference model for an induction motor drive
23. A. Yoneya, T. Kondo, Y. Hashimoto, Y. Togari, "Two-valued PID controller," Trans. on Industrial Electronics, vol. 45, no. 1, pp. 183-184, Feb 1998. Full Text Link
Abstract : A discrete-time proportional integral derivative (PID) controller, the manipulated variable of which takes two values, i.e., ON and OFF, is proposed and analyzed. Oversampling technology is employed in the controller design. As to the structure of the controller, a cascade type and a built-in type are proposed. An experimental example is presented
24. M.R. Matausek, D.M. Miljkovic, B.I. Jeftenic, "Nonlinear multi-input-multi-output neural network control of DC motor drive with field weakening," Trans. on Industrial Electronics, vol. 45, no. 1, pp. 185-187, Feb 1998. Full Text Link
Abstract : A new multi-input-multi-output nonlinear control system, based on a simple and straightforward modification of the internal model control, is proposed. The nonlinear modified internal model control structure is completely defined by the inverse process model and guarantees the offset-free control. A feedforward neural network (NN) inverse model with one hidden layer and a small number of hidden neurons is successfully applied in a real-time control of the nonlinear process considered
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