In this paper, we propose a call admission control scheme which can be used in real environment for the traffic cibtrik if a base station if DS-CDNA cellular systems. The proposed scheme estimates the mean and variance of other cell interference by using the values used for the closed loop power control. The reerse link capacity of the base station can be calculated by using the estimated mean and variance of other cell interference. The base station admits a call only if the number of users is less than the calculated reverse link capacity. In addition, we propose a simple method to obtain the equivalent number of voice call users per one data call user in multi-rate traffic environment. The method can be applied to call admission control in multi-rate traffic environment.

Personal Communication Networks will be composed of ATM-based broadband ISDN in the future. However, unlike the wired networks, many challenges will arise in the wireless communication service such as PCS. These callenges are frequency alteration of cell routing path, relatively very high error rate at transmission over the wireless interface, etc. Particularly, the alteration of cell routing path caused by handoff makes temporary deterioration of QoS. In this paper, the signaling flows of handoff scenarios which may occur on Personal Communication Networks are presented, and verified by Pertri-Net toolkit. In addition, the cell flow control scheme which minimizes the lagging gap between cells and maintains the cell sequence during handoff is proposed. The proposed scheme can be summarized as the differentiation of normal queue and handoff queue, and the cell flow control between these queues. For verification of the proposed scheme, we used two approaches, which are mathermatical manipulation and SLAM simulation.

The economical detection of dulal-tone multifrequency(DTMF) signals is an important factor when developing cost-effective telecommunication equipment. Each channel have independently a DTMF receiver, and it informs the detected signal to processors of the TDX. This paper proposes the linear prediction algorithm for the spectrum analysis. As a experimental resutls, it can obtain the improved performance to the DTMF receivers and reduce the real-time processing and memory waste.

On ATM-based wired/wireless integrated network, we apply the connection re-routing method[1] which reduced the inter-cluster handoff delay by reserving VPI/VCLs for possible inter-cluster handoff calls in advance. Additionally, we propose wired resource reservation methods, which are ausiliary method and split method, for handoff QoS guarantee of various expected services. The characteristics of these methods reserve wired connection resources based on the information on the possible inter-cluster handoff calls. With mathematical analysis, we also propose each algorithm and cost function for deciding an optimal amount in reserving resources. With numberical examples, we can see that the auxiliary method effectively reduces the cost in all cases(.alpha.>.betha., .alpha.=.betha., and .alpha.<.betha.). The split method has a little cost-reduction effects, when handoffs call does not have priority over new calls (that is, .alpha..leq..betha.) and the total capacity is relatively large. In other cases, the split method, however, has effective cost-reduction effects. The numerical resutls show that these reservation methods ca flexibly cope with the time-variant environment and meet the QoS requriements on the inter-cluster handoff calls.

In this paper, we consider methods of robust stabilization of the interval plant with a PID controller. Suppose that we know apriori a sign of the coefficients of the numerator of the PID controller. Under this condition, it sufficies to make eight polynomials stable for robust stabilization of the interval plant with a minimum phase PID controller. In addition, with a nonminimum phase PID controller, it suffices to make different eight polynomials stable. Especially, with the nonminimum phase PID controller it is shown that stabilization of eight plants is necessary and sufficient for robust stabilization of the interval plants.

Until now, considerable progress has been made in the application of range finding techanique performing direct 3-D measurement from the object. However, ther are few use of the method in the area of the application of material handing. We present a range finding vision system consisting of static and dynamic range finders to automate a reclaimer used for material handling. A static range finder detects range data of the front part of the piles of material, and a height map is obtained from the proposed image processing algorithm. The height map is used to calculate the optimal job path as features for required information for material handling function. A dynamic range finder attached on the side of the arm of the reclaimer detects the change of the local properties of the material with the handling function, which is used for avoiding collision and detecting the ending point for changing direction. the developed vision systm was applied to a 1/20 simulator and the results of test show that it is appropriate to use for automating the material handling.

This paper introduces a methodology of the precise control of a mobile/task robot using visual information captured bythe camera attached at the hand of the task robot. The major problem residing in the precise control of mobile/task robot is providing an accurate and stable base for the task robot through the precise control of mobile robot. On account of uncertainties on the surface, the precise control of mobile robot is not feasible without using external position sensor. In this paper, the methodology for the precise control of mobile robot is proposed, which recognizes the position of mobile robot using the camera attached at the hand of the task robot. While the task robot is approaching to an assembly part, the position of mobile robot is measured using the line correspondence between the image capturesd by the camera and the real assembly part, and using the kinematic transformation from the hand of the task robot to the mobile robot. To verify the solidness of this method, experimental data for the measurement of camera position/orientation and for the precise control of mobile robot using measurement are shown.

This paper describes a design of a Wavelet Adaptive Filter(WAF) for the removal of the baseline wandering and the minimization of the signal distortion using by wavelet transform and adaptive filter in the ECG signal. WAF consists of two parts. The first part is wavelet transform that decomposes the ECG signal into seven frequency bands using Vaidyanathan and Hoang wavelet. The second part is adaptive filter that uses the signal of seventh low frequency band among the wavelet transformed signals as primary input and a unit impulse sequence as reference input. For the evaluation of the performance of WAF, we used several baseline wandering elimination filters such as commerical standard filter with cutoff frequency of 0.5Hz and general adaptive filter. We made use of MIT/BIH database and real patient data for the evaluation. In conclusion, WAF showed a lower ST segement distortion than standard filter and adaptive filter and has a higher eliminated noise power than standard filter and adaptive filter.

To extract time-varying evoked potential (EP), segement latency corrected average method is presented. This method is composed of three steps. First, adaptive filtering for reducing the effect of artifacts and removing background noise is performed. Next, validated intervals of individual segments are aligned, and latency components are detected by cross-correlation between the previously obtained and measured EPs within the intervals. Finally, after the detected latency component, responses of segments are groupe and averaged, the shole corrected EP signal is obtained. In the experiments, the resutls of the conventional methods including simple averaging, Woody's method, and peak component latency corrected averaging are obtained, the results compared with the present method for evaluating performance. Therefore, the presented method confirms that it reflects the latency variations of fundamental peaks and gets the improved EP.

Given the small bit allocation for motion information in very low bit-rate coding, motion estimation using the block matching algorithm(BMA) fails to maintain an acceptable level of prediction errors. The reson is that the motion model, or spatial transformation, assumed in block matching cannot approximate the motion in the real world precisely with a small number of parameters. In order to overcome the drawback of the conventional block matching algorithm, several triangle-based methods which utilize triangular patches insead of blocks have been proposed. To estimate the motions of image sequences, these methods usually have been based on the combination of optical flow equation, affine transform, and iteration. But the compuataional cost of these methods is expensive. This paper presents a fast motion estimation algorithm using a multiple linear regression model to solve the defects of the BMA and the triange-based methods. After describing the basic 2-D triangle-based method, the details of the proposed multiple linear regression model are presented along with the motion estimation results from one standard video sequence, representative of MPEG-4 class A data. The simulationresuls show that in the proposed method, the average PSNR is improved about 1.24 dB in comparison with the BMA method, and the computational cost is reduced about 25% in comparison with the 2-D triangle-based method.

It is known as a difficult problem to recognize text-background mixed documents. In this paper a new string extraction algorithm, using mathematical morphology for the document consisting of text and overlapped periodic background pattern, is proposed. The algorithm consists of pattern periodicity feature extraction and background removal. The extracted pattern periodicity feature is used to determine the shape of structuring elements for morphological pre- and post-processing to remove background. The effectiveness of the proposed algorithm over the existing one is also verified through the experiments with various test documents.

Zerotreeimage coding is known as a simple and effective image comprssion algorithm. It has the property that the compression is generated in order of improtance. Conventionally, a fixed threshold is applied to the entire wavelet coefficients regardless of frequency and local features of an image. In this paper, we propose a new zerotree coding scheme with adaptive threshold. The adaptive threshold is determined by human visual characteristics. It is shown that the image quality of the proposed method is better than that of the conventional method.

This paper prsents a new method that automatically recognizes the dimension lines (consisting of shape lines, tail lines and extension lines) from the mechanical drawings. In the proposed method, the object and closed-loop symbols are separated from the character-free drawings. Then the object lines and interpretation lines are vectorized by using several techniques such as thinning, line-vectorization, and vector-clustering. Finally, after recognizing arrowheads by using pattern matching, we recognize dimension lines from interpretation lines by using arrohead's directional vector and centroid. By using the methods of geometric modeling and mathematical operation, the proposed method readility recognizes the dimension lines from complex drawings. Experimental resuls are presented, which are obtained by applying the proposed method to drawings drawn in compliance with the KS drafting standard.

This paper proposes systolic array architectures for compuataion of the 1-D and 2-D discrete wavelet transform (DWT). The proposed systolic array for compuataion of the 1-D DWT consists of L processing element (PE) arrays, where the PE array denotes the systolic array for computation of the one level DWT. The proposed PE array computes only the product terms that are required for further computation and the outputs of low and high frequency filters are computed in alternate clock cycles. Therefore, the proposed architecuter can compute the low and high frequency outputs using a single architecture. The proposed systolic array for computation of the 2-D DWT consists of two systolic array architectures for comutation of the 1-D DWT and memory unit. The required time and hardware cost of the proposed systolic arrays are comparable to those of the conventional architectures. However, the conventional architectures need extra processing units whereas the proposed architectures fo not. The proposed architectures can be applied to subband decomposition by simply changing the filter coefficients.

In this paepr, we propose an intelligent double talk detector that can enhance the performance of the acoustic echo cancellation system. The conventional double talk detection methods often misunderstand the echo path changes as double talk. Although there exist several detection methods that can distinguish the echo path changes from the double-talks, they show poor tracking performance because of the excessive decision delay for the discrimination and can only be used after the adaptive digital filter converges. A new and more effective ditetion algorithm has been proposed, where the detection mechanism is performed by observing the change rate of the reflection coefficients of the two lattice predictors that re placed on the near-end and far-end terminals. The excellence of the proposed method is verified by extensive computer simulations using real speech signals.

Switched relutance motor(SRM) has the advantages of simple structure, low rotor intertia, and high power rate per unit volume. However, SRM has the disadvantages of high current harmonics, and low power factor because of the discontinuous excitation of pulse type. The harmonics brings about the distortion and loss of power system, and brings about the incorrect opertion of electronic system. This paper investigates the SRM drive system with the reduced harmonics and improved power factor. The system consists of the switching power converter with poewr factor correction(SPC-PFC), DC/DC converter and 3-phase inverter. The performances in the proposed system are verified through the simpuation and experiment.