• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.777-780
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• 2003

We have tried to create a vision system like human eye for a long time. We have obtained some distinguished results through many studies. Stereo vision is the most similar to human eye among those. This is the process of recreating 3-D spatial information from a pair of 2-D images. In this paper, we have designed a stereo matching algorithm based on systolic array architecture using edges and pixel data. This is more advanced vision system that improves some problems of previous stereo vision systems. This decreases noise and improves matching rate using edges and pixel data and also improves processing speed using high integration one chip FPGA and compact modules. We can apply this to robot vision and automatic control vehicles and artificial satellites.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.816-820
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• 2011

A method for increasing the difference of side-lobe level in spherical microphone array is presented. In array signal processing, it is known that narrow interval between sensors can increase the difference between main lobe and side-lobe of array response which eventually increase the source recognition capability. Recent commercial array being used, however, have shown certain limitation in using the number of sensors due to its costs and geometrical size of array. To overcome this problem, we have adapted MEMS sensors into spherical microphone array. To check out the improvement, two different types of spherical microphone array were designed. One array is composed with 32 regular instrument microphones and the other one is 85 MEMS sensors. Simulation and experiments were conducted on a sinusoidal noise source with two arrays. The time history data were analyzed with spherical harmonic decomposition and beamforming technique. 85 MEMS sensors array showed the improved side-lobe level suppression by more than 4 dB above the frequency content of 2 kHz compared to 32-sensor array.

• Journal of the Korea Convergence Society
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• v.8 no.1
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• pp.1-6
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• 2017

In this paper, we propose a new method for a correlative phase comparison direction finding(DF) which detects the arrival direction of radio waves by data fusing the calculated phase difference and the measured phase difference between the antennas when the radio waves are incident on the circular array antenna composed of 7 antennas respectively. The correlation type phase comparison method uses a uniform circular array(UCA) and a linear array method. The phase difference data calculated formally and the phase difference data measured in the test environment are fused with a correlation function, therefore, it is superior to the currently used phase comparison direction detection method. When the signal-to-noise ratio (SNR) of the received signal is 20dB and the inter-antenna distance to the wavelength of the received signal($L/{\lambda}$) is 0.5, the accuracy of the correlative DF is $1.7^{\circ}$ while measurement phase comparison's is larger than $2.5^{\circ}$, It can be used for electromagnetic signal monitoring and military direction detection.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.4
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• pp.34-41
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• 1999

Unlike the traditional radar system, Synthetic Aperture Radar(SAR) system is capable of imaging a target scene to ceertain degree of cross-range resolution. And this resolution is mainly depends on the size of aperture synthesized. Thus, a good system model and inversion scheme should be developed to actually give effect of synthesizing aperture size, which in turn gives better cross range resolution of reconstructed target scene. Among several inversion schemes for SAR imaging, we used an inversion scheme called wavefront reconstruction which has no approximation in wave propagation analysis, and tried to verify whether the collected data with synthesized aperture actually give the same support as that with physical aperture in the same size. To do this, we performed a signal subspace comparison of two imaging models with physical and synthesized arrays, respectively. Theoretical comparisons and numerical analysis using Gram-Schmidt procedures have been performed. The results showed that the synthesized array data fully span the physical array data with the same system geometry. This result strongly supports the previously proposed inversion scheme valuable in high resolution radar imaging.

• ETRI Journal
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• v.40 no.1
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• pp.111-121
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• 2018

To find the emerging patterns (EPs) in streaming transaction data, the streaming is first divided into some time windows containing a number of transactions. Itemsets are generated from transactions in each window, and then the emergence of itemsets is evaluated between two windows. In the tilted-time windows model (TTWM), it is assumed that people need support data with finer accuracy from the most recent windows, while accepting coarser accuracy from older windows. Therefore, a limited array's elements are used to maintain all support data in a way that condenses old windows by merging them inside one element. The capacity of elements that accommodates the windows inside is modeled using a particular number sequence. However, in a stream, as new data arrives, the current array updating mechanisms lead to many null elements in the array and cause data incompleteness and inaccuracy problems. Two models derived from TTWM, logarithmic TTWM and Fibonacci windows model, also inherit the same problems. This article proposes a novel push-front Fibonacci windows model as a solution, and experiments are conducted to demonstrate its superiority in finding more EPs compared to other models.

• Transactions of Materials Processing
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• v.7 no.2
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• pp.127-138
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• 1998

Process design of multi-step wire drawing process, conducted by means of finite element analysis and ANN(Artificial Neural Network) has been considered. The investigated problem involves the ade-quate selection of the drawing die angle and the correspondent reduction rate in the condition of desired initial and final diameter. Combinations of the process parameters which are used in finite ele-ment simulation are selected by using the orthogonal array. Also the orthogonal array. Also the orthogonal array and the results of finite element simulation which are related to the process energy are used as train data of ANN. In this study it is shown that the application of new technique using ANN and Othogonal array table to the process design of metal forming process is useful method.

• The Journal of Information Technology
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• v.10 no.3
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• pp.33-45
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• 2007

Systolic Array Processor is used for designing the special purpose processor in Digital Signal Processing, Computer Graphics, Neural Network Applications etc., since it has the characteristic of parallelism, pipeline processing and architecture of regularity. But, in case of using general design method, it has intial waiting period as large as No. of PE-1. And if the connected system needs parallel and simultaneous outputs, processor has some problems of the performance, since it generates only one output at each clock in output state. So in this paper, one dimensional Systolic Array Processor that is designed according to the dependance of data and operations using the partitioned sub-matrix is proposed for the purpose of improving the performance. 1-D Systolic Array using 4 partitioned sub-matrix has efficient method in case of considering those two problems.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.11
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• pp.1880-1885
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• 1989

In this paper, a new approach for systolic array realizing the discrete cosine transform (DCT) based on discrete Fourier transform (DFT) of an input sequence is presented. The proposed array is based on a simple modified DFT(MDFT) version of the Goertzel algorithm combined with Kung's approach and is proved perfectly. This array requires N cells, one multiplier and takes N clock cycles to produce a complete N-point DCT and also is able to process a continuous stream of data sequences. We have analyzed the output signal-to-noise ratio(SNR) and designed the circuit level layout of one-PE chip. The array coefficients are static adn thus stored-product ROM's can be used in place of multipliers to limit cost as eliminate errors due to coefficients quantization.

• 한국데이터정보과학회:학술대회논문집
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• 2003.05a
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• pp.65-75
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• 2003

In the Taguchi parameter design, the product array approach using orthogonal arrays is mainly used. However, it often requires an excessive number of experiments. An alternative approach, which is called the combined array approach, was suggested by Welch et. al. (1990) and studied by others. In these studies, only single response variable was considered. We propose how to simultaneously optimize multiple responses when we use the combined array approach.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.8
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• pp.1178-1186
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• 1989

In this paper, a systolic array for polyadic-nonserial DP problems is designed, the performance is analyzed and the efficient operating method is proposed. The algorithm is transformed to remove the broadcasting and global communication paths in the data dependence step by step. The transformed algorithm is mapping to the systolic array using the method proposed by D. I. Moldovan. The designed array is homogenous, had the processing elements of (n+1)/2 and 2n computation time ( n is the size of problem). In case of being many problems to process, the efficiency of array can be upward by inputing the problems successively. The interval between the initiations of two successive proboem instances is [n/2]+1 and the speed-up is about 4. The processor utilizations of each case are calculated.