• Journal of the Society of Naval Architects of Korea
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• v.30 no.1
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• pp.87-93
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• 1993

The motion response of a ship moored in a rectangular harbor excited by long waves has been studied theoretically and experimentally. Experiments are performed in a shallow basin. A ship model is set moored by soft springs at various positions in a model harbor subjected to regular waves with period ranging from 2 to 3 seconds. Wave and ship responses are measured and compared with theory. It is found that theoretical results agree qualitatively with experimental results. The main source of quantitative discrepancies is presumably due to real fluid effects such as separation at the harbor entrance and friction on harbor boundaries.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.4
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• pp.270-274
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• 2019

In this paper, we analyze a planar electromagnetic absorber by using the mode matching technique(MMT). The proposed electromagnetic absorber has a periodic structure composed of a perfect conductor and ferrite, and the transmitted and reflected powers in response to the incident wave with parallel polarization are calculated according to the thickness of the plate. The proposed absorber shows a high absorption compared to the cases of periodic slits with vacuum or the ferrite plate itself. The solution to the reflected and transmitted powers by MMT is also verified with the results from a commercial simulator.

• Journal of the Korea Computer Industry Society
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• v.4 no.10
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• pp.731-740
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• 2003

Since motion estimation remove the redundant data to employ the temporal correlations between adjacent frames in a video sequence, it plays an important role in digital video coding. And in the block matching algorithm, search patterns of different shapes or sizes and the distribution of motion vectors have a large impact on both the searching speed and the image quality. In this paper, we propose a new fast block matching algorithm using the small-cross search pattern and the block-based gradient descent search pattern. Our algorithm first finds the motion vectors that are close to the center of search window using the small-cross search pattern, and then quickly finds the other motion vectors that are not close to the center of search window using the block-based gradient descent search pattern. Through experiments, compared with the block-based gradient descent search algorithm(BBGDS), the proposed search algorithm improves as high as 26-40% in terms of average number of search point per motion vector estimation.

• Journal of the Korea Society of Computer and Information
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• v.3 no.2
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• pp.119-124
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• 1998

Block Matching Motion Estimation(BMME) Algorithm is demands a very large amount of computing power and have been proposed many fast algorithms. These algorithms are many problem that larger size of VLSI scale due to non-localized search block data and problem of non-reuse of input data for each processing step. In this paper, we designed systolic arry of high processing capacity, constraints input output pin size and reuse of input data for small VLSI size. The proposed systolic array is optimized memory access time because of iterative reuse of input data on search block and become independent of problem size due to increase of algorithm's parallelism and total processing elements connection is localized spatial and temporal. The designed systolic array is reduced O(N6) time complexity to O(N3) on moving vector and has O(N) input/output pin size.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.9
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• pp.179-185
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• 2013

In this paper, the RTA-ERP(Response Time Aligned-Evoked Relative Potential) was modelled to analyze the effect of motor activation pattern in response to visual sensory stimuli. Simon effect was analysed using the amplitude response of RTA-ERP and measured response time. The 'odd number' experiments, which identify an odd number mixed with same numbers, was performed with 15 healthy adult participants(9 males and 6 females, whose mean age of 31) for 7 minutes for each participant. Throughout experimentation, we observed that the proposed RTA-ERP can compensate the timing variation due to different neural processing procedures in the brain, and shows enhanced LRP(Lateralized Readiness Potential) and Pe(Error Related Positivity). Regarding to 'congruence' and 'incongruence' testing patterns, the amplitude of RTA-ERP and the response time for the 'congruence' are $0.03{\mu}V$ larger, and 43 ms faster than those for the 'incongruence', respectively. The amplitude characteristics of RTA-ERP, obtained by synchronizing the onset times with respect to response time, corresponds more likely to that of P300 in the ERP pattern (the characteristics of the Simon effect).

• Journal of the Korea Computer Industry Society
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• v.10 no.5
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• pp.227-234
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• 2009

The Paper introduces a new technique for block matching motion estimation. since the temporal correlation of a animation sequence between the motion vector of current block and the motion vector of previous block. In this paper, we propose the scene change detection algorithm for block matching using the temporal correlation of the animation sequence and the center-biased property of motion vectors. The proposed algorithm determines the location of a better starting point for the search of an exact motion vector using the point of the smallest SAD(sum of absolute difference) value by the predicted motion vector from the same block of the previous frame and the predictor candidate point on each search region. Simulation results show that the PSNR values are improved as high as 9~32% in terms of average number of search point per motion vector estimation and improved about 0.06~0.21dB on an average except the FS(full search) algorithm.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.49 no.2
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• pp.69-75
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• 2012

This paper presents a novel de-interlacing algorithm that can make up motion compensation errors by using maximum a posteriori (MAP) estimator. First, a proper registration is performed between a current field and its adjacent fields, and the progressive frame corresponding to the current field is found via MAP estimator based on the computed registration information. Here, in order to obtain a stable solution, well-known bilateral total variation (BTV)-based regularization is employed. Next, so-called feathering artifacts are detected on a block basis effectively. So, edge-directional interpolation is applied to the pixels where feathering artifact may happen, instead of the above-mentioned temporal de-interlacing. Experimental results show that the PSNR of the proposed algorithm is on average 4dB higher than that of previous studies and provides the better subjective quality than the previous works.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.8
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• pp.24-32
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• 2000

In this paper, we have designed and fabricated a new type power divider to be efficient to a size and electrical performance by folding each quarter-wavelength 70.7 Ω section into a tightly-coupled "meander-line" and inserting a slit. In this type, because of coupling, the electrical phase of quarter -wavelength line and the performance change. For this reason, with the inductive slit and the tuning of quarter-wavelength line length, we have compensated for those. The inductance value of the inserted slit is decided by its width and depth, therefore, we could improve the electrical performance through optimization of inductance. Input and output return losses of the designed power divider were -34.2 dB, -34.3 dB respectively, and isolation was -36.7 dB at 1.75 GHz. Besides, a new design approach reduced occupied substrate area by 3:1 approximately.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.3
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• pp.22-28
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• 2008

It proposes the novel design conditions to maximize the power coupling of active directional couplers with mismatched access guides. To verify the validity and accuracy of the conditions proposed, a new coupling efficiency is defined and it depends on the reflection coefficients occurred at the discontinuous input/output interfaces. The numerical results reveal that the phase-matched condition and the minimum-gap condition for those couplers are no longer suitable to optimize the design parameters and a new criterion is needed.

• Management & Information Systems Review
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• v.37 no.2
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• pp.259-281
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• 2018

Advocates of mandatory IFRS adoption claim that IFRS increase financial statement comparability, which in turn leads to greater cross-border investment(Securities and Exchange Commision, 2008). The notion is that improved financial statement comparability reduces the information acquisition costs of global investors and thereby increase their investment in foreign firms. The purpose of this study is to examine this assertion by examining whether the K-IFRS adoption rusults in improved comparability that leads to increased investment by foreign investment. We also examined whether the relation between comparability and foreign investment has strengthen after adoption of K-IFRS. To achieve the purpose of our study, we measure Korean firms comparability using stock price model, stock return model and cash flow from operation model by Barth et al.(2012). We use both foreign ownership in the end of year and average during the year for dependent variables were to reduce bias. We test our hypothesis using 1,817 firm-year observation of KOSPI firms during the period of our analysis, 2011-2015. Consistent with our hypothesis, we find K-IFRS adoption results in a greater increase in foreign investment in firms with high comparability firms. This result indicate that the adoption of K-IFRS intends to achieve the international accounting convergence as stated in the roadmap and to reduce the Korea Discount.