• ETRI Journal
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• v.39 no.3
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• pp.301-309
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• 2017

In this paper, we propose a parallelization method for a High Efficiency Video Coding (HEVC) deblocking filter with transform unit (TU) split information. HEVC employs a deblocking filter to boost perceptual quality and coding efficiency. The deblocking filter was designed for data-level parallelism. In this paper, we demonstrate a method of distributing equal workloads to all cores or threads by anticipating the deblocking filter complexity based on the coding unit depth and TU split information. We determined that the average time saving of our proposed deblocking filter parallelization method has a speed-up factor that is 2% better than that of the uniformly distributed parallel deblocking filter, and 6% better than that of coding tree unit row distribution parallelism. In addition, we determined that the speed-up factor of our proposed deblocking filter parallelization method, in terms of percentage run-time, is up to 3.1 compared to the run-time of the HEVC test model 12.0 deblocking filter with a sequential implementation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.10a
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• pp.446-449
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• 2001

A LLU system is developed for efficient use of existing local loop. By this system, new entrant ran use the local loop indifferently comparing with incumbent telecommunications operator. To implement the LLU, bottom-up typed LRIC model by network redesigning was accepted for costing system in Korea. In this paper, local loop redesigning methodology is presented to build a bottom-up typed LRIC model.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.10
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• pp.130-138
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• 2002

This paper presents the modeling and analysis of dynamic characteristics of hydraulic snubber in electric power plant. The nonlinear state-space model of 14th order to describe the dynamics of the snubber was established by Simulink. The simulation results show that the hydraulic snubber reacts as like the conventional shock absorbers against the high pulse shock load. The snubber also shows the peculiar characteristics to the small step load, which temporarily lock the control valves up, however maintain same steady-state pressures of all internal chambers in the long run. Two case studies for the analysis of the snubber were addressed. Practical pulse testing method was also proposed to identify the frequency response characteristics of the snubber.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3B
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• pp.345-354
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• 2008

In this present study, we made a first attempt to investigate physical transformations of incident waves in surf and swash zone and hydrodynamic phenomena of detached and submerged breakwaters. For an accurate simulation of the complicated wave deformation, Three-Dimensional numerical model with Large Eddy Simulation has been developed recently and expanded properly for the current applications, which is able to simulate an accurate and direct WAve Structure Sandy seabed interaction (hereafter, LES-WASS-3D). LES-WASS-3D has been validated through the comparison with experimental results for limited cases, and has been used for the simulation of wave run-up on sandy beach, mean fluid flows over and around submerged structures and swash zone (alongshore/rip current), and spatial distribution of wave height in wide fluid regions. In addition, a strategy of efficient deployment ($Y/L_i=1.50{\sim}1.75$, $W/L_r=0.50$) of the submerged breakwaters has been discussed.

• International Area Studies Review
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• v.15 no.3
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• pp.215-237
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• 2011

The paper is basically designed to reveal substitutability or complementary nature of export and import among Korea, China, and Japan by employing unit root test, cointegration technique, and vector error correction model(VECM). Empirical evidences are shown that the trading among these countries has been dominated by a complementary nature in the short run which enables it to promote trading in those countries. In the long run, however, the substitutability nature effects strongly to the trading among Korea, China, and Japan. To this end, it could be tentatively concluded that market-oriented trading policies are more effective to stimulate the export and import in those countries in the short run, while a trading policy has to be selectively implemented by the substitutability nature in the long run basis. For instance, a stability policy for exchange rates and various commercial policies could be set for a short term target. Whereas, the substitutability nature should be counted in building up a new industrial structure or in implementing FTA agreement among Korea, China, and Japan.

• Journal of Power Electronics
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• v.12 no.6
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• pp.982-991
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• 2012

In this study, a new method has been presented for the detection of broken rotor bar (BRB) faults in inverter driven induction motors controlled via Field Oriented Control (FOC). To this end, a FOC controlled induction motor with a BRB fault was modeled using the Matlab/Simulink program. Experiments were carried out using the prepared simulation model at various loads and operating speeds. The motor current and speeds were monitored for healthy, 1, 2 and 3 BRB faults. The Resampling Based Order Tracking Analysis (RB-OTA) method was applied to the monitored signals. The obtained results were compared by using the classic Fast Fourier Transform (FFT) method. When the obtained results were analyzed via the FFT method no information regarding any faults was determined in the run up or run down regions of the motor and the presented method gave very good results. The reliability of the proposed method was validated with experimental results. The main innovative part of this study is that the RB-OTA method was implemented on the induction motor current signal for detecting BRB faults.

• Journal of Information Technology Applications and Management
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• v.21 no.4_spc
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• pp.485-499
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• 2014

Sharing Economy is the modern main item with ICT Development. Of course sharing economic item is the old and long run mainstream, but by the ICT technological development sharing economy is the fostering and affluent factors in the world economic growth. Though, in Korea, till now sharing economy is minimal, that will growth sharply. We can track various business models of sharing economy. Sharing economy is to buy use right not ownership. With the sharing economic business model wee can make also financial sharing model. In finance model we can divide two kind models. First, we can trace small size lending model with p2p type. And second, we can make financial information transaction model. But till now sharing economic system is not activated, because of many reasons. To activate, first we have to set law and various standards, and also government actively support many sharing economy firms and institutions. To catch up developed countries in the field of sharing economy we have to make aggressive and flexible rules and standards.

• Journal of the Earthquake Engineering Society of Korea
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• v.7 no.1
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• pp.41-55
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• 2003

A dynamically-interfaced multi-grid finite difference model for simulation of tsunamis in the East Sea(Choi et al.) was established and further applied to produce detailed feature of coastal inundations along the whole eastern coast of Korea. The computational domain is composed of several sub-regions with different grid sizes connected in parallel of inclined directions with 16 innermost nested models. The innermost sub-region represents the coastal alignment reasonably well and has a grid size of about 30 meters. Numerical simulations have been performed in the framework of shallow-water equations(linear, as well as nonlinear) over the plane or spherical coordinate system, depending on the dimensions of the sub-region. Results of simulations show the general agreements with the observed data of run-up height for both tsunamis. The evolution of the distribution function of tsunami heights is studied numerically and it is shown that it tends to the log-normal curve for long distance from the source.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.336-340
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• 2014

The noise and vibration have been evaluated by using the finite element model in the vehicle developing stage. The sound pressure of the vehicle compartment is predicted by the acoustic cavity model coupled with the body structure. In general, the structural model has been focused to study in the improvement of the noise. It is not easy to treat the structural model, instead the acoustic cavity model is relatively simple and aids in root cause analysis of vibro-acoustic issues. Therefore, the acoustic transfer function of the cavity is more efficient for finding out the main contribution parts of the vehicle booming noise. And examples about the run-up booming noise demonstrate the validity of the AFT analysis for improving the vibro-acoustic sensitivity.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.735-739
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• 2002

경제적 비용을 토대로 한 접속료 산정방식을 적용한다는 취지하에 주요 통신선진국에서는 장기증분비용 (LRIC ; Long Run Incremental Costs)모형에 대한 연구가 활발히 진행중에 있다. 이러한 LRIC 모형에는 미국의 HAI 모형, BCPM 모형, 일본 우정성 모형 둥의 공학적인 방법에 의한 LRIC 모형과 영국의 Top-Down 모형과 같이 회계적 자료를 바탕으로 한 LRIC 모형으로 구분될 수 있다. 이에 본고는 현재 세계적으로 선호되고 있는 Bottom-up 방식의 LRIC모형을 구축하기 위한 선진외국의 가입자망 재설계 방법을 살펴보았다.