사실적인 유동 재현을 위한 계층적 미분 모델

송오영,김도엽,고형석 (사)한국컴퓨터그래픽스학회 2006 컴퓨터그래픽스학회논문지 Vol.12 No.3

이 논문은 비물리적인 속도 감쇄현상을 감소시키는 새로운 유체 시뮬레이션 방법을 제시한다. 제시된 방법은 물리량뿐만 아니라 물리량의 미분정보도 함께 이용하기 때문에 보다 정확한 물리현상을 반영할 수 있다. 나비어-스톡스 방정식을 푸는 일반적인 시뮬레이터는 수치소산의 대부분은 대류항을 풀 때 발생한다. 따라서, 우리는 소산현상을 효과적으로 막는 CIP 대류방법을 이용하여, 옥트리 기반의 유체 시뮬레이터를 개발하였다. 우리는 실험을 통해, 제안된 방법이 높은 레이놀즈수를 갖는 유체의 상세한 움직임 (예를 들어, 작은 물방울/공기방울, 얇은 수막, 작은 소용돌이 등)을 효과적으로 모사함을 보인다.

공유기억장치 멀티프로세서에서의 고장시뮬레이션 알고리듬에 관한 연구 ( A Fault Simulation Algorithm in A Shared Memory Multiprocessor )

송오영 대한전자공학회 1997 대한전자공학회 학술대회 Vol.1997 No.01

고장시뮬레이션의 병렬화 알고리듬에 관한 연구

송오영 한국통신학회 1996 韓國通信學會論文誌 Vol.21 No.11

As design of very large circuits is made possible by rapid development of VLSI technologies, efficient fault simulation is needed. Ingeneral, fault simulation requires many computer resources. As general-purpose multiprocessors become more common and affordable, these seem to be an attractive and effective alternative for fault simulation. Efficient fault simulation of synchronous sequential circuits has been reported to be attainably by using a linear iterative array model for such a circuit, and combining parallel fault simulation with russogate fault simulation. Such fault simulation algorithm is parallelized on a general-purpose multiprocessor with shard memory for acceleration of fault simulation. Through the experimenal study, the effect of the number of processors on speed-up of simulation, processor utilization, and the effect of multiprocessor hardware on simulation performance are studied. Some results for experiments with benchmark circuits are shown.

복잡한 영상으로 부터의 선형 특징 추출

송오영,석민수 대한전자공학회 1983 전자공학회지 Vol.20 No.1

직선 및 곡선과 같은 선형 특징은 영상 처리에 있어 중요한 특징중의 하나이다. 본 논문에서는 의미있는 선형 특징의 새로운 기법이 제안된다. 이 기법은 그래프 이론의 미니멀 스패닝 트리를 이용하여 경계점들을 연결하고 그 다음, 헤어(의미없는 잔가지)와 불합리한 선분을 제거한다. 이와 같이 추적된 선형 특징을 근사화 묘사하기 위하여 부분 선형 근사화를 수행한다. 본 논문에서 제안된 기법으로 실험을 수행하여 그 결과를 보여 주었다. Linear feature such as lines and curves are one of important features in image processing. In this paper, new method of linear feature detection is suggested. Also, we have studied approximation technique which transforms detected linear feature into data structure for the practical. This method is based on graph theory and principle of this method is based on minimal spanning tree concept which is widely used in edge linking process. By postprocessing, Hairs and inconsistent line segments are removed. To approximate and describe traced linear feature, piecewise linear approximation is adapted. The algorithm is demonstrated through computer simulations.

고장시뮬레이션의 가속화를 위한 기술동향

송오영 대한전자공학회 1995 전자공학회지 Vol.22 No.12

A Physics-Based Modelling of Multiphase Fluid Phenomena

송오영,신현철,고형석,Song, Oh-Young,Shin, Hyun-Cheol,Ko, Hyeong-Seok Korea Computer Graphics Society 2004 컴퓨터그래픽스학회논문지 Vol.10 No.4

This paper presents a physically based technique for simulating complex multiphase fluids. This work is motivated by the "stable fluids" method developed by Stam to handle gaseous fluids. We extend this technique to water, which calls for the development of methods for modeling multiphase fluids and suppressing dissipation. We construct a multiphase fluid formulation by combining the Navier-Stokes equations with the level set method. By adopting constrained interpolation profile (CIP)-based advection, we reduce the numerical dissipation and diffusion significantly. We further reduce the dissipation by converting potential1y dissipative cel1s into droplets or bubbles that undergo Lagrangian motion. Due to the multiphase formulation, the proposed method properly simulates the interaction of water with surrounding air, instead of simulating water in a void space. Moreover, the introduction of the non-dissipative technique means that, in contrast to previous methods, the simulated water does not unnecessarily lose mass and its motion is not damped to an unphysical extent. Experiments showed that the proposed method is stable and runs fast. It is demonstrated that two-dimensional simulation runs in real-time.

A Physics-Based Modelling of Multipbase Fluid Phenomena

송오영,신현철,고형석,Song, Oh-Young,Shin, Hyun-Cheol,Ko, Hyeong-Seok Korea Computer Graphics Society 2004 컴퓨터그래픽스학회논문지 Vol.10 No.3

This paper presents a physically based technique for simulating complex multiphase fluids. This work is motivated by the "stable fluids" method developed by Stam to handle gaseous fluids. We extend this technique to water, which calls for the development of methods for modeling multiphase fluids and suppressing dissipation. We construct a multiphase fluid formulation by combining the Navier-Stokes equations with the level set method. By adopting constrained interpolation profile (CIP)-based advection, we reduce the numerical dissipation and diffusion significantly. We further reduce the dissipation by converting potentially dissipative cells into droplets or bubbles that undergo Lagrangian motion. Due to the multiphase formulation, the proposed method properly simulates the interaction of water with surrounding air, instead of simulating water in a void space. Moreover. the introduction of the non-dissipative technique means that, in contrast 10 previous methods, the simulated water does not unnecessarily lose mass and its motion is not damped to an unphysical extent. Experiments showed that the proposed method is stable and runs fast. It is demonstrated that two-dimensional simulation runs in real-time.

Efcient Transmission Algorithm in Smart Power Strips for Advanced Metering Infrastructure

송오영 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.6

This paper proposes an efcient transmission algorithm that reduces trafc load for advanced metering in wireless transmissions between smart power strips and a corresponding gateway in wireless personal area networks. The aim of this paper is to reduce the transmission data as much as possible and increase quality of service in the smart grid network. In the proposed algorithm, the smart power strip continues transmitting the average of accumulated electrical power values measured during proper periods of time to the gateway only if the sum of the diference between the last transmitted power and each power value that was measured since the last transmission during the intervals exceeds a given value, called the transmission threshold. The results gleaned through experiments show that the proposed algorithm efciently reduce trafc load even if watt-hours calculated in the smart power strips are the same as the watt-hours in the gateway.

Compact Design of the Advanced Encryption Standard Algorithm for IEEE 802.15.4 Devices

송오영,김지호 대한전기학회 2011 Journal of Electrical Engineering & Technology Vol.6 No.3

For low-power sensor networks, a compact design of advanced encryption standard (AES)algorithm is needed. A very small AES core for ZigBee devices that accelerates computation in AES algorithms is proposed in this paper. The proposed AES core requires only one S-Box, which plays a major role in the optimization. It consumes less power than other block-wide and folded architectures because it uses fewer logic gates. The results show that the proposed design significantly decreases power dissipation; however, the resulting increased clock cycles for 128-bit block data processing are reasonable for IEEE 802.15.4 standard throughputs.

RC 배선에 의한 커패시턴스의 모델링에 관한 새로운 방법

송오영 중앙대학교 기술과학연구소 1996 기술과학연구소 논문집 Vol.26 No.-

최근의 선폭의 감소와 스윗칭 속도의 고속화로 인하여, chip상의 금속 배선(metal interconnect)의 저항이 논리게티트들의 타이밍에 많은 영향을 주고 있다. 논리게이트의 스윗칭 속도는 빨라지고 배선의 지연시간은 선폭의 scaling-down으로 인하여 점점 커지고 있다. 이런 이유로 RC 배선에 의한 지연시간에 대한 영향이 게이트에 의한 것보다 점점 커지고 있다. 본 논문에서는 RC 배선의 등가적인 부하 커패시턴스(effective load capacitance)를 계산하는 방법을 제안한다. 또한 이를 이용하여 게이트와 배선에 의한 지연시간을 계산하는 통합적인 방법을 제시한다. With finer line widths and faster switching speeds, the resistance of on-chip metal interconnect is having a dominant impact on the timing behavior of logic gates. The gates are switching faster and the interconnect delays are getting longer due to scaling-down. Due to the reasons, RC interconnect delay is getting more dominant than gate delay. In this paper, we propose a method for calculating the "effective load capacitance" of an RC interconnect. In addition, we develop a method for integrating the gate and the interconnect delay.