• Journal of the Korean housing association
• /
• v.19 no.4
• /
• pp.21-29
• /
• 2008

The purpose of this study is to evaluate preferences for spatial composition by urban design guidelines of detached housing areas using CG simulation, with the aim of contributing to the improvement and management of residential townscapes. The list of urban design guidelines for detached housing areas was derived from an analysis of urban design guidelines and landscape regulations from the U.S.A, Japan, and Korea. These guidelines comprise building guidelines, landscape guidelines, street guidelines, and sign guidelines. Through the preferences revealed by CG simulation, an optimum presentation method for the urban design guidelines was determined. Based on the results of preferences, an appropriate management system and regulation standards were proposed. In conclusion, the efforts carried out on the study and legislation of a management system and regulation standards for the urban design guideline will accomplish the amenity of residential environments.

• Journal of the Korea Computer Graphics Society
• /
• v.21 no.5
• /
• pp.21-27
• /
• 2015

In this paper, we presents visual effect(water, fire, smoke) simulation and interaction system for TV virtual studio. TV virtual studio seamlessly synthesizes CG background and a live performer standing on a TV green studio. Previous virtual studios focus on the registration of CG background and a performer in real world. In contrast to the previous systems, we can afford to make new types of TV scenes more easily by simulating interactive visual effects according to a performer. This requires the extraction of the performer motion to be transformed 3D vector field and simulate fluids by applying the vector field to Navier Stokes equation. To add realism to water VFX simulation and interaction, we also simulate the dynamic behavior of splashing fluids on the water surface. To provide real-time recording of TV programs, real-time VFX simulation and interaction is presented through a GPU programming. Experimental results show this system can be used practically for realizing water, fire, smoke VFX simulation and the dynamic behavior simulation of fish flocks inside ocean.

• The Journal of the Korea Contents Association
• /
• v.10 no.9
• /
• pp.18-25
• /
• 2010

Computer Graphics(CG) are very important in the movie industries. Recently, many domestic CG Companies participate in a movie creation. However, most companies only use commercial tools, and do not concentrate on developing techniques. This is why they use the commercial tools in spite of its lack of functions. In this paper, we explain the importance of developing technical tools to complement the shortage of commercial tools through the previewer for fluid simulation. We present how we design and implement the previewer to specialize it for fluid simulation. Finally, we estimate our previewer's performance and discuss with result.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.48 no.1
• /
• pp.90-100
• /
• 2011

We present a parallel bi-conjugate gradient (Bi-CG) matrix solver for large scale Bio-FET simulations based on recent graphics processing units (GPUs) which can realize a large-scale parallel processing with very low cost. The proposed method is focused on solving the Poisson equation in a parallel way, which requires massive computational resources in not only semiconductor simulation, but also other various fields including computational fluid dynamics and heat transfer simulations. As a result, our solver is around 30 times faster than those with traditional methods based on single core CPU systems in solving the Possion equation in a 3D FDM (Finite Difference Method) scheme. The proposed method is implemented and tested based on NVIDIA's CUDA (Compute Unified Device Architecture) environment which enables general purpose parallel processing in GPUs. Unlike other similar GPU-based approaches which apply usually 32-bit single-precision floating point arithmetics, we use 64-bit double-precision operations for better convergence. Applications on the CUDA platform are rather easy to implement but very hard to get optimized performances. In this regard, we also discuss the optimization strategy of the proposed method.

• Proceedings of the Korean Information Science Society Conference
• /
• 1999.10c
• /
• pp.155-157
• /
• 1999

본 논문에서는 CC-NUMA 시스템인 고성능 멀티미디어 서버(MX Server)상에서 다중 스레드 프로세스의 CG(CPU Group) 바인딩 설계 및 구현 내용을 소개한다. 고성능 멀티미디어 서버의 컴퓨팅 서버용 운영체제인 COSMIX(cache COherent Shared Memory unIX)에서는 서버의 플랫폼에 알맞은 하드웨어 및 시스템 관련하여 CC-NUMA 시스템에 적합한 운영체제 기능을 설계하였다. 고성능 멀티미디어 서버에서는 데이터의 지역성을 고려하여 한 노드인 CG에 프로세스를 바인드 하는 기능이 있으나, 다중 스레드로 구성된 프로세스의 바인딩 기능은 없었다. Oracle8i와 같은 인터넷 DBMS에서는 하나의 프로세스내의 다중 스레드가 일정한 노드의 디스크를 점유하여 사용할 수 있으므로 이와 같은 다중 스레드의 프로세스를 해당 디스크가 있는 하나의 CG에 바인딩 하는 기능이 필요하다. 현재는 가용한 플랫폼이 없어서 MX Server 대신 PC 태스트베드인 CC-NUMA 시스템 시뮬레이션 환경에서 다중 스레드의 CG 바인딩 기능을 구현하고 그 시험을 완료하였다.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.50 no.12
• /
• pp.40-48
• /
• 2013

This paper presents multi-channel transimpedance amplifier(TIA) arrays in short-range LADAR systems for unmanned vehicles, by using a 0.18um CMOS technology. Two $4{\times}4$ channel TIA arrays including a voltage-mode INV-TIA and a current-mode CG-TIA are introduced. First, the INV-TIA consists of a inverter stage with a feedback resistor and a CML output buffer with virtual ground so as to achieve low noise, low power, easy current control for gain and impedance. Second, the CG-TIA utilizes a bias from on-chip bandgap reference and exploits a source-follower for high-frequency peaking, yielding 1.26 times smaller chip area per channel than INV-TIA. Post-layout simulations demonstrate that the INV-TIA achieves 57.5-dB${\Omega}$ transimpedance gain, 340-MHz bandwidth, 3.7-pA/sqrt(Hz) average noise current spectral density, and 2.84mW power dissipation, whereas the CG-TIA obtains 54.5-dB${\Omega}$ transimpedance gain, 360-MHz bandwidth, 9.17-pA/sqrt(Hz) average noise current spectral density, and 4.24mW power dissipation. Yet, the pulse simulations reveal that the CG-TIA array shows better output pulses in the range of 200-500-Mb/s operations.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.19 no.4
• /
• pp.1-5
• /
• 2011

The free-wing tilt-body aircraft is researched in the flight performance characteristics for center of gravity (CG) change. All of speed, body tilt angle and center of gravity change are simulated to determine the flight envelope by a non-linear 3-DOF mathematical model. In flight, this aircraft configuration changes by the tiltable empennage. Then, flight dynamics distinguishes from those of a conventional fixed-wing aircraft. Though flight performance and trimmability are studied by CG change, the flight model of free-wing tilt-body aircraft is to reduce the hidden risk and to achieve the successful flight test. It is analyzed the flight characteristics by CG change that distinguishes free-wing tilt-body aircraft from the conventional aircraft.

• Smart Media Journal
• /
• v.4 no.4
• /
• pp.120-129
• /
• 2015

Explosion effect on CG (Computer Graphic) a visual effect on which a higher degree of technological difficulty is required with a variety of effect elements such as Fire, Smoke, Flame, Dust, Debris, etc. integrated on it. As skills for CG software have been advanced, solutions loaded with functions of various fluid simulation have been developed. So more realistic special effects came to be available. However, in Korea, it depends just on CG program functions. Besides, enough R&D's concerned have not been followed up. Accordingly, this study is aimed at offering a production method that may effectively implement more realistic explosion effects under experimentations. To begin with, the study derives problems through a precedent study of the implementation of existing explosion effects. Then to solve them, experimental studies are performed depending on four solutions. There are accesses to the four solutions: first, Numerous Turbulent Flow, a method to allow an attribute of turbulent air in the stage of fluid simulation; second, Cache Retiming Solution produced in script; third, Multiple Volume Container based on cached data; and fourth, RGB Lighting Pipeline, a method to enhance the completion of the result from the stage of composition. Characteristics of effects applied in each stage and consecutive connections of them proved the effective implementation of more realistic explosion effects. This study may not only suppose the production method for efficient explosion effects differentiated from the previous ones but also be utilized as basic data for relevant researches.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.17 no.4
• /
• pp.1-7
• /
• 2003

This is basic study for analyzing the character of the evaluation according to the ways of exterior lighting through the image prediction experiment by computer simulation. The aim of this research is to verify the validity of physical quantity & subjective evaluation on the basis of Online experiment. The following carried out the experiment procedure by conditions of Online experiment, 1) to make a photo of Online experirrent, 2) to measure physical quantity of luminance, and 3) to do subjective evaluation in Online experiment by means of vocabulary of the evaluation through preparation experiment. Then to verify the validity of Online and CG experiment, Online and photo experiment with each subjective evaluation results. The result of this study is that the validity difference is within 5% in the verification the validity of the physic amount, which showed little difference. While in verification of subjective evaluation of online and CG, online and photo experiment, the result is showed little difference as well except a little the item.

• The Journal of the Korea Contents Association
• /
• v.13 no.6
• /
• pp.48-54
• /
• 2013

In these days, the state-of-art technologies employ the heterogeneous parallelization of CPU and GPU for fluid simulations in the field of computer graphics. In this paper, we present a novel CPU-GPU parallel algorithm that solves projection step of fluid simulation more efficiently than existing sequential CPU-GPU processing. Fluid simulation that requires high computational resources can be carried out efficiently by the proposed method.