• Proceedings of the Korean Radioactive Waste Society Conference
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• 2016.10a
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• pp.435-436
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• 2016

• Journal of the Korean Society for Nondestructive Testing
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• v.3 no.2
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• pp.40-43
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• 1984

• Geophysics and Geophysical Exploration
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• v.19 no.3
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• pp.145-152
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• 2016

We used graphics processing units for an efficient time-domain 3D wave propagation modeling. Since graphics processing units are designed for massively parallel processes, we need to optimize the calculation and memory management to fully exploit graphics processing units. We focused on the memory management and examined the performance of programs with respect to the memory management methods. We also tested the effects of memory transfer on the performance of the program by varying the order of finite difference equation and the size of velocity models. The results show that the memory transfer takes a larger portion of the running time than that of the finite difference calculation in programs transferring whole 3D wavefield.

• The KIPS Transactions:PartD
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• v.8D no.3
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• pp.257-264
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• 2001

We developed a SIFG (Slice-based Information Graph), which modelled the information flow on program on the basis of the information flow of data tokens on data slices. Then we defied a SCM (Slice-based complexity measure), which measured the program complexity by measuring the complexity of information flow on SIFG. SCM satisfied the necessary properties for complexity measure proposed by Briand et al. SCM could measure not only the control and data flow on program but also the physical size of program unlike the existing measures.

• Tunnel and Underground Space
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• v.30 no.6
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• pp.509-518
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• 2020

This study constructed a new simulation platform, including mesh generation process, numerical simulation, and post-processing for results analysis based on exploration data to perform real-scale numerical analysis considering the actual geological structure efficiently. To build the simulation platform, we applied for open-source programs. The source code is open to be available for code modification according to the researcher's needs and compatibility with various numerical simulation programs. First, a three-dimensional model(3D) is acquired based on the exploration data obtained using a drone. Then, the domain's mesh density was adjusted to an interpretable level using Blender, the free and open-source 3D creation suite. The next step is to create a 3D numerical model by creating a tetrahedral volume mesh inside the domain using Gmsh, a finite element mesh generation program. To use the mesh information obtained through Gmsh in a numerical simulation program, a converting process to conform to the program's mesh creation protocol is required. We applied a Python code for the procedure. After we completed the stability analysis, we have created various visualization of the study using ParaView, another open-source visualization and data analysis program. We successfully performed a preliminary stability analysis on the full-scale Dokdo model based on drone-acquired data to confirm the usefulness of the proposed platform. The proposed simulation platform in this study can be of various analysis processes in future research.

• Annual Conference of KIPS
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• 2017.04a
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• pp.963-965
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• 2017

최근 3D 프린터에 대한 관심이 커지고 있다. 3D 프린팅을 위해서 전용 소프트웨어를 이용하여 설계 파일을 생성하고 출력하지만, 각 3D 프린트마다 지원하는 파일 형식이 다르고, 특정 데이터 파일 형식을 변환할 때에는 별도의 프로그램이 필요하기 때문에 많은 시간과 노력이 필요하다. 본 논문에서는 이러한 일련의 복잡한 과정을 개선하기 위해 입력 파일을 각 3D 프린터가 지원하는 파일 형태로 손쉽게 변환하여 출력할 수 있는 모델링 기법을 제안한다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2014.07a
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• pp.257-258
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• 2014

본 논문에서는 유니티 3D에 대해서 설명하려고 한다. 기본적인 특징, 사용 환경, 인터페이스(Interface)와 함께 다양한 기술과 함께 로봇 팔의 시뮬레이터 개발 구현까지 연구하였다. 컴퓨터 내에서와는 다르게 안드로이드, 아이폰 게임에서, 필요 없이 높은 사양을 가지고 있는 다른 프로그램들과 다르게, 최적의 제작환경을 가지고 있다. 유니티 3D에서 가능한 여러 가지 기능을 이용해서 가상 세계이지만 간단하게 실제 세계와 비슷한 상황의 로봇 팔 시뮬레이터 제작에 대해서 설명하였다.

• Proceedings of the Korea Society for Simulation Conference
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• 2005.05a
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• pp.89-92
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• 2005

Each 3D visualization program has its own different structure as for the purpose. This paper describes the design and development of an on-line 3D core data visualization program, $RocDis^{TM}$, for the nuclear simulator. It is possible to analyze the inside of the core status including neutron flux, relative power, moderator and fuel temperature in 3D distribution. Some of other essential information, axial flux distribution etc. could also display in 2D graphs. This program would be design, tuning and training for the simulator core model.

• Geophysics and Geophysical Exploration
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• v.20 no.2
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• pp.72-77
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• 2017

We calculated 3D frequency- and Laplace-domain wavefields using time-domain modeling and Fourier transform or Laplace transform. We adopted OpenACC and GPU for an efficient parallel calculation. The OpenACC makes it easy to use GPU accelerators by adding directives in conventional C, C++, and Fortran programming languages. Accordingly, one doesn't have to learn new GPGPU programming languages such as CUDA or OpenCL to use GPU. An OpenACC program allocates GPU memory, transfers data between the host CPU and GPU devices and performs GPU operations automatically or following user-defined directives. We compared performance of 3D wave propagation modeling programs using OpenACC and GPU to that using single-core CPU through numerical tests. Results using a homogeneous model and the SEG/EAGE salt model show that the OpenACC programs are approximately 53 and 30 times faster than those using single-core CPU.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2013.06a
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• pp.130-133
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• 2013

방송 수신기는 종래의 디지털 방송 프로그램의 시청을 넘어서 인터넷 연결을 제공하는 스마트 TV 로 발전하고 있다. 본 논문은 초기 스마트 TV 의 단순한 인터넷 접속 기능을 넘어서 스마트 TV 가 가진 하이브리드 망 접속 능력을 십분 활용할 수 있는 증강방송 서비스를 실현하기 위한 증강방송 서비스 플랫폼의 구현기술을 소개한다. 증강방송은 방송사에서 송출하는 방송 프로그램과 융화된 양방향 실감형, 몰입형 증강 콘텐츠를 시청자에게 제공한다. 증강 콘텐츠는 시청자의 방송 프로그램 시청을 도와줄 수 있는 2D, 3D 그래픽 콘텐츠뿐만 아니라 촉각 등의 다양한 형태의 미디어로 제공 가능하다.