• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2002년도 추계학술대회 논문집 전력기술부문
• /
• pp.171-173
• /
• 2002

This paper presents a power system decomposition technique for digital simulation of large power system. To decompose power system, distributed transmission line model is used. But this model can be used only for long transmission lines. In this paper, capacitor compensation method is proposed to use distributed transmission line model for short transmission line. And case study shows proposed method can be used for effective power system decompositon in digital simulation of large power system.

• 한국시뮬레이션학회:학술대회논문집
• /
• 한국시뮬레이션학회 2001년도 춘계 학술대회 논문집
• /
• pp.54-54
• /
• 2001

인터넷으로 비롯된 신경제의 큰 특징중의 하나는 계층간의 격차 (Digital Divide)이다. 이러한 계층간의 격차는 인터넷의 특성인 Winner-takes-all 현상에 의해 일어나며 이는 확률적으로 Nonlinear Polya Game을 따르는 것으로 알려져 있다. 본 논문에서는 다양한 가정하에서 Nonlinear Polya Game의 행태를 분석해 보고 Digital Divide를 최소화시키거나 제거할 수 있는 방안을 모색해 보고자 한다. 또한 이러한 분석의 경제적이고 정책적인 의미를 제시해 보고자 한다.

• 한국콘텐츠학회논문지
• /
• 제19권1호
• /
• pp.117-124
• /
• 2019

이 논문은 디지털 테크놀러지가 영화 이미지의 미학적 존재론을 어떻게 변화시키고 있는지에 대해 다룬다. 영화 예술의 물질적 기초로서 셀룰로이드 필름을 통한 이미지 생산과 소비의 시대는 이미 막을 내렸다. 컴퓨터와 인터넷 시대의 도래는 영화의 세계에 새로운 이미지 존재론의 출현을 불가피하게 만든다. 오늘날 디지털 시네마 시대에 벤야민의 기계 복제 개념을 재해석할 필요가 있다. 필름 이미지의 기계 복제는 컴퓨터 시뮬레이션에 기초한 디지털 합성 개념으로 변형된다. 또한, 디지털 테크놀러지는 영화의 몽타주 미학에 중대한 변화를 초래한다. 쇼트들의 시간적 연결에 기초한 필름의 몽타주 미학은 컴퓨터 데이터와 픽셀 이미지의 공간적 시뮬레이션에 기초한 '디지털 꼴라주' 미학으로 변화한다. 이 논문은 영화적 환영과 표현의 미학이 확장되는 디지털 하이브리드 이미지 존재론을 탐구함으로써 기존 연구와의 차별성을 제시한다.

• 대한인간공학회지
• /
• 제26권2호
• /
• pp.81-88
• /
• 2007

The objective of this study was to investigate the validity of the digital ergonomic simulation (DES) method as a prospective alternative to the ergonomic analyses conducted by experts. The DES method utilizes commercial digital manufacturing software, and can compute the RULA scores continuously throughout the simulated work cycle. It was shown in a case study that the accuracy and objectivity of the DES method are superior to those obtained by experts. Also, it was demonstrated that the DES method has a distinct capability to simulate and validate a proposed work plan. Major limitations of the current DES method lie in the extensive time and efforts required for accurate digital simulation, which may be overcome through an automatic module for RULA data acquisition and a motion capture system.

• 한국전산유체공학회지
• /
• 제11권4호
• /
• pp.90-100
• /
• 2006

A digital wave tank (DWT) simulation technique has been developed by authors to investigate the interactions of fully nonlinear waves with 3D marine structures. A finite-difference/volume method and a modified marker-and-cell (MAC) algorithm have been used, which are based on the Navier-Stokes (NS) and continuity equations. The fully nonlinear kinematic free-surface condition is implemented by the marker-density function (MDF) technique or the Level-Set (LS) technique developed for one or two fluid layers. In this paper, some applications for various engineering problems with free-surface are introduced and discussed. It includes numerical simulation of marine environments by simulation equipments, fully nonlinear wave motions around offshore structures, nonlinear ship waves, ship motions in waves and marine flow simulation with free-surface. From the presented simulations, it seems that the developed DWT simulation technique can handle various engineering problems with free-surface and reliably predict hydrodynamic features due to the fully-nonlinear wave motions interacting with such marine structures.

• 한국해양공학회지
• /
• 제22권5호
• /
• pp.119-125
• /
• 2008

Musculoskeletal disorders(MSDs) are one of the major issues in shipbuilding industry. Main risk factors of MSDs include manual handling of heavy weight, awkward posture, repetitive tasks, prolonged static muscle contraction, and so on. in this study, Using the three-dimensional digital human modeling and simulation method we made up a worker and work posture on a virtual environment. To verify this simulation we compared both traditional ergonomic analysis on a real worker and digital program analysis on a digital human. And this paper shows that it is possible to reduce the rate of MSDs in the shipbuilding industry because it means we can change poor posture mid surroundings into better ones.

• 한국해양공학회지
• /
• 제17권6호
• /
• pp.7-15
• /
• 2003

A Digital Wave Tank simulation technique, based on a finite-difference method and a modified marker-and-cell (MAC) algorithm, is applied in order to investigate the characteristics of nonlinear Tsunami propagations and their interactions with a 2D sloping beach, Ohkushiri Island, and to predict maximum wove run-up around the island. The Navier-Stokes (NS) and continuity equation are governed in the computational domain, and the boundary values are updated at each time step, by a finite-difference time-marching scheme in the frame of the rectangular coordinate system. The fully nonlinear, kinematic, free-surface condition is satisfied by the modified marker-density function technique. The near shore Tsunami is assumed to be a solitary wave, and is generated from the numerical wave-maker in the developed Digital Wave Tank. The simulation results are compared with the experiments and other numerical methods, based on the shallow-water wave theory.

• 한국해양공학회:학술대회논문집
• /
• 한국해양공학회 2003년도 춘계학술대회 논문집
• /
• pp.231-239
• /
• 2003

A Digital Wave Tank simulation technique based on a finite-difference method and a modified marker-and-cell (MAC) algorithm is applied to investigate the characteristics of nonlinear Tsunami propagations and their interactions with a 2D sloping beach and Ohkushiri island, and to predict maximum wave run-up around the island. The Navier-Stokes (NS) and continuity equation are governed in the computational domain and the boundary values updated at each time step by a finite-difference time-marching scheme in the frame of rectangular coordinate system. The fully nonlinear kinematic free-surface condition is satisfied by the modified marker-density function technique. The Nearshore Tsunami is assumed to be a solitary wave and generated from the numerical wavemaker in the developed Digital Wave Tank. The simulation results are compared with the experiments and other numerical methods based on the shallow-water wave theory.

• 한국멀티미디어학회논문지
• /
• 제25권8호
• /
• pp.1007-1021
• /
• 2022

Autonomous driving of unmanned aerial vehicles may have to pay expensive cost to create and switch new routes if unexpected obstacles exist or local map updates occured by the control system due to incorrect route information. Integrating digital twins into the path-following process requires more computing resources to quickly switch the wrong path to an alternative path, but it can quickly update the path during flight. In this study, we design a DEVS-based simulation environment which can modify optimized paths through short-term simulation of multi-virtual UAVs for applying digital twin concepts to path follow. Through simulation, we confirmed the possibility of increasing the mission stability of UAV.

• 한국시뮬레이션학회논문지
• /
• 제29권2호
• /
• pp.11-20
• /
• 2020

제조환경이 더욱 복잡해짐에 따라 전통적인 시뮬레이션만으로는 실시간 현장 결과를 평가하는 데 많은 어려움을 겪고 있다. 이를 극복하기 위한 대안으로 Digital Twin개념이 활발히 논의되고 있지만, 제품설계 단계에 국한되어 연구가 진행되고 있는 실정이다. 본 연구는 Digital Twin개념이 생산 공정 프로세스에 적용되기 위한 Digital Twin 기반 제조환경 프레임워크를 제시하였다. 구성요소는 실제 생산환경인 물리적 시스템과 데이터베이스, 그리고 가상 시스템인 트윈 모델을 제안하였다. 본 연구에서는 Arena 소프트웨어와 엑셀 VBA를 활용하여 컨베이어 시스템을 대상으로 간단한 Digital Twin 기반 제조시스템을 모의실험하였다. 실험결과 트윈 모델이 실제 물리적 시스템의 실시간 데이터를 전송받아 동일한 시간단위로 작동됨을 확인하였고, 엑셀 VBA에서 축적된 실시간 데이터와 학습 데이터를 기반으로 조정된 파라미터를 생성하고 있음을 확인하였다. 또한, 간단한 모의실험을 통해 Digital Twin 모델 구동 방법을 제안하였으며, Digital Twin 모델의 구현 가능성을 보여주었다.