• 전자공학회논문지B
• /
• 제33B권3호
• /
• pp.96-108
• /
• 1996

In this paper, we propose an object-oriented coding method in low bit-rate channels using block-based motion vectors and residual image compensation. First, we use a 2-stage algorithm for estimating motion parameters. In the first stage, coarse motion parameters are estimated by fitting block-based motion vectors and in the second stage, the estimated motion parametes are refined by the gradient method using an image reconstructed by motion vectors detected in the first stage. Local error of a 6-parameter model is compensted by blockwise motion parameter correction using residual image. Finally, model failure (MF) region is reconstructed by a fractal mapping method. Computer simulation resutls show that the proposed method gives better performance than the conventional ones in terms of th epeak signal to noise ratio (PSNR) and compression ratio (CR).

• 한국통신학회논문지
• /
• 제21권12호
• /
• pp.3033-3045
• /
• 1996

In this paper, we propse an object-oriented coding method in low bit-rate channels using pyramid structure and residual image compensation. In the motion estimation step, global motion is estimated using a set of multiresolution images constructed in a pyramid structure. We split an input image into two regions based on the gradient value. Regions with larte motions obtain observation points at low resolution level to guarantee robustness to noise and to satisfy a motion constraint equation whereas regions with local motions such as eye, and lips get observation points at the original resolution level. Local motion variations and intesity variations of an image reconstructed by the golbal motion are compensated additionally by using the previous residual image component. Finally, the model failure (MF) region is compensated by the pyramid mapping of the previous displaced frame difference (DFD). Computer simulation results show that the proposed method gives better performance that the convnetional one in terms of the peak signal to noise ratio (PSNR), compression ratio (CR), and computational complexity.

• 한국정보과학회:학술대회논문집
• /
• 한국정보과학회 2000년도 가을 학술발표논문집 Vol.27 No.2 (1)
• /
• pp.430-432
• /
• 2000

시뮬레이션을 구현할 때 대부분의 경우 eventlist 라는 자료구조를 사용하여 사건(event)를 처리하고 시간을 스케쥴링(scheduling)한다. 그러나 eventlist를 사용하는 것은 객체 스스로가 사건을 처리하고 시간 스케쥴링을 하지 않는다는 점에서 객체지향적이지는 못하다. 그래서 본 논문에서는 객체 스스로가 상태를 가지며 사건을 처리하고 시간을 스케쥴링하는 전차대 전차, 전차대 헬기 교전을 위한 시뮬레이션을 설계 및 구현하였다. 설계는 상태변화를 쉽게 하고 시간 전진 문제를 쉽게 처리할 수 있는 Fa$\square$ade Pattern방법을 사용하였으며, 시간전진 방법은 상태변화에는 논리시간(logical time)을 이용한 이산사건(discrete event) 전진방법을 사용하였고 Graphic Visualization에는 실시간(real time)을 이용한 이산(discrete) 전진방법을 사용하여 논리시간과 실시간을 병렬로 동기화시켜 처리하였다. 구현은 Visual C++의 MFC 라이브러리를 사용한 MDI구조로 구현하였다. 논문의 시뮬레이션은 교전모델을 응용하였고 객체지향(Objected-Oriented)으로 설계 및 구현되어 각 객체의 재사용과 확장 및 수정이 용이하다는 장점을 가진다.

• 전자공학회논문지A
• /
• 제33A권3호
• /
• pp.163-175
• /
• 1996

This paper invetigates estimation methods of mapping parameters in object-oriented coding. In this paper, we propose a fast parameter estimation method with its performance similar to that of the conventional methods. We employ hierarchical structure in difference images to redcue the computational complexity and also combine conventional six- and eight-mapping parameter estimation methods to compensate for the performance degradation caused by employment of hierarchical structure. Computer simulation shows that the proposed mehtod gives results similar to conventional methods with greatly reduced computational complexity.

• 산업경영시스템학회지
• /
• 제20권43호
• /
• pp.163-174
• /
• 1997

Development of control model and system for AMS (Automated Manufacturing Systems) has long been interested by researchers. Presented in the paper is a systematic approach to constructing a Petri-nets(PNs) model of AMS and method for design a graphical model of a AMS by using a new modeling tool which is called PNs. So, the procedure of modeling in the AMS is the same as current practice of AMS design and is based on the IOM (Integrated Object-oriented Modeling) paradigm. An AMS, which consists of various machine groups, can produce machine parts in different physical dimensions and lot size. To model such a system, the method which utilizes Sub-PNs are proposed. This enables the models according to part routings. The machine group which causes bottleneck is obtained and modified to relieve the problem. By iterating these steps which consist of modelling, simulation, and performance evaluation, an AMS can e obtained which satisfies the required manufacturing conditions. Finally, the implementation issues of PN modeling are addressed. The approach is the IOM from PN modeling by Sub-PNs and the other is a development of IOM tool for the performance evaluation of AMS.

• 한국시뮬레이션학회:학술대회논문집
• /
• 한국시뮬레이션학회 1998년도 The Korea Society for Simulation 98 춘계학술대회 논문집
• /
• pp.6-10
• /
• 1998

RTO(Real-time Object) 모델로 불리는 실시간 객체지향 모델은 컴퓨터에 의해 제어되는 실시간 제어기 및 이의 응용 환경 시뮬레이터를 정밀하게 표현하는데 유용한 모델로 정착되었다. 이 모델은 실시간 분산 컴퓨터 시스템과 이의 응용 환경에 대한 실시간 시뮬레이터를 통합적으로 설계하는데 강력한 표현력을 보여주고 있다. RTO 기반의 접근 방법에 의한 통합 설계는 RTO로 불리는 객체의 네트워크 형태로 표현된다. 본 논문에서는 이와 같은 설계 방법을 자동판두께제어기(Automatic Gauge Controller, AGC)라고 불리는 실시간 분산 시스템의 설계 사례를 통해 제시하고자 한다. AGC 시스템은 압연공정 제어기로서 압연공정 실시간 시뮬레이터의 소재 이송 및 압하 공정을 제어한다. 설계과정을 통해서 실시간 분산 시스템 명세의 추상화 방법에 대하여 논하고, 네트워크의 구축 과정을 통한 시뮬레이션 모델의 정밀한 표현 방법을 제시하며, RTO의 분산구조 및 명확하고 엄밀한 실시간 설계 방법에 대하여 논한다.

• 한국시뮬레이션학회:학술대회논문집
• /
• 한국시뮬레이션학회 2000년도 추계학술대회 논문집
• /
• pp.174-179
• /
• 2000

Proposed in the paper is a V-FMS (Virtual Flexible Manufacturing System) model to be used as a prototyping tool for FMS design. The proposed V-FMS framework follows an object-oriented modeling (OOM) paradigm and is based on a set of user requirements for FMS prototyping. The V-FMS model consists of four types of object: virtual device, transfer handler, state manager and flow controller. A virtual device model, which corresponds to a static model in OOM, consists of two parts, shell and core, for reusability. A transfer handler corresponds to a functional model of OOM and it stores low level device commands required to perform job flow operations between giving and taking devices. The state manager and the flow controller constitute a dynamic model of OOM. The proposed V-FMS model has been implemented for a couple of linear type FMS-lines

• 대한조선학회논문집
• /
• 제45권4호
• /
• pp.441-454
• /
• 2008

Shipyard design and equipments layout problem, which are directly linked with the productivity of ship production, is an important issue serving as reference data of production plan for later massive production of ships. So far in many cases, design of a shipyard has been relying on the experienced engineers in shipbuilding, resulting in sporadic and poorly organized processes. And thus, economic losses as well as trials and errors in that accord have been pointed out as inevitable problems. This paper extracts a checklist of major elements to fine tune the shipbuilding yard designing process and the input/output data based on the simulation based shipbuilding yard layout designing framework and methodology proposed in existing researches, and executed initial architecture to develop software that integrates all the relevant processes and designing tools. In this course, both user request and design data by the steps are arranged and organized in the proposed layout design template form. In addition, simulation is done based on the parent shipbuilding process planning and scheduling data of the ship product, shipbuilding process and work stage facilities that constitute shipbuilding yard, and design items are verified and optimized with the layout and equipment list showing optimal process planning and scheduling effects. All the contents of this paper are based on simulation based shipbuilding yard layout designing methodology, and initial architecture processes are based on object oriented development methodology and system engineering methods.

• 한국시뮬레이션학회논문지
• /
• 제20권2호
• /
• pp.11-17
• /
• 2011

본 논문은 해양구조물 rig의 굴착시스템의 하부 부분의 3차원 모델링과 굴착과정의 시뮬레이션에 있다. 최근 조선사들은 높은 부가가치성과 신조의 감소로 인해 해양구조물 rig에 관심이 집중되고 있다. 그러나 대부분의 경우 해양구조물 rig의 기본 설계, 설치 및 운영은 외국회사들이 수행하고 있다. 따라서 굴착에 대한 지식과 정보를 얻기가 쉽지 않다. 본 논문에서는 해양구조물 rig의 핵심장비로 굴착장비, 폭발방지장치인 BOP, 시멘트 작업 및 머드 순환 장치 관련 장비들을 포함하였다. 이들의 구조와 기능은 객체지향기술 관점에서 분석하였다. 이 분석에 기초하여 3차원 소프트웨어 도구인 CATIA와 3DVIA Composer 를 이용하여 이 장비들을 모델링하였다. 굴착과정은 굴착작업의 시나리오에 따라 시뮬레이션되었다. 이 시뮬레이션 시스템은 해양플랜트 산업분야의 엔지니어와 학생들에게 교육도구로 유용하게 활용될 수 있다.

• 한국BIM학회 논문집
• /
• 제5권1호
• /
• pp.35-43
• /
• 2015

Existing pedagogical issues of digital design including BIM have been focused not on potential of Digital Design but on skills of BIM or digital modeling tool. Kinetic facade can move or change material state to react surrounding environment conditions. It is a suitable design object for teaching principle of Performance Oriented Digital Design. Variables of movements affect multi-criteria of performances of kinetic facade, so different design approach from fixed facade design should be explored. Kinetic facade design process is proposed to study pedagogical issues of Performance Oriented Digital Design in this paper. Through Kinetic facade design process, students can understand conditions, variables, and performances of digital design.