• Nuclear Engineering and Technology
• /
• 제44권8호
• /
• pp.929-938
• /
• 2012

The Computerized Procedure System (CPS) is one of the primary operating support systems in the digital Main Control Room. The CPS displays procedure on the computer screen in the form of a flow chart, and displays plant operating information along with procedure instructions. It also supports operator decision making by providing a system decision. A procedure flow should be correct and reliable, as an error would lead to operator misjudgment and inadequate control. In this paper we present a modeling for the CPS that enables formal verification based on Petri nets. The proposed State Token Petri Nets (STPN) also support modeling of a procedure flow that has various interruptions by the operator, according to the plant condition. STPN modeling is compared with Coloured Petri net when they are applied to Emergency Operating Computerized Procedure. A converting program for Computerized Procedure (CP) to STPN has been also developed. The formal verification and validation methods of CP with STPN increase the safety of a nuclear power plant and provide digital quality assurance means that are needed when the role and function of the CPS is increasing.

• Computers and Concrete
• /
• 제33권6호
• /
• pp.725-738
• /
• 2024

This study presents a macro-modeling procedure for nonlinear finite element analysis of reinforced and prestressed concrete panels under blast loading. The analysis procedure treats cracked concrete as an orthotropic material based on a smeared rotating crack model within the context of total-load secant stiffness-based formulation. A direct time integration method compatible with the analysis formulation is adapted to solve the dynamic equation of motion. Considerations are made to account for strain rate effects. The analysis procedure is verified by modeling 14 blast tests from various sources reported in the literature including a blast simulation contest. The analysis results are compared against those obtained from experiments, simplified single-degree-of-freedom (SDOF) methods, and sophisticated hydrocodes. It is demonstrated that the smeared crack macro-modeling approach is a viable alternative analysis procedure that gives more information about the structural behavior than SDOF methods, but does not require detailed micro-modeling and extensive material characterization typically needed with hydrocodes.

• 대한조선학회논문집
• /
• 제33권1호
• /
• pp.173-181
• /
• 1996

본 논문은 조선공업에 동시공학 개념을 적용하기 위한 것으로 선박 구조설계 및 모델링을 대상으로 한 것이다. 본 연구에서는 선박의 구조부재를 모델링하기 위한 방법으로서 범용 CAD시스템의 사용자 정의 언어(PPL, Parametric Programming Language)를 이용하는 방법과 이를 이용한 parametric macro를 이용하는 것을 제안하였다. 한편 모델링의 효율성 및 그 결과의 활용성을 고려하여 모델링 절차에 대하여 검토하였으며 각각의 모델링 절차들이 갖는 장단점을 비교하였다. 마지막으로 구조부재의 모델링 결과를 어떻게 활용하는가에 대하여 간략히 설명하였다.

• 농업과학연구
• /
• 제43권2호
• /
• pp.163-175
• /
• 2016

For the past decades, advances in computational devices have propelled mathematical modeling to become an effective tool for solving the black box of complex biological systems because of its prominent analytical power and comprehensive insight. Nevertheless, modeling is still limitedly used in the fields of agriculture and food which generally concentrate on producing experimental data rather than processing them. This study, hence, intends to introduce modeling in terms of its procedure types of structure, formulation, analyses, and software, with reviews of current notable studies from micro to macro scales so as to propose the modeling technique as a novel approach in discerning conundrums in agriculture and food systems. We expect this review to provide an eligible source for researchers who are willing to apply modeling techniques into the unexplored fields related to bio-systems that comprehensively include biology, nutrition, agriculture, food, animal science, and ecology.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1997년도 추계학술대회 논문집
• /
• pp.647-650
• /
• 1997

A complete dome structure is based on a basic dome modeling, and the basic dome modeling affects safety of the dome structure. In other to save the manufacture expenses, an optimum shape modeling of a dome structure is necessary work of before manufacture of the dome. In this study, modeling of the triangle optimum shape in the surface of an aluminum dome is more focused to optimize shape of the dome and save manufacture expenses. After being made the systematic procedure of the basic modeling, the programming work of the procedure is performed. The program is made by C language, and the trust of the program is proved by comparison between output data of the program and basic modeling in PATRAN.

• Nuclear Engineering and Technology
• /
• 제37권1호
• /
• pp.118-126
• /
• 2005

While emergency operating procedures (EOPs) occupy an important role in the management of various abnormal situations in nuclear power plants (NPPs), current technology for the validation of EOPs still largely depends on manual review. A validation method for EOPs of NPPs is thus proposed based on dynamic multi-level flow modeling (MFM). The MFM modeling procedure and the EOP validation procedure are developed and provided in the paper. Application of the proposed method to EOPs of an actual NPP shows that the proposed method provides an efficient means of validating EOPs. It is also found that the information on state transitions in MFM models during the management of abnormal situations is also useful for further analysis on EOPs including their optimization.

• 한국정밀공학회지
• /
• 제13권7호
• /
• pp.100-114
• /
• 1996

In order to create a solid model more efficiently for a plastic or sheet metal product with a thin and constant thickness, various methods have been proposed up to now. One of the most typical approaches is to create a sheet model initially and then transform it into a solid model automatically for a given thickness. The sheet model as well as the transitive model in sheet modeling procedure is a non-manifold model. However, the previous methods adopted the boundary representations for a solid model as their topological framework. Thus, it is difficult to represent the exact adjacency relationship between topological entities and to implement the topological operations for sheet modeling and the transformation procedure of a sheet into a solid. In this paper, we proposed a sheet modeling system based on a non-manifold topological representation which can represent solids, sheets, wireframes, and their mixture. A set of generalized Euler operators for non-manifold topology as well as the sheet modeling capabilities including adding, bending, and punching functions are provided for easy modeling of sheet objects, and they are perfomed interactively with a two dimensional curve editor. Once a sheet model is completed, it can be transformed into a solid automatically. The transformation procedure is composed of the offset functions and the Boolean operations of sheet models, and it is even more comprehensive and easier to be implemented than the precious methods.

• 한국빅데이터학회지
• /
• 제7권1호
• /
• pp.99-111
• /
• 2022

불확실성과 복잡성이 존재하는 제조시스템의 생산성 분석과 의사결정을 위하여 시뮬레이션 기법이 활용될 수 있다. 이러한 시스템의 시뮬레이션을 위해 대상의 특성을 반영하는 입력 모델링 과정이 필요하다. 하지만 건설기계 조립라인과 같은 수작업 중심과 긴 리드타임을 가지는 복잡한 환경에서는 시뮬레이션에 활용할 데이터의 수집이 제한된다. 본 연구는 입력 데이터의 수집이 어려운 환경에서 동영상 데이터를 이용한 시뮬레이션 입력 모델링 절차를 제안한다. 동영상 데이터 기반 작업분석을 통해 측정시간을 정미시간과 표준시간으로 산정하고, 시뮬레이션의 입력 분포로 활용할 수 있다. 제안하는 절차로 산정된 확률분포를 시뮬레이션에 이용하여 대상 시스템의 주요 생산성 지표를 분석하였다. 본 연구에서 제안하는 절차는 데이터가 적은 상황에서 시뮬레이션을 활용한 생산성 분석으로 의사결정 보조에 도움을 줄 것으로 기대된다.

• 한국CDE학회논문집
• /
• 제15권1호
• /
• pp.60-69
• /
• 2010

Outfitting systems in marine vessels have many kinds of standard parts. Ship CAD system should support the designers with an efficient tool for the modeling of outfitting parts such as pipes and valves. We develop a practical procedure for a part master model that combines ship CAD systems with the industrial standard. Part master or catalogue database of standard equipments is included in the database of ship CAD. The part master makes the associations of three dimensional modeling with the industrial standard. Moreover, it reflects the automatic modeling to maintain attributes that are disclosed in the entity of each part master in order to reduce the modeling time. Entity and attributes of pipe and valves are chosen from JIS(Japanese Industrial Standards) in order to explain the proposed procedure. Suggested procedure explains that three dimensional model of equipment is generated by parsing the pre-defined attributes after the entities of part masters is stored in database.

• 한국항공우주학회지
• /
• 제39권3호
• /
• pp.261-268
• /
• 2011

복합재료 로터 블레이드는 각종 보강재와 더불어 적층된 형태로 구성되어 있어 그 단면 구조가 매우 복잡하고, 이로 인해 모델링에 어려움이 존재한다. 본 논문에서는 효율적인 로터 블레이드 단면 모델링을 위해 집합 연산에 기반 한 2차원 모델링 알고리듬을 활용하여 그래픽 사용자 환경을 갖춘 프로그램 KSec2D를 구현하였다. 구현된 프로그램을 이용하여 복잡한 로터 블레이드 단면 형상 모델링을 수행하고 이를 통해 복합재료 로터블레이드 모델링 시 개발된 프로그램의 유용성을 확인하였다.