• 한국시뮬레이션학회논문지
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• 제32권1호
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• pp.13-21
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• 2023

본 논문은 실제 시스템의 빅데이터가 확보되었고 시스템에 대한 정보를 일부 알고 있을 때 파라미터를 가진 그레이박스 혹은 블랙박스 형태의 가설모델을 설정하고 기계학습을 통해 모델을 자동 생성하는 기법을 제안하였다. 제안된 프레임워크를 구현하고 다양한 가설모델에 대한 실험을 통해 학습된 모델의 정합도와 가설모델의 학습에 소요되는 비용에 대해 분석하였다. 실험결과 제안된 가설모델 기반 기계학습 기법으로 상미분방정식으로 기술될 수 있은 연속시스템의 그레이박스 혹은 화이트 박스 가설모델과 주어진 빅데이터를 이용하여 모델링을 했을 때 상당히 좋은 성능과 정확도를 보인 모델을 찾아낼 수 있음을 확인하였다. 이 기법은 최근 생성된 빅데이터를 이용하여 디지털트윈 모델의 일치성을 자동 갱신하거나 새로운 입력에 대한 출력을 예측하는 목적으로도 잘 활용될 수 있을 것으로 기대된다.

• 대한조선학회논문집
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• 제45권4호
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• pp.441-454
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• 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.

• 한국CDE학회논문집
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• 제10권5호
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• pp.356-364
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• 2005

As a ritual of modern people is getting higher, the safety assessment of the structure related to people has become the most important part in the process of the design. Especially, in the case of a ship, as regulations about the safety of passengers and the pollution in the ocean are strictly reinforcing, the safety assessment has become the most important part in the process of the design. However, because the established safety assessment is mostly depend on the experienced theory, it is so difficult to assess the safety considering a lot of situations such as various ocean environments, the mistake of sailors and emergency situations. As the way to solve this problem, lately the study of the simulation using a computer has been processed. In this paper, we suggested network-based simulation system framework using HLA (High Level Architecture) among many kind of simulations to assess the safety of the ship. Because HLA has already become a standard of the future simulation system in the U.S. DoD(Department of Defense) and Korea army, we expect to raise the possibility in the future. In addition, because HLA makes a standard of documents and a reused component(Federate) of simulation(Federation) by OMT(Object Model Template) and RTI(Runtime Infrastructure), we expect that this study will be developing the safety assessment of ship as well as operation in warship and cooperation with another applications.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2002년도 추계학술대회 논문집
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• pp.157-162
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• 2002

A distributed simulation with HLA/RTI provides stable and satisfactory results. In this study, a distributed simulation of Petri net models under the HLA/RTI framework is considered. Throughout our experiences, it is recognized that the proper use of interface specification and time management services are important in order to achieve successful implementation of RTI. The interfacing tokens that are delivered to other models are distinguished as information entity and physical entity. Both entities are modeled as Interaction Class in order to send and receive messages. In synchronizing local simulation clocks, a conservative method with NERA service is considered. A eel manufacturing system is modeled and implemented with RTI to illustrate the distributed simulation of Petri net models.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 춘계 학술논문 발표대회
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• pp.301-302
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• 2012

Recently, high-rise building projects have been in the spotlight in South Korea. Curtain wall construction, as one of important operations in the high-rise building projects is composed of various, entangled and complex unit processes that require a systematic planning to prevent unexpected delays. A schedule simulation technique has been used for deriving more efficient planning and accurate performance measurement. However, the simulation technique has difficulty in collecting actual data and in applying data fluctuations during construction. Thus, this paper suggests a concept model of Modular Simulation Model(MSM) that overcomes such limitations of traditional simulation technique based on curtain wall operations.

• 한국CDE학회논문집
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• 제19권1호
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• pp.29-40
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• 2014

Conceptual Modeling is the process of abstracting a model from a real or proposed system. It is probably the most important aspect of a simulation study. Relate works show that the elementary developers devoted little time to understanding how the systems actually worked, namely they didn't build appropriate conceptual model. Thus, the result of simulation is inconsistent because it depends on developer's competence. Although many researchers suggested various techniques enabling developer to build conceptual model, there were several limitations. In this study, to overcome the limitations of existing techniques, we proposed COMBINE-DES (COnceptual Model BuildINg framEwork using ontology for Discrete Event Simulation). The COM-BINE-DES supports expediting the conceptual modeling with Solution ontology generated by Domain ontology and Simulation ontology. Moreover, it provides consistent simulation result regardless of repeated modeling.

• 한국지구과학회지
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• 제39권4호
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• pp.388-400
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• 2018

The purpose of this study was to explore the nine components of computational thinking (CT) practices and their operational definitions from the view of science education and to develop a CT practice framework that is going to be used as a planning and assessing tool for CT practice, as it is required for students to equip with in order to become creative problem solvers in $21^{st}$ century. We employed this framework into the earlier developed STEAM programs to see how it was valid and reliable. We first reviewed theoretical articles about CT from computer science and technology education field. We then proposed 9 components of CT as defined in technology education but modified operational definitions in each component from the perspective of science education. This preliminary CTPF (computational thinking practice framework) from the viewpoint of science education consisting of 9 components including data collection, data analysis, data representation, decomposing, abstraction, algorithm and procedures, automation, simulation, and parallelization. We discussed each component with operational definition to check if those components were useful in and applicable for science programs. We employed this CTPF into two different topics of STEAM programs to see if those components were observable with operational definitions. The profile of CT components within the selected STEAM programs for this study showed one sequential spectrum covering from data collection to simulation as the grade level went higher. The first three data related CT components were dominating at elementary level, all components of CT except parallelization were found at middle school level, and finally more frequencies in every component of CT except parallelization were also found at high school level than middle school level. On the basis of the result of CT usage in STEAM programs, we included 'generalization' in CTPF of science education instead of 'parallelization' which was not found. The implication about teacher education was made based on the CTPF in terms of science education.

• 인터넷정보학회논문지
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• 제6권6호
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• pp.85-97
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• 2005

본 논문은 도로상에 설치된 각종 교통정보 기기로부터 수집된 정보를 이용하여 교통정보 데이터베이스를 구축하고 이를 이용하여 교차로를 기점으로 도로의 구간별 실시간 교통흐름을 동적으로 관리할 수 있는 교차로 시뮬레이션 시스템을 제안한다. 본 시스템은 계층적인 3 부분으로 구성된다. 하위계층은 실제 도로 상에서 교통정보가 수집되는 물리계층이다. 중간계층은 하위계층의 교통정보를 이용하여 교차로들의 그룹, 실시간 교통흐름 정보의 수집, 원격 모니터링 및 제어를 지원하는 교통흐름 제어 프레임워크가 존재한다. 본 계층은 분산객체그룹 프레임워크를 확장하여 설계됐다. 상위계층에는 교차로들의 그룹화로 교통흐름을 제어하는 교차로 시뮬레이터 응용들이 존재한다. 교차로 응용은 TMO(Time-triggered Message-triggered Object) 스킴 기반의 구현객체들로 이루어진다. 교차로 시뮬레이션 시스템에서는 도로상의 각 교차로를 하나의 응용 그룹으로 고려하며, 교차로들 간에 상호통신으로 수집된 실시간 도로소통 상태정보를 이용하여 주어진 도로상황에 따라 동적인 교통흐름 제어기법들의 적용이 가능하도록 하였다. 본 시스템 구축을 위해 TMO 스킴과 TMOSM(TMO Support Middleware) 지원교통흐름 제어 프레임워크 기반에서 시스템 구조와 구성요소의 상호작용을 정의했으며, 교통흐름 모니터링 및 제어를 위한 응용 시뮬레이터와 사용자 인터페이스를 설계했다.

• Journal of Computing Science and Engineering
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• 제8권4호
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• pp.181-186
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• 2014

Web data mining aims at discovering useful knowledge from various Web resources. There is a growing trend among companies, organizations, and individuals alike of gathering information through Web data mining to utilize that information in their best interest. In science, cloud computing is a synonym for distributed computing over a network; cloud computing relies on the sharing of resources to achieve coherence and economies of scale, similar to a utility over a network, and means the ability to run a program or application on many connected computers at the same time. In this paper, we propose a new system framework based on the Hadoop platform to realize the collection of useful information of Web resources. The system framework is based on the Map/Reduce programming model of cloud computing. We propose a new data mining algorithm to be used in this system framework. Finally, we prove the feasibility of this approach by simulation experiment.

• 제어로봇시스템학회논문지
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• 제6권8호
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• pp.666-671
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• 2000

With the current advances in optical WDM (Wavelength Division Multiplexing) networking technologies and the increasing demand for network bandwidth the Next Generation Internet is expected to be a network that runs IP(Internet Protocol) directly over WDM-based optical networks. The network control architecture for the IP over WDM networks is different from that of traditional Internet since the underlying WDM devices have more constraints than electronic IP routers such as the lack of optical buffers and wavelength continuity property etc. In this paper we introduce several architectural models for implementing IP over WDM networks and propose an integrated network control framework for the IP over WDM networks. This framework leverages the traffic engineering control architecture for the MPLS (Multi-Protocol Label Switching) networks and is mainly developed for the IP over packet-switched WDM networks. We also report several preliminary simulation results of contention resolution schemes in the packet-switched WDM networks.