• 한국경영과학회지
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• 제23권2호
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• pp.131-156
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• 1998

Cooperative query answering is a research effort to develop a fault-tolerant and intelligent database system using the semantic knowledge base constructed from the underlying database. Such knowledge base has two aspects of usage. One is supporting the cooperative query answering Process for providing both an exact answer and neighborhood information relevant to a query. The other is supporting ongoing maintenance of the knowledge base for accommodating the changes in the knowledge content and database usage purpose. Existing studies have mostly focused on the cooperative query answering process but paid little attention on the dynamic knowledge base maintenance. This paper proposes a multi-level knowledge representation framework called Knowledge Abstraction Hierarchy (KAH) that can not only support cooperative query answering but also permit dynamic knowledge maintenance. The KAH consists of two types of knowledge abstraction hierarchies. The value abstraction hierarchy is constructed by abstract values that are hierarchically derived from specific data values in the underlying database on the basis of generalization and specialization relationships. The domain abstraction hierarchy is built on the various domains of the data values and incorporates the classification relationship between super-domains and sub-domains. On the basis of the KAH, a knowledge abstraction database is constructed on the relational data model and accommodates diverse knowledge maintenance needs and flexibly facilitates cooperative query answering. In terms of the knowledge maintenance, database operations are discussed for the cases where either the internal contents for a given KAH change or the structures of the KAH itself change. In terms of cooperative query answering, database operations are discussed for both the generalization and specialization Processes, and the conceptual query handling. A prototype system has been implemented at KAIST that demonstrates the usefulness of KAH in ordinary database application systems.

• 한국건설관리학회논문집
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• 제12권2호
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• pp.101-110
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• 2011

사회기반시설물 중 교량은 다른 시설물보다 열악한 환경에 노출되며, 파손 등이 발생할 경우 훨씬 심각한 결과를 야기할 수 있으므로 일정 수준 이상의 안전에 관한 성능을 반드시 유지하여야 한다. 하지만 향후 교량의 유지관리를 위한 예산 및 인적자원은 더욱 한정되어 갈 것이다. 자산관리기법은 이러한 한정된 자원으로 효율적인 교량의 유지관리를 위한 중요한 대안이 될 수 있다. 자산관리기법을 적용하기 위해서는 교량이 제공하는 서비스의 수준(Level of Service; LOS)을 평가하기 위한 방법이 결정되어야 하며, LOS는 성능척도(Performance Measures; PM)를 통해 정량적으로 결정될 수 있다. 본 논문은 교량 자산관리를 위한 PM을 개발하였으며, PM을 활용한 LOS 평가 방법을 정립하였다. 이러한 LOS 평가 결과를 활용하여 자산관리 대상, 항목 등을 결정할 수 있으며, 효율적이고 합리적인 교량의 자산관리관련 의사결정을 도울 수 있을 것으로 판단된다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2011년도 춘계 학술논문 발표대회 2부
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• pp.77-79
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• 2011

As residents and building owners demand maintenance that is required to achieve sustainable building performance, efficient building management methods are required. Even though the demand for maintenance systems is increasing, current maintenance work for high-rise buildings mostly uses conventional ropes and gondolas that pose a high risk of accidents and exhibit poor performance and efficiency. Thus, there is an urgent need to develop an automation robot system that can reduce accidents and improve the maintenance efficiency of the conventional high-rise building façade maintenance system. As a preceding work for the development of an automation robot system, this study classified and analyzed the work processes of actual construction sites and proposed basic techniques for the work mechanisms of the robot system by investigating the motions of cleaning workers.

• 한국산학기술학회논문지
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• 제19권12호
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• pp.717-724
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• 2018

사회기반시설물의 노후화에 따른 교량 유지관리비용의 급격한 증가에 대비하기 위해서는 미래 발생 가능한 유지관리비용의 예측이 선행되어야 한다. 이를 위해 본 논문에서는 교량 관리주체의 유지관리 현황 분석을 통해 교량의 관리수준을 파악하고, 이를 생애주기에 따른 목표관리수준과 성능향상 한계 값으로 모델링하였다. 이와 함께 교량 안전점수에 따른 보수보강비용 예측모델, 성능열화모델, 평균개축비용단가, 평균 개축시기로 구성된 기존의 비용 및 성능 예측모델과 연계하여, 교량 유지관리비용 추계분석을 위한 방법론 및 절차를 제안하였다. 제안된 방법의 활용성 검증을 위해 특정 관리주체가 관리하는 교량의 규모, 노후화 정도, 현재 관리현황을 고려하여 미래 유지관리비용 추계 분석을 수행하였다. 연차별로 개별 교량 수준의 안전등급과 유지관리 조치에 따른 비용 추정 결과와 이들을 관리주체 수준으로 합산하여 연차별 평균 안전점수, 안전등급 구성비, 점검진단비용, 보수보강비용, 개축비용을 합리적으로 추정할 수 있다. 향후 목표성능관리수준의 변경에 따른 생애주기 예산의 변화를 추정하여 최적의 관리수준을 제안할 수 있을 것으로 판단된다.

• International Journal of Internet, Broadcasting and Communication
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• 제8권3호
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• pp.58-62
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• 2016

Due to the rapidly changing global business environment and global management environment, companies must actively act for competitiveness. By examining the development process of Enterprise Resource Planning (ERP), there is a chance to optimize the organization and find measures to improve the company competitiveness. It seems examining task process, and studying the influence of ERP introduction to management performance by considering whether the excessive maintenance cost or repetitive investment toward ERP is quiet significant. The companies which instituted ERP uses "business process model" provided by "Best Practice" compare own task to choose much efficient method. This allows simultaneous realization of ERP institution and Business Reengineering (BR).

• 한국철도학회:학술대회논문집
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• 한국철도학회 2001년도 추계학술대회 논문집
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• pp.422-428
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• 2001

This paper provides a brief overview of the process for the introduction of new train in England since privatization in 1994. They have railway safety case which the safety management for the introduction of new trains is to be considered in all process including design, manufacturing, test, maintenance etc. To achieve safety in track, they also consider evidence available from the design and build process.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.149-156
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• 2003

Recently, the importance of plant maintenance(PM) was highly raised to provide efficient plant operation which highly affects the productivity. For this reason, a number of engineering methodologies, such as riskbased inspection(RBI), fitness for service guidelines(FFS), plant lifecycle management(PLM), have been applied to improve the plant operation efficiency. Also, a network-based business operation system, which is called ERP(Enterprise Resource Planning), has been introduced in the field of plant maintenance. However, there was no attempt to connect engineering methodologies to the ERP PM system. In this paper, a knowledge-based information system for the plant operation of steel making company has been proposed. This system, which is named as K-VRS(Knowledge-based Virtual Reality System), provides a connection between ERP plant maintenance module and knowledge-based engineering methodologies, and thus, enables network-based highly effective plant maintenance process. The developed system is expected to play a great role for more efficient and safer plant maintenance.

• 대한기계학회논문집A
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• 제27권11호
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• pp.1933-1940
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• 2003

Recently, the importance of plant maintenance(PM) was highly raised to provide efficient plant operation which highly affects the productivity. For this reason, a number of engineering methodologies, such as risk-based inspection(RBI), fitness for service guidelines(FFS), plant lifecycle management(PLM), have been applied to improve the plant operation efficiency. Also, a network-based business operation system, which is called ERP(Enterprise Resource Planning), has been introduced in the field of plant maintenance. However, there was no attempt to connect engineering methodologies to the ERP PM system. In this paper, a knowledge-based information system for the plant operation of steel making company has been proposed. This system which is named as K-VRS(Knowledge-based Virtual Reality System), provides a connection between ERP plant maintenance module and knowledge-based engineering methodologies, and thus, enables network-based highly effective plant maintenance process. The developed system is expected to play a great role for more efficient and safer plant maintenance.

• 산업경영시스템학회지
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• 제45권3호
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• pp.18-30
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• 2022

Predicting remaining useful life (RUL) becomes significant to implement prognostics and health management of industrial systems. The relevant studies have contributed to creating RUL prediction models and validating their acceptable performance; however, they are confined to drive reasonable preventive maintenance strategies derived from and connected with such predictive models. This paper proposes a data-driven preventive maintenance method that predicts RUL of industrial systems and determines the optimal replacement time intervals to lead to cost minimization in preventive maintenance. The proposed method comprises: (1) generating RUL prediction models through learning historical process data by using machine learning techniques including random forest and extreme gradient boosting, and (2) applying the system failure time derived from the RUL prediction models to the Weibull distribution-based minimum-repair block replacement model for finding the cost-optimal block replacement time. The paper includes a case study to demonstrate the feasibility of the proposed method using an open dataset, wherein sensor data are generated and recorded from turbofan engine systems.

• 한국정밀공학회지
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• 제31권7호
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• pp.591-596
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• 2014

Augmented reality is a novel human-machine interaction that overlays virtual computer-generated information on a real world environment. It has found good potential applications in many fields, such as training, surgery, entertainment, maintenance, assembly, product design and other manufacturing operations. In this study, a smartphone-based augmented reality system was developed for the purpose of monitoring and managing injection molding production lines. Required management items were drawn from a management content analysis, and then the items were divided into two broad management categories: line management and equipment management. Effective work management was enabled by providing those working on the shop floor with management content information combined with the actual images of an injection molding production line through augmented reality.