• Journal of the Korea Society for Simulation
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• v.15 no.1
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• pp.51-58
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• 2006

Virtual Manufacturing is a powerful methodology for developing a new product, new equipment and new production system. It enables the checking errors in design before production. This paper is a case study of virtual manufacturing in an excavator factory. The final welding operations of the boom and the rotating table of upper body are selected for application. 3D models of parts and fixtures are developed with $CATIA^{(R)}$ and 3D simulation models are developed with $IGRIP^{(R)}$. These models are used for verifying the design of fixture and for the motion design of robot. As a result, the manual welding systems are replaced by automatic systems and many design errors are corrected in the design phase, which reduces the developing cost and time.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.3
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• pp.100-107
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• 2015

Recently as the manufacturers want competitiveness in dynamically changing environment, they are trying a lot of efforts to be efficient with their production systems, which may be achieved by diminishing unplanned operation stops. The operation stops and maintenance cost are known to be significantly decreased by adopting proper maintenance strategy. Therefore, the manufacturers were more getting interested in scheduling of exact maintenance scheduling to keep smooth operation and prevent unexpected stops. In this paper, we proposedan integrated maintenance approach in injection molding manufacturing line. It consists of predictive and preventive maintenance approach. The predictive maintenance uses the statistical process control technique with the real-time data and the preventive maintenance is based on the checking period of machine components or equipment. For the predictive maintenance approach, firstly, we identified components or equipment that are required maintenance, and then machine parameters that are related with the identified components or equipment. Second, we performed regression analysis to select the machine parameters that affect the quality of the manufactured products and are significant to the quality of the products. By this analysis, we can exclude the insignificant parameters from monitoring parameters and focus on the significant parameters. Third, we developed the statistical prediction models for the selected machine parameters. Current models include regression, exponential smoothing and so on. We used these models to decide abnormal patternand to schedule maintenance. Finally, for other components or equipment which is not covered by predictive approach, we adoptedpreventive maintenance approach. To show feasibility we developed an integrated maintenance support system in LabView Watchdog Agent and SQL Server environment and validated our proposed methodology with experimental data.

• Journal of the Korea Society of Computer and Information
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• v.12 no.1 s.45
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• pp.9-15
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• 2007

As the information of the internet increased, importance of sematic web for collecting and integration of these informations to support decision making of some group or ordinary people are growing as well. Basis structure that composes semantic web is ontology and languages like XML, RDF/RDF schema and OWL are basis means that compose ontology schema. When composes and manages Ontology schema, one of the important consideration point is that schema is changed as times go by. Therefore, change of domain of schema, change of data concept or change of relation between resource etc. are reflected in the ontology system. In this study, we suggest semantic web schema management skill in terms of version management. We categorized version change forms and created version graph for checking of version transition. With created version graph, we define transitivity rule and propose schema tag for detail application which enables extending of applicable version schema.

• Water for future
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• v.23 no.3
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• pp.319-328
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• 1990

The Parameter Identification of 2-demensional estuarine model was carried out using new output ADI-FDM numerical semi-implicit schem transformed in boundary fitted(BF) - coordinate. The hydrodynamic equations which is coupled with the transport equations were used as basic equations in the model. Thompson's equations were used to transform governing equations into rectangular plane equations and his elliptic grid generation scheme was used to generate curvilinear grid system. in BF - coordinates. The parameters to be identified are friction coefficient and disperse coefficient embedded in the governing equations. The numerical output scheme is tidally averaged salinity model in BF - coordinates. The algorithm to optimize norm of error between observations and calculations is the influence coefficinet algorithm associated with least square criterion. The lumped model is conssidered in identification. This paper was concetrated on checking whether the new output scheme might be useful to identify parameters in estuarine salinity model or not. The proposed method was tested through experimental application with hypothetical simple model. The result of the test shows that the proposed method can be used for parameter identification in estuarine model.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.3
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• pp.397-404
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• 2011

In this research, wish to suggest method to embody system that can accommodate defect of PLC and find actual propriety. Defect permission control system minimizes production damage because enables repair and checking without discontinuance and improve believability about whole system. Propose duplexing of system to embody this fault tolerant system. Therefore, composed control system that can permit defect or breakdown duplexings of various module proposing this system, and confirms to simulation and actuality kiln of defect permission control system through an application experiment, and compares for mean time between defect by estimate and defect special quality and system configuration of failure(failure) to improve believability of PLC control system together. In proposed system expression method and system mode and relation with operation mode, error discovery mode and switching tube of duplexing mode, and PLC's central processing unit of node study algorithm about master-standby conversion driving and continuous operation of 2 channels method that have 2 that is not one and deduced continuous operation method and result about defect permission in this algorithm and applies this result to actuality kiln control system and confirms continuous operation about PLC defect permission.

• Journal of KIISE:Software and Applications
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• v.31 no.7
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• pp.869-882
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• 2004

This paper proposes an effective method to create logically consistent and structured requirement model by applying consistency control approach of the formal method to the use-case modeling. This method integrates the multi-perspective scattered requirement segments that may overlap and conflict each other into a structured requirement model. The model structure can be analyzed based on context goal and concerned area overlap analysis. The model consistency can be achieved by using specification overlap-based consistency checking method as an integration vehicle. An experimental application to case study shows that the Proposed method can successfully identify requirement overlaps and inconsistency. It can also transfer multi-viewpoint requirement segments into a consistently integrated use-case model to clarify software behaviors and functionality This method helps users to enhance capability to identify specification inconsistency in the use-case modeling at the early stage of software engineering development. The proposed approach can also facilitate communication between users and developers to ensure customer satisfaction.

• Journal of KIISE:Databases
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• v.31 no.4
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• pp.432-443
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• 2004

As the XML data has been widely used in the Internet, it is necessary to store and retrieve the XML data by using DBMSs. However, relational DBMSs suffer from the model difference between graph structure of the XML data and table forms in relational databases. We propose an ORDBMS-based DTD-dependent XML data management system Xing. Xing stores XML data in a DTD-dependent form in an object database. Since the object database schema has a graph structure and supports multi-valued attributes, mapping from an XML data model and queries into an object data model and OQLs is a simple problem. For rapid storing of large quantities of the XML data, we use SAX parser with customized Xing-tree which requires a small memory space compared with the DOM-tree. Xing also returns the query result in an XML document form. We have implemented the Xing system on top of UniSQL object-relational DBMS for the validity checking and performance comparison. For XML genome data from GenBank, and experimental evaluation shows that Xing can provide significant performance improvement (maximum 10 times) compared with the relational approach.

• Communications for Statistical Applications and Methods
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• v.17 no.3
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• pp.413-421
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• 2010

In this study, we considered bivariate conditional auto-regressive model taking into account spatial association as well as correlation between the two dependent variables, which are the counts of murder and burglary. We conducted likelihood ratio test for checking over-dispersion issues prior to applying spatial poisson models. For the real application, we used the annual counts of violent crimes at 25 districts of Seoul in 2007. The statistical results are visually illustrated by geographical information system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.9
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• pp.4223-4238
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• 2011

The advantages of grouting are the simple instrument, the simple procedure of practice and the simple verification of grouting result. but the more grouting practice there is, the more damages of environment from grouting practice and grouting materials there are. so, the grouting materials and methods with the character of environment friendly are introduced in construction field, recently. This paper is to study of the physical characteristics that has thixotropic character and that consists of inorganic and polycarboxylate co-polymer. In study, various testing methods are performed such as a viscosity, a thixotropy, a compressive strength, a heavy metal detection and pH measurement in lab test and a low pressure injection test and a high pressure injection test in field with different soil type. As a result, a optimum mix ratio is proposed by analyzing the result of lab test. the field applicability is verified by checking a injection pressure, a grout volume and a hardened body of grout by excavating the practice site.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.700-710
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• 2017

In the revision of the national curriculum, various creative activities and career activities are highlighted under the goal of fostering creative talent. Following the implementation of this policy, which is represented by creative activities, teachers are burdened with comprehensive responsibilities, such as planning and executing safety procedures and preventing accidents. Existing systems for teacher management had limitations that allowed only the provision of standardized information and management. The main purpose of this study is to help teachers manage their classes systematically through a class management system. The teachers' overall management system includes several functions, such as checking students' locations, registering students' reviews, or registering various kinds of activities for the creative experiential activities of the curriculum. This system not only helps teachers to systematically manage the creative experiential activities, but also allows teachers to share the history of their activities with each other. Furthermore, this system will be helpful in achieving the objectives of the revised curriculum.