• The KSFM Journal of Fluid Machinery
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• v.10 no.2 s.41
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• pp.22-31
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• 2007

This paper describes the shape optimization of rotor blade in a transonic axial compressor rotor. Three surrogate models, Kriging, radial basis neural network and response surface methods, are introduced to find optimum blade shape and to compare the characteristics of object function at each optimal design condition. Blade sweep, lean and skew are considered as design variables and adiabatic efficiency is selected as an objective function. Throughout the shape optimization of the compressor rotor, the predicted adiabatic efficiency has almost same value for three surrogate models. Among the three design variables, a blade sweep is the most sensitive on the object function. It is noted that the blade swept to backward and skewed to the blade pressure side is more effective to increase the adiabatic efficiency in the axial compressor Flow characteristics of an optimum blade are also compared with the results of reference blade.

• Journal of KIISE:Databases
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• v.30 no.4
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• pp.397-407
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• 2003

Transactions of updating spatial dta with mobile clients are log transactions because a user disconnected from a server surveys real features and updates them. In this environment, it is appropriate to exploit the optimistic approach based on the validation test in order to control the concurrency of transactions. On the contrary, the pessimistic concurrency control scheme makes transactions wait for a long time due to the lock. In this paper, we propose the surrogate transaction model and implement its manager for the S-S-M(Server-Surrogate PC-Mobile Client) structure which is appropriate for updating spatial data in mobile environments. In the S-S-M structure, the mobile client communicates with the server by the surrogate PC. We extend the validation condition in consideration of spatial relationships between spatial objects in this model. We also present the commit protocol where the user of a surrogate PC adjusts objects of the conflicted surrogate transaction to minimize costs for the abortion of the transaction.

• Journal of the Institute of Convergence Signal Processing
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• v.10 no.4
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• pp.256-261
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• 2009

While .NET and J2EE bisects recent distributed environment, .NET displays "Remoting" as a technology to call remote object. Remoting is frequently used as a protocol in OLTP's WEB program development in form of RPC that exchange data in XML form under HTTP environment. Purpose of this research is to draw problems when applying security to .NET remoting technology that is recently used in web programming, and to find effective application plan by implementing. The main discussion is following. First, network layer security should be replaced to application layer security for better performance and flexibility. Second, the serialization procedure that is repeated in both remoting and encryption module should take place once. Lastly, implementation of "Surrogate" and "Compress" will be discussed that enables to eliminate unnecessary data(table relations, keys, etc) that is used in dataset object of .NET in order to reduce the size of data. It is possible to achieve improvement in speed by two times through immediate implementation in these cases. In order for easier use, component based framework should be supplied hereafter.

• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.543-544
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• 2006

Shape optimization of a transonic axial compressor rotor operating at the design flow condition has been performed using three-dimensional Navier-Stokes analysis and three different surrogate models: i.e.., Response Surface Method(RSM), Kriging Method, and Radial Basis Function(RBF). Three design variables of blade sweep, lean and skew are introduced to optimize the three-dimensional stacking line of the rotor blade. The object function of the shape optimization is selected as an adiabatic efficiency. Throughout the shape optimization of the rotor blade, the adiabatic efficiency is increased for the three different surrogate models. Detailed flow characteristics at the optimal blade shape obtained by different optimization method are drawn and discussed.

• Tribology and Lubricants
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• v.30 no.1
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• pp.36-45
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• 2014

Understanding steel/skin contact phenomena is important for the study of object manipulation in robotics and has been a topic of great interest. In this study, pig skin was taken as a surrogate model for human skin, and its adhesive, friction, and deformation behaviors were measured under various exposure times to air. Indentation, friction, and scratch tests were performed at $25^{\circ}C$ and 45% relative humidity. The influences of adhesion and deformation on the coefficient of friction were characterized; the pig skin was found to be sensitive to the sliding velocity and normal load under the controlled experimental conditions.

• The Journal of Information Systems
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• v.12 no.1
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• pp.87-116
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• 2003

One of the important applications for business-to-business electronic commerce is in procurement and inventory management using electronic data interchange(EDI). Using online catalogs and approved supplier lists, firms can easily create requisitions and purchasing documents. The emerging trend in EDI technology is changed from VAN(Value Added Network) based EDI to XML based EDI. This paper intends to suggest a component-based XML/EDI system using Unified Modeling Language(UML), as an application system for automobile part industry. Applying component based XML/EDI systems designed with UML methodology, we analyzed the workflow and the document on procurement process between trading partners and implemented a prototype of efficient XML/EDI system, as a surrogate of existing VAN/EDI. The result of applying object-oriented CBD(Component Based Development) technique is to minimize the risk of life cycle and facilitate the reuse of software as mentioned to limitation of information engineering methodology. It enables the interoperability with corporate legacy systems such as ERP(Enterprise Resource Planning), SCM(Supply Chain Management). This system proposes a solution to apply analysis phase and design phase in implementation of XML/EDI system. The implementation of XML/EDI system using CBD shows the ease of use in software reuse and the interoperability with corporate internal information system. The purchasing department with XML/EDI system can electronically communicate purchase orders, delivery schedules to external suppliers and interoperate with other application systems.

• The Journal of Information Systems
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• v.12 no.2
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• pp.129-149
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• 2003

One of the important applications in Enterprise Resource Planning(ERP) systems is the Manufacturing Resource Planning(MRPII) system using Bill of Material(BOM). The manufacturing resource planning determines the quantity and timing of the production or purchase of subassemblies and raw materials needed to support the Master Production Scheduling(MPS). The bill of material is the recipe, a list of the materials needed to make a product. This paper intends to suggest a component-based materials management system using Unified Modeling Language(UML), as an application system for automobile part industry. Applying component based materials management systems designed with UML methodology, we analyzed the workflow and the document on materials management process from production planning to inventory management, and implemented a prototype of efficient materials management system, as a surrogate of existing material requirement planning(MRPI) system. To produce many other assemblies for a automobile part firm, component parts are assembled into subassemblies that are joined to assemble the finished product. Through the system suggested in this study, the level of inventory has cut down and the cost of inventory management has decreased. Also, the development method using UML makes the analysis and design phase to shorten in implementation period of MRPII system. The implementation of materials management system using CBD shows the ease of use in software reuse and the interoperability with corporate Internal information system. The result of applying object-oriented CBD technique is to minimize the risk of life cycle and facilitate the reuse of software as mentioned to limitation of information engineering methodology.