• Journal of the Korea Society of Computer and Information
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• v.27 no.11
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• pp.13-18
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• 2022

In this paper, we proposed VW-FedAVG(Validation based Weighted FedAVG) which updates the global model by weighting according to performance verification from the models of each device participating in the training. The first method is designed to validate each local client model through validation dataset before updating the global model with a server side validation structure. The second is a client-side validation structure, which is designed in such a way that the validation data set is evenly distributed to each client and the global model is after validation. MNIST, CIFAR-10 is used, and the IID, Non-IID distribution for image classification obtained higher accuracy than previous studies.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.10
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• pp.877-886
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• 2016

A validation study is conducted for the conceptual design and performance analysis of UH-60A Black Hawk in order to establish the conceptual design and performance analysis techniques for conventional helicopters using a single main rotor and a tail rotor. As a tool for conceptual design and analysis, NDARC(NASA Design and Analysis of Rotorcraft) is used for the present study. The conceptual design for UH-60A is successfully validated as compared with the target values. Then, various performance analyses in hover and forward flight are conducted for the UH-60A model obtained from the present design work, and they are compared well with the wind tunnel test, flight test, and previous analyses using various analysis tools. Through this validation work, the conceptual design and performance analysis techniques for the conventional helicopter are appropriately established.

• Journal of computational fluids engineering
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• v.8 no.2
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• pp.42-48
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• 2003

The issues associated with the application of CFD for ship design are addressed. Doubtlessly at the moment, CFD tools are very useful in evaluating hull forms prior to traditional towing tank tests. However, time-consuming pre-processing is an obstacle in the daily application of CFD tools to improve hull forms. The accuracy of computational modeling without sacrificing the usability of CFD system is also to be assessed. The wave generation is still predicted by using potential panel methods, while velocity profiles entering into propeller plane is solved using turbulent flow solvers. The choice of turbulence model is a key to predict nominal wake distribution within acceptable accuracy. The experimental data for CFD validation are invaluable to improve physical and numerical modeling. Other applications of CFD for ship design than hull form improvement are also given. It is certain that CFD can be a cost-effective tool for the design of new and better ships.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.5-8
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• 2002

The issues associated with the application of CFD for ship design are addressed. It is quite certain that the CFD tools are very useful in evaluating hull forms a prior to traditional towing tank tests. However, the time-consuming pre-processing is an obstacle in the daily application of CFD tools to improve hull forms. The accuracy of computational modeling without sacrificing the usability of CFD system is also to be assessed. The wave generation is still predicted by using potential panel methods, while velocity profiles entering into propeller plane is solved using turbulent flow solvers. The choice of turbulence model is a key to predict nominal wake distribution within acceptable accuracy. The experimental data for CFD validation are invaluable to improve physical and numerical modeling. Other applications of CFD for ship design than hull form improvement are also given. It is certain that CFD can be a cost-effective tool for the design of new and better ships.

• 한국연소학회:학술대회논문집
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• 2015.12a
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• pp.271-272
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• 2015

Gas turbine combustors is critical part due to high temperature operating conditions and the optimization of cooling design is required to avoid combustor failure. In gas turbine combustor, effusion cooling, impingement cooling and thermal barrier coating (TBC) are commonly used to improve cooling characteristics. In conceptual design, these cooling schemes are designed by 1D heat transfer calculation. Therefore, these design should be validated ted by nemurical or experiment methods. In this study, Conjugate Heat Transfer (CHT) analysis is performed for validation of gas turbine combustor cooling design.

• KEPCO Journal on Electric Power and Energy
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• v.3 no.2
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• pp.89-97
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• 2017

The substation is a critical node in the power network where power is transformed in the power generation, transmission and distribution system. The IEC 61850 is a global standard which proposes efficient substation automation by defining interoperable communication and data modelling techniques. In order to achieve this level of interoperability and automation, the IEC 61850 (Part 6) defines System Configuration description Language (SCL). The SCL is an XML based file format for defining the abstract model of primary and secondary substation equipment, communications systems and also the relationship between them. It enables the interoperable exchange of data during substation engineering by standardizing the description of applications at different stages of the engineering process. To achieve the seamless interoperability, multi-vendor devices are required to adhere completely to the IEC 61850. This paper proposes an efficient algorithm required for verifying the interoperability of multi-vendor devices by checking the adherence of the SCL file to specifications of the standard. Our proposed SCL validation algorithm consists of schema validation and other functionalities including information model validation using UML data model, the Vendor Defined Extension model validation, the User Defined Rule validation and the IED Engineering Table (IET) consistency validation. It also integrates the standard UCAIUG (Utility Communication Architecture International Users Group) Procedure validation for quality assurance testing. Our proposed algorithm is not only flexible and efficient in terms of ensuring interoperable functionality of tested devices, it is also convenient for use by system integrators and test engineers.

• International Journal of Naval Architecture and Ocean Engineering
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• v.6 no.4
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• pp.800-812
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• 2014

The paper provides some results of a new procedure to analyze the hydrodynamic aspects of the interactions between maritime emerged breakwaters and waves by integrating CAD and CFD. The structure is modeled in the numerical domain by overlapping individual three-dimensional elements (Tetrapods), very much like the real world or physical laboratory testing. Flow of the fluid within the interstices among concrete blocks is evaluated by integrating the RANS equations. The aim is to investigate the reliability of this approach as a design tool. Therefore, for the results' validation, the numerical run-up and reflection effects on virtual breakwater were compared with some empirical formulae and some similar laboratory tests. Here are presented the results of a first simple validation procedure. The validation shows that, at present, this innovative approach can be used in the breakwater design phase for comparison between several design solutions with a significant minor cost.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.379-382
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• 2010

This study proposes a way to validate BIM data quality in BIM applications. Solibri model checker is adopted as a module development platform, which is based on Java programming language. The platform makes application developers implement BIM model checker for their own purpose. This study has developed a BIM validation module for circulation analysis of building design. The validation module enables end-users to automatically detect data corrupted or not defined. In case studies, the module found that an IFC file generated from a BIM software has wrong relation information between a space and boundary elements. A building model should satisfy modeling requirements and then domain users can get analysis results. The BIM data validation module needs to be developed in each BIM application domain.

• Proceedings of the KSR Conference
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• 2000.05a
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• pp.157-163
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• 2000

Testing evaluation is a part of process for design, production, evaluation, operation and abolition, and is the process of certifying system performance. The main purpose of testing evaluation is to reduce the risk factor under the determining process. Testing process has the three step such as design qualification, integration and validation test in factory, system integration and commissioning test. Design Qualification is to verify errors on the design process. Integration and validation test in factory is for the H/W and S/W of an equipment and is to verify interface of subsystem, communication protocol and main functions. System integration and commissioning test is a functional test to adjust successful installation of equipment. According to the testing process, briefly consideration for test item, test method and test contents about signalling system is carried out.

• Journal of Electrical Engineering and Technology
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• v.3 no.2
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• pp.243-253
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• 2008

This paper deals with the analysis, design, and implementation of a single phase AC-DC Zeta converter with high frequency transformer isolation and power factor correction(PFC) in two modes of operation, discontinuous current mode of operation(DCM), and continuous current mode of operation(CCM). A Digital Signal Processor(DSP) based implementation is carried out for validation of the Zeta converter developed design in discontinuous mode of operation. A comparison of both modes of operation is presented for a 1kW power rating from the point of view of steady state and dynamic behavior, power quality, simplicity, control technique, device rating, and converter size. The experimental results of a developed prototype of Zeta converter are presented for validation of the developed design. It is observed that CCM is most suitable for higher power applications where it requires some complex control and sensing of the additional variables.