• Proceedings of the KSME Conference
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• 2003.04a
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• pp.2076-2082
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• 2003

A cross-flow fan is widely used on many industrial fields: mining industry, automobile and home appliances, etc. The design point of the cross-flow fan is generally based on the region within low static pressure and high flow rate. It relatively makes high dynamic pressure at low speed because a working fluid passes through an impeller blade twice. However, it has low static pressure efficiency between 30% and 40% because of relative high impact loss. Recently, in the air-conditioning systems, the operating behaviors at the off-design points are highly regarded to broaden the application area for various air-cooling loads. Especially, at the lower flow rate, there exists a rapid pressure head reduction, a noise increase and an irregular flow field against a rearguider as a scroll of centrifugal fan. Numerical analyses are carried out for investigating the flow characteristics in a cross-flow fan including the impeller, the rearguider and the stabilizer. Especially, various types of rearguiders are estimated by numerical and experimental methods to insure the stable operation in the region of lower flow rate. Numerical domains are discretized by hexahedral cells. Three-dimensional, unsteady governing equations are solved using FVM, PISO algorithm, sliding grid system and standard ${\kappa}-{\varepsilon}$ turbulence model. ASHRAE standard fan tester is also used to estimate the performance of the modeled crossflow fan.

• The Journal of Society for e-Business Studies
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• v.21 no.4
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• pp.151-159
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• 2016

The user interface is an important factor in providing efficient services to application users. In particular, mobile applications that can be executed anytime and anywhere have a higher priority of usability than applications in other domains.Previous studies have used prototype and storyboard methods to improve the usability of applications. However, this approach has limitations in continuously identifying and improving the usability problems of a particular application. Therefore, in this paper, we propose a usability analysis method using touch gesture data. It could identify and improve the UI / UX problem of the application continuously by grasping the intention of the user after the application is distributed.

• Research in Community and Public Health Nursing
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• v.19 no.1
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• pp.101-111
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• 2008

Purpose: This study was to analyze the trends of research on school health by examining papers related to school health. Method: This studt was analyzed all related papers published in journals concerning school health from 2000 to 2006. The data were processed statistically by frequency percentage and content analysis. Results: Among 463 papers in 6 journals related to school health. 'The Journal of the Korean Society of School Health' had the largest number of articles. Descriptive research design was the most frequently used research design, and students were the most frequent research target. Among research writers, the professor group was largest, and schools were the most frequently used place for research. The most common sampling method was convenient sampling. The most common research instrument was questionnaire survey. Parametric statistics were the main methods of data analysis. Among the themes of school health, the adoption of nursing process frames and assessment domains occupied the largest portion. Health was the most common key concept, and the mainly used theory in the journals was factor-isolating. Conclusion: Through the analysis of research trends, we expect a higher level of school health research.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.10
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• pp.866-872
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• 2008

Torsional oscillations of the mechanical drivetrain in electric vehicles are generated under rapid driving conditions. These lead to an uncomfortable jerking of the vehicle and to an increased stress of the mechanical components. To analyze this phenomenon, a drivetrain model is constructed with lumped parameters. The model parameters are identified by geometrical design data and experimental tests. The proposed model is validated by simulation and experimental tests in the time and the frequency domains. As a result, the torsional oscillations are observed at 7Hz of a low damped natural frequency. Also, the analysis of the effect of the parameter variations on the oscillations shows that the oscillation characteristic is mainly dependent on the rotor inertia, and the stiffness of the mounting of the drive aggregate and the driveshaft. The results will be utilized on the basis of the design of an electric drivetrain and an active control of drivetrain oscillations.

• Korean Journal of Computational Design and Engineering
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• v.13 no.2
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• pp.89-97
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• 2008

Today's manufacturing environment is becoming a distributed manufacturing process in which a unique and specialized technological background is required in specific domains rather than having a single company execute all the manufacturing processes. This phenomenon is especially true in the automotive industry, where the sharing of product data between companies is rampant; however, this kind of interoperability causes many problems. When each company has its own method of managing product data, the sharing of product data in a distributed environment is a major problem. A data translator module or a data mapping module had to be developed for the exchange of data in heterogeneous systems of product data management (PDM); moreover, this type of module must be continually changed and improved due to the fact that PDM systems change for many reasons. In addition, the growth in corporate partnerships deepens the burden of developing and maintaining this module and creates further data exchange problems due to the increasing complexity of the system. This paper introduces a way of exchanging product data among heterogeneous PDM systems through the use of OpenPDM, which is a kind of virtual data warehouse. The implementation of a PDM integrating system is also discussed with respect to the requirement for a logical integration of product data which are physically distributed.

• Asia pacific journal of information systems
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• v.8 no.2
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• pp.1-18
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• 1998

As the management and preservation of the environment become an important social issue, information required to support environmental task is required. So, there is an increasing demand for environmental information and appropriate systems to manage it. The vast volume of environmental data is distributed in different knowledge domains and systems. Environmental data objects have the complex structure containing environmental quality data and attribute data. Environmental information systems must be able to address these properties. This research has aimed at constructing well-defined schema design of environmental data, and making system architecture that environmental data kept by authorities should be made available to the public user. There are 3 major components in environmental information systems architecture ; User interface, Catalog libraries, Communication Provider. Web browsers provide consistent and intuitive user interfaces on Internet. The communication provider is a collection of diverse CGI functions. The main roles of the CGIs are to build interfaces between the Web, databases. Catalog libraries is libraries of various matadata including administration matadata. Administration matadata support the environmental administration and the managerial aspects of environmental data rather than explain a database itself or its properties.

• The Journal of Korean Association of Computer Education
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• v.7 no.4
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• pp.43-50
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• 2004

Multi-lingual query answering system is the system which answers on the queries with several languages. LASSO[l] is the system that aims to answer the multi-lingual query. In this paper, we design and implement a Korean analysis system for LASSO. The Korean analysis system for query answering needs processing techniques of dialogue style. And the system must be practical and general so as to use on various domains. This system uses not dialogue processing techniques with high cost and low utility but heuristic rules with low cost and high utility. It is designed and implemented as a Korean interface of multi-lingual query answering system. The techniques of this system highly contribute to information retrieval and Korean analysis researches.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.804-807
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• 2005

Design Up/Down converters which use Digital IF(Intermediate Frequency) techniques from the present paper, against hereupon performance the criticism. The reason which uses Digital IF techniques is configured of passive elements and the positions IF frequency domains are fixed and they do not use in the position one frequency but, the external fringe land of the board which comes to be configured with Digital IF without from the communication frequency domain which is various there to be a flexibility, the use was under possibility. Like this configuration compares in analog Heterodyne mode of existing and it has the performance upgrade which is excellent it shows a high flexibility.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.8
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• pp.1774-1779
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• 2005

This paper propose the design method of the constructing the digital logic systems over galois fields using by the galois field decision diagram(GFDD) that is based on the graph theory. The proposed design method is as following. First of all, we discuss the mathematical properties of the galois fields and the basic properties of the graph theory. After we discuss the operational domain and the functional domain, we obtain the transformation matrixes, $\psi$GF(P)(1) and $\xi$GF(P)(1), in the case of one variable, that easily manipulate the relationship between two domains. And we extend above transformation matrixes to n-variable case, we obtain $\psi$GF(P)(1) and $\xi$GF(P)(1). We discuss the Reed-Muller expansion in order to obtain the digital switching functions of the P-valued single variable. And for the purpose of the extend above Reed-Muller expansion to more two variables, we describe the Kronecker product arithmetic operation.

• The KIPS Transactions:PartD
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• v.11D no.6
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• pp.1341-1348
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• 2004

As of an international standard in e-business domains, ebXML solutions are required to be tested and authenticated whether they can satisfy the conformance and interoperability requirements. In this paper, we design and implement the ebXML conformance and interoperability testing tools that observe the standard specification in conformity with ebXML Message Service v2.0, ebXML Registry Service v2.0 and ebXML CPP/A Y2.0. With this regard, our research would serve in building the verification and authentication service infrastructure for fitting standard ebXML e-business solutions with ebXML conformance and interoperability testing tools.