• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.103-105
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• 1994

A novel structure of a lineal microactuator has been designed and analyzed. The proposed structure can overcome serious problems from which conventional linear microactuators suffer, primarily due to the moving principle that is the repetition of attachment and detachment of the moving part to the fixed part. According to the calculated results, the proposed microactuator can generate force of a few mN and the moving sled of 13 cm/min under the condition of 100 volts and the frequency of 1.4 kHz.

• International Journal of Air-Conditioning and Refrigeration
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• v.13 no.2
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• pp.61-70
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• 2005

This study treats the numerical analysis of performance and design for plume abatement wet/dry cooling tower with a dry type heat exchanger. A two-dimensional analysis is performed using the finite volume method for mechanical draft counterflow and crossflow tower. For a coupling problem between water and air system, a turbulent two phase flow is considered. The Effectiveness-NTU method is used for modeling of the dry type heat exchanger. The parametric simulations such as the relative flowrate of air and attachment length of an air mixer are performed to examine the effect on plume abatement. It is found that if the relative air flowrate ratio and the adequate air mixer type are chosen well in addition to the ratio of water to air flowrate, the loss of cooling capacity and the additional cost are reduced and the plume is abated.

• Journal of Advanced Marine Engineering and Technology
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• v.23 no.2
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• pp.131-139
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• 1999

An experimental study was conducted to investigate the fouling effects of geothermal water scale deposited onto a heating surface upon its forced convection heat transfer characteristics. Scales deposited onto the heating surfaces of heat exchangers seriously reduce the heat transfer perfor-mance and also increase the hydrodynamic drag. Accordingly fouling is an important problem in the design and operation of heat exchangers. The cylinders were settled in tandem with equal dis-tance between neighbouring cylinders and only the test cylinder was heated under the condition of constant heat flux. The Reynolds number was varied from 13000310 through 50003100. It is found that the heat transfer of the in-line tube banks greatly varies with the fouling of geothermal water scale especially its scale height. Further the local and average Nusselt numbers strongly depend upon the cylinder spacing and the Reynolds number.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.150-155
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• 2005

In recent years, as the demands of VBNS(Very high speed Backbone Network Service) and VDSL(Very high-data rate Digital Subscriber Line) increase, the development of kernel parts of optical communication such as PLC(Planar Light Circuit), Coupler, WDM elements increase. The alignment and the attachment technology are very important to fabricate the optical elements for communication. In this paper, the mechanism of rotational stage are studied. with the three different method and the results of them are applied to the design of the system. The performance test of resolution and travel is performed.

• Transactions of Materials Processing
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• v.19 no.2
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• pp.113-119
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• 2010

Hydroforming is the technology that utilizes hydraulic pressure to form tube or sheet materials into desired shapes inside die cavities. Tube hydroforming provides a number of advantages over the conventional stamping process, including fewer secondary operations, weight reduction, assembly simplification, adaptability to forming of complex structural components and improved structural strength. In many case, hydroformed parts have to be structurally joined at some point. Therefore it is useful if the hydroformed automotive parts can be given a localized attachment flange. In this study for the numerical process design FE analysis was performed with DYNAFORM 5.5. Die parting angle and circumferential expansion ratio was optimized. With optimized condition, bulge and hydroforming experiments to form flange were performed. Forming characteristic at various pressure conditions was analyzed and optimized internal pressure condition was evaluated. The results show that flanged parts can be successfully produced by tube hydroforming process.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.3 s.96
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• pp.222-232
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• 1999

This paper describes the development of a precision 3-component load cell with plate beams which may be used for measuring forces Fx, Fy and moment Mz simultaneously in industry. We have derived equations to predict the bending strains on the surface of the beams under forces or moment. We have also determined the attachment location of strain gages of each sensor and fabricated 3-component load cell. To evaluate the rated strain and interference error of each sensor, we have carried out characteristic test of precision 3-component load cell. It reveals that the rated strain calculated from the derived equations are good agreement with the results from Finite Element Method analysis.

• Journal of IKEEE
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• v.23 no.1
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• pp.306-309
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• 2019

Wireless charging is a technology of transmitting power through an air gap to an electrical load for the purpose of energy dissemination. Compared to traditional charging with code, wireless power charging has many benefits of avoiding the hassle from connecting cables, rendering the design and fabrication of much smaller devices without the attachment of batteries, providing flexibility for devices, and enhancing energy efficiency, etc. A transmitting coil and a receiving coil for inductive coupling or magnetic resonant coupling methods are available for the near field techniques, but are not for the far field one. In this paper, the wireless power transfer (WPT) circuit by using magnetic resonant coupling method with a resonant frequency of 13.45 Mhz for the low power system is implemented to measure the power transmission efficiency in terms of mutual distance and omnidirectional angles of receiver.

• Journal of the Korean Society of Visualization
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• v.21 no.1
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• pp.74-79
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• 2023

Thrombogenesis, which is the process of blood clot formation, can be initiated by platelet activation. Excessive formation of blood clot in the bloodstream can lead to thrombosis. Therefore, when dealing with patients with disseminated intravascular coagulation (DIC) or children, it is necessary to use small amounts of blood. Hence, it is important to develop methods for the rapid and accurate measurement of the platelet function using a small amount of blood. In this study, 3D printing technology was utilized to facilitate the production of micro channels. The amount of platelet adhesion in smokers and non-smokers was compared by repeatedly exposing the structure of the channel to adjust the number of blood injections and facilitate thrombosis attachment to simple stenosis structures.

• Child Health Nursing Research
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• v.16 no.4
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• pp.249-258
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• 2010

Purpose: This study was done to provide a basis for future theory development by analyzing the phenomenon of parent-child relationships based on the 4 areas described by Kim (2000). Methods: A descriptive research design was used to identify research trends in nursing related to the phenomenon of parent-child relationships. Results: Before 1990, the trend in research design was quantitative designs, but since 1990, qualitative research has also been done. Mothers were the most popular research target for these studies followed by mothers and children together. In analyzing the 4 areas outlined by Kim (2000), it was found that most of the research was done on client domain and parents. The research concepts relevant to the essentialistic concept of research target, were 'child rearing', 'breast-feeding' and 'attachment'. For problematic concepts, the concept of 'stress' was continuously dealt with over the period and for the health-care experiential concept, 'adjustment' and 'coping' by parents were the main focus of research. Conclusion: The results show that parent-child relationship research was mainly concentrated on research participants and concepts. In the future, improvements should be made in research development of nursing practice programs and development of theory, to address the complete phenomenon of parent-child relationships.

• Journal of architectural history
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• v.12 no.2 s.34
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• pp.61-69
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• 2003

Manfredo Tafuri's Ideological criticism in architecture has opened a new horizon to interpreting architecture in modern capitalist architecture for it views architecture not just as a style or formal invention, but in terms of socio-economical process. It offered a comprehensive understanding of a chaotic situation of contemporary architecture and historical meaning modern architectural movements in relation with capitalistic development. However, it has been criticized as architectural pessimism which does not allow any possibility for progressive architectural practice. It was also criticized of epistemological problem of how one could be outside ideology without assuming true consciousness against false consciousness of ideology. Tafuri solves this problem by assuming Althusserian activist concept of knowledge and suggest the concept of labor of writing history of critical historians, instead of a design for utopian society, as a possible critical architectural practice. However, I argue that ultimately ideological criticism does not deny architectural practice itself, nor researches on formal characteristics of architecture. The problem lies rather in the architectural Intellectuals' attachment to the traditional concept of architect as a form giver to the society. By rejecting this myth and broadening the concept of architectural practice from design to production, we can find that Ideological problem is not architectural pessimism, but rather it opens up a new way of approaching to the problem of architectural practice in modern capitalist society.