• Nuclear Engineering and Technology
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• v.38 no.7
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• pp.689-696
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• 2006

For a perforated plate, it is challenging to develop a finite element model due to the necessity of the fine meshing of the plate, especially if it is submerged in fluid. This necessitates the use of a solid plate with equivalent material properties. Unfortunately, the effective elastic constants suggested by the ASME code are deemed not valid for a modal analysis. Therefore, in this study the equivalent material properties of a perforated plate are suggested by performing several finite element analyses with respect to the ligament efficiencies.

• Journal of the Korea Fashion and Costume Design Association
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• v.21 no.1
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• pp.163-180
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• 2019

A pattern is a symbolic mark of the psychological expression and ornamental desire of the human interior. In particular, plant patterns, from ancient times to modern times, express beauty across both the east and the west. The Joseon dynasty had a strong national will, and it was a time when the symbolism of Korea was established. Plant patterns were decorative and symbolic, filled with meaning in both the textile and craft sectors. This study looked at the frequency and figurative characteristics of the types of plant patterns in textiles, ceramics, woodworking, and metal craftsmanship of the Joseon dynasty. In addition, pattern designs were developed by extracting unit patterns to maintain the original shape, and by adding, magnifying, reducing, and superimposing flat steps and employing the four-fold sequence. The data collected was 826 examples in textiles and crafts, and 34 species of plants were analyzed as follows. In general, the flower patterns preferred soft flowers, flowers, apricot, and peony patterns, and fruit patterns emerged as decorative designs for pottery and woodwork from the 17th century, featuring pomegranates, grapes, fluorines, peaches, and walnut floss. Textiles and woodwork were arranged with many circular designs, while pottery and metal crafts were filled in many ways. Expressive types appeared to be the same as stylistic types for textiles and ceramics, and the construction types were the same in pottery and metal crafts. As such, it was found that even in the different areas of the sculpture, the same aesthetic values were reflected in the common figurative features today. Therefore, in this study, we developed a unique and competitive pattern design that accommodates the modern times and the Joseon dynasty. This development is expected to contribute not only to the development of cultural and tourism products in the future, but also to the tourism industry induced by the Korean wave.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.330-333
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• 2002

This study Presents improvement of Precision in the non-contacted laser application measuring techniques. The phase map of deformation obtained by phase shifting method in Electronic Speckle Pattern Interferometry displays the wrapped image by the arctangent function, which is a characteristic of 4-step phase shifting method. To obtain deformation distribution from the results, the wrapped phase map is processed by an unwrapping method. But a previous method cannot apply discontinuous object as like plate with a circular hole to obtain precious deformation distribution To solve this problem, new algorithm is developed and the result is compared with previous method.

• Journal of Microbiology and Biotechnology
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• v.23 no.9
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• pp.1287-1292
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• 2013

Extracellular biogenic synthesis of silver nanoparticles with various shapes using the rice bacterial blight bacterium Xanthomonas oryzae pv. oryzae BXO8 is reported. The synthesized silver nanoparticles were characterized by UV-Vis spectroscopy, powder X-ray diffractometry (XRD), scanning electron microscopy, energy dispersive X-ray spectrometry, and high-resolution transmission electron microscopy (HR-TEM). Based on the evidence of HR-TEM, the synthesized particles were found to be spherical, with anisotropic structures such as triangles and rods, with an average size of 14.86 nm. The crystalline nature of silver nanoparticles was evident from the bright circular spots in the SAED pattern, clear lattice fringes in the high-resolution TEM images, and peaks in the XRD pattern. The FTIR spectrum showed that biomolecules containing amide and carboxylate groups are involved in the reduction and stabilization of the silver nanoparticles. Using such a biological method for the synthesis of silver nanoparticles is a simple, viable, cost-effective, and environmentally friendly process, which can be used in antimicrobial therapy.

• Transactions of Materials Processing
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• v.15 no.9 s.90
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• pp.686-691
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• 2006

Powder blasting technique was introduced to micromachine the micro patterns of circular and rectangular shape in LGP mould. The machinability of these patterns and matt treatment by powder blasting were verified. Then a prototype of LGP was injected by the developed LGP mould with micro patterns. Shape analysis of micro patterns and performance test of the injected LGP were carried out. The results showed printless LGP with micro patterns could be produced by just single injection using the mould with micro patterns, and powder blasting technique could be successfully applied to micrornachining of micro patterns and matt treatment of LGP mould.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.2
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• pp.47-55
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• 1996

A microwave incoherent imaging method for a conducting cyliner by using multi-frequency tiem-harmonic field is presented in this study. In this paper, an incoherent intensity pattern of th econducting cylinder is obtained by averagin gout the multi-frequency intensities of the coherent field such as the time-harmonic field scattered from this cylinder. This phenomenon is hsown numerically in scattering by a conducting circular cylinder illuminated by the time-harmonic plane wave, and is interpreted analytically by the mutual coherence functon defined as a frequency-averaged intensity of the time-harmonic fields in th frequency domain.

• Journal of electromagnetic engineering and science
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• v.7 no.3
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• pp.129-133
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• 2007

In this paper, we present the development of an antenna specialized for the maritime collision avoidance system. This antenna is configured as the dielectric rod partially embedded in the metal cavity to reduce the overall size, simultaneously assuring the mechanical sturdiness against the challenging oceanic weather conditions. More importantly, the design has been carefully done to meet the requirements on the radiation pattern(with the slope < 5 dB/deg in the elevation(E-plane), circular in the azimuth) suitable to receiving the reflected signals from the other objects on the sea. To find the optimal design parameters, the genetic algorithm has been used to meet the goals of the desired return loss and pattern. This design methodology is validated by the good agreement between the calculation and measurement.

• Journal of information and communication convergence engineering
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• v.12 no.2
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• pp.83-88
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• 2014

The simultaneous suppression of sidelobes and the sharpening of the central peak in the process of diffraction pattern detection based on asymmetric apodization have been investigated. Asymmetric apodization is applied to a semicircular array of two-dimensional (2D) aperture functions, which is a series of 'coded-phase arrays of semicircular rings randomly distributed over the central circular region of a pupil function' and is similar to that used in the field of diffractive optics. The point spread function (PSF) of an imaging system with asymmetric apodization of the discrete type has been found to possess a good side with suppressed sidelobes, whereas its bad side contains enhanced sidelobes. Further, the diffracted field characteristics are obtained in the presence of these aperture functions. Asymmetric apodization is helpful in improving the performance of the optical gratings or 2D arrays used in real-time imaging techniques.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.807-808
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• 2008

This is concerned with the radiation pattern of elastic waves in a plate generated by an orientation-adjustable patch-type magnetostrictive transducer. In general, not only the Lamb waves but also shear horizontal (SH) waves are produced by the deformation of the circular magnetostrictive patch bonded to a plate. Among the two types of waves, this paper investigates the radiation patterns of SH waves. A number of experimental results are presented. They are also accurately predicted by a theory developed by the present authors. Experimental findings were explained by a theoretical analysis.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.5
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• pp.385-390
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• 2002

To clarify the hydraulic characteristics of ice slurry which made from 6.5% ethylene glycol-water solution flowing through circular pipes of small diameter, experimental studies were performed. The flow pattern was observed and the pressure drop was measured in acrylic pipes with inner diameter of 24 mm. The results of flow visualization revealed that ice particles flowed along the top of pipes in the ranges of small ice fraction and low flow rate, while Ice particles diffused into the whole region of pipes flowed like a homogeneous flow for high flow rate and high ice fraction. An increase in frictional pressure drop was measured as the ice fraction increased in all pipes and unstable flow was observed for up-ward vertical pipe.