• The Journal of the Acoustical Society of Korea
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• v.22 no.8
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• pp.660-669
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• 2003

This paper describes a theory to calculate sound source field from the spatial transform of sound field and the measured cross-power spectrum of sound pressure over a hologram plane close to a sound source, Calculating method is proposed to solve sound pressures from cross-power spectrums over a hologram plane, For this, Taylor series for the nonlinear equations is expanded, and it is calculated using Newton-Raphon method, Also, a wave number filter is used to reduce errors that is occurred on the backward propagation, and is performed numerical simulation of the circular piston sound source with infinite baffle in water to verify the proposed theory.

• Journal of Korean Society for Geospatial Information Science
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• v.19 no.4
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• pp.55-63
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• 2011

Having a wide angle of view, a fisheye lens is useful for obtaining images of the inside wall of a tunnel. A circular fisheye tunnel image can be transformed into a familiar rectangular image by applying the concept of cylindrical projection. This projection transformation causes several types of distortions in the projected image. This paper discusses the distortion on the boundary lines between smoothly curved wall and flat ground. We analyzed the cause of this boundary distortion, developed transformation model, and derived a correction formular. A distortion correction software programmed in Visual C++ applied to projected image. Consequently, boundary-corrected image could be obtained. Research into other distortions of projected image will helpful in obtaining tunnel image that resembles real tunnel from fisheye tunnel image.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.10
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• pp.1950-1956
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• 2017

In food-printing field, precise positioning technique for a printing object is very important. In this paper, we propose cup positioning method for a latte-art printer through image processing. A camera sensor is installed on the upper side of the printer, and the image obtained from this is projected and converted into a top-view image. Then, the edge lines of the image is detected first, and then the coordinate of the center and the radius of the cup are detected through a Circular Hough transformation. The performance evaluation results show that the image processing time is 0.1 ~ 0.125 sec and the cup detection rate is 92.26%. This means that a cup is detected almost perfectly without affecting the whole latte-art printing time. The center point coordinates and radius values of cups detected by the proposed method show very small errors less than an average of 1.5 mm. Therefore, it seems that the problem of the printing position error is solved.

• Journal of the Korea Society of Computer and Information
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• v.17 no.4
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• pp.41-49
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• 2012

This paper proposes a detection method of wipes including horizontal wipes with linear moving borders, such as horizontal or vertical wipes, Barn Doors, and Iris Rounds with circular moving borders. The suggested method first obtains a difference image between two adjacent frames, and extracts lines and circles by applying Hough transformation to the extracted difference image. Then, we detect wipe transitions by employing an evaluation function that analyzes the number of moving trajectories of lines or circles, their moving direction and magnitude. To evaluate the performance of the suggested algorithm, experimental results show that the proposed method can effectively detect wipe transitions with linear and circular moving borders rather than some existing methods.

• Korean Journal of Plant Resources
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• v.26 no.4
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• pp.511-515
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• 2013

Hypocotyls explants of melon seedling were cultured on Murashige and Skoog's (MS) medium supplemented with 1 mg/L 2,4-dichlorophenoxy acetic acid (2,4-D) and 0.5 mg/L benzyl aminopurine (BA) for 6 weeks to produce somatic embryos. In somatic embryos produced through intervening bright yellow friable (BYF) from the explants, somatic embryos with two-cotyledon (26%) and horn-type cotyledon (74%) were observed. The procambial strand of cotyledons was originated from circular procambial tissues of lower hypocotyls. The circular procambial independently divided into two procambial strand at the edge of cotyledonary-node, and then connected to each cotyledon to form somatic embryos with two-cotyledon. When cotyledon was horn-type, the circular procambial strand in lower hypocotyls would continuously remain connected to the cotyledon. However, somatic embryos with two or horn type cotyledon formed an abnormal shoot apex without the tunica-corpus structure or dome shape in the inter-cotyledonary area. These results demonstrated that the variation of cotyledon in somatic embryos was closely related to procambial tissue differentiation and shoot apical formation.

• Korean Journal of Microbiology
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• v.39 no.3
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• pp.128-134
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• 2003

Transformation-associated recombination (TAR) cloning is based on co-penetration into yeast spheroplasts of genomic DNA along with TAR vector DNA that contains 5'- and 3'-sequences (hooks) specific for a gene of interest, followed by recombination between the vector and the human genomic DNA to establish a circular YAC. Typically, the frequency of recombinant insert capture is 0.01-1% for single-copy genes by TAR cloning. To further refine the TAR cloning technology, we determined the effect of GC content on target hooks required for gene isolation utilizing the $Tg\cdot\AC$ mouse transgene as the targeted region. For this purpose, a set of vectors containing a B1 repeated hook and Tg AC-specific hooks of variable GC content (from 18 to 45%) was constructed and checked for efficiency of transgene isolation by radial TAR cloning. Efficiency of cloning decreased approximately 2-fold when the TAR vector contained a hook with a GC content ～${\leq}23$% versus ～40%. Thus, the optimal GC content of hook sequences required for gene isolation by TAR is approximately 40%. We also analyzed how the distribution of high GC content (65%) within the hook affects gene capture, but no dramatic differences for gene capturing were observed.

• Current Research on Agriculture and Life Sciences
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• v.4
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• pp.36-41
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• 1986

The transformation of Saccharomyces cerevisiae with YIp26, YRp7 and YEp13 was investigated. Transformation frequences of YIp5, YIp26, YRp7 and YEp13 in Escherichia coli HB101 was $5.1{\times}10^{-4}$, $1.5 {\times}10^{-3}$, $1.3{\times}10^{-3}$, $3{\times}10^{-3}$, respectively. When plasmids were used in covalently closed circular form, transformation frequency of YEp13 was $1.2{\times}10^{-4}$ in S. cerevisiae DBY747 and $3.3{\times}10^{-4}$ in S. cerevisiae MC16 and that of YRp7, YIp26 was $3{\times}10^{-6}$, below $6{\times}10^{-8}$ respectively in S. cerevisiae DBY747 by the method of Ito. Cotransformation of YIp26 and YEp13 in linear form increased the frequency of transformation with efficiences 270-fold higher than transformation of YIp26 only in S. cerevisiae DBY747. In cotransformation of YIp5+YEp13 and YIp26+YRp7 with S. cerevisiae DBY747 by Beggs' method. Expression frequency of YIp5+YEp13 and YIp26+YRp7 was $4{\times}10^{-6}$, $1.5{\times}10^{-6}$, respectively. The recombinant plasmid of cotransformant was thought that YIp26 and YEp13, YIp5 and YEp13, and YIp26 and YRp 7 were ligated in vivo in S. cerevisiae DBY747.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.8
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• pp.2079-2087
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• 1993

The effects of subcooling and natural convection are studied numerically on the melting process of an initially subcooled phase-change medium filled inside a horizontal circular cylinder. It is postulated that melting continues with the tube wall kept at a constant temperature and with the unmelted solid core fixed. Primary emphasis is placed on the evolution of interface morphology, the local/overall heat transfer rate at the tube wall and at the interface, and the structure of natural convection. The numerical results are mainly presented in terms of the Rayleigh and subcooling numbers. As the degree of subcooling intensifies, the melting rate and the movement of the interface are impeded but the interfaces are of similar shape with the passage of time. The heat transfer characteristics are found to be mostly governed by the formation pattern of natural convection in the liquid phase. Good agreement with available experimental data is found.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.2
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• pp.71-79
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• 2002

In this paper, an oil hydraulic pipeline is terminated by both rotary sinusoidal flow generator at upstream oriffice at down stream. The pulsating pressure wave from generated by the rotary sinusoidal flow generator, is measured by using sensor. In the analysis of this paper, a component of the fundamental frequency is obtained by using Laplace transformation.. The experimental and analytical results make clear that (1) viscosity is significant role in hydraulic pipe. (2) When pulsating frequency is matched with the natural frequency, resonance frequency occured periodically. According to the study proposed here, dynamic pressure in a circular oil pipe is expressed in propagation of pressure wave with respect to frequency and Bessel function. The resonance at oil temperature $20^{\circ}$$0^{\circ}C$ in this study. The abrupt change of gain value is due to effect of resonance frequency. The results of experiment are compared with the calculated results, and agreement of both results is fairly good.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.459-463
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• 1996

The lateral-shearing interferometer specially devised for production line inspection lenses is presented. The interferometer is composed with immersion oil and four prisms whose relative sliding motion provide lateral-shearing and phase-shifting. A special phase-measuring algorithm of a-bucket is adopted to compensate the phase-shifting error caused by the thickness reduction in the immersion oil Three different algorithm for determinating quantitative aberration of aspherical lenses are presented and compared with one another.