• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.361-361
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• 2010

The separated quasi-one-dimensional ($7{\times}7$) and ($5{\times}5$) phases on vicinal Si(557) surfaces were successfully realized by changing the crystallographic orientation and thermal treatment conditions. A small change in the crystallographic orientation of the Si(557) surface stabilized the quasi-one-dimensional ($5{\times}5$) phase of a (111) facet on vicinal Si(557) surfaces and made it coexist with a quasi-one-dimensional ($7{\times}7$) phase after an optimal thermal treatment, whereas only the quasi-one-dimensional ($7{\times}7$) phase was stable on the Si(557) surface. Interestingly, this causes the (111) terraces with different widths (L) to prefer only one of the $5{\times}5$ (L=12) and $7{\times}7$ (L=9) phases resulting in long-range order of both phases along the step edge direction, which was observed by scanning tunneling microscopy (STM) and was supported by first principle calculations. In contrast, the quasi-one-dimensional ($5{\times}5$ and ($7{\times}7$) phases were arranged randomly across the step edge direction. The change of surface morphology of vicinal Si(557) surfaces will be discussed with STM images and theoretical calculations by changing crystallographic cutting angles and thermal treatment conditions.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.6
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• pp.626-630
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• 2022

A 100 mm × 50 mm-sized (100) gallium oxide (Ga₂O₃) single crystal ingot was successfully grown by edge-defined film-fed growth (EFG). The preferred orientation and the quality of grown Ga₂O₃ ingot were compatible with a commercial Ga₂O₃ substrate by showing strong (100) orientation behaviors and 246 arcsec in X-ray rocking curve. Raman characterization was also performed for both samples; thereby providing various Raman-active characteristics of Ga₂O₃ crystals. In particular, we observed A_g(5) and A_g(10) peaks of Raman active mode, directly related to the impurity of the grown Ga₂O₃ crystal. Hence, the comparison of the crystal quality and Raman analysis might be useful for further enhancement of Ga₂O₃ single crystal quality in the future.

• Journal of the Korea Society of Computer and Information
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• v.18 no.9
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• pp.53-62
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• 2013

This paper proposes a method of automatically predicting the vanishing point for the purpose of detecting the road region from natural images. The proposed method stably detects the vanishing point in the road environment by analyzing the dominant orientation of the image and predicting the vanishing point to be at the position where the feature components of the image are concentrated. For this purpose, in the first stage, the image is partitioned into sub-blocks, an edge sample is selected randomly from within the sub-block, and RANSAC is applied for line fitting in order to analyze the dominant orientation of each sub-block. Once the dominant orientation has been detected for all blocks, we proceed to the second stage and randomly select line samples and apply RANSAC to perform the fitting of the intersection point, then measure the cost of the intersection model arising from each line and we predict the vanishing point to be located at the average point, based on the intersection point model with the highest cost. Lastly, quantitative and qualitative analyses are performed to verify the performance in various situations and prove the efficiency of the proposed algorithm for detecting the vanishing point.

• Journal of Broadcast Engineering
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• v.17 no.2
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• pp.316-324
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• 2012

In this paper, a novel descreening method using HOG(histogram of gradient)-based adaptive smoothing filter is proposed. Conventional edge-oriented smoothing methods does not provide enough smoothing to the halftone image due to the edge-like characteristic of the halftone noise. Moreover, clustered-dot halftoning method, which is commonly used in printing tends to create Moire pattern because of the intereference in color channels. Therefore, the proposed method uses HOG to distinguish edges and the amount of smoothing to be performed on the halftone image is then calculated according to the magnitude of the HOG in the edge and edge normal orientation. The proposed method was tested on various scanned halftone materials, and the results show that it effectively removes halftone noises as well as Moire pattern while preserving image details.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.14 no.2
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• pp.47-59
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• 2019

Various studies have been carried out on the subject of entrepreneurship, which is required to create new businesses and organizations during the early process of startups based on innovative technologies and ideas. At the same time, the concept of organizational entrepreneurial orientation, which explains how to manage enterprises in the process of pioneering new products and markets, is drawing more and more attention for the purpose of continuously creating and maintaining a competitive edge of startups. This study focused on the relationship between entrepreneurial orientation and startup performance and the role of technological orientation and social capital. An empirical research was conducted on 144 different startup companies residing in startup supporting institutions. To evaluate the suitability of the research model, a PLS-based structural equation model was used. The research results are as follows: First, the entrepreneurial orientation of startups was found to have a positive effect on startup performance. Second, it was shown that entrepreneurial orientation had a positive effect on all three dimensions of social capital and technological orientation. Third, it has been shown that technological orientation and the cognitive dimension of social capital mediates the relationship between entrepreneurial orientation and startup performance. Through this, it was confirmed that entrepreneurial orientation directly affects startup performance, and it even influences the growth of startups by increasing technological superiority and social capital which is inherent in the network. Also, the research identified the need for additional research on the relationship between the strengthening of technological orientation and strategical orientation in startups. This study is expected to expand the discussion about social capital in the field of startup related research by affirming the role and importance of the cognitive system embedded in the network as well as the connectivity of networks, which has been already emphasized in previous startup related studies. Finally, the results of this study were reflected to present new practical implications.

• Journal of Korea Multimedia Society
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• v.23 no.10
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• pp.1229-1235
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• 2020

A line parallel to the ground is frequently shown in our daily life, which enables us to guess its direction. Especially, such a guess tends to become clear when a vanishing line of the ground is shown together. In this paper, a vision based pallet measurement method is suggested, which uses a technique for estimating three-dimensional direction of a line parallel to the ground. The technique computes actually a vector heading to intersection of a given imaged line parallel to the ground and the ground vanishing line determined previously on calibrating a measurement camera. Through an experiment of measuring a real commercial pallet with various orientation and distance, we found that the technique could measure the orientation of the pallet correctly and accurately. The technique worked well even though an edge line available on the front plane of a pallet was almost parallel to the ground vanishing line.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.32B no.1
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• pp.73-84
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• 1995

New morphological positioning algorithm and inspection method are presented and compared with a method by means of the Hough transform. The positioning algorithm is the process of finding the center and the rotated angle of the surface mounted device (SMD). The inspection method is capable of detecting the location of broken or bent leads. In order to obtain the center and the orientation of the SMD rapidly, the Hough transform method utilizes feature points (concave points) and is executed on a DSP board. The proposed morphological method is implemented by using the morphological skeleton subsets, and an ultimate orientation is decided by the Hit-or-Miss transform (HMT). In the inspection process, two inspection methods also are presented. The first method utilizes the morphological methods, i.e., opening and closing. It is performed before the positioning process and called an initial inspection. The second method follows the positioning process and is performed by an inspection of intersections of rulers and the lead edge (or the skeleton). It is a ruling technique which is referred to as a detailed inspection. We find the morphological approach is preciser and faster than the Hough approach by the comparison of the proposed algorithms.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.6 s.237
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• pp.876-888
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• 2005

Tensile properties and fracture toughness of monolithic aluminum, fiber reinforced plastics and glass fiber/aluminum hybrid laminates under tensile loads have been investigated using plain coupon and single-edge-notched specimens. Elastic modulus and ultimate tensile strength of GFMLs showed different characteristic behaviors according to the Al kind, fiber orientation and composition ratio. Fracture, toughness of A-GFML-UD which was determined by the evaluation of $K_{IC}$ and $G_{IC}$ based on critical load was similar to that of GFRP-UD and was much higher than monolithic Al. Therefore, A-GFML-UD presented superior fracture toughness as well as prominent damage tolerance in comparison to its constituent Al. By separating Al sheet from GFMLs after the test, optical microscope observation of fracture zone of GFRP layer in the vicinity of crack tip revealed that crack advance of GFMLs depended on the orientation of fiber layer as well as Al/fiber composition ratio.

• Journal of the Korean institute of surface engineering
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• v.43 no.2
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• pp.51-56
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• 2010

The zinc electroplating with respect to the chloride concentration was investigated by X-ray diffraction(XRD), scanning electron microscope (SEM), and cathodic polarization measurement. The cathodic overpotential during electroplating was first decreased and then increased with increase of chloride concentration in electrolyte. The decreased cathodic overpotential leads to preferred orientation of (002) plane, high current efficiency and satisfactory zinc deposits. The increased cathodic overpotential causes random orientation, low current efficiency and edge burning. The cathodic overpotential was affected by chloride concentration in electrolyte, not by the kind of chloride, such as NaCl and KCl. An optimized chloride concentration was 3 M for zinc electroplating. Also, it is considered that NaCl can be a alternation for KCl as a main salt of zinc electroplating bath.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.31 no.7 s.262
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• pp.628-634
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• 2007

The present study investigated the heat/mass transfer characteristics in an equilateral triangular channel simulating the leading edge cooling passage in gas turbine blade. Using naphthalene sublimation method and pressure measurement experiments, local mass (heat) transfer and pressure coefficients were obtained. The experiments were conducted with three rotating numbers between 0.0 and 0.1; two channel orientations of $0^{\circ}$ (model A) and $30^{\circ}$ (model B); the fixed Reynolds number of 10,000. The results showed that the channel rotation caused the heat transfer discrepancy between suction and pressure sides. Due to the secondary flow induced by Coriolis force, the high heat transfer appeared on the pressure side. When the channel orientation was $30^{\circ}$ (model B), the secondary flow caused the more uniform heat transfer distribution among leading edge and inner wall on pressure side than that of the model A.