• Journal of ILASS-Korea
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• v.26 no.3
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• pp.127-134
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• 2021

Fire sprinkler initial spray was analyzed by Large eddy simulation (LES) and Volume of Fluid (VoF) integrated method. The IsoAdvector geometric VoF was used to identify the liquid-gas interface clearly even with the large Courant-Friedrichs-Lewy number. To reduce the computational costs, sector meshes and Adaptive Mesh Refinement up to level 3 were used. Base mesh size was 1 mm, which is roughly equivalent to the initial sprinkler droplet. Top surface radius of boss and deflector size were modified to investigate the effects of sprinkler head design on primary breakup process. When top surface radius of boss was increased, vertical liquid sheet was formed. This phenomenon reduced the sheet breakup radius, sheet thickness and velocity. Due to reduced liquid sheet thickness, a large amount of ligaments was created from the liquid sheet. As a result, there was a dramatic decrease in volume per surface area, indicating an increase in breakup process. Spray pattern viewed in radial direction also changed when top surface radius of boss increased. When top surface radius of boss was increased, a T-shaped pattern was observed while a V-shaped pattern was observed in all other cases. When the deflector size increases, the spray pattern remains V-shaped, even if the top surface radius of boss increased. Further studies on promoting atomization of the water supplied to the lower part of the sprinkler head in the T-shape pattern should be conducted.

• The Journal of the Korea Contents Association
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• v.14 no.7
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• pp.45-57
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• 2014

This study examines subjects' eye movement pattern and surveys their attitudes to the exposed advertisements on the Facebook. Different from the F-shaped pattern of the typical Web pages, users' eye movements on the Facebook have shown a rough H-shape. Even though a large number of users have shown F-shaped pattern on the ordinary Web pages in order to skip the contents of a Web, subjects' eye-movement pattern on the Facebook has H -shaped pattern due to the unique User Interface (UI) of the Facebook. With the right side and vertical arrangement of ads on the Facebook, users skip the page with having a large H-shaped pattern. In addition, this study set four AOIs(Area of Interest) that are advertising sections comprised on the Facebook Web page and measured fixation length within the AOIs then surveyed subjects' attitudes about the exposed ads. Through the experiment and survey, this study offers the optimum advertising position that can attract Facebook users' attention. As the result of experiment and survey, the second ad has the subjects' highest attitude to advertising and fourth ad is the next effectiveness and first and third ad followed. This study highlights the key implications to provide better user experiences(UX) and marketing strategies to users who are the consumers of companies and organizations which have a plan to put their advertising on the Facebook.

• Knowledge Management Research
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• v.23 no.2
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• pp.193-210
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• 2022

The rapid development of mobile technology and the improvement of network speed are providing convenience to various services, and mobile shopping malls are no exception. Although efforts are being made to promote sales by combining various technologies such as customized recommendations using big data and specialized personalization services based on artificial intelligence, most mobile shopping malls have the same detailed page information structure including detailed product information. In this context, in this study, it was determined that the content layout of the product detail page and the mobile product detail page layout tailored to the consumer's preference should be presented according to the consumer's preference. Based on Higgins' Regulatory Focus Theory, a study of consumer propensity revealed that the content layout arrangement on a product detail page, when presented in an F-shape, informs the consumer that it is organized. If presented in a Z-shape, vivid information was recognized, and it was examined whether the product attitude and purchase intention were affected. As a result, when the content layout composition was presented as a layout arrangement in the form of a sense of unity and organization, prevention-focused consumers were positively affected by product attitudes and purchase intentions, and promotion-oriented consumers felt freedom. When presented in an arrangement, it was confirmed that the product attitude and purchase intention were affected.

• Journal of Plant Biology
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• v.29 no.2
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• pp.135-143
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• 1986

The distributional pattern of the bast fibres strands or bundles in the stems of Sida species represented in Nigeria is studied. Three major patterns of arrangement are recognized, namely aggregation of fibre strands into units with wedge-shaped, or triangular, rectangular, rhomboidal, square and trapezoid outlines; serial arrangement of fibre strands into rings or circular, ovoid, semi-circular or crescentic rows; and intermediate pattern in which both fibre strands-aggregates and serial rows of strands patterns are combined. The first pattern is found in S. linifolia, S. urens and S. scabrida, the second in S. cordifolia, S. pilosa, S. ovata, S. rhombifolia and S. spinosa, and the third in S. garckeana, and S. acuta. A dichotomous key based on these features is presented. Dimensional characteristics of the bast fibre cells are also given.

• Journal of Plant Biology
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• v.5 no.3
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• pp.1-4
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• 1962

A district (Sae-Bong) and 13 district (Sae-Jang Dong) grassland could be divided into four type of Community: Miscanthus-Community, Glyceria-Community, Festuca-Community, and Plantago-Community. Chose 17 or 20 stands from each district A and B and calculated F.I. with the Curtis method, finally vegetational continuum could be recognized while discontinuous boundary line of species distribution could not be recognized. As a rule the distributional curve of species was binominal or bell shaped. It had a distribution pattern peculiar to itself. As to the relationship of cattles' density and vegetation. I found that the tendency of F.I. moving from small to large paralleled that of disturbance-pressure from weak to strong. Found that the more the steepness of environmental factors be controlled by a rule " from large to small", the more F.I. might be controlled by a rule "from small to large" and that pH, soil-moisture-content, loss on ignition was in relation with the steepness. with the steepness.

• Journal of the Optical Society of Korea
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• v.13 no.1
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• pp.146-151
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• 2009

A Gaussian beam of single mode fiber laser was changed into a ring-shaped pattern after it was transmitted through the hollow optical fiber. The ring-shaped beam was focused on a plane by an f-. lens and it was scanned by a Galvano-mirror. The spatial profile of laser energy incident on a plane had two peaks at both sides of the scanned linear track. The profile was compared with the result obtained when the Gaussian beam was dithered transversely by an acousto-optic modulator. It is found that hollow optical fiber beam shaper can replace acousto-optic beam dithering device which is employed in a laser induced thermal printing system.

• Composites Research
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• v.17 no.5
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• pp.1-6
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• 2004

Composite pressure vessels with HDPE (high density polyethlyne) liner with metal boss at each end were developed by Filament Winding Process. The vessel is composed of a dome-shaped part at each end and a cylinder-shaped part at the middle of the vessel. The environmental tests carried out for possible vessel materials such as High Density Polyethlyn (HDPE), resins and reinforcing fibers up to a year showed no significant damages. The boss was designed to minimize the gas leak which was verified by FEM analysis. Most ideal fiber tension was obtained by experimental method and the fiber volume fraction, $\textrm{V}_{f}$, obtained by image analyzer were 55.4 % in cylinder and 55.6 % in dome parts, respectively. Winding pattern is programmed to control the composite thickness in the dome areas such that the failure of the vessel may occur in the cylinder. During the cure, the vessel was rotated and a constant internal pressure of 0.62 bar was applied. From this, the vessel's burst pressure is improved by 28 %. The burst and fatigue tests for under-wound and fully wound vessel showed satisfactory results.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.2
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• pp.291-298
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• 2018

In this paper, we propose an antenna that improves narrow band characteristics which is a disadvantage of inverted-F type antenna and utilizes the structural advantages of small size and low profile by modifying the inverted-F type antenna structure and applying CPW feeding method. Experimental results show that the broadband characteristic of about 40% at the center frequency of 3 GHz is seen, and it is found that the narrow band characteristic which is a disadvantage of the conventional inverted F antenna can be improved. The radiation pattern showed almost omnidirectional characteristics and the maximum gain was about 2.0dBi.

• Journal of the Korean Electrochemical Society
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• v.11 no.2
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• pp.100-104
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• 2008

Titanium sheet metal substrates used in thin film batteries were wet etched and their surface area was increased in order to increase the discharge capacity and power density of the batteries. To obtain a homogeneous etching pattern, we used a conventional photolithographic process. Homogeneous hemisphere-shaped wells with a diameter of approximately $40\;{\mu}m$ were formed on the surface of the Ti substrate using a photo-etching process with a $20\;{\mu}m{\times}20\;{\mu}m$ square patterned photo mask. All-solid-state thin film cells composed of a Li/Lithium phosphorous oxynitride (Lipon)/$LiCoO_2$ system were fabricated onto the wet etched substrate using a physical vapor deposition method and their performances were compared with those of the cells on a bare substrate. It was found that the discharge capacity of the cells fabricated on wet etched Ti substrate increased by ca. 25% compared to that of the cell fabricated on bare one. High discharge rate was also able to be obtained through the reduction in the internal resistance. However, the cells fabricated on the wet etched substrate exhibited a higher degradation rate with charge-discharge cycling due to the nonuniform step coverage of the thin films, while the cells on the bare substrate demonstrated a good cycling performance.

• Journal of Families and Better Life
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• v.17 no.4
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• pp.47-60
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• 1999

The predictions derived from Sternberg's triangular theory of love were tested in order to explain the love relationships in marriage among Korean people. We were first interested in whether the subjective love experiences of respondents could be characterized by three components: intimacy passion and commitment we then attempted to examine the time course of each component as the marital relationships continued. 16897 married men and women were asked to complete the questionnaire including the love scale developed by researchers based on Sernberg's and other researchers' work. The results are as follows: First the love experienced by Korean men and women in their marriage can be classified by 3 dimensions: intimacy passion and commitment. Secon intimacy is the most powerful indicator of love in marital rlationships follows bgy passion and commitment. Third each of the 3 dimensions of marital love showed a U-shaped pattern as the marriage continued. Fourth commitment was more table than the other 2 dimensions throughout the marriage. The resultso f the study showed that Sternberg's triangular theory of love is useful to explain the marital love among Korean people.