• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.11
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• pp.1561-1568
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• 2001

In the present study, flow characteristics of turbulent pulsating flow in a square-sectional 180$^{\circ}$curved duct were experimentally investigated. The experimental study for air flows in a curved duct are carried out to measure axial velocity profiles, wall shear stress distributions and entrance length in a square-sectional 180$^{\circ}$curved duct by using the Laser Doppler Velocimeter(LDV) system and the data acquisition. Velocity profiles are obtained using the Rotating Machinery Resolver(RMR)and PHASE software in case of turbulent pulsating flow. Finally, it was plotted by the ORIGIN software. The experiment was conducted in seven sections from the inlet (ø = 0$^{\circ}$) to the outlet (ø=l80$^{\circ}$) at 3 0$^{\circ}$intervals of the duct.

• Journal of Navigation and Port Research
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• v.30 no.2
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• pp.125-130
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• 2006

Waves, which are the main source of ship motions in a seaway, considerably affect the performance of a ship. The study of waves and their impact on ship motions within harbors is an important aspect of the design and operation of harbors. The prediction of incoming groups of waves is particularly important for evaluating ship motion within a harbor. Such a prediction makes it possible to evaluate ship safety more accurately. The wave transformation model reported here is applied to actual ports based on Boussinesq wave equations both non-linear and dispersive wave processes be considered in order to capture physical effects such as wave shoaling, refractions, reflection and diffraction in variable depth environments. The prediction of incoming groups of waves is particularly important for evaluating ship motion within a harbor, Such a prediction makes it possible to evaluate ship safety more accurately and provide safe wave informations for navigation. Furthermore, a wave information support system is proposed for entering ships as one technique for improving the safety of ship operations. This system predicts the run of waves and reduces the danger by identifying the most dangerous point near the harbor entrance at the small wave groups.

• Elastomers and Composites
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• v.22 no.3
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• pp.213-218
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• 1987

In this study, the rheological properties of a partially valcanized black filled EPDM were investigated as a function of degree of crosslinks using capillary rheometer. In order to obtain the samples having various degree of crosslinks between 0 and 6 percent, the vulcanization kinetics was also studied by Monsanto rheometer. The results showed that the die swell ana the pressure drop at the capillary entrance and exit increase nearly linearly with the increase in degree of crosslinks. However, melt fracture occurred at a lower shear rate for the samples of higher degree of crosslinks. These results were discussed in terms of the melt elasticity produced at the entrance region of capillary by the partial vulcanization. It is also interesting to note that the fluctuation of die swell during the practical extrusion or calendering process in the factories can be caused by the partial vulcanization occurred during the process.

• Journal of architectural history
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• v.7 no.2 s.15
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• pp.63-76
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• 1998

Seowon(書院) was an institute for education and sacrificial rite, established privately in rural villages throughout the middle period of the Chosun dynasty(1392-1910), where scholars researched classic studies, cultivated personal characters in accordance with the Neo-Confucianism, nurtured young disciples, and performed rites at a secluded shrine where spiritual tablets of honorees were housed. This study examines the architectural characteristics of Pilamseowon(筆巖書院) in Chans'seong, Chollanamdo Province, Korea. Through the study, the architectural characteristics of Pilamseowon were found as follows: First, Pilamseowon moved twice since it had been established. Second, through the moving, the area of Pilamseowon was expanded and buildings were added. Third, some buildings of Pilamseowon reflect the previous condition of the seowon site. Take Hwakyeonroo(廓然樓) as an example, which is the main entrance pavilion of Pilamseowon. Pavilion is an appropriate type of building in sloped site. Before Hwakyeonroo was moved to the present site, it was located on sloped site, where Hwakyeonroo accordingly took the pavilion type of building. Present site condition of Pilamseowon is plane, nonetheless, Hwakyeonroo has the pavilion type of building, which reflects the previous condition of the building site. Forth, Pilamseowon consists of six spatial domains and each domain has its own entrance gate to outer area.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.5
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• pp.95-103
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• 2013

Protection of the electrical and electronic equipment against surges in low voltage AC power distribution systems is based on wide applications of surge protective devices(SPDs). Cascade application of SPDs located at the service entrance of a building and near sensitive equipment is intended to ensure the optimal voltage protection level and energy sharing among cascade SPDs. In this paper, when surges impinge at the service entrance of the building of interest, the protection characteristics of two-stage cascade SPD systems were investigated. The influence of the distance between the upstream and downstream SPDs on the voltage protection level and energy sharing of the two-stage cascade SPD systems were analyzed experimentally. It was found that the energy sharing of two-stage cascade SPD systems strongly depends on the distance between the two SPDs and the component of SPD. As the distance between the two SPDs increases, the energy absorbed by the upstream SPD increases while the energy absorbed by the downstream SPD decreases. Consequently, it is desirable to select the upstream and downstream SPDs having the proper energy capability with due consideration of the distance between the two SPDs.

• Journal of the Korean Institute of Rural Architecture
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• v.18 no.4
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• pp.33-40
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• 2016

The campus outdoor space in each city is a very important space for students and local residents. Especially, for students, indoor space such as classroom is the main place to learn knowledge. But the outdoor space provides an opportunity to interact with people in other sectors and it also gives an opportunity that can make students sense the flow of the times. Moreover, students have the opportunity to integrate knowledge of the other fields in the outdoor space. The campus also provides an important resting place for residents. Therefore the campus should be convenient for both local residents and students, and should be designed to let students and local residents communicate with each other in outdoor space. This study attempts to identify the problems of the outdoor space in such a point. The high scores of campus evaluation indexes are as follows: First, the lighting in the favorite space and installing seats in a green space of the vestibule get the highest score. Also, separation of a sidewalk and a roadway, the ease of holding events, simple food and beverage near the entrance, the interacting place of people, the resting place near the porch in cold winter, the lighting in a bus stop and parking lot also get good evaluations.

• Journal of Hydrogen and New Energy
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• v.23 no.5
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• pp.545-550
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• 2012

This work is for the design study of natural gas reformer (40 $m^3/hr$ over). We used experimental kinetic data from literature. After that, we set up theoretical model based on experimental reaction kinetic data. The shape of reactor is 1.7 m long and 200 mm dia. with cylinder geometry. Volume of reactor is 53.4 liter. Average flow velocity of gases in the reactor has been determined 0.272 m/sec and residence time is 9.26 sec. Reaction temperature is $850^{\circ}C$, with pressure 9.3 Bar. Used natural gas volume is about 9.21 $m^3/hr$. Produced hydrogen is 43.7 $m^3/hr$ with no change of pressure. Unreacted natural gas is 0.09 $m^3/hr$ and the amount of steam is 26.9 $m^3/hr$. Steam to $CH_4$ (s/c ratio) is 2.91. Reforming reaction take place from the reactor entrance to 120 cm region of cylinder type reactor. After the entrance of reacting gases to 120 cm region, the reaction reaches equilibrium which is close to products. This study can be applicable to design various reactors. Output data is in good agreements with the data in literatures1).

• Journal of Fashion Business
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• v.23 no.4
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• pp.1-12
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• 2019

The study investigated trends in wall-covering displays in interior design stores. Although studies reported design trends at well-known exhibitions overseas such as Heimtextil and Maison objet, many different cases present actual realistic design flows. This study analyzes the actual market flow rather than design as an exhibition concept, and presents the interior CMF trends in 2019. The CMF design of wall-covering displayed in New York D&D Building in 2019 can be summarized as follows: W was the most frequently seen show-window, but like R, which is a strong color, it is also used to convey surrealistic images. The store entrance was designed to attract consumers' attention inside, and was constructed to reflect the actual trend. In the 2019 New York market, the wall-covering of Gray and YR were displayed through the shop entrance to suggest substantial sales. In addition, the demand for gold metallic wall-covering is significant as gold was strong in many forms. This study represents a valuable resource to identify trends in wall-covering from 2017 to 2019 compared with previous studies. This study represents a valuable foundation for a wide range of topics related to the use of wall-covering for interior decoration.

• Korean Journal of Materials Research
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• v.31 no.8
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• pp.450-457
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• 2021

From measured thermal conductivity and modeling by simulation, this study suggests that U-factors are highly related to materials used between steel and polymer. The objective and prospective point of this study are to relate the relationship between the U-factor and the thermal conductivity of the materials used. For the characterization, EDX, SEM, a thermal conductive meter, and computer simulation utility are used to analyze the elemental, surface structural properties, and U-factor with a simulation of the used material between steel and polymer. This study set out to divide the curtain wall system that makes up the envelope into an aluminum frame section and entrance frame section and interpret their thermal performance with U-factors. Based on the U-factor thermal analysis results, the target curtain wall system is divided into fix and vent types. The glass is 24 mm double glazing (6 mm common glass +12 mm Argon +6 mm Low E). The same U-factor of 1.45 W/m²·K is applied. The interpretation results show that the U-factor and total U-value of the aluminum frame section are 1.449 and 2.343 W/m²·K, respectively. Meanwhile, those of the entrance frame section are 1.449 and 2.

• Journal of English Language & Literature
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• v.64 no.2
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• pp.187-201
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• 2018

Horatio Alger's Ragged Dick (1868) betrays the economic and social system of nineteenth-century America through a self-reformative bootblack's quest for respectability. Being considered a space of constant danger, nineteenth-century New York City serves as a game board, and both visitors and residents of the city are supposed to avoid dangers while moving across its space. Dick Hunter, the juvenile protagonist of the novel, illustrates a street-child who starts his game of life from the backline of the game board. Continuing his quest for respectability, not only must he abandon the bad habits that he acquired as a street-child, but he also must avoid thieves and swindlers just like a tourist or like a player of nineteenth-century American board games. As Dick's social rise goes parallel with his movement in the city space, his entrance to a bank brings him the access to other respectable places, and a series of entrance turns him into a legitimate subject in the official system of the American society. While he continues his game of life successfully with the help of gentlemen patrons, in reality it is almost impossible for a disadvantaged player to escape the backline of the society. Thus, Dick's success story presents Alger's fantasy about the ideal economic system in which materials and persons are endlessly circulated.