• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.7
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• pp.1175-1181
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• 2001

An efficient hybrid method is proposed to analyze discontinuities in a rectangular waveguide. Only with a small number of meshes around a discontinuity, the typical finite element method is shown to give an exact solution through several iterative updates of the boundary conditions. To show the validity of the proposed method, a simple circular aperture in a rectangular waveguide is analyzed and its result is compared with FEBIM.

• Animal Systematics, Evolution and Diversity
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• v.36 no.2
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• pp.164-166
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• 2020

Herein, we report a new record of Notodontidae moth, Neodrymonia marginalis (Matsumura) in Korea. This species is characterized by grayish forewing that shows thick dark grayish band between basal and antemedial line, smooth postmedial line costally with blackish crescent line, dark grayish subtermen with dark brownish thick band costally, and whitish and black dot shaped discal dot. The female genitalia can be distinguished by the broad, plate-shaped postvaginalis, strongly sclerotized ductus dursae with three long spike shaped and several small spike shaped processes, and large, ovate corpus bursae with a large fan-shaped plate signum. Neodrymonia marginalis can be distinguished from N. deliana by the shape and color of the costal part of postmedial line and subtermen of forewing. The female genitalia of N. marginalis can be distinguished from those of N. deliana by the rectangular postvaginalis and more spike like processes of the anterior of ductus bursae. Up to now, four species of Neodrymonia are recorded in Korea: N. delia (Leech, 1889), N. coreana Matsumura, 1922, N. deliana Gaede, 1933, and Neodrymonia marginalis.

• KIEAE Journal
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• v.8 no.1
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• pp.37-44
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• 2008

Though they have advantages in terms of aesthetic in modern architecture, however, rectangular-shaped towers causes being short of natural light due to deep interior space. There are compromised attempts to take advantages of each building shape selectively. As a result, we now witness the advent of Y-shaped, T-shaped, V-shaped and ㅈ-shaped buildings on the market. The mutative type of apartment houses usually faces southwest or southeast, which has lot of daylighting availability but anyhow, the proportion of the apartment houses which have a full south aspect. The need to verify the potential of daylighting in new building-block shapes exists. At the same time, the expansion of balcony area was legalized and thus, a visual buffer area does not exist any more. All-glass window wall on apartment houses without a balcony produces pretty harmful area with direct sunbeam. Recently, the refurbished version of conventional windows has been developed for the purposed of minimizing energy loss occurred around windows. This research initialized a series of research to deal with almost all on window wall for apartment houses. First of all, huge amount of already-designed examples of apartment houses have been analyzed in terms of floor plan, elevation, orientation and glazing materials.

• Journal of electromagnetic engineering and science
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• v.16 no.1
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• pp.35-43
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• 2016

A compact ultra-wide band antenna with a quadruple band-notched characteristic is proposed. The proposed antenna consists of a slotted trapezoid patch radiator, an inverted U-shaped band stop filter, a pair of C-shaped band stop filters, and a rectangular ground plane. To realize the quadruple notch-band characteristic, a U-shaped slot, a complementary split ring resonator, an inverted U-shaped band stop filter, and two C-shaped band stop filters are utilized in this antenna. The antenna satisfies the -10 dB reflection coefficient bandwidth requirement in the frequency band of 2.88-12.67 GHz, with a band-rejection characteristic in the WiMAX (3.43-3.85 GHz), WLAN (5.26-6.01 GHz), X-band satellite communication (7.05-7.68 GHz), and ITU 8 GHz (8.08-8.87 GHz) signal bands. In addition, the proposed antenna has a compact volume of $30mm{\times}33.5mm{\times}0.8mm$ while maintaining omnidirectional patterns in the H-plane. The experimental and simulated results of the proposed antenna are shown to be in good agreement.

• The KSFM Journal of Fluid Machinery
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• v.18 no.3
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• pp.66-73
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• 2015

This paper deals with a parametric study on boot-shaped ribs in a rectangular cooling channel. Numerical analysis of the flow and heat transfer was performed using three-dimensional Reynolds averaged Navier-Stokes equations with the Speziale, Sarkar and Gatski turbulence model. The parametric study was performed for the parameters, tip width-to rib width, tip height-to-rib height, rib height-to-channel height, and rib height-to-width ratios. To assess the cooling performance and friction loss, Numsselt number and friction factor were defined as the performance parameter, respectively. The results showed that the cooling performance and friction loss were seriously affected by the four geometric parameters.

• Journal of architectural history
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• v.30 no.2
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• pp.19-28
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• 2021

The purpose of this study is to research about the construction of Chiseong around the Heunginjimun Gate area in the 18th century. the conclusions derived from the historical evidence of the number, location, size, and form, and construction method of Chiseong was as follows. First, the Chiseong(Square-shaped lookout) of Hanyangdoseong was built in the 29th year of King Yeongjo(1753) and can be found in the national record. Five sites of the Chiseong are currently identified. It is assumed that the Foru was installed on top of some of the Chiseongs. Second, Chiseong was destroyed sequentially in the first half of the 20th century. Third, Chiseong is a rectangular in shape and six are constructed. Fourth, Sixth Chiseong could figure out through Hengryeopungsokdo, the drawing of Jeong Seon.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.5
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• pp.107-114
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• 2019

In many military aircraft, s-shaped diffusers are used to prevent the fan blades of the turbofan engine from being exposed to the outside. The inlet configurations of the air intakes for military aircraft vary, such as the rectangular intake of the F-22, the crescent-like intake of the F-16, elliptical intake of the MQ-25. In this study, the aerodynamic performance of s-shaped diffusers with various inlet configurations was evaluated using numerical analysis. In addition, the configuration of the middle section of an s-shape duct was changed to the crescent shape, and the effects on its aerodynamic performance were investigated. As a result, there was a slight difference in total pressure recovery according to various inlet configurations with ellipse-shaped middle sections. Also, the total pressure distortion was the lowest in the rectangular inlet shape. When the configuration of the middle section was changed from an ellipse to a crescent shape, the total pressure recovery remained at a high level, except for the ellipse-shaped inlet configuration. In terms of total pressure distortion, the duct with the crescent-shaped middle section showed a significantly more uniform pressure distribution than that with the ellipse-shaped middle section.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.3
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• pp.465-473
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• 2012

In this study, a novel dual band planar monopole antenna for wireless local area network (WLAN)/ Worldwide Interoperability of Microwave Access (WiMAX) application was designed, fabricated, and measured. The proposed antenna consists of two hook shaped strips, an asymmetric ground plane, and a rectangular slit in the ground plane. Acceptable agreements between the measured and simulated results are achieved. Numerical and experimental results demonstrate that the proposed antenna satisfies the 10 dB impedance bandwidth requirement while covering the WLAN and WiMAX bands simultaneously. This paper also presents and discusses the 2D radiation patterns and 3D gains according to the results of the experiment that was conducted.

• Journal of the Korean housing association
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• v.17 no.2
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• pp.55-62
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• 2006

This study aims to analyze exterior spatial characteristics of the detached houses in Korea which were designed by professional architects. For this, plans, pictures and data of 113 houses which appeared in architectural publications from July 1998 to June 2002 were collected and analyzed. The results of the study are like this. 1) For the shape of buildings, the number of the non-rectangular shaped buildings is higher than that of the rectangular shaped ones. ; 2) For the location of exterior gardens, the number of the houses with front gardens is higher than that of the houses with back gardens. The exterior gardens are mostly accessed from the living rooms. 3) For the interior gardens, 50% of the surveyed houses have this type of gardens. They are mostly located at the back of the living rooms. The interior gardens are mostly accessed from the living rooms, dining rooms and corridors respectively. 4) For the terraces which are located in the 1st floor, they are mostly accessed from the living rooms. : 5) For the balconies which are located in the 2nd floor, they are mostly accessed from the bedrooms.; 6) For the location of the entrances, they are mostly located in the front side of the buildings and mostly facing south.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.83-84
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• 2016

A wideband stacked patch antenna with parasitic elements, rectangular and triangle shaped patches, is proposed. Two different shaped parasitic elements are placed in the above of main rectangular microstrip patch antenna in order to achieve wide bandwidth for 860 MHz band. Coupling between the main patch and parasitic patches is realized by thick air gap. The gap and locations of parasitic patches are found to be the main factor of the wideband impedance matching. The proposed antenna is designed on a ground plane with small size of $119mm{\times}109mm$ for application of compact transceivers. And the impedance bandwidth of the antenna should satisfied CDMA band to the 780MHz~890MHz.