• International Journal of Aerospace System Engineering
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• v.10 no.1
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• pp.1-13
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• 2023

The present study was attempted to investigate flow interference effects and the aerodynamic characteristics of the front and rear wings of a joined-wing aircraft by changing the configuration variables. The study was performed using a computational fluid dynamics(CFD) tool to demonstrate forward flight and analyze aerodynamic characteristics. A total of 9 configurations were analyzed with variations on the position, height, dihedral angle, incidence angle, twist angle, sweepback angle, and wing area ratio of the front and rear wings while the fuselage was fixed. The quantities of aerodynamic coefficients were confirmed in accordance with joined-wing configurations. The closer the front and rear wings were located, the greater the flow interference effects tended. Interestingly, the rear wing did not any configuration change, the lift coefficient of the rear wing was decreased when adjusted to increase the incidence angle of the front wing. The phenomenon was appeared due to an effective angle of attack alteration of the rear wing resulting from the flow interference by the front wing configurations.

• The Bulletin of The Korean Astronomical Society
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• v.45 no.1
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• pp.44.1-44.1
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• 2020

Hα jets of cool chromospheric plasma are protruding into the solar corona 10-100 Mm above the photosphere. The driving mechanisms of Hα jets have been widely studied for decades. However, the detailed process is still elusive. We observed shock signatures moving along a dark jet using 1.6 meter Goode Solar Telescope at Big Bear Solar Observatory. The first shock front of the jet shows sharp --- when it moves upward, while fuzzy and granulated when it moves downward. The jet itself extends upward when the second shock front of the jet reaches the top of the jet. We find abrupt EUV brightenings when the second shock front collides with the edge of the jet. The third front and the fouth front quasi-periodically. These phenomena might be the signs of the rebound shock waves triggered by p-mode wave leakages at the bottom of the jets. Our observation suggests that the jet can be triggered by the rebound shock waves generated by the p-mode waves leaked at the bottom of the jets.

• Journal of Haehwa Medicine
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• v.24 no.2
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• pp.17-24
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• 2016

Objectives : This study was aimed to widen range of comprehesion about meridian muscle system through myological study of meridian muscle system and comparison with deep front arm line in anatomical train Methods : We have studied the similarity and difference between Hand Great Yin Lung Meridian Muscle System and Deep Front Line in Anatomical Train through Principles of Meridians & Acupoints, publications about myology, Anatomical trains. Results : I. Like another advanced studies, muscular system of hand great yin showed similarity to deep front line in anatomical train. II. It is considered that muscular system of hand great yin contains Musculus abductor pollicis brevis, Musculus extensor hallucis longus, Musculus brachioradialis, Musculus biceps brachii, Musculus subclavius, Musculus pectoralis major. III. Comparing muscular system of hand great yin to deep front arm line in anatomical train it showed similarity to part of muscles and pathological symptoms. But it showed difference to part of muscles and pathological symptoms. Conclusions : Hand Great Yin Lung meridian muscle system showed similarity and difference to deep front arm line in anatomical train. Further studies would be needed.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.11
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• pp.61-68
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• 2008

In this paper, we propose a RF front-end developments for vehicle UWB radar systems. UWB systems have a very narrow pulse width that is below 1ns. Therefore, UWB is designed to have broadband quality of low power several GHz and must coexist with the radio communication system. UWB's advantages include high channel capacity and data rate, because precise resolution for multi-path can easily position estimate and Rake receiver. Also, UWB has low interference because it displays broadband quality of low power. Positioning is made possible by short range accuracy, which can reduce the expense of system design. An RF front-end module is designed using the DCR(Direct ConveRsion) method and is composed in RF for vehicles at a low-cost.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.12
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• pp.49-55
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• 2013

A high-voltage highly-integrated analog front-end (AFE) IC for medical ultrasound imaging applications is implemented using standard 0.18-${\mu}m$ CMOS process. The proposed AFE IC is composed of a high-voltage (HV) pulser utilizing stacked transistors generating up to 15 Vp-p pulses at 2.6 MHz, a low-voltage low-noise transimpedance preamplifier, and a HV switch for isolation between the transmit and receive parts. The designed IC consumes less than $0.15mm^2$ of core area, making it feasible to be applied for multi-array medical ultrasound imaging systems, including portable handheld applications.

• Journal of KSNVE
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• v.7 no.6
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• pp.959-966
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• 1997

In general, the booming noise intensity at tunnel exit is strongly related to the gradient of the compression wave front created by high speed train entering the tunnel. This paper presents some results in relation with the compression wave front produced when the high speed train enters a tunnel. Four kinds of tunnel entrance shape with real dimensions were studied to investigate the formation of compression wave front inside tunnel by train entering tunnel. Computations were carried out using three-dimensional compressible Euler equation with vanishing viscosity and conductivity of fluid. According to the results, the flow disturbances occured at tunnel entrance were eliminated by tunnel hood with same cross sectional area. The compression wave front is formed completely at 30-40m from tunnel entrance. The maximum pressure gradient of compression wave front is reduced by 29.8% for the inclined tunnel hood and reduced by 21.5% for the tunnel hood with holes at the top face with tunnel without hood. The length of the inclined hood is 15m and the length of the hood with holes is 20m.

• Korean Institute of Interior Design Journal
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• v.17 no.1
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• pp.155-161
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• 2008

In Seowon architecture, there are four kinds of space conditions according to the site plan and the figure of education area. The education area has three main buildings such as Kangdang, Dongjae, Seojae. In case Kangdan locates in front of Dongjae and Seojae(so called Junkangdang-Hoojaesa), but in another case Dongjae and Seojae locates in front of Kangdang(so called Junjaesa-Hookangdang). This four space conditions affect to decide the floor plan and the window & door system of Kangdang. In Junjaesa-Hookangdang type, the front and rear wall has more open system than in Junkangdang-Hoojaesa type. In Junjaesa-Hookangdang type the direction of Kangdang is absolutely open to front education area, but in Junkangdang-Hoojaesa type the direction of Kangdang is absolutely open to rear education area. These floor plan aims at making up education area more closely. In window & door system the rear parts of Junjaesa-Hookangdang type have generally opaque system such as Golpanmoon or Panjangmoon, but Junkangdang-Hoojaesa type breaks this rule in order to emphasize front facade of building.

• Proceedings of the KSRS Conference
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• v.2
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• pp.740-743
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• 2006

We identify two distinct finer-scale frontal bands: 'Mainland China Coastal Front' (MCCF) and 'Kuroshio Front' (KF). The MCCF is along the 50-m isobath with large temperature gradient. The front is a boundary between the Mainland China Coastal Current and the offshore shelf waters. On the other hand, the KF is extending from the northeastern coast of Taiwan toward the northeast and into the shelf of south ECS. It forms a broad semicircle-shape and curving along 100-m isobath, it also deviates from eastward at around 26.5N-122E and leaves the shelf of ECS. This front should be the boundary between the Kuroshio water and the other shelf waters.

• Journal of the Korean housing association
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• v.13 no.4
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• pp.1-10
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• 2002

The purpose of this study was to contribute to planning and developing various new apartment unit plans of the future through examining the differences on the spatial behavioral patterns and the post-occupancy evaluation between DK-front type and DK-rear type. 245 households which were included 79 DK-front types and 166 DK-rear types, were collected and analyzed at Masan and Gimhae cities in Kyungnam area. The result is as follows: 1) The analysis of the spatial behavioral patterns revealed that Anbang was the room for the couple independent from guests and children. Living room was the family's room for every activity, used more frequently DK-front types than DK-rear types. The family lift cycles of households, the visual unification between Living room and DK, the closed figures of DK in DK-front types have been influenced for the activities of Living room. 2) In the post-occupancy evaluation, DK-front types were positive in the lighting of DK area and its connection with Living room, while negative in the proximity from entrance to DK, cooking convenience, and the proximity between rooms. It was explained clearly through the reasons of the rejection of DK-front types from now.

• Journal of the Korean housing association
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• v.26 no.6
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• pp.139-146
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• 2015

In this study, the plane type of main building relics of unified Silla period house site which excavated in Gyeongju city after 1990s was classified and the architectural characteristic of them was investigated. The chronology of building relics in Silla capital city site was mostly known as 8-9th century, and by standard of column arrangement, the plane types of them could be classified as grid type, front veranda-grid type, outer column type. The outstanding characteristic of plane is wide span and open front veranda. In most relics the span were over 4 meters, and inner foundations for small post and strip foundation were found between columns. The front veranda added type buildings were composited of enclosed main room and open front veranda, and column arrangement of them dose not fall into line in most case. Thus it thought that the structures of enclosed main room and open front veranda were independent. The interior space of enclosed main room were divided two rooms by partition wall in some case. In this case, one room is enclosed by wall, and the other room has open front side. This plane is considered for the pleasant life in cold winter and hot summer.