• Journal of the Korean Society for Railway
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• v.19 no.2
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• pp.213-223
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• 2016

Traffic jams occur frequently due to the dense populations of cities. Accordingly, the discomfort of citizens has increased. In order to minimize traffic inconveniences, various public transportation facilities have been suggested. In this paper, for the economical construction of a near-surface railway system, the design of a trench shield is developed and a review of its applicability is done by creating and testing trench shield equipment on a small scale. The trench shield consists of an excavation part, a shield part and an advancement part. To examine the applicability of the trench shield, a laboratory test is carried out. The results of the laboratory test confirm the possibility of reducing the construction time at open-cut construction sites through the excavation of the trench shield. Although the laboratory test is an indoor and relatively small-scale experiment, it is considered to be possible to secure a construction speed of 3m/day when the trench shield equipment is used.

• Journal of the Korean Society of Costume
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• v.57 no.9
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• pp.49-66
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• 2007

Trench coat derived from military uniforms was one of the classical fashion items and has been endeared as everyday outfits thanks to useful traits. Since 1990s classical design of trench coat began to be modified and many variant styles were appeared after 2000s. Trench coat designs after 2000s were appeared as tradition type that was stick to basic British classic style, variation type that was changed in details, colors, materials, and silhouettes, evolution type that was changed into new items, deconstruction type that was dissolved and open-structured. Modern trench coat expressed modern chic, elegance feminine, stylish casual, military and gangster images. The characteristics of trench coat as classic fashion were utility for everyday life style, excellent ability to express images, and strong visual effects of characteristic details. Trench coat was timeless as classic fashion, at the same time, changed into new fashion styles suitable for the sense of the times.

• Structural Engineering and Mechanics
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• v.11 no.5
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• pp.503-518
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• 2001

In this paper, the procedure for deriving an infinite element that is compatible with the quadrilateral Q8 element is first summarized. Enhanced by a self mesh-expansion procedure for generating the impedance matrices of different frequencies for the region extending to infinity, the infinite element is used to simulate the far field of the soil-structure system. The structure considered here is of the box type and the soils are either homogeneous or resting on a bedrock. Using the finite/infinite element approach, a parametric study is conducted to investigate the effect of open and in-filled trenches in reducing the structural vibration caused by a train passing nearby, which is simulated as a harmonic line load. The key parameters that dominate the performance of wave barriers in reducing the structural vibrations are identified. The results presented herein serve as a useful guideline for the design of open and in-filled trenches concerning wave reduction.

• KIEE International Transactions on Electrophysics and Applications
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• v.2C no.5
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• pp.262-267
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• 2002

In this paper, we first studied the factors affecting the motor current (MC) signal, which was strongly affected by the systematic hardware noises depending on polishing such as pad conditioning and arm oscillation of platen and recipe, head motor. Next, we studied the end point detection (EPD) for the chemical mechanical polishing (CMP) process of shallow trench isolation (STI) with reverse moat structure. The MC signal showed a high amplitude peak in the fore part caused by the reverse meal. pattern. We also found that the EP could not be detected properly and reproducibly due to the pad conditioning effect, especially when conventional low selectivity slurry was used. Even when there was no pad conditioning effect, the EPD method could not be applied, since the measured end points were always the same due to the characteristics of the reverse moat structure with an open nitride layer.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.10 no.2
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• pp.13-18
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• 2014

This paper proposes an optimum pipe material (PVC vs. PE) design & selection for open loop ground heat exchangers. Heat exchange efficiency and/or workability, and the need for trench insulation were investigated by comparing EWT (cooling mode) of each system. CFD simulations for the PVC and PE pipe with the same inner diameter show similar EWT. This is because the PVC pipe has a small thickness but a low thermal conductivity as compared to the PE pipe, and thus these two properties tend to offset each other. However, a hypothetically insulated pipe led to a meaningful drop of EWT. This means pipe insulation is of importance in performance of ground heat exchangers. From analyzing climate data and system operation, it is not advantageous to insulate trench pipes due to construction difficulties and ground temperature characteristics that are seasonally varied.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2007.11a
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• pp.87-88
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• 2007

무전해 구리 도금 공정에서 첨가제로 사용되는 HIQSA 화합물이 Damascene 공정을 이용한 60nm급 trench 패턴 내 무전해 구리 배선 형성 과정에 미치는 효과를 전기 화학적 기법과 광학적 기법을 이용하여 관찰하였다. HIQSA 농도별 open circuit potential의 변화를 관측한 결과, 3ppm 수준으로 첨가되었을 때, 무전해 도금 과정 중 가장 안정한 전위가 유지됨을 볼 수 있었다. 무전해 도금액 내 HIQSA 농도가 높아짐에 따라 구리 도금층의 두께는 지수적으로 감소하였으며, 표면의 결정 크기도 감소하였다. 60nm급 trench 내 무전해 구리 도금 시, 용액 내 침적 시간 60초가 무결함 superconformal copper filling을 얻기 위한 최적 시간이었다.

• Economic and Environmental Geology
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• v.54 no.2
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• pp.177-186
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• 2021

For disaster management and mitigation of earthquakes in Korea Peninsula, active fault investigation has been conducted for the past 5 years. In particular, investigation of sediment-covered active faults integrates geomorphological analysis on airborne LiDAR data, surface geological survey, and geophysical exploration, and unearths subsurface active faults by trench survey. However, the fault traces revealed by trench surveys are only available for investigation during a limited time and restored to the previous condition. Thus, the geological data describing the fault trench sites remain as the qualitative data in terms of research articles and reports. To extend the limitations due to temporal nature of geological studies, we utilized a terrestrial LiDAR to produce 3D point clouds for the fault trench sites and restored them in a digital space. The terrestrial LiDAR scanning was conducted at two trench sites located near the Yangsan Fault and acquired amplitude and reflectance from the surveyed area as well as color information by combining photogrammetry with the LiDAR system. The scanned data were merged to form the 3D point clouds having the average geometric error of 0.003 m, which exhibited the sufficient accuracy to restore the details of the surveyed trench sites. However, we found more post-processing on the scanned data would be necessary because the amplitudes and reflectances of the point clouds varied depending on the scan positions and the colors of the trench surfaces were captured differently depending on the light exposures available at the time. Such point clouds are pretty large in size and visualized through a limited set of softwares, which limits data sharing among researchers. As an alternative, we suggested Potree, an open-source web-based platform, to visualize the point clouds of the trench sites. In this study, as a result, we identified that terrestrial LiDAR data can be practical to increase reproducibility of geological field studies and easily accessible by researchers and students in Earth Sciences.

• Korean Journal of Materials Research
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• v.13 no.5
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• pp.333-337
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• 2003

We report a new fabrication process for carbon nanotube field emitters with high performance. The key of the fabrication process is trim-and-leveling the carbon nanotubes grown in trench structures by employing a planarization process, which leads to a uniform distance from the carbon nanotube tip to the electrode. In order to enable this processing, spin-on-glass liquid is applied over the CNTs grown in trench to have them stubborn adhesion among themselves as well as to the substrate. Thus fabricated emitters reveal an extremely stable emission and aging characteristics with a large current density of 40 ㎃/$\textrm{cm}^2$ at 4.5 V/$\mu\textrm{m}$. The field enhancement factor calculated from the F-N plot is $1.83${\times}$10^{5}$ $cm^{－1}$ , which is a very high value and indicates a superior quality of the emitter originating from the nature of open-tip and high stability of the carbon nanotubes obtained new process.

• The korean journal of orthodontics
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• v.25 no.5 s.52
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• pp.511-523
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• 1995

The elastic open activator is one of the modified myodynamic activator. The reduced size of the appliance mass motivates the patients' comfort and longer time of wearing. Its peculiarities in loose fitting and the lack of appliance stabilization in the mouth draws the tongue and the surrounding functional matrices on close interaction with the appliance, consigns the physiologic exertion to target structures, and eventually makes it feasible to the inland of non-extraction treatment In the context of the sagittal malocclusion, the orthodontic trench is dependent upon the growth of basal structure aimed, therefore, it is contemplated to grabble the effects of Elastic Open Activator upon the class II malocclusion of growing child retrospectively. The cephalometric headfilms and study models of nine Class II malocclusion of growing child retrospectively. The cephalometric headfilms and study models of nine class II division 1 and five division 2 patients were evaluated and analyzed, and the following observations were drawn, 1. The maxilla maintained a normal growth pattern in both groups. 2. The mandible grew anteroinferiorly in both groups. 3. The upper incisors tipped ligually in Class II division 1 and tipped labially in Class II division 2 and anterior vertical alveolar growth was interrupted in both groups. 4. The lower incisors tipped labially. 5. There was an arch expansion in both groups and increase of available space in Class II division 2

• Journal of Korean Tunnelling and Underground Space Association
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• v.6 no.4
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• pp.345-356
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• 2004

Open-cut method has been widely used to construct underground structures, but it causes several problems such as traffic congestion and public resentment resulting from severe construction noise and ground settlement. In many cases, it is very difficult to build underground structures safely due to the unknown locations of buried facilities such as water pipes, drainage pipes, gas pipes and high-pressure cable conduits etc. Also in open-cut method, moving buried facilities causes additional cost and extension of construction period. Therefore, this paper is to present a case study in which Tubular Roof construction Method (T.R.c.M.), a newly developed construction method for underground structures using slab steel pipes and PC wall trench, is applied for the construction of a subway tunnel in Seoul. As a result, it is found that T.R.c.M. is a construction method by which tunnels can be constructed safely without any effect on the surrounding environment and traffic flow due to the minimized construction vibration and noise.