• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.11a
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• pp.154-155
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• 2005

A trial excavation of underwater cultural properties at Dongsam site in Busan has been conducted. The site is located in the vicinity of Dongsam shell mound. The trial excavation consists of the shore investigation and the underwater investigation. For the shore investigation four trenches were digged. For the underwater investigation twenty boreholes were cored, and sediments at four predetermined sites were removed by air lifting technique. From the trial excavation a stump of a tree with many pieces of wood, and a few fragments of earthenwares were found. A comprehensive study of the trail excavation might furnish data for studying ancient coastal environment.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.911-913
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• 1999

Shallow Trench Isolation (STI) has become the most promising isolation scheme for ULSI applications. The stress of STI structure is one of several factors to degrade characteristics of a device. The stress contours or STI structure vary with the trench depth. Isolation characteristics of STI was analyzed as the depth of trench varied. And transistor characteristics was compared. Isolation punch-through voltage for n$^{＋}$ to pwell and p$^{＋}$ to nwell increased as trench depth increased. n$^{＋}$ to pwell leakage current had nothing to do with trench depth but n$^{＋}$ to pwell leakage current decreased as trench depth increased. In the case of transistor characteristics, short channel effect was independent on trench depth and inverse narrow width effect was greater for deeper trenches. Therefore in order to achieve stable device, it is important to minimize stress by optimizing trench depth.

• 한국지구물리탐사학회:학술대회논문집
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• 2006.06a
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• pp.209-210
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• 2006

The Bismarck Sea represent a unique region in the equatorial western Pacific where one can explore the relationship between tectonic and magmatic processes associated with back-arc opening. The sea, located north of Papua New Guinea and just south of the equator, formed during the final stages of a long, complex geological development of the Melanesian Borderland. The development resulted from the Cenozoic convergence between the Australian and Pacific- Caroline Plates and the opening of back-arc basins. At present, the Bismarck Sea straddles two oppositely facing trenches, the inactive Manus trench and the active New Britain trench, and covers two basins, the New Guinea Basin (NGB) to the west and the Manus Basin (MB) to the east. The two basins are separated by the shallow Willaumez-Manus Rise (WMR), which trends roughly from WNW to ESE. The origin of these major structural units and their relationship with the presentday zone of major seismicity along the Bismarck Sea Seismic Lineation (BSSL) remains unclear and is the main focus of our study.

• International Journal of Highway Engineering
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• v.19 no.1
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• pp.29-36
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• 2017

PURPOSES : This study mechanically analyzed the performance of road substructures with focus on infiltration trenches of pavement substructures. METHODS : Water contents and response times for precipitation of pavement substructures were investigated via sensors buried near the infiltration trench to measure water contents. RESULTS : The results of the water contents of pavement systems constructed with an infiltration trench yield levels that were slightly increased by approximately 2% compared to those measured from general pavement systems. This water content difference of 2% resulted in a decrease in service life of less than two years. CONCLUSIONS : Service life reduction due to an infiltration trench is minimal, particularly when the trench is installed with proper caution.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1900-1906
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• 2000

In this study, the vibration screening effectiveness of barriers which can isolate structures from ground-transmitted vibration generated by harmonic forces is performed. For high frequencies, the vibration screening effectiveness of barriers is analyzed from field tests, and compared with the results from numerical analyses using a commercial program, ANSYS. Using these numerical analysis procedures, the effectiveness for vibration with various low frequencies is predicted. The frequency analysis tests of surface waves are performed in order to estimate the dynamic material properties of soil for 100 Hz, 150 Hz, 200 Hz, and 250 Hz. Three-dimensional solid elements are used in order to consider the diffraction of waves in all directions. Spring-damper combination elements are used in order to avoid the reflection of waves on the boundary. The results of numerical analysis agree with those of field tests. From the results of this numerical analyses, the reduction of vibration for low frequencies induced by the traffic loads can be predicted.

• Journal of the Korean institute of surface engineering
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• v.41 no.1
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• pp.23-27
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• 2008

The effect of solution agitation on the copper electroless deposition process of ULSI (ultra large scale integration) interconnections was investigated by using physical, electrochemical and electrical techniques. It was found that proper solution agitation was effective to obtain superconformal copper configuration within the trenches of $130{\sim}80nm$ width. The transition of open potential during electroless deposition process showed that solution agitation induced compact structure of copper deposits by suppressing mass transfer of cuprous ions toward substrate. Also, the specific resistivity of copper layers was lowered by increasing agitation speed, which made the deposited copper particles smaller. Considering both copper deposit configuration and electric property, around 500 rpm of solution agitation was the most suitable for the homogeneous electroless copper filling within the ultra-fine patterns.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.5
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• pp.342-350
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• 2008

This paper presents the results of a laboratory study on the thermal conductivity of sand (silica, quartzite, limestone and masonry sand)-water mixtures used in ground heat exchanger backfilling materials. Nearly 150 tests were performed in a thermal conductivity measuring system (TPSYS02) to characterize the relationships between the thermal conductivity of mixtures and the water content. The results show that the thermal conductivity of mixtures increases with increasing dry density and with increasing water content. The results also show that for constant water contents and a dry density value, the thermal conductivity of mixtures increases with increasing thermal conductivity of solid particles. The measurement results were also compared with the most widely used empirical prediction models for the thermal conductivity of soils.

• Applied Chemistry for Engineering
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• v.10 no.7
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• pp.985-989
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• 1999

Silica($SiO_2$) thin film was synthesized by a low pressure metal organic chemical vapor deposition(LPMOCVD) using organic silane compound. Triethyl orthosilicate was used as a source material. Operation pressure was 1~100 torr at outlet of the reactor and deposition temperature was $600{\sim}900^{\circ}C$. The experimental results showed that the high reaction temperature and high source gas concentration led to higher growth rate of $SiO_2$. The step coverage of films on micro-scale trenches was fairly good, which resulted from the phenomena that the condensed oligomers flow into the trenches. We estimated a reaction path that the source gas polymerizes and produces oligomers (dimer, trimer, tetramer, etc.), which diffuse and condense on the solid surface. The chemical species in the gas phase at the outlet of reactor tube were analyzed by quadrapole mass spectrometer. The peaks, assigned to be monomer, dimer of source gas and geavier molecules, were observed at 650 or $700^{\circ}C$. At higher temperature($900^{\circ}C$), the peaks of the heavy molecules disappeared, because almost all the source gas and intermediate(polymerized oligomer) molecules were oxidized or condensed on colder tube wall.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.18 no.1
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• pp.91-102
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• 2020

According to the Korea Radioactive Waste Agency's (KORAD's) medium and low level radioactive waste management implementation plan, the Domestic 3rd Step Landfill Disposal Facility has planned to accept a total of 104,000 drums (2 trenches) of very low level radioactive waste (VLLW), from the decommissioning site from April 2019 - February 2026 (total budget: 224.6 billion Won). Subsequently, 260,000 drums (5 trenches) will be disposed in a 34,076 ㎡. Accordingly, KORAD is preparing a waste acceptance criteria (WAC) for this facility. Every disposal facility for VLLW in other countries such as France and Spain, operate their WAC for each VLLW facility with a reasonable application approach, This, paper focuses on analyzing the WAC conditions in VLLW sites in the USA and discusses whether these can be met in domestic VLLW WAC. It also helps in the preparation of WAC for the 3rd Step Landfill Disposal Site in Gyeongju, since the USA has prior experience on decommissioning nuclear waste.

• Journal of Powder Materials
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• v.20 no.2
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• pp.120-124
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• 2013

This study is carried out to develop the new process for the fabrication of ultra-fine electrodes on the flexible substrates using superhydrophobic effect. A facile method was developed to form the ultra-fine trenches on the flexible substrates treated by plasma etching and to print the fine metal electrodes using conductive nano-ink. Various plasma etching conditions were investigated for the hydrophobic surface treatment of flexible polyimide (PI) films. The micro-trench on the hydrophobic PI film fabricated under optimized conditions was obtained by mechanical scratching, which gave the hydrophilic property only to the trench area. Finally, the patterning by selective deposition of ink materials was performed using the conductive silver nano-ink. The interface between the conductive nanoparticles and the flexible substrates were characterized by scanning electron microscope. The increase of the sintering temperature and metal concentration of ink caused the reduction of electrical resistance. The sintering temperature lower than $200^{\circ}C$ resulted in good interfacial bonding between Ag electrode and PI film substrate.