• Journal of Korean Library and Information Science Society
• /
• v.49 no.3
• /
• pp.111-132
• /
• 2018

The purpose of this study was to identify the structure and pattern of conclusions chapters in research articles selected in four representative journals published in Korean LIS. To analyse the structure and pattern five categories and eleven elements drawn from RA conclusions were used such as 'Drawing Attention', 'Summarizing', 'Discussing', 'Applying' and 'Extending'. The Findings are as follows. 'Conclusions' was the most used title of the chapter, and then 'conclusions and suggestions'. The conclusions sections were consisted averagely 4.2 elements. 'Summary of findings' was the most frequently elements, followed by 'summary of research process', 'suggestion of further research' and 'implication'. Also, 'summary of findings' was the most used in lengths. 'Summarizing' was the highest frequency in five categories, followed by 'Extending', and 'Applying'. The dominant first element begun conclusions sections was 'summary of findings' and the final element closed conclusion was 'suggestion of further research'. 'Summary of research process - summary of findings' order was found in the most frequent pattern of conclusions. 'Summary of findings' and 'summary of research processes' in 'Summarizing' were found as essential functions, while other elements, such as significance, 'application', 'limitations' in 'Applying' and 'Extending' were found as optional functions in the conclusions of Korean LIS research articles.

• Journal of Korea Water Resources Association
• /
• v.45 no.9
• /
• pp.915-928
• /
• 2012

Han River estuary (HRE) is located at the middle of the western coast of Korea, and tidal currents were measured at 4 stations in this estuary during the winter season, and previously observed tide data was analyzed. The results of amplitude ratio of $M_4/M_2$ showed that increasing upward to estuary in the HRE. Tide harmonic constants of relative phase $2M_2-M_4$ represent flood dominance, with under 180 degree. But this method has a limit of analysis that typically based on the non-linear distortion of the tidal current in tidal lagoon system where freshwater discharge is assumed to be relatively small. The results of statistically tidal current data indicated that ebb current velocity would be great unlike tide data. Ebb and flood duration time is calculated by slack time of tidal current showed that ebb duration time is longer than flood. The results of correlation of analysis show high value (0.9) between tidal current stations from Incheon harbor to north entrance of Yeomha channel. We reconstructed to find the reasons for the features of ebb dominance the results of harmonic analysis. As major component ($M_2$) in combination with shallow water component ($M_4$), the tidal curve was presented flood dominance that has a flood current is stronger. However, these curve were changed to ebb dominance add up the non-harmonic components that had ebb direction flow by calculated tidally averaged current. The characteristic of enhancement on ebb is showed around the Yeomha channel in the HRE, because averaged flow which acts seaward such as long-term tidal current components due to non-linear effect and freshwater which overcome the flood current.

• Journal of the Korean earth science society
• /
• v.29 no.3
• /
• pp.255-262
• /
• 2008

Late Cretaceous to early Tertiary paleostress was evaluated by analyzing the healed microcracks in the Cretaceous granite of the Goheung area, south Korea. Healed microcracks in five granite samples (GH-1, GH-3, GH-4, GH-5, GH-8) were investigated and measured according to direction. The directions of maximum horizontal principal stress in GH-1, GH-3, and GH-4 are dominantly $N60^{\circ}W\;and\;N70^{\circ}E,\;N20^{\circ}W\;and\;N50^{\circ}W$, while minor directions are N-S and $N30^{\circ}E$. In GH-5 and GH-8, $N40^{\circ}E\;and\;N10^{\circ}E$ are the most dominant directions, while $N40^{\circ}W$ is the minor direction. Thus overall, the most dominant directions of healed microcracks in the study area are oriented $N60^{\circ}W$, while minor directions are oriented $N20^{\circ}W,\;N20^{\circ}E\;and\;N70^{\circ}E$, essentially NE. Combining the paleostress results of this study with other studies, the direction of the maximum horizontal principal stress in the study area during the late Cretaceous to the early Tertiary should perhaps be changed WNW to NE. The reason for this is thought to be the complex tectonic movements which occurred in northeast Asia at that time.

• Proceedings of the Acoustical Society of Korea Conference
• /
• 1998.06e
• /
• pp.147-150
• /
• 1998

천해에서의 음파전달은 심해와 비교하여 복잡하고 경계면의 영향을 많이 받으며 서해에서 하계의 평균 수온자료로 잔향음을 계산한 결과 해저면 잔향음(reverberation)이 가장 우세한 것으로 나타났다. 특히 서해에서는 하계에 내부파에 의한 강한 수온약층의 생성이 관측되었으며, 이런 현상은 음파전달에 많은 영향을 줄 것으로 예측된다. 내부파를 조석에 의한 장주기와 단주기로 구분하여 적용한 결과 고주파 음원을 사용할 경우 장주기 내부파에 의한 수온약층의 수식변동에 따른 잔향음은 최대 13dB까지 차이가 났으며 단주기 내부파의 경우 수온약층의 하강한 경우 수온약층이 상승한 경우보다 근거리에서 전달손실 변화가 작았다.

• 한국지구물리탐사학회:학술대회논문집
• /
• 2006.06a
• /
• pp.35-38
• /
• 2006

The polarized direction of MT field was analyzed using the MT dataset measured in the Korean Peninsula. The atmospherics above 1 Hz has a large dispersion of polarized direction, whereas the Schumann resonance near 8 Hz exhibits the predominant direction ranging from $N20^{\circ}W$ to NS. The electromagnetic field variations below 0.1 Hz, induced by magnetic pulsations, show a strongly polarized direction of nearly NS. It results from the regular pulsations since the regular pulsation fields, driven by Alfv.n's wave in the magnetosphere, has a worldwide predominant direction of NS. The MT field strongly polarized along NS direction causes the poorly behaved XY impedance.

• Journal of the Korean Geotechnical Society
• /
• v.38 no.11
• /
• pp.69-86
• /
• 2022

The railway is widely used to transport passengers and freight due to its punctuality and large transport capacity. The recent remarkable development in construction technology enables various subsea railway tunnels for continent-continent or continent-island connectivity. In Korea, design and construction experience is primarily based on the successful completion of the Boryeong subsea tunnel (2021) and the Gadeok subsea tunnel (2010). However, frequent earthquakes with diverse magnitudes, globally induced and continuously increased the awareness of seismic risks and the frequency of domestic earthquakes. The effect of an earthquake on the subsea tunnel is very complicated. However, ground conditions and seismic waves are considered the main factors. This study simulated four ground types of 3-dimensional numerical models, such as soil, rock, composite, and fractured zone, to analyze the effect of ground type and seismic wave. A virtual subsea railway shield tunnel considering external water pressure was modeled. Further, three different seismic waves with long-term, short-term, and both periods were studied. The dynamic analyses by finite difference method were performed to investigate the displacement and stress characteristics. Consequently, the long-term period wave exhibited a predominant lateral displacement response in soil and the short-term period wave in rock. The artificial wave, which had both periodic characteristics, demonstrated predominant in the fractured zone. The effect of an earthquake is more noticeable in the stress of the tunnel segment than in displacement because of confining effect of ground and structural elements in the shield tunnel. 

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.30 no.4
• /
• pp.324-327
• /
• 2019

This study analyzes the low-frequency magnetic shielding effectiveness (SE) of a metal plate, in terms of diffusion and slot effects, by conducting a numerical simulation and implementing an analytical solution. When the metal has a low conductivity, the SE is dominated by the diffusion effect. However, when the conductivity and frequency both increase, the slot has a major influence on the SE. These results can be used as guidelines in the shielding design and SE requirements of electromagnetic pulse protection facilities.

• Journal of the Korean earth science society
• /
• v.30 no.1
• /
• pp.19-32
• /
• 2009

Paleostress was interpreted by analyzing the healed microcracks and the secondary fluid inclusions in quartz of the Jurassic granites distributed in the southwestern Ogcheon Folded Belt, South Korea. The most dominant direction of healed microcracks in the study area was oriented $N30^{\circ}W$, and $N70^{\circ}W$ direction was also recognized. The formation temperatures of fluid inclusions were ranged $380-550^{\circ}C$ and the age of healed microcrack formations might have been approximately 166-200 Ma. Comparing the paleostress orientation obtained from the direction of healed microcracks to the formation age of healed microcracks estimated from the secondary fluid inclusions, it is considered that granitic rock body in study area was subject to a maximum horizontal principal stress along the NNW-SSE and WNW-ESE directions in the early Jurassic to middle Jurassic.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.10 no.3
• /
• pp.151-159
• /
• 2012

The potential repository domains for A-KRS (Advanced Korean Reference Disposal System for High Level Wastes) in geological characteristics of KURT (KAERI Underground Research Tunnel) facility site were proposed to develop a repository system design and to perform the safety assessment. The host rock of KURT facility site is one of major Mesozoic plutonic rocks in Korean peninsula, two-mica granite, which was influenced by hydrothermal alteration. The topographical features control the flow lines of surface and groundwater toward south-easterly and all waters discharge to Geum River. Fracture zones distributed in study site are classified into order 2 magnitude and their dominant orientations are N-S and E-W strike. From the geological features and fracture zones, the potential repository domains for A-KRS were determined spatially based on the following conditions: (1) fracture zone must not cross the repository; and (2) the repository must stay away from the fracture zones greater than 50 m. The western region of the fracture zones in the N-S direction with a depth below 200 m from the surface was sufficient for A-KRS repository. Because most of the fracture zones in N-S direction were inclined toward the east, we expected to find a homogeneous rock mass in the western region rather than in the eastern region. The lower left domain of potential domains has more suitable geological and hydrogeological conditions for A-KRS repository.

• The Journal of Engineering Geology
• /
• v.8 no.1
• /
• pp.75-86
• /
• 1998

Eighteen oriented samples from the Jeongsun limestone of the Joseon Supergroup are collected. The orientations of C-axis of calcite and e twin plane, the average thickness, numbers of twins and the widths of calcite grains in 10 samples are measured. Then, the twin strain, mean width, intensity of twin and relative magnitude and orientations of principal stresses are calculated using Calcite Strain Gauge program. Twin strain, mean width and intensitv rainge between 0.801%~10.927%, $0.43{\mu\textrm{m}}~2.03{\mu\textrm{m}}$, and 33.5~113.4twim/mm, respectively. Metamorphic temperatures calculated from twin show below $70^{\circ}C$, indicating that twins were developed within 2.3km depth. In five samples, two events with different orientations of principal stress produced calcite twins, while only one event produced calcite twins in five samples. The direction of the maximum stress is almost horizontal and the minimum is almost vertical, indicating that the stress regirne is identical with thrust fault. E-W and NW-SE are the most dominant directions of comressive stress and N-S and NE-SW directions are also shown. Comparision between paleostress orientations measured in the study and others indicates that the maximum horizontal stress oriented to E-W may represent the paleostress of period either from the Silurian to the Triassic or from the Silulian to the Permian. Paleostress oriented to NW-SE may be the major direction of stress during the Daeho orogeny.