• Geophysics and Geophysical Exploration
• /
• v.4 no.4
• /
• pp.124-132
• /
• 2001

Electrical resistivity survey has been conducted for delineating geological fault structure in Kaekok-ri near Kyungju. In general, electrical resistivity survey has an advantage of searching buried faults and its traces compared with other geophysical survey methods. Distribution of electrical conductivity in the ground is influenced by the ratio of pores, groundwater and clay minerals. These properties are evidenced indirectly to explain for weathering condition, faults and fracture Bones. Thus the electrical resistivity survey can be an effective method to find buried faults. We have carried out two dimensional (2-D) interpretation by means of smoothness-constrained least-squares and finite element method. Field data used in this paper was acquired at Kaekok-ri, Wuedong-eup, Kyungju-si, where is Ulsan Fault and is close to the region in which debatable quaternary fault traces were found recently. The dipole-dipole array resistivity survey which could show the 2-D subsurface electrical resistivity structure, was carried out in the area with three lines. The results showed good property of fault, fracture zone and fault traces which we estimated were congruous with the results. Through this study, 2-D electrical resistivity survey interpretation for fault is useful to apply.

• Geophysics and Geophysical Exploration
• /
• v.9 no.2
• /
• pp.139-147
• /
• 2006

We had conducted a numerical modeling to investigate seismic properties of gas hydrate with field parameters acquired over the East sea in 1998. We used a 2-D staggered grid finite difference method to generate synthetic elastic seismograms for multi-channel seismic survey, OBC (Ocean Bottom Cable) survey and VCS (Vertical Cable Seismic) survey. The results of this study showed that the method using staggered grid yielded stable results and could be used to seismic imaging. We could find out the high amplitude anomaly and the phase reversal phenomenon of reflection wave at interface between the gas hydrate layer and free gas layer such a BSR (Bottom Simulating Reflector) which is the evidence for existence of gas hydrate in seismic reflection data. And we computed the reflection coefficients at the incident angles corresponding to offset distance with the synthetic seismograms. The reflection coefficients acquired from the numerical modeling were nearly consistent with the reflection coefficient computed by Shuey's equation.

• Geophysics and Geophysical Exploration
• /
• v.11 no.2
• /
• pp.148-152
• /
• 2008

Multichannel seismic profiles reveal a strong bottom simulating reflector (BSR) occurring below the seafloor in the plain of the Ulleung Basin, East Sea (Japan Sea). The essential characteristics of the BSR include its cross-cutting relationship to strata, strong amplitude, and reverse polarity with respect to the seafloor reflection, representing the base of the gas hydrate stability zone (BHSZ). The BSR reflection coefficient ranging from -0.23 to -0.26 is 1.5${\sim}$1.7 times that of the seafloor reflection and interval velocities decrease to less than 700 m/s below the BSR. These features indicate the existence of free gas beneath the GHSZ. Heat flow, estimated from the BSR depth as $95{\sim}98mW/m^2$, is in good agreement with measured values. Therefore, the BSR can be efficiently used to estimate regional distribution of heat flow in the Ulleung Basin.

• Korean journal of applied entomology
• /
• v.46 no.2
• /
• pp.235-249
• /
• 2007

The multicolored Asian lady beetles (Harmonia axyridis) has characteristic color patterns, which show great variability within species. Up to now, it has been well known that main factors affected on individual color pattern variations in the population of H axyridis are external, physical, and environmental characteristics. Indeed, there is as yet no evidence to indicate whether the variation is genetic or environmental factors. Also the factors which produce this variation are unknown in this species, although it is suspected that much of the variation is under genetic control. However, the genetic relationships among many of color types were investigated by observing the progeny of each particular pairs. It is worth mentioning a few particular breeding cases to illustrate certain facets of variability, and to indicate examples suitable for genetic analysis of the color pattern variation.

• The Korean Journal of Archival Studies
• /
• no.30
• /
• pp.89-123
• /
• 2011

Archival materials in film archives is a memories and archival documents of human which is generated from cultural activities of human being, and provided long-term relevant information. However, it is different general public audio-visual records because main purpose of representing culture to create the contents of private sector rather than evidence of the factual information of public service activities. Therefore, should determine the description principle and rule in order to reflect specific physical, intellectual characteristics. So as to control the description, that is need in the textual standards to base the specific purposes and rules thus analyzed the international description standards as Dublin Core, ISAD(G), FIAF Cataloguing Rules For Film Archives. As a result, more effectively to describe archival materials in film archives required significant modifications in the organizations of the areas and the elements. This study argues that first, to divide existence the concept and the reality (work/item) of archival materials in film archives. Second, to need understanding and indicating their content, context, structure. Third, to establish of the areas and the elements including a characteristic of it. The final suggestion organizes separately to 6th and 8th areas, 22th and 25th elements in two parts. This conclusion does not prepare to refer the status and/or policy of a particular film arhicve, can be set accordingly to a specific elements or sub-elements by the film archives.

• Geophysics and Geophysical Exploration
• /
• v.3 no.1
• /
• pp.1-6
• /
• 2000

The 1 $km^2$ area studied is located in Sukchun-ri, Hwasung-koon, the southern part of Kyeonggi-do. Even though this site has been known as a contaminated area caused by seawater intrusions, geophysical and geochemical surveys have never been carried out at the site to determine the extent of the seawater contamination and to investigate whether the seawater intrusion is in progress. The purpose of this study is to determine the extent of seawater contamination and a preferred channel of the seawater intrusion using geophysical methods such as DC resistivity surveys with Schlumberger array and a dipole-dipole array. In order to determine whether the seawater intrusion is in progress in the area, DC resistivity monitoring with Schlumberger array was performed. According to the resistivity map obtained from the inversion of the resistivity data measured with Schlumberger array, the study area is divided into two districts as relatively lowly resistive (less than 30 ohm-m) and highly resistive (more than 30 ohm-m) areas. The distribution of the lowly resistive area is consistent with the distribution of the layer composed of clay minerals, and the resistivity of this layer decreases slowly as approaching to the old seashore. Hydrogeological analysis shows that the clay layer within a distance of about 200 m from the seashore has been already contaminated by sea-water and its electric conductivity is 8 times higher than that of the sand layer covered by the clay layer. According to the results of the 2-dimensional DC resistivity surveys with a dipole-dipole array, there are two preferred channels of the seawater intrusion in the site, and both the channels are in the NW-SE direction from the old seashore. The lowly resistive zone in the southern channel extends to a depth of 80 m. The DC resistivity monitoring with Schlumberger array was carried out along the preferred channel which has the low resistivity Bone (fracture zone) that extended to a depth of 80 m. The time series of apparent resistivity, measured at a distance of 260 m from the old coast line, fluctuates with a period of 12 hours. From these observations, it can be concluded that the seawater intrusion caused by tidal action is still in progress along the fractured zone interpreted by the DC resistivity surveys with a dipole-dipole array.

• The Korean Journal of Petroleum Geology
• /
• v.12 no.1
• /
• pp.34-42
• /
• 2006

Ichnology is the study of traces made by various organisms, which includes classification and description of traces, and interpretation of sedimentary process, behavior of organism and depositional environment based on traces and organism behavior. Ichnofacies, which is defined as the association of several traces related together with substrate characteristics and sedimentary processes, is closely related to depositional environment. Ichnology has been applied to sedimentology (to understand physical characteristics of depositional environment, sedimentation pattern and event bed), sequence stratigraphy (to recognize sequence boundaries and biostratigraphic discontinuities such as MFS, TSE and RSE), oil exploration (providing of many information without big cost) and palaeocology. Preliminary ichnological study on the Ganghwa intertidal flat shows that dominant ichofacies are changing with season and location, suggesting that their seasonal variation would be a good indicator to understand the seasonal change of sedimentary processes, the small- scale change of sedimentary environment and the preservation potential of such units. Ichnology on intertidal flat in western coast of Korea has a great potential to apply its results to petroleum geology as well as sedimentology.

• The Journal of the Korea Contents Association
• /
• v.17 no.11
• /
• pp.331-341
• /
• 2017

As increasing the importance of the R&D strategy planning based on S&T evidence, the S&T DB was conducted to develop appropriate basic research support strategies by collecting 49 multiple-nations' statistics and information, extracting 6446 raw data, categorizing 877 indicators including 208 core indicators. An statistical and knowledge map analysis using the highly cited publication-related indicators was conducted to examine the expansion of DB utilization by demonstrating effectiveness of Korea's basic research. As a result, basic research investment have a strong influence on creating outstanding R&D outcomes and on producing a foundation of various S&T based-growth engines.

• The Korean Journal of Blood Transfusion
• /
• v.29 no.3
• /
• pp.229-239
• /
• 2018

The circulatory system is closely related to the inter-relationship between the anatomy of the heart and blood vessels, and the fluid dynamic properties of blood. The physical properties of blood, which affect blood flow, are called hemorheologic factors. Hemorheologic factors, such as blood viscosity and erythrocyte aggregation, are influenced mainly by hematocrit. A higher hematocrit level results in an increase in blood viscosity, erythrocyte aggregation, which impedes the circulation itself, and tissue oxygenation. An excess of serum ferritin causes injury to vascular endothelial cells and erythrocytes via oxygen free radicals. In addition, an excess of blood can aggravatee the adverse effects of the hemorheologic parameters and induce atherogenesis, microcirculatory disturbances, and major cardiovascular events. A preventive and therapeutic approach with a phlebotomy or blood donation has been stimulated by the knowledge that blood loss, such as regular donations, is associated with significant decreases in key hemorheologic variables, including blood viscosity, erythrocyte aggregation, hematocrit, and fibrinogen. Major cardiovascular events have been improved in regular blood donors by improving blood flow and microcirculation by decreasing the level of oxidative stress, improving the hemorheologic parameters, and reducing the serum ferritin level. Confirmation of the positive preventive and therapeutic effects of blood donations on cardiovascular disease by a well-designed and well-controlled Cohort study may be good news to patients with cardiovascular disease or at risk of these diseases, as well as patients who require a transfusion.

• Journal of the Korean Society of Earth Science Education
• /
• v.15 no.3
• /
• pp.373-390
• /
• 2022

Science museums are platforms of PUS (public understanding of science). The purpose of this study was to explore the science communicators' competencies critical in interacting with visitors from the comparison of their training and professional development programs nationally and internationally. The managers running science communicators' programs and communicators themselves from six different national science museums and those from five different international ones participated in the structured survey. The data from surveys were compared among respondents to draw common and specific descriptions for communicators' competencies. In addition, the experienced exemplary science communicator, Ms. Park, participated in this study and the data from her observation field notes, her own developed science communicators' manual, and interviews were used to support the result. The contextual model of learning in science museums (Falk, 2006) was used to illustrate science communicators' expertise. National managers and science communicators showed difference in their perception about science communicators' roles, difficulties, and improvement for their competencies. Internationally, the managers and science communicators showed similar perception about communicators' competencies in terms of the contextual model of learning. It is highly suggested that practice-based science communicators' training and professional development programs must be offered on the basis of interaction between experienced and novice communicators as mentors and mentees systems.