• The Journal of Engineering Geology
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• v.31 no.2
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• pp.187-197
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• 2021

Clay mineral content of weathered zone is a key parameter for landslide studies. Electrical resistivity tomography is usually performed to delineate the geometry of complex landslides and to identify the sliding surface. In clay-bearing weathered zone, parallel resistivity Archie equation is employed to investigate the effect of conductivity added (resistivity reduced) by clay minerals of kaolinite and montmorillonite, which is dependent on their specific surface area and cation exchange capacities (CEC). A decrease of overall resistivity and apparent formation factor is observed with increasing pore-water resistivity, significantly in montmorillonite. Formation factor is found decreased with increasing porosity and decreasing cementation factor. Parallel Archie equation was applied to the electrical resistivity data from the test area (Sinjindo-ri, Taean-gun, Chungcheongnam-do, Korea) which experienced land creeping in the year of 2014. A panel test with varying clay-mineral contents provides the best fit section when the theoretical section constructed with the assumed contents approaches the field section, from which the clay-mineral content of the weathered zone is estimated to be approximately 10%. Resistivity interpretation schemes including the clay mineral contents for land creeping studies explored in this paper can be challenged more when porosity, saturation, and pore-water resistivity are provided and they are included in the numerical resistivity modeling.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.09a
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• pp.47-50
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• 2001

The laboratory tests were peformed to investigate the relationship between electrical resistivity and the unsaturated subsurface condition and to evaluate the contamination due to leachate based on measuring electrical resistivity. For weathered granite soil, the electrical resistivity of soil decreases as moisture density increases. The electrical resistivity of soil decreases as the concentration of leachate in pore fluid increases since leachate contains various ionic constituents. And the modified Archie's equation for applying to unsaturated sand is derived by regression analysis.

• Journal of Plant Biotechnology
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• v.3 no.1
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• pp.39-44
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• 2001

Plastid transformation was attempted with soybean [Glycine max (L.) Merr.] leaves and photoautotrophic and embryogenic cultures by particle bombardment using the transforming vector pZVII that carries the coding sequences for both subunits of Chlamydomonas reinhardtii Rubisco and a spectinomycin resistance gene (aadA). Spectinomycin resistant calli were selected from the bombarded leaves but the transgene was not present, indicating that the resistance was due to mutations. The Chlamydomonas rbcL and rbcS genes were shown to be site-specifically integrated into the plastid genome of the embryogenic cells with a very low transformation efficiency. None of the transformed embryogenic lines survived the plant regeneration process so no whole plants were recovered. This result does indicate that it should be possible to insert genes into the plastid genome of the important crop soybean if the overall methods are improved.

• Geophysics and Geophysical Exploration
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• v.9 no.2
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• pp.155-162
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• 2006

An abnormal seepage flow, which is mainly caused by the piping, is one of the major reasons for embankment dam failure. A leakage detection is therefore a vital part of an embankment dam's monitoring. Resistivity method, which is an efficient tool to detect leakage zones, has been used all over the world for an embankment dam's monitoring. Although the resistivity method gives us very useful information about the leakage problem, there is no more quantitative interpretation than the low resistivity zones in the 2-dimensional resistivity section are regraded simply as the anomalous seepage zones. Recently, resistivity monitoring technique is applied for the detection of leakage zones. However, its interpretation still remains in the stage of presenting the resistivity ratio itself. An increased seepage flow increases a porosity and an increasing porosity decreases the dam's stability. Therefore, the porosity is one of the major factors for an embankment dam's stability. Based on Archie's experimental formula, we try to evaluate a porosity distribution from the resistivity data which is obtained on the dam's crest. We also attempt to represent a procedure to evaluate a safety index of the embankment dam from the resistivity monitoring data.

• Geophysics and Geophysical Exploration
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• v.22 no.1
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• pp.1-11
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• 2019

Well logging technologies are used to measure the physical properties of reservoirs through boreholes. These technologies have been utilized to understand reservoir characteristics, such as porosity, fluid saturation, etc., using equations based on rock physics models. The analysis of well logs is performed by selecting a reliable rock physics model adequate for reservoir conditions or characteristics, comparing the results using the Archie's equation or simandoux method, and determining the most feasible reservoir properties. In this study, we developed a joint inversion algorithm to estimate physical properties in shaly sandstone reservoirs based on the pre-existing algorithm for sandstone reservoirs. For this purpose, we proposed a rock physics model with respect to shale volume, constructed the Jacobian matrix, and performed the sensitivity analysis for understanding the relationship between well-logging data and rock properties. The joint inversion algorithm was implemented by adopting the least-squares method using probabilistic approach. The developed algorithm was applied to the well-logging data obtained from the Colony gas sandstone reservoir. The results were compared with the simandox method and the joint inversion algorithms of sand stone reservoirs.

• Korean Management Science Review
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• v.31 no.4
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• pp.117-134
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• 2014

Today the concept of corporate social responsibility has become an essential element for coexistence of corporations and the society. In this study the impact of four responsibilities of business organizations proposed by Archie Carroll (economic, legal, ethical, and discretionary) on customer loyalty through the mediating effect of trust and company-consumer identification is analyzed. A questionnaire survey was conducted for four well-known Korean companies (Dong Suh Food, LG Household and Health Care, Samsung Electronics, and Hyundai Motor). After factor analysis, legal and ethical responsibilities were grouped as the same factor, thus three social responsibilities were finally used for hypotheses testing. Major findings were as follows: First, economic responsibilities had positive impact on honesty trust, professionalism trust, favorableness trust, and company-consumer identification, Second, legal/ethical responsibilities were found to have significant effects on honesty trust, favorableness trust, and company-consumer identification. Third, in the case of discretionary responsibilities, professionalism trust, favorableness trust, and company-consumer identification were revealed to have a significant positive relationship. Fourth, only two trust variables (honesty and professionalism) and company-consumer identification had positive influence on the loyalty of customers. These findings are expected to help decision makers to set up corporate objectives and choose action items for corporate social responsibility. At the last part, implications of the study and future research directions were discussed.

• Geomechanics and Engineering
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• v.14 no.6
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• pp.581-588
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• 2018

In order to explore the comprehensive evaluation means of the extent of hydraulic fracturing region in coal seams, we analyzed the feasibility of detecting the response of coal rock direct current (DC) apparent resistivity to hydraulic-fracturing using Archie's theory, and conducted experimental researches on the response of DC resistivity in the hydraulic fracturing process using small-scale coal rock samples. The results show that porosity and water saturation are the two factors affecting the apparent resistivity of coal rock while hydraulic fracturing. Water has a dominant effect on the apparent resistivity of coal rock samples. The apparent resistivity in the area where water flows through is reduced more than 50%, which can be considered as a core affect region of hydraulic fracturing. Stress indirectly impacts the apparent resistivity by changing porosity. Before hydraulic fracturing, the greater axial load applied, the more serious the rupture in the samples, resulting in the greater apparent resistivity. Apparent resistivity testing is a potential regional method to evaluate the influence range of hydraulic fracturing in coal seams.

• Journal of the Korean earth science society
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• v.28 no.7
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• pp.838-846
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• 2007

A measurement system of tri-axial pressure was designed and constructed to measure permeability and resistivity under changing confining pressure. The system was designed to measure the permeability and resistivity of a core simultaneously, consisting of tri-axial supporting device and sets of dual-flow measurement. In this measurement system the permeability and resistivity of a sample can be directly measured and porosity can be obtained using Archie's laws. As for physical properties, artificial core samples are made from mixtures of standard commercial sand and mud of illite. In-situ sediment cores were sampled at the water-depth of 1,800m in the Ulleung Basin East Sea. In order to investigate the effects of confining pressure changes on physical properties, permeability and resistivity changes were monitored with increasing confining pressure. In this study, it was found that with the increase of confining pressure, permeability and porosity tend to decrease and resistivity tend to increase exponentially.

• Archives of Plastic Surgery
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• v.43 no.2
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• pp.145-152
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• 2016

Background Innovation has molded the current landscape of plastic surgery. However, documentation of this process only exists scattered throughout the literature as individual articles. The few attempts made to profile innovation in plastic surgery have been narrative, and therefore qualitative and inherently biased. Through the implementation of a novel innovation metric, this work aims to identify and characterise the most prevalent innovations in plastic surgery over the last 50 years. Methods Patents and publications related to plastic surgery (1960 to 2010) were retrieved from patent and MEDLINE databases, respectively. The most active patent codes were identified and grouped into technology areas, which were subsequently plotted graphically against publication data. Expert-derived technologies outside of the top performing patents areas were additionally explored. Results Between 1960 and 2010, 4,651 patents and 43,118 publications related to plastic surgery were identified. The most active patent codes were grouped under reconstructive prostheses, implants, instruments, non-invasive techniques, and tissue engineering. Of these areas and other expert-derived technologies, those currently undergoing growth include surgical instruments, implants, non-invasive practices, transplantation and breast surgery. Innovations related to microvascular surgery, liposuction, tissue engineering, lasers and prostheses have all plateaued. Conclusions The application of a novel metric for evaluating innovation quantitatively outlines the natural history of technologies fundamental to the evolution of plastic surgery. Analysis of current innovation trends provides some insight into which technology domains are the most active.

• The Journal of Engineering Geology
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• v.31 no.3
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• pp.269-281
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• 2021

Land creeping is the imperceptibly slow, steady, downward movement o f slope-forming soil or rock. Because creep-related failures occur frequently on a large scale without notice, they can be hazardous to both property and human life. Korea Forest Service has operated the prevention and response system from land creeping which has been on the rise since 2018. We categorized and proposed three survey steps (e.g., preliminary, regional, detailed) for investigation of creeping susceptibility site with a focus on geophysical mapping of a selected test site, Yongheung-dong, Pohang, Korea. The combination of geophysical (dipole-dipole electrical resistivity tomography and reciprocal seismic refraction technique, well-logging), geotechnical studies (standard penetrating test, laboratory tests), field mapping (tension cracks, uplift, fault), and comprehensive interpretation of their results provided the reliable information of the subsurface structures including the failure surface. To further investigate the subsurface structure including the sliding zone, we performed high-resolution geophysical mapping in addition to the regional survey. High-resolution seismic velocity structures are employed for stability analysis because they provided more simplified layers of weathering rock, soft rock, and hard rock. Curved slip plane of the land creeping is effectively delineated with a shape of downslope sliding and upward pushing at the apex of high resistive bedrock in high-resolution electrical resistivity model with clay-mineral contents taken into account. Proposed survey steps and comprehensive interpretation schemes of the results from geological, geophysical, and geotechnical data should be effective for data sets collected in a similar environment to land-creeping susceptibility area.