• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.6
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• pp.37-44
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• 2018

This study proposed the modified weighting values for jointed rock slopes. The studies on deduction of evaluation index and calculation of weighting, development of criteria for evaluation and evaluation models have been conducted through decision making techniques such as the Delphi method and the AHP method by many researchers. Because these decisions making techniques may be less objective, it is necessary to calculate reasonable weighting considering both an objective weighting and a subjective weighting simultaneously. In this study, utilizing the inspection data of jointed rock slopes, an objective weighting that the concept of entropy is applied was calculated. And the subjective weighting values by AHP technique was calculated based on the opinion of experts. And a modified weighting was suggested by combining the two. As a result, it was found that jointed rock slopes have higher weighting in artificial factors and the damage status items. In addition based on the finally suggested weighting (mixed weighting), the revised evaluation criteria could be presented by converting it into the evaluation score (76 points). And it is expected that it could be usefully utilized upon inspections on cutting slopes and safety diagnosis since objective and highly reliable criteria compared to the condition evaluation criteria that are currently used could be presented through the results of the study.

• Journal of Elementary Mathematics Education in Korea
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• v.7 no.1
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• pp.65-86
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• 2003

Mathematics textbooks are substitutive showing real characters of didactic transposition in pseudo-contextualization and pseudo-personalization. This study analyzed statistical graphs in elementary school mathematics textbooks according to the first to the 7th curriculum in Korea. It focused on the didactic principles used in those methods through those view of Didactic Transposition Theory. The features of the elementary school mathematics textbooks in Korea are investigated and described ethnomethodologically according to each curriculum periods in dividing bar graph, line graph, pictograph, graph of ratio, histogram. The teaching sequences and methods of the statistical graphs, order and methods of sub-learning activities, teaming data, matter of the learning activity indicator were summarized. Usually, the teaching sequences, excepting the graphs of ratio, statistical graphs are introduced in the second semester of each grade. The graph of ratio is introduced in the first semester of 6th grade. As a result of analysing sub-Loaming activities, using them increased from the first to the 7th curriculum and its form was fixed constructive and stable at the 4th curriculum textbooks. As a result of analysing the teaming data, the data of the social aspects are used more frequently and the data of the individual preferences trended more gradually. As a result of analysing the matter of the teaming activity indicators, concept-explanation question style were used more frequently. Statement-practice style and consideration style trended gradually. Concluding remarks are: First, the didactic transposition of the elementary school mathematics textbooks developed systematically according to the first to the 7th curriculum; Second, mathematics textbooks gradually introduced the positive learning style of activity and the learners' spontaneousness; Third, more concrete practice activities and reflective activities were variously introduced considering the level and interest of each elementary student.

• Economic and Environmental Geology
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• v.41 no.4
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• pp.453-464
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• 2008

This study is to examine a relation between coal mining subsidence occurrence at abandoned underground coal mines and underground goaf with respect to surface geology, subsurface structure, depth and thickness of coal beds and the distribution of drifts. A study is carried out at the site where susceptibility of coal mining subsidence was proven high in a previous study. In that previous study, the susceptibility of coal mining subsidence was spatially analyzed by GIS using digitized geological maps, investigation reports, digitized mining tunnel maps without consideration of subsurface structure and the multi-level arrangement of drifts. Here we analyze geological characteristics around the goaf and the distribution of coal seam based upon digitized geological maps and investigation reports on the study area. And digitized mining tunnel maps are also used to analyze the depth and multi-level arrangement of drifts. The results show that weakened surface rock strength, relatively shallow depth and large thickness of coal seam below the surface are closely related to the coal mining subsidence occurrence. Complicatedly inter-connected drifts, shallow depth of drifts and surface rock fractures are revealed as additional control factors affecting coal mining subsidence. These factors examined in this study as well as original factors should be taken into account for the quantitative estimation of coal mining subsidence occurrence at abandoned underground coal mine.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.3
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• pp.87-95
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• 2020

As an experimental study on the corrosion behavior of steel materials to which ATMS method using EIS was applied in concrete, immersion of Ca(OH)₂ saturated aqueous solution and NaCl aqueous solution simulating the environment inside concrete The corrosion behavior was tested. The equivalent circuit was derived through the analysis of the Nyquist plot, and the interfacial resistance and the polarization resistance of the Ca(OH)₂ aqueous solution were compared, and Al ATMS was the best interfacial resistance and Zn ATMS was the best polarization resistance. After burying ATMS steel material of cement mortar, the initial immersion impedance measurement value was the highest in the Zn ATMS test body in the impedance measurement by the immersion time by immersing it in the NaCl aqueous solution. Al ATMS test piece has the highest impedance and is highly reliable. This is because Al, which has a high ionization tendency, is continuously oxidized in a strong alkaline environment to form a film and protect the steel from permeation of chlorine ions.

• Tunnel and Underground Space
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• v.31 no.1
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• pp.10-24
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• 2021

Rock mass classification for construction of underground facilities is essential to secure their stabilities. Therefore, the reliable values for rock mass classification from the precise information on rock discontinuities are most important factors, because rock mass discontinuities can affect exclusively on the physical and mechanical properties of rock mass. The conventional classification operation for rock mass has been usually performed by hand mapping. However, there have been many issues for its precision and reliability; for instance, in large-scale survey area for regional geological survey, or rock mass classification operation by non-professional engineers. For these reasons, automated rock mass classification using LiDAR becomes popular for obtaining the quick and precise information. But there are several suggested algorithms for analyzing the rock mass discontinuities from point cloud data by LiDAR scanning, and it is known that the different algorithm gives usually different solution. Also, it is not simple to obtain the exact same value to hand mapping. In this paper, several discontinuity extract algorithms have been explained, and their processes for extracting rock mass discontinuities have been simulated for real rock bench. The application process for several algorithms is anticipated to be a good reference for future researches on extracting rock mass discontinuities from digital point cloud data by laser scanner, such as LiDAR.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.9 no.4
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• pp.11-22
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• 1999

Least-mean-square(LMS) adaptive filters have proven to be extremely useful in a number of signal processing tasks. However LMS adaptive filter suffer from a slow rate of convergence for a given steady-state mean square error as compared to the behavior of recursive least squares adaptive filter. In this paper an efficient signal interference control technique is introduced to improve the convergence speed of LMS algorithm with tap weighted vectors updating which were controled by reusing data which was abandoned data in the Adaptive transversal filter in the scheme with data recycling buffers. The computer simulation show that the character of convergence and the value of MSE of proposed algorithm are faster and lower than the existing LMS according to increasing the step-size parameter $\mu$ in the experimentally computed. learning curve. Also we find that convergence speed of proposed algorithm is increased by (B+1) time proportional to B which B is the number of recycled data buffer without complexity of computation. Adaptive transversal filter with proposed data recycling buffer algorithm could efficiently reject ISI of channel and increase speed of convergence in avoidance burden of computational complexity in reality when it was experimented having the same condition of LMS algorithm.

• The Journal of the Petrological Society of Korea
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• v.21 no.3
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• pp.335-365
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• 2012

Fission-track (FT) thermochronological records from SE Korean Cretaceous-Paleogene granitic plutons in different fault-bounded blocks reveal contrasting cooling and later thermal histories. Overall cooling patterns are represented by a monotonous (J-shaped) curve in most plutons except some Cretaceous granites retaining a complicated (N-shaped) path due to post-reset re-cooling. Discriminative cooling rates over different temperature ranges can be explained for individual plutons with respect to relative pluton sizes, differences in initial heat loss depending on country rocks, and the presence and proximity of later igneous activity. Even within a single batholith, cooling times for different isotherms were roughly contemporaneous with respect to positions. Insignificant deviations in cooling ages from two different plutons in succession across the Yangsan fault may suggest their contemporaneity before major horizontal fault movement. The extent of later thermal rise recorded locally along the Yangsan and Dongnae fault zones were reached the Apatite Partial Stability Zone ($70-125^{\circ}C$), but did not exceed $200^{\circ}C$. Thermal alteration from fractured zones in the Yangsan-Ulsan fault junction may suggest a thermal reset above $290^{\circ}C$ resulting a complete reset in FT sphene age (31 Ma), caused by a tectonic subsidence in Early Oligocene. A consistency in FT zircon/apatite ages (24 Ma) may imply a sudden rapid cooling over $200-105^{\circ}C$, plausibly related to the abrupt tectonic uplift of the Pohang-Gampo Block including the fault junction in Late Oligocene. A remarkable trend of lower cooling ages for $300-200-100^{\circ}C$ isotherms (i.e., 19% for FT sphene and K-Ar biotite; 20% for FT zircon; 27% for FT apatite) from the east of the Ulsan fault (Pohang-Gampo Block) comparing to the west of the fault may be attributed to retarded cooling times from the Paleogene granites and also reflected by their partially-reduced apatite ages due to later thermal effects.

• Journal of Ginseng Research
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• v.29 no.1
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• pp.1-18
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• 2005

Ginseng Radix, the root of Panax ginseng C. A. Meyer has been used in Eastern Asia for 2000 years as a tonic and restorative, promoting health and longevity. Two varieties are commercially available: white ginseng(Ginseng Radix Alba) is produced by air-drying the root, while red ginseng(Ginseng Radix Rubra) is produced by steaming the root followed by drying. These two varieties of different processing have somewhat differences by heat processing between them. During the heat processing for preparing red ginseng, it has been found to exhibit inactivation of catabolic enzymes, thereby preventing deterioration of ginseng quality and the increased antioxidant-like substances which inhibit lipid peroxide formation, and also good gastro-intestinal absorption by gelatinization of starch. Moreover, studies of changes in ginsenosides composition due to different processing of ginseng roots have been undertaken. The results obtained showed that red ginseng differ from white ginseng due to the lack of acidic malonyl-ginsenosides. The heating procedure in red ginseng was proved to degrade the thermally unstable malonyl-ginsenoside into corresponding netural ginsenosides. Also the steaming process of red ginseng causes degradation or transformation of neutral ginsenosides. Ginsenosides $Rh_2,\;Rh_4,\;Rs_3,\;Rs_4\;and\;Rg_5$, found only in red ginseng, have been known to be hydrolyzed products derived from original saponin by heat processing, responsible for inhibitory effects on the growth of cancer cells through the induction of apoptosis. 20(S)-ginsenoside $Rg_3$ was also formed in red ginseng and was shown to exhibit vasorelaxation properties, antimetastatic activities, and anti-platelet aggregation activity. Recently, steamed red ginseng at high temperature was shown to provide enhance the yield of ginsenosides $Rg_3\;and\;Rg_5$ characteristic of red ginseng Additionally, one of non-saponin constituents, panaxytriol, was found to be structually transformed from polyacetylenic alcohol(panaxydol) showing cytotoxicity during the preparation of red ginseng and also maltol, antioxidant maillard product, from maltose and arginyl-fructosyl-glucose, amino acid derivative, from arginine and maltose. In regard to the in vitro and in vivo comparative biological activities, red ginseng was reported to show more potent activities on the antioxidant effect, anticarcinogenic effect and ameliorative effect on blood circulation than those of white ginseng. In oriental medicine, the ability of red ginseng to supplement the vacancy(허) was known to be relatively stronger than that of white ginseng, but very few are known on its comparative clinical studies. Further investigation on the preclinical and clinical experiments are needed to show the differences of indications and efficacies between red and white ginsengs on the basis of oriental medicines.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.21 no.4
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• pp.181-186
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• 2011

Thermal stability of the $TiO_2$ SCR catalyst with W03 loading was investigated in terms of structural and morphological analyses. The $TiO_2$ catalysts with 10 w% $WO_3$ content and without $WO_3$ were prepared. which were heat-treated at $800^{\circ}C$ for 5 h. It was found that the catalytic acidity was decreased by thermal degradation in the $WO_3-TiO_2$ specimen that relatively less than the $TiO_2$ specimen from FT-IR analysis. The phase transition of the $TiO_2$ catalyst from anatase to rutile was increased by heal-treatment, and the percentage of the rutile phase was 28.4 % in the $WO_3-TiO_2$ and 22.9 % in the $TiO_2$. A shell region of $WO_3$ distinguished from a $TiO_2$ particle was also observed in the grain boundary region, and the $WO_3$ led to the suppression of grain growth. It could be confirmed that the suppression of grain growth can contribute to the improvement of catalytic properties for thermal stability more than the increase of anatase-rutile phase transformation which cause the reduction of the catalytic activity in the $TiO_2$ SCR catalyst by the presence of $WO_3$.

• Korean Journal of Environment and Ecology
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• v.32 no.4
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• pp.381-391
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• 2018

The purpose of this study is to investigate the influence of artificial disturbances occurring during water conveyance frequency on benthic macro-invertebrate by comparing and analyzing data before and after the construction of Boryeong dam in Boryeong-si, Chungcheongnam-do. We conducted the survey eight times in four points from April 2016 to September 2017. A total of 13,447 individuals from 125 species, 70 families, 19 orders, 7 classes, and 4 phyla were collected. The result of the community analysis showed that the dominant index was 0.55 (${\pm}0.07$) to 0.47 (${\pm}0.08$), diversity index was 2.06 (${\pm}0.26$) to 2.23 (${\pm}0.28$), evenness index was 0.69 (${\pm}0.05$) to 0.70 (${\pm}0.04$), and richness index was 3.43 (${\pm}0.72$) to 4.03 (${\pm}0.91$). After conveyance, the dominance decreased while the diversity, evenness, and richness increased. The result of the functional group analysis showed the portion of scrapers, filtering-collectors increased while that of shredders, gathering-collectors decreased in the functional feeding group and that the proportion of climbers and clingers increased while that of burrowers and sprawlers decreased in the habitat orientation group. The result of analysis of community stability showed that St. 1 and St. 2 decreased resistance and resilience after conveyance and new species appeared in the III characteristics group while St. 3 and St. 4 did not show much difference. The result of multidimensional scaling analysis showed that the variation of similarity was the highest at St. 1 after conveyance, and the variation of similarity at St. 4 was the lowest.