• Geophysics and Geophysical Exploration
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• v.27 no.3
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• pp.159-170
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• 2024

The bioreactor method, in which leachate is reinjected into a landfill for rapid decomposition and stabilization of buried waste, is being applied and tested at many landfills because of its numerous advantages. To apply the bioreactor method to a landfill successfully, it is very important to understand the behavioral characteristics of the injected leachate. In this study, electrical resistivity monitoring was performed to estimate the behavior of a landfill leachate in Korea where the bioreactor method was applied. For the electrical resistivity monitoring, a baseline survey was conducted in August 2013 before the leachate was injected, and time-lapse monitoring surveys were conducted four times after injection. The electrical resistivity monitoring results revealed reductions in electrical resistivity in the landfill attributable to the injected leachate, and the change in its characteristics over time was confirmed. In addition, by newly defining the electrical resistivity change ratio and applying it in this study, the spatial distribution and behavior of the leachate over time were effectively identified. More research on optimization of data acquisition and integrated monitoring methods using various techniques should be conducted in the near future.

• Journal of the Korean Wood Science and Technology
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• v.2 no.3
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• pp.3-16
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• 1974

One of the disadvantages of. wood and wood products is their hydroscopicity or dimensional instability. This is responsible for the loss of green volume of lumber as seasoning degrade. Dimensional stabilization is needed to substantially reduce seasoning defects and degrades and for increasing the serviceability of wood products. Recently, considerable world-wide attention has been drawn to the so-called Wood-Plastic Composites by irradiation-and heat-catalyst-polymerization methods and many research and developmental works have been reported. Wood-Plastic Composites are the new products having the superior mechanical and physical properties and the combinated characteristics of wood and plastic. The purpose of this experiment was to obtain the basic data for the improvement of wooden materials by manufacturing WPC. The species examined were Mulpurae-Namoo (Fraxinus, rhynchophylla), Sea-Namoo (Carpinus laxiflora), Cheungcheung-Namoo (Cornus controversa), Gorosae-Namoo (Acermono), Karae-Namoo(Juglans mandshurica) and Sanbud-Namoo (Prunus sargentii), used as blocks of type A ($3{\times}3{\times}40cm$) and type B ($5{\times}5{\times}60cm$), and were conditioned to about 10~11% moisture content before impregnation in materials humidity control room. Methyl methacrylate (MMA) as monomer and benzoyl peroxide (BPO) as initiator are used. The monomer containing BPO was impregnated into wood pieces in the vacuum system. After impregnation, the treated samples were polymerized with heat-catalyst methods. The immersed weights of monomer in woods are directly proportionated to the impregnation times. Monomer impregnation properties of Cheungcheung-Namoo, Mulpurae-Namoo and Seo-Namoo are relatively good, but in Karae-Namoo, it is very difficult to impregnate the monomer MMA. Fig. 3 shows the linear relation between polymer retentions in wood and polymerization times; that is, the polymer loadings are increasing with polymerization times. Furthermore species, moisture content, specific gravity and anatomical or conductible structure of wood, bulking solvents and monomers etc have effects on both of impregnation of monomer and polymer retention. Physical properties of treated materials are shown in table 3. Increasing rates of specific gravity are ranged 3 to 24% and volume swelling 3 to 10%. ASE is 20 to 46%, AE 14 to 50% and RWA 18 to 40%. Especially, the ASE in relation to absorption of liquid water increases approximately with increase of polymer content, although the bulking effect of the polymerization of monomer may also be influential. WPCs from Mulpurae-Namoo and Cheungcheung-Namoo have high dimensional stability, while its of Karae-Namoo and Seo-Namoo are-very low. Table 4 shows the mechanical properties of WPCs from 6 species. With its specific gravity and polymer loading increase, all mechanical properties are on the increase. Increasing rate of bending strength is 10 to 40%, compression strength 25 to 70%, ;impact bending absorbed energy 4 to 74% and tensile strength 18 to 56%. Mulpurae-Namoo and Cheungcheung-Namoo with high polymer content have considerable high increasing rate of strengths. But incase of Karae-Namoo with inferior monomer impregnation it is very low. Polymer retention in cell wall is 0.32 to 0.70%. Most of the polymer is accumulated in cell lumen. Effective. of polymer retention is 58.59% for Mulpurae-Namoo, 26.27% for Seo-Namoo, 47.98% for Cheungcheung-Namoo, 25.64% for Korosae-Namoo, 9.96% for Karae-Namoo and 25.84% for Sanbud-Namoo.

• Pediatric Infection and Vaccine
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• v.8 no.2
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• pp.135-149
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• 2001

Purpose : To describe the characteristics of the claims for compensation and the methodology of investigations concerning adverse events following immunization(AEFI) and epidemiologic characteristics of the AEFI. From these results, to give a suggestion for improving AEFI surveillance system, consequently to stabilize National Immunization Program. Methods : Totally 61 cases were reported to the National Compensation Program and surveillance system of AEFI from 1995 to 2000. Documents from National Compensation Program, medical records and epidemiologic investigation reports of the cases were collected and analyzed. Results : The number of reported cases was 12 in 1995, 3 in 1996, 12 in 1998, 5 in 1999, and 29 in 2000, respectively. That of deaths was 24(39.3%) and 16 cases among them were autopsied(66.7%). That of claims for compensation was 36 and 17 cases among them were compensated(47.2%). The proportion of claim was lower in 1999~2000 than in 1995~1998, but proportion of compensation increased. Although proportion of investigation was lower in 1999~2000 than in 1995~1998, cases which were not epidemiologically investigated, decreased. The epidemiologic investigation launched within 24 hours after report increased from 25% in 1995~1998 to 48.3% in 1999~2000. Among reported cases, the number of boys was 31(50.8%), and 75.4% of subjects were from 2 months to 24 months old. 78.4% of adverse events occurred within one week after immunization. Conclusion : We can find that surveillance system of AEFI and quality of epidemiologic investigation has been somewhat improved. But, it seems that severe cases were more frequently reported than moderate or mild cases, and reporting rate was lower than that of other developed countries. We could not identify the detailed epidemiologic characteristics of AEFI due to these limitation of data. To achieve the stabilization of National Immunization Program, reporting rate and the quality of investigation should be improved.

• Clinical and Experimental Pediatrics
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• v.46 no.8
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• pp.789-794
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• 2003

Purpose : We intended to evaluate the effect of hypoxia-ischemia on extracellular striatal monoamine metabolism in neonatal rat brains by in vivo microdialysis. Methods : The right common carotid arteries of five or six-day old rats were surgically ligated, and the probes for microdialysis were inserted into the right striatum with stereotaxic instrument. After stabilization for two hours, artificial cerebrospinal fluid was infused via the probe for microdialysis and samples were collected during hypoxia-ischemia and recovery periods at 20 minute intervals. The concentrations of DA(dopamine), DOPAC(3,4-di-hydroxyphenyl acetic acid), HVA(homovanillic acid), NE(norepinephrine), and 5-HIAA(5-hydroxy indole-acetic acid) were measured by HPLC(high performance liquid chromatography) and the changes were analysed. Results : The striatal levels of dopamine metabolites such as DOPAC and HVA, were significantly decreased during hypoxia-ischemia, and increased to their basal level during reoxygenation(P<0.05). Dopamine mostly increased during hypoxia but statistically not significant(P>0.05). DOPAC showed the most remarkable decrease($23.0{\pm}4.2%$, P<0.05), during hypoxia-ischemia and increase to the basal levels during reoxygenation($120.8{\pm}54.9%$, P<0.05), and HVA showed the same pattern of changes as those of DOPAC during hypoxia-ischemia($35.3{\pm}7.6%$ of basal level, P<0.05) and reoxygenation ($105.8{\pm}32.3%$). However, the level of NE did not show significant changes during hypoxia-ischemia and reoxygenation. The levels of 5-HIAA decreased($74.9{\pm}3.1%$) and increased($118.1{\pm}7.8%$) during hypoxia-ischemia and reoxygenation, respectively(P<0.005). Conclusion : Hypoxia-ischemia had a significant influence on the metabolism of striatal monoamine in neonatal rat brains. These findings suggest that monoamine, especially dopamine, and its metabolites could have a significant role in the pathogenesis of hypoxic-ischemic injury of neonatal rat brains.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.3
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• pp.305-313
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• 2014

Purpose: A correlation between the rotating direction and rotation amount according to the eccentricity was analyzed in the present study when fitting the toric soft contact lens. Methods: One hundred fourteen eyes of with-the-rule astigmatism in 20s and 30s were appropriately applied toric soft contact lens by the guideline of manufacturer and fitting evaluations and analyzed the rotating direction and rotation amount when fixating at primary position and 8 different directions of gaze. The speed of reorientation and the correlation between the rotation amount and cornea eccentricity were also analyzed when rotating $45^{\circ}$ each toward the temporal and nasal direction. Results: The cornea eccentricity and rotation amount was shown positive correlation. For the gaze of direction, it was identified that the gaze of directions other than the gaze of direction towards the nasal and temporal had correlation, and among them, the gaze of directions to superior and the superior-temporal showed the tendency of decreasing rotation amount as the cornea eccentricity increased. On the contrary, the gaze of direction towards the inferior, inferior-temporal, superior-nasal, and inferior-nasal showed tendency of increasing rotation amount as the cornea eccentricity increased thus, it was identified that the cornea eccentricity showed different correlation according to the gaze of direction. For the case of re-orientational speed, the speed of lens reorientation in the group having the smallest corneal eccentricity was fastest in both direction but was not significantly different. Conclusions: Considering cornea eccentricity to current method of prescribing toric soft contact lens which is based on total astigmatism, it will be helpful to establish the optimal axis stabilization.

• Clinical and Experimental Pediatrics
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• v.49 no.4
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• pp.431-438
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• 2006

Purpose : Insulin-like growth factor binding protein(IGFBP)-3 has been known as a tumor suppressor gene, and its anti-tumor function was divided into insulin-like growth factor(IGF)-dependent and IGF-independent mechanism. In IGF-independent mechanism, IGFBP-3 directly interacts with a cell without binding of IGFs, becoming an interesting object in oncology. Several studies demonstrate that one of the well-known tumor suppressor genes, p53, induces directly IGFBP-3 transcription, and the increment of IGFBP-3 expression induces apoptosis of many cancer cells. Recently, the anti-tumor mechanisms of IGFBP-3 have been reported, but post-translational modification of IGFBP-3 and its anti-tumor mechanism are not well known. In this study, we examined whether p53 regulated the glycosylation of IGFBP-3, and analysed the meaning of IGFBP-3 glycosylation related to the apoptosis of cancer cell. Methods : The p53-mutated status of MDA-MB-231 human breast cancer cells was used in this experiment. The expression and glycosylation of IGFBP-3 were tested by Western blot analysis after infection of adenovirus mediated Ad/p53 and/or Ad/IGFBP-3. Results : Ad/p53 infected cells resulted in growth retardation and the induced apoptosis. p53 induced direct expression and glycosylation of IGFBP-3. The increase of glcosylated IGFBP-3 was able to promote cellular apoptosis, and the glycosylation of IGFBP-3 was more activated by the double treatment of Ad/p53 and Ad/IGFBP-3. Conclusion : From this study, the anti-tumor activity of IGFBP-3 was shown to improve the stabilization of IGFBP-3 through the increment of glycosylation of IGFBP-3 by p53. This result suggests that the combined gene therapy of p53 and IGFBP-3 may appropriate treatment of cancer.

• Journal of Korean Society of Forest Science
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• v.39 no.1
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• pp.1-34
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• 1978

On July 8, 1977, 432mm of precipitation which is the largest daily storm in Korea fell on the city of Anyang where a nearby suburban community of Seoul. Average storm intensities of 90mm per hour were recorded during the period from 1900~2200 hours on this date. Area of landslides triggered by this storm is about 96 hectares resulting from 1,876 places within about 12,600 hectares of the watershed studied. These hazards injured hundreds of human lives and took 122 human lives. Rail and highway systems were disrupted and about 30 hectares of rice paddies were washed away and hundreds of hectares were inundated. About 500 houses were destroyed. The objectives of this study are (a) to describe the problem areas, identifying critical factors causing the landslide hazards including earth and stone-debris avalanches, (b) suggest measures which might enhance the effectiveness of stabilization measures, and (c) also suggest the landslide and flood damage prevention methods from the point view of the upper-watershed conservation techniques in Anyang hollow-basin.

• The Journal of Korean Academy of Prosthodontics
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• v.51 no.3
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• pp.199-207
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• 2013

Purpose: The importance of occlusal contacts of the natural dentition for durability of teeth, mandibular stabilization, and restorative dentistry is well known. The purpose of this study is to analyze the occlusal contact and guidance pattern of Koreans by evaluating the static occlusion on maximal intercuspal position and measuring dynamic occlusion during straight protrusion. Materials and methods: The occlusal contacts at maximal interincisal position and the occlusal guidance pattern during straight protrusion of 29 subjects were recorded with shimstock foil (Whaledent, Langenau, Germany), T-Scan III (Tekscan Inc., Boston, MA, USA), polyvinylsiloxane registration material (Genie Bite, Sultan Healthcare, Hackensack, NJ, USA) and compared. Occlusal registration procedures were repeated 3 times. The position was fixed to an upright position and the head position was fixed with the Frankfurt horizontal plane paralleling the horizontal plane. Fisher's Exact Test (R-General Public License, ver. 2.14.1) and Pearson's Test were used to assess the significance level of the differences between the experimental groups (${\alpha}=.05$). Results: When using shimstock foil, T-Scan III system, and polyvinylsiloxane registration material, most of the patients showed contact on anterior, premolar, and molar teeth during maximal intercuspal position. Approximately 51% of maximal intercuspal position showed anterior contact using shimstock foil. When examining the protrusive movement using shimstock foil and T-Scan III system, guidance pattern with the central incisor was the most common. Conclusion: During maximal intercuspal position, there were cases in which not all of the teeth showed occlusal contact. During mandibular protrusive movements, one or more maxillary central incisors frequently joined in straight protrusion and the posterior teeth were disoccluded. Therefore, the anterior teeth protect the posterior teeth, and vice versa. Thus, mutually protected occlusion should be applied when reconstructing occlusion.

• Journal of Korean Society of Forest Science
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• v.81 no.1
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• pp.53-65
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• 1992

For elucidating effective methods of restoration of forest recreational sites where management goals are maintaining naturalness and conserving natural ecosystem, seeding, fertilization and soil surface treatment were used for four years at the devastated forest-floor. For restoration of forest-floor vegetation, factorial experiment was used with a split plot design(main plot : fertilization, subplot : soil surface${\times}$seeding) and a randomized complete block design (fertilization${\times}$seeding) at the Kwanaksan Aboretum, Anyang, Kyonggido. Results were summarized as follows : Soil surface softening with tipping and ripping and straw-mat mulching (70% coverage) treatment was effective on germination, survival and growth of seeded vegetation at devastated forest-floor. Especially, straw-mat mulching treatment was effective on soil surface stabilization and seedling's survival at eroded soil surface, while complete soil surface softening treatment was effective on germination, survival and early growth of tree species of late-successional series. Introducing seeds of native species of pioneer or early-successional series, with good growth capability in barren soil was effective on rapid restoration in devastated forest-floor with its soil surface previously compacted and its surviving seeds washed away. When the seeding and straw-mat mulching after partial soil surface softening with tipping and ripping treatment were employed, it took about three years to restore the devastated forest-floor where surface erosion had been undertaken for an extended period of time and where naturally surviving seeds of native species had been washed away. Softening treatment of soil surface was effective for about two years, and seeding and soil surface treatment increased number of seedlings and improved soil surface environment through fixing of movement of the fallen leaves. Fertilizing effect was not oberserved, mainly due to seeding exposure and poor physical condition including soil surface erosion, low soil water potential and drought, etc, at the field experimental site. However, application of nitrogen and phosphate fertilizers was effective on seedling survival of the species in late-successional series, while lime application adversely affected the seedling survival.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.1
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• pp.51-62
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• 2009

This study was carried out development a new composting system to lower copper and zinc concentration in plg sludge compost and conduct an inquiry into the possibility of crop cultivation. The concentrations of nitrogen, phosphorus and pH averaged 4.4%, 6.3% and 7.57, respectively, which were higher concentrations than in commercial organic fertilizers, and the concentrations of copper and zinc averaged 805 and 1,704 mg/kg, respectively, which were beyond the heavy metal concentration limit in byproduct compost. Hydrated citric acid I lowered the concentrations of copper and zinc by 58% and 97%, respectively and hydrated oxalic acid II lowered the concentrations of copper and zinc by 48% and 56%, respectively in pig sludge compost. Lower concentrations of copper and zinc in pig sludge resulted from the enhanced hydrated-citric acid concentration in organic acid solution mixed with distilled water. The concentrations of copper and zinc were 330, and 41 mg/kg in the pig sludge treated with 100% hydrated citric acid. Agitation composting system stabilized the compost earlier than the stationary composting system, in which the stabilization condition was confirmed by higher temperature by $4^{\circ}C$ at highest temperature and 7 days earlier cooling down after highest temperature. The levels of germination index (G.I) 80 were obtained 15 and 20 days after composting in agitation and stationary composting system, respectively. The concentrations of copper and zinc were 2.4 and 4.26 mg/kg respectively in soils amended with pig sludge compost after removing process of heavy metals by citric acid, but 8.0 and 22.37 mg/kg, respectively in soils amended with Pig Sludge. The concentrations of heavy metals was highest in com cultivated in soils amended with pig sludge. The copper and zinc concentrations In corn leaves were 75.2 and 50.56 mg/kg respectively, which were 4 and 2 fold higher than the com cultivated in soils amended with pig sludge compost after heavy metal removing process by hydrated citric acid.