• Journal of the Korean Chemical Society
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• v.59 no.3
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• pp.209-214
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• 2015

The formation of complexes between SO₂ and acetic acid was studied theoretically. The ab initio and DFT calculations were performed with MP2 and B3LYP methods using 6-311++G(d,p), aug-cc-pVDZ and aug-cc-pVTZ basis sets. Six stable complexes were identified, and three stable bidentate complexes, C1, C2 and C3, were formed between SO₂ and syn-acetic acid, which is more stable form of acetic acid. Anti-acetic acid also form three complexes, C4, C5 and C6, with SO₂. C4 is bidentate and C5, C6 are monodentate complexes, which are less stable. The most stable complex, C1 has S⋯O=C and O⋯H-O interactions, and the S⋯O and O⋯H distances are less than the sum of van der Waals radii. The vibrational frequencies of complexes were calculated and were compared with those of monomers. The frequency shifts after formation of complex were found, and the overall pattern of frequency shifts relative to monomers is similar among the six complexes.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.4 no.2
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• pp.148-154
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• 2001

Purpose: Ingested foreign bodies present a common clinical problem. It is well known that most of them pass uninterrupted through the gastrointestinal tract. We evaluated the role of endoscopy and Foley catheter for removal of foreign bodies in the gastrointestinal tract. Methods: We investigated retrospectively 60 cases with foreign bodies in the gastrointestinal tract. They had been treated at Wonju Christian Hospital, Yonsei University of Korea, from January, 1996 through December, 1999. Results: The age of the patients ranged from 7 months to 13 years. Patients under 5 years were 57 cases (97%) and there was no significant difference in sex (M : F=1.07 : 1). 45 cases of the patients had no symptom. The most common foreign bodies were coins (43 cases). The most common location was esophagus (31 cases). The number of foreign body removal using flexible endoscopy and Foley catheter was 22 (36.7%) and 18 (30.0%) cases, respectively. In 18 cases (30.0%), foreign bodies passed spontaneously. Only 1 case (1.7%), curtain pin impaction at ileocecal region, required surgery. Conclusion: Early foreign body removal from esophagus and stomach is recommended to lessen the morbidity and complication. Fluoroscopic foley catheter technique and flexible endoscopy for removal of esophageal foreign bodies in children is safe and effective.

• Journal of Environmental Impact Assessment
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• v.29 no.5
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• pp.307-322
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• 2020

This study was conducted to obtain information relevant to resolving problems related to artificially introduced plants in ecological restoration projects. We investigated artificially introduced plants and plants growing naturally from its surroundings in the active restoration sites of the Ecosystem Conservation Fund Return Project (ECFRP) of the Ministry of Environment and the Civilian Control Zone Forest Restoration Project (CCZFRP) of the Korea Forest Service. We also analyzed the characteristics of native, exotic, and cultivated plants in addition to their Raunkiaer's life forms. Furthermore, we compared the planted areas and inhabited areas, as well as the characteristics of the habitats of native plants among the planted plants. We found that among the plants planted in the ECFRP, 50.4% were native, 6.8% were exotic, and 42.9% were cultivated. Meanwhile, in the CCZFRP, 78.6% were native, 21.4% were exotic. We also noted that many native plants were found in the planted areas that were far from their habitats. In addition, we identified many native plants that were planted in areas judged to have characteristics different from that of their natural habitat. In the case of Raunkiaer's life forms, the planted plants showed high ratios of megaphanerophytes (MM) and microphanerophytes (N), while the invasive plants showed high ratios of therophytes (Th) and hemicryptophytes (H). When restoring the ecosystem, the ratio of planting native plants should be higher than that of exotic or cultivated plants. Moreover, the habitats and ecological characteristics should be considered when selecting native plants to enhance the effect of ecological restoration.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.10
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• pp.14-22
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• 2010

The source/channel/drain regions are formed by ion implantation with different dopant types of $n^+/p^{(+)}/n^+$ in the fabrication of the conventional n-type metal-oxide-semiconductor field effect transistor(NMOSFET). In implementing the ultra-small devices with channel length of sub-30 nm, in order to achieve the designed effective channel length accurately, low thermal budget should be considered in the fabrication processes for minimizing the lateral diffusion of dopants although the implanted ions should be activated as completely as possible for higher on-current level. Junctionless (JL) MOSFETs fully capable of the the conventional NMOSFET operations without p-type channel for enlarging the process margin are under researches. In this paper, the optimum design of the JL MOSFET based on silicon nanowire (SNW) structure is carried out by 3-D device simulation and the basic radio frequency (RF) characteristics such as conductance, maximum oscillation frequency($f_{max}$), current gain cut-off frequency($f_T$) for the optimized device. The channel length was 30 run and the design variables were the channel doping concentration and SNW radius. For the optimally designed JL SNW NMOSFET, $f_T$ and $f_{max}$ high as 367.5 GHz and 602.5 GHz could be obtained, respectively, at the operating bias condition $V_{GS}$ = $V_{DS}$ = 1.0 V).

• Korean Journal of Ichthyology
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• v.13 no.2
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• pp.136-142
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• 2001

The ichthyoplankton were sampled during six different months (January, March, May, July, September and November 1998) to study seasonal variation and species composition of the ichthyoplankton in Sunchon Bay. During the study, fish eggs collected in May and July were identified as belonging to 4 species. The most of dominant species Engraulis japonicus accounted for 54.1% of the total fish eggs, followed by Leiognathus nuchalis (21.8%), Ilisha elongata (12.7%) and Konosirus punctatus (11.4%). The collected larvae and juveniles were identified into 12 taxa. 11 of which were identified to species level, and 1 taxa identif ied only to family level, respectively. The dominant species, Ilisha elongata, accounted for 48.9% of the total larvae and juveniles: it was followed by Pholis nebulosa at 31.8%. A species of Gobiidae and Thryssa hamiltoni accounted for 15.8% and 2.2% of the total, respectively. The 4 taxa constituted 98.7% of the total collected larvae and juveniles.

• The Mathematical Education
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• v.59 no.2
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• pp.131-146
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• 2020

Regarding the formula for measuring the area of a circle, the Archimedes' constant is generally written in front of the square of radius length, but there were a few cases where the Archimedes' constant was written after that in Germany and France. In this study, two things are studied: First, how many students are writing the Archimedes' constant after that? Second, what do the students think about the written order of characters in the formula for measuring the area of a circle? In the online survey of 201 people aged 14 to 21 in Korea, there was a perception of more than 86% that both are possible or only after that are possible. In this study, it is suggested that there is a difference between the general written order of characters and the natural perception of students formed through school education. In addition, students aged 14 to 16 thought more that the Archimedes' constant should be written after that, and after that age, there was a greater perception that both are possible without confusion of meaning. It can be seen that the change in students' perception has emerged through school education on natural mathematical written order of characters after middle school courses. From this point of view, the most common perception can be that if there is no confusion in meaning, then both expressions are possible.

• Korean Journal of Environmental Biology
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• v.35 no.3
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• pp.398-412
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• 2017

The aim of this study was to collect the basic data for effective creation and management of hilly pasture. The investigation of flora and vegetation was conducted at 59 $relev\acute{e}s$ in hilly pasture of Daegwallyeong from 2014 to 2016. The vascular plants of the hilly pasture were 121 listed taxa which contain 38 families, 90 genera, 104 species, 13 varieties, and 12 subspecies. The biological type of the hilly pasture was determined as the $Th-D_4-R_5-e$ type. Twelve taxa were of naturalized plants composed of 5 families, 9 genera, 12 species. The urbanization index and the naturalized index were 3.7% and 9.9%, respectively. The vegetation types in the hilly pasture were classified into the following 3 communities: the Spiraea miyabei-Spiraea salicifolia community, the Persicaria thunbergii community, and the Agrostis alba-Phleum pratense community. The Agrostis alba-Phleum pratense community was classified into the following 5 subcommunities: the Poa pratensis subcommunity, the Artemisia princeps subcommunity, the Festuca ovina subcommunity, the Rumex acetosella subcommunity, and the typical subcommunity. Two factors (slope and EC) had the strongest impact on plant community distribution. Especially, the steep sloping sites (over $40^{\circ}$) did not play a crucial role in maintaining adequate pasture because of the invasion and establishment of shrubs.

• Journal of the Korean Geotechnical Society
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• v.32 no.7
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• pp.25-34
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• 2016

Recently, in Korea, problems related with unstability of slope or sinkhole in urban area due to erosion of compacted granite soil which was used as a backfill or embankment material have been treated as important issues. Small hole might develop inside of backfill area due to erosion of not only weathered granite soil but also clay, silt, fine sand size particles when underground water flows. Once erosion starts in a soil mass, erosion rate increases gradually to cause rapid destruction. In this study, a rotating cylinder test (RCT) was performed to evaluate the hydraulic resistance characteristics of compacted weathered granite soil under various relative densities and preconsolidation pressures. Meanwhile, an image analysis method was introduced to analyze radius of irregularly eroded sample. It was found that image analysis is an effective means of minimizing the error in calculating a critical shear stress and threshold shear stress on the irregularly eroded sample. Furthermore, in general, hydraulic resistance capacity increases with the increase of relative density and preconsolidation pressure.

• Journal of Acupuncture Research
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• v.19 no.4
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• pp.56-73
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• 2002

Objective : We need to develop a new treatment method which can curve cancer growth and enhance immunity of patients with various kinds of cancer more safely and effectively, for conventional anticancer treatment has lots of problems to be overcomed, in other words, Its efficacy can be recognizible but it doesn't actually give aid to patients due to its side effects. This study was taken up to evaluate the anticancer and immune-enhancing effect of Scutellariae Barbatae Herba, Alli bulbus, Oldenlandiae Herba(SAO) Herbal acupuncture. Methods : SAO Herbal acupuncture solution was made from Scutellariae Barbatae Herba, Alli bulbus, Oldenlandiae Herba by decoction. Experimental group was divided into normal(N), control(TC, cancer group induced by S 180), high and low concentration SAO complex Herbal acupuncture group. In the high and low concentration SAO complex Herbal acupuncture group, SAO Herbal acupuncture solution was injected, on the left and right Chok-samni(足三里, ST36) of ICR-male S 180 rats alternatively, by 200mg/kg and 100mg/kg respectively. In vitro, S 180 was cultured with $200{\mu}g$ and $500{\mu}g$ of SAO Herbal acupuncture solution. In each experimental group, we examined the effect of SAO complex Herbal acupuncture on body weight, antitumor, organ weight, activity of macrophage, activity of B cell, spleen cell division, IL-2 production and population of lymphocytes. Results : 1. In Body weight, no significant change was shown, but In solid cancer weight, the high concentration SAO complex Herbal acupuncture group showed signigicant(P<0.05) decrease and significant(P<0.05) increase in the weight of kidney, compared with control group. 2. In activity of macrophage, low concentration SAO complex Herbal acupuncture group showed significant(P<0.01) increase, but in vitro, there was no significant increase, compared with control group. 3. In activity of B cell, high and low concentration SAO complex Herbal acupuncture group showed no significant decrease, but in vitro, low concentration SAO complex Herbal acupuncture group showed significant(P<0.01) increase, compared with control group. 4. In spleen cell division, high and low concentration SAO complex Herbal acupuncture group had no significant influence on spleen cell division induced by Co A, meanwhile, it was found that macrophge promote spleen cell division in low concentration SAO complex Herbal acupuncture group(P<0.05), compared with control group. 5. In IL-2 production, high concentration SAO complex Herbal acupuncture group showed significant((P<0.05) increase, compared with control group. 6. In population of lymphocytes, high concentration SAO complex Herbal acupuncture group showed significant increase of CD3+(P<0.05), CD4+(P<0.05), CD3+ and CD4+ T cell(P<0.01) and B cell(P<0.05), while low concentration SAO complex Herbal acupuncture group showed significant increase of CD4+(P<0.05), CD8+ T cell(P<0.05) and B cell(P<0.01), compared with control group. Conclusion : SAO Herbal acupuncture inhibited cancer growth and enhanced immunity.

• Journal of Korean Society of Forest Science
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• v.105 no.3
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• pp.284-293
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• 2016

In order to assess th changes in vegetation characteristics over time in the forest-lands which is isolated by urbanization, vegetation surveys based on the Braun-Blanquet phytosociological method was carried out in 1996 and 2015 on Mt. Hwangyeong located in the center of Busan metropolitan city, South Korea. The number of vegetation types based on floristic composition showed no significant changes, the vegetation units under the community levels was more or less represents the difference. the average total vegetation cover and average number of species per unit area ($100m^2$) was increased 16% and 2 species, respectively. The relative importance value (RIV) for each tree species, Quercus spp. like as Q. mongolica and Q. serrata was decreased, while the warmth-tolerant trees, evergreen broad-leaved trees, and mesophyte like Lindera erythrocarpa, Styrax japonica, Osmanthus heterophyllus, and Stephanandra incisa was increased significantly. Changes of the life form spectrums of vascular plants did not substantially, hemicryptophyte(H) and therophyte (Th) was decreased, while nanophanerophyte(N) was increased significantly. Also through the creating of large-scale vegetation map (based on physiognomic vegetation types) was compared the spatial distribution characteristics of each vegetation types.