• Korean Journal of Soil Science and Fertilizer
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• v.24 no.3
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• pp.225-233
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• 1991

This study was conducted to evaluate the potential of indigenous vesicular-arbuscular mycorrhizal fungi(VAMF) in the rhizosphere soil of horticultural crops grown under greenhouse and open-field condition, in the southern area of Kores. Soil samples collected from the rhizosphere of some sellected horticultural crops, such as cucumber, hot pepper, lettuca, tomato and eggplant grown under greenhouse or open-field condition. All tested crops are considered as mycorrhizal plants. The infection rate of horticultural crops investigated ranged from 38% to 70%, hot pepper and eggplant grown under greenhouse condition showed the highest infection being 66.0% and 70.0%, respectively. Spore densities were from 4.8 to 20.0g-1 on dried soil basis. Spore densities of VAMF in the rhizosphere soils under greenhouse condition were higher than that of open-field conditions. The highest distribution of spores in diameter ranged from $75{\mu}m$ to $106{\mu}m$ in the rhizosphere soil of lettuce, cucumber and tomato while those in hot pepper and eggplant ranged from $75{\mu}m$ to $250{\mu}m$. Glomus sp.-type spores predominated in the slightly acid soil(pH 6.3), while Acaulospora sp.-type spores greatly predominated in the very strongly acid field(pH 4.9).

• Journal of Wetlands Research
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• v.2 no.1
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• pp.31-40
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• 2000

The flora, vegetation structure and physico-chemical characteristics of surface sediment were investigated in Paksil-nup wetland of Hapcheon-gun, Gyeongsangnam-do, Korea in 1990~1998. Ranges of the surface sediment characteristics such as pH, conductivity, organic matter, total nitrogen, available phosphorus, exchangeable K, exchangeable Ca, exchangeable Mg, and exchangeable Na were 4.36~4.34, $19.0{\sim}1260.0\;{\mu}mho\;cm^{-1}$, 0.01~6.35%, 0.001~0.14%, 0.01~0.31 mg/l00g, 1.01~13.98 ppm, 16.75~143.80 ppm, 0.93~14.85 ppm and 0.21~3.86 ppm, respectively. Percentages of the particle size such as sand, silt, and clay were 13.0~93.3%, 5.4~71.7%, and 0.5~37.5%, respectively. The flora of the study area was composed of 72 families, 182 genera, 223 species, 36 varieties and 2 form or total 261 kinds, and those were 45 kinds of vascular hydrophytes and 216 kinds of vascular hygrophytes. The life form of vascular hydrophytes was classified as 27 kinds (60%) of emergent plants, 8 kinds (18%) of submerged plants, 6 kinds (13%) of free-floating plants and 4 kinds (9%) of floating-leaved plants, respectively. The importance value of Salix nipponica was highest as 123.78 in the shrub and tree layers, and that of Trapa japonica was highest as 16.69 in the herb layer. The vegetation type was divided into two groups according to the association analysis. The vegetation of the littoral zone was classified into 7 associations according to the cluster analysis based on the coverage data. These results showed significant differences with those of stand ordination by correspondence analysis based on the species composition and by PCA based on the sediment properties. Factors affecting the distribution of the vascular hydrophytes and hygrophytes were the gradient of particle size, altitude, and water depth.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.3
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• pp.214-221
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• 2011

Purpose: To date most of finite element analysis assumed the presence of 100% contact between bone and implant, which is inconsistent with clinical reality. In human retrieval study bone-implant contact (BIC) ratio ranged from 20 to 80%. The objective of this study was to explore the influence of bone-implant contact pattern on bone of the interface using nonlinear 3-dimensional finite element analysis. Materials and methods: A computer tomography-based finite element models with two types of implant (Mark III Br${\aa}$nemark$^{(R)}$, Inplant$^{(R)}$) which placed in the maxillary 2nd premolar area were constructed. Two different degrees of bone-implant contact ratio (40, 70%) each implant design were simulated. 5 finite element models were constructed each bone-implant contact ratio and implant design, and sum of models was 40. The position of bone-implant contact was determined according to random shuffle method. Elements of bone-implant contact in group W (wholly randomized osseointegration) was randomly selected in terms of total implant length including cortical and cancellous bone, while ones in group S (segmentally randomized osseointegration) was randomly selected each 0.75 mm vertically and horizontally. Results: Maximum von Mises strain between group W and group S was not significantly different regardless of bone-implant contact ratio and implant design (P=.939). Peak von Mises strain of 40% BIC was significantly lower than one of 70% BIC (P=.007). There was no significant difference between Mark III Br${\aa}$nemark$^{(R)}$ and Inplant$^{(R)}$ in 40% BIC, while average of peak von Mises strain for Inplant$^{(R)}$ was significantly lower ($4886{\pm}1034\;{\mu}m/m$) compared with MK III Br${\aa}$nemark$^{(R)}$ ($7134{\pm}1232\;{\mu}m/m$) in BIC 70% (P<.0001). Conclusion: Assuming bone-implant contact in finite element method, whether the contact elements in bone were wholly randomly or segmentally randomly selected using random shuffle method, both methods could be effective to be no significant difference regardless of sample size.

• Journal of the Korean earth science society
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• v.31 no.6
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• pp.600-607
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• 2010

In 2008, multiple episodes of large-scale transport of natural airborne particles and anthropogenically affected particles from different sources in the East Asian continent were identified in the National Oceanic and Atmospheric Administration (NOAA) satellite RGB-composite images and the mass concentrations of ground level particulate matters. To analyze the aerosol size distribution during the large-scale transport of atmospheric aerosols, both aerosol optical depth (AOD; proportional to the aerosol total loading in the vertical column) and fine aerosol weighting (FW; fractional contribution of fine aerosol to the total AOD) of Moderate resolution Imaging Spectroradiometer (MODIS) aerosol products were used over the East Asian region. The six episodes of massive natural airborne particles were observed at Cheongwon, originating from sandstorms in northern China, Mongolia and the loess plateau of China. The $PM_{10}$ and $PM_{2.5}$ stood at 70% and 16% of the total mass concentration of TSP, respectively. However, the mass concentration of $PM_{2.5}$ among TSP increased as high as 23% in the episode in which they were flowing in by way f the industrial area in east China. In the other five episodes of anthropogenically affected particles that flowed into the Korean Peninsula from east China, the mass concentrations of $PM_{10}$ and $PM_{2.5}$ among TSP reached 82% and 65%, respectively. The average AOD for the large-scale transport of anthropogenically affected particle episodes in the East Asian region was measured at $0.42{\pm}0.17$ compared with AOD ($0.36{\pm}0.13$) for the natural airborne particle episodes. Particularly, the regions covering east China, the Yellow Sea, the Korean Peninsula, and the east Korean sea were characterized by high levels of AOD. The average FW values observed during the event of anthropogenically affected aerosols ($0.63{\pm}0.16$) were moderately higher than those of natural airborne particles ($0.52{\pm}0.13$). This observation suggests that anthropogenically affected particles contribute greatly to the atmospheric aerosols in East Asia.

• Journal of the Korean earth science society
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• v.40 no.6
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• pp.584-598
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• 2019

In this study, the effects of air-sea interactions on precipitation over the Seoul-Gyeonggi region of the Korean Peninsula from 28 to 30 August 2018, were analyzed using a Regional atmosphere-ocean Coupled Model (RCM). In the RCM, a WRF (Weather Research Forecasts) was used as the atmosphere model whereas ROMS (Regional Oceanic Modeling System) was used as the ocean model. In a Regional Single atmosphere Model (RSM), only the WRF model was used. In addition, the sea surface temperature data of ECMWF Reanalysis Interim was used as low boundary data. Compared with the observational data, the RCM considering the effect of air-sea interaction represented that the spatial correlations were 0.6 and 0.84, respectively, for the precipitation and the Yellow Sea surface temperature in the Seoul-Gyeonggi area, which was higher than the RSM. whereas the mean bias error (MBE) was -2.32 and -0.62, respectively, which was lower than the RSM. The air-sea interaction effect, analyzed by equivalent potential temperature, SST, dynamic convergence fields, induced the change of SST in the Yellow Sea. In addition, the changed SST caused the difference in thermal instability and kinematic convergence in the lower atmosphere. The thermal instability and convergence over the Seoul-Gyeonggi region induced upward motion, and consequently, the precipitation in the RCM was similar to the spatial distribution of the observed data compared to the precipitation in the RSM. Although various case studies and climatic analyses are needed to clearly understand the effects of complex air-sea interaction, this study results provide evidence for the importance of the air-sea interaction in predicting precipitation in the Seoul-Gyeonggi region.

• Journal of Korean Ophthalmic Optics Society
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• v.3 no.1
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• pp.103-113
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• 1998

Until now, the study of eye refractive error examination for high school students are a few report that in Korea. In particular, there is few report about the visual power for same group during several years. We compared the study of refractive error done this year with that reported three years ago at the same high school. From the these data, the distribution of ammetropia was investigated. The study of refractive error for high school students was also compared with those reported before for the Adults and the middle school student. When the visual power is refered to spherical equivalent, the 36% of the whole students examined above had emmetropia and the other part of them fumed out to be ammetropia which is classify to 60.6% belonged to myopia and 4.4% belonged to hyperpia. The ratio of myopia for this year students is increased in comparision with the students in 1995. The ratio of emmetropia for this year students is 7.4% higher, and the ratio of myopia for this year students is 4% higher, but the ratio of hyperopia is very lower than that for the adults in 1997. In the kind of refractive error, it is classified that a simple myopia is shown to highest ratio as a 28.6% of 1212 eyes examined, a compound myopic astigmatism to the next high ratio as a 22.4%, a simple myopic astigmatism as 14.4%, a simple hyperopic astigmatism as 3.1%, a mixed astigmatism as a 1.7%, a simple astigmatism as 1.2%, a compound hyperopic astigmatism as 1.2%, respectively. The percentage of an astigmatism is a 76.7% of total eyes examined if Cyl-0.25 Dptr is included to an astigmatism. On the other hand, The percentage of an astigmatism is a 45.6% of total eyes examined if Cyl-0.25 Dptr is excluded to an astigmatism. In the kind of astigmatism, the number of students had an astigmatism with the rule is about 4.5 times than that of astigmatism against the rule. From the result of comparision the right eye with the left eye, the right eye of the students had more a myopic refractive error than the left eye, which is same as adults' case, there is no difference in a refractive error between the boy students and the girl students.

• Progress in Medical Physics
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• v.9 no.3
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• pp.155-162
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• 1998

Ho-l66 was produced by neutron reaction in a reactor at the Korea Atomic Energy Institute (Taejon, Korea). Ho-l66 emits a high energy beta particles with a maximum energy of 1.85 MeV and small proportion of gamma rays (80 keV). Therefore, the radiation absorbed dose estimation could be based on the in-vivo quantification of the activity in tumors from the gamma camera images. Approximately 1 mCi of Ho-l66 in solution was mixed into the flood phantom and planar scintigraphic images were acquired with and without patient interposed between the phantom and scintillation camera. Transmission factor over an area of interest was calculated from the ratio of counts in selected regions of the two images described above. A dual-head gamma camera(Multispect2, Siemens, Hoffman Estates, IL, USA) equipped with medium energy collimators was utilized for imaging(80 keV${\pm}$10%). Fifty-nine year old female patient with hepatoma was enrolled into the therapeutic protocol after the informed consent obtained. Thirty millicuries(110MBq) of Ho-166-CHICO was injected into the right hepatic arterial branch supplying hepatoma. When the injection was completed, anterior and posterior scintigraphic views of the chest and pelvic regions were obtained for 3 successive days. Regions of interest (ROIs) were drawn over the organs in both the anterior and posterior views. The activity in those ROIs was estimated from geometric mean, calibration factor and transmission factors. Absorbed dose was calculated using the Marinelli formula and Medical Internal Radiation Dose (MIRD) schema. Tumor dose of the patient treated with 1110 MBq(30 mCi) Ho-l66 was calculated to be 179.7 Gy. Dose distribution to normal liver, spleen, lung and bone was 9.1, 10.3, 3.9, 5.0 % of the tumor dose respectively. In conclusion, tumor dose and absorbed dose to surrounding structures were calculated by daily external imaging after the Ho-l66 therapy for hepatoma. In order to limit the thresholding dose to each surrounding organ, absorbed dose calculation provides useful information.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.5 no.4
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• pp.305-319
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• 2000

A total of 50 diatom species and 1 subspecies belonging to 31 genera except Chaetoceros resting spores were identified in the 45 sediments subsampled from a gravity core GH98-1223 collected from the western Hokkaido Island located in the northeastern East Sea (Sea of Japan). The most dominant species is Thalassionema nitzschioides (Grunow) Hustedt, ranging 29 to 59% of the total assemblages, and most species including Denticulopsis seminae (Simonsen and Kanaya) Simonsen and Pseudoeunotia doliolus (Wallich) Grunow were less than 5% in average. Frequencies of cold-water species are generally higher than those of warm-water species and the vertical distribution of cold-water species was largely opposite to that of warm-water species in spite of ecological habitat difference. Frequency of cold-water species, D. seminae is reverse to that of P. doliolus, an indicator of the Tsushima Warm Current, which is consistent with diatom temperature value (T$_{d}$ value). The variation of T$_{d}$ values shows that the upper part of core with greater-than-average T$_{d}$ values represents postglacial warming trend. These T$_{d}$ values clearly demonstrate that the study area located in the northern part of the East Sea is gradually influenced by Tsushima Warm Current. In addition, the zig-zag variation in the lower part reflects the unstable seawater for diatom habitat. Chaetoceros resting spores indicating productivity and upwelling was 5.3 to 40%, with maximum peak at 80 cm. Chaetoceros resting spores/Chaetoceros vegetative cells, an indicator of relative amounts of biogenic material in the sediments was high at the upper 80 cm level, corresponding to the change of T$_{d}$ values. On the basis of diatom assemblages, the northeastern part of East Sea has experienced the effects of Tsushima Warm Current during the postglacial period of Holocene, which is similar to the modem climatic environment. However, the variation of P. doliolus reflects that the intensity of Tsushima Warm Current has been oscillated in the East Sea.

• Journal of Dairy Science and Biotechnology
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• v.27 no.2
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• pp.55-62
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• 2009

Milk is called an almost complete food in terms of nutrition, especially for the younger generations because it contains a number of nutrients required for growth and development. Lactose intolerance is defined as a malabsorption of lactose in the intestine with some typical symptoms of abdominal pains and bloating, and occurred at 75% of global populations, which hampers milk consumption worldwide. Lacks of milk consumption in the underdeveloped countries frequently lead to many nutrients deficiencies, so that diseases including osteoporosis, hypertension, and colon cancer are more prevalent in the recent days. Lactose in foods needs to be hydrolyzed prior to intestinal absorption. The hydrolytic enzyme responsible for splitting lactose into its monomeric forms, glucose and galactose, is called as lactase or $\beta$-galactosidase. The former is primarily used as blood sugar and energy source and the latter used in glycolipid synthesis of brain tissues in infants. Lactose is clinically diagnosed with the breath hydrogen production test as well as intestinal biopsy. Reportedly, symptoms of lactose intolerance are widely prevalent at 25% of Europeans, 50 to 80% of Hispanics, South Indians, Africans, and Jews, almost 100% of Asians and native Americans. For the adults, phenotype of lactase persistence, which is able to hydrolyse lactose, is more common in the northern Europeans, but in the other area lactase non-persistence or adult-type hypolactasia is dominant. Genetic analysis on human lactase gene continued that lactase persistence was closely related to the err site of 1390 single nucleotide polymorphism from the 5'-end. To alleviate severity of lactose intolerance symptoms, some eating patterns including drinking milk a single cup or less, consumption along with other foods, whole milk rather than skimmed milk, and drink with live yogurt cultures, are highly recommended for the lactose maldigesters. Also, delay of gastric emptying is effective to avoid the symptoms from lactose intolerance. Frequency of lactose intolerance with conventional diagnosis is thought overestimated mainly because the subjects are exposed to too much lactose of 50 g rather than a single serving amount. Thus simple and accurate diagnostic method for lactose intolerance need to be established. It is thought that fermented milk products and low- or free lactose milks help improve currently stagnant milk consumption due to lactose intolerance which contributes to major barrier in milk marketing especially in Asian countries.

• Korean Journal of Environmental Agriculture
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• v.25 no.1
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• pp.77-84
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• 2006

This study was conducted to find a system for screening organic resources with 16 species, 62 samples which were selected to randomizing point from city, province and industrial areas in the whole country. Content of organic matters were $65.3%{\sim}98.0%$ in all samples so that they were largely over than 60%, raw material regulation of compost. Concentrations of total nitrogen and total phosphorus were $0.7{\sim}4.8%\;and\;0.8{\sim}5.0$, they could look for effect of the nitrogen and phosphorus supply as a raw material of compost. In case of 8 elements concentrations of heavy metal, they were too high to use as raw materials of compost which were over to regulation limit in Cu, Cr, Ni, and As from fiber industry, Ni from food company and leather industry, and the others are adapt to limit levels. HEM contents fro the highest to $113mg\;kg^{-1}$ from liber industry and PAHs content were the highest to $3,462ug\;kg^{-1}$ from paper-mill manufacture. Distribution of PAHs concentiations were naphthalene>phenanthrene>pyrene>fluoroanthene>acenaphthene. $Microtox{(R)}\;EC_{50}$ values for bioassay were pharmaceutical company>paper-mill manufacture>industrial area sewage sludge>fiber industry>urban sewage sludge>metropolitan sewage sludge. HEM between Zn, Cu, and Ni was significant at the 99% and between Cd was significant at the 95%, Microtox between Hg and BEM significant at the 95%.