• Journal of Korean Society of Forest Science
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• v.70 no.1
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• pp.103-108
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• 1985

This paper is concerned with estimating equations of leaf area(A) obtained from linear measurements - leaf length(L) and leaf width(W) - on the leaves of 13 species composing a natural mixed stand in Mt. Jiri. This method is known to be rapid and non-destructive in estimating leaf area. The equation of A=bLW is frequently used in rough and rapid estimation. Each species in this study has its own coefficient b according to its geometrical leaf shape. The range of coefficients of 13 species was 0.579 to 0.717. This means that the relationship A=2/3LW is suitable to most broad leaf species in a natural mixed stand in Mt. Jiri. When more precise estimation of leaf area is needed, full regression equation is used. In this study, the form of ${\log}A=b_0+b_1{\log}LW$ was the most precise estimation equation in 8 species. In addition to this, the form of $A=b_0+b_1LW$ and $A=b_0+b_1L^2+b_2W^2$ were founded to be suitable for estimation of leaf area. In comparision of these two forms, the determination coefficient were about the same, but the F-value of the former was greater than that of the latter. Therefore, the use of the former seems to be more reliable and practical.

• Journal of the Korea Concrete Institute
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• v.28 no.4
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• pp.463-471
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• 2016

A shear strength model for the high-shear ring anchor consisting of a steel ring and a rod was developed based on the shear tests on single high-shear ring anchors. The shear strength was found to be proportional to $f_{ck}{^{0.75}}$ which is a similar characteristic to the strength of shear connectors used in composite structures. The effects of the compressive strength of concrete, edge distance, and embedment length of rod are included in the proposed model. Comparison with 22 tests shows that the average and the coefficient of variation of test-to-prediction ratios are 1.01 and 7.57%, respectively. Push tests on the specimens having four high-shear ring anchors at each face were conducted and the measured shear strengths were compared with the predictions by the proposed model. For the specimen with an edge distance of 100 mm, a splitting failure occurred and for the specimens with an edge distance of 150 mm, a failure mode mixed with splitting and bearing occurred, which were very similar to the failures of shear tests on single high-shear ring anchors. In case of a splitting failure, the overlap of failure surfaces could be prevented by providing the longitudinal spacing of 400 mm which is four times of the edge distance. In case of a bearing failure, the failure area is less than 150 mm from the center of the anchor and therefore the overlap of failure surfaces could be prevented by providing the longitudinal spacing of 200 mm. The average of the test-to-prediction ratios of Push tests is 98%, which means that the proposed mode can be applied to predict the shear strength of the multiple high-shear rings.

• Journal of Animal Environmental Science
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• v.9 no.2
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• pp.123-130
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• 2003

In this study, current status of domestic deer farms and its feeding were surveyed. The information of supply and demand of feed f3r deers including its industry were also examined and then analyzed to make fundamental data for deer farms and government policy. The results are as follows. 1. Over 40 years old farmers were about 63％ of total deer farms while 20­30 years olds were less than 1％ indicating that young people still evade agriculture. Moreover, considering education, over 52％ of the farmers have bachelor degree showing much higher rates compared to the other agricultural fields. The reason can be assumed that the labor burden is not serious in deer farming while it is not dirty job compared to the other livestock management. Those high­educated people can be easily trained as experts of deer farming to improve its international competition. 2. Most of investigated farms raise Korean spotted deers and Elk showing that the percentage of Elk has greatly increased(However, many farmers have complained about purchasing methods and they insisted that the sales organization should be controlled by government). 3. 57％ of total cost of production is for feed while most of feeds are imported from abroad. It indicated that it is urgent to make counterplan for saving feed cost. 4. It is necessary to develop feeds for deers in the near future while most of the examined farmers currently use normal assorted feed. Typical roughage sources feeds are rice straw, alfalfa hay, browses feed, and so on. Most of them are currently imported except the rice straw indicating urgently needed to develop domestic bulky feed. 5. The present questions are development of processed goods of velvet antler, establishment of reasonable management system, difficulty of velvet antler selling, feed supply, and so on. It is necessary for government and academic world to develop reasonable policy and scientific research program.

• Korean Journal of Food Science and Technology
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• v.28 no.4
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• pp.632-637
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• 1996

Effects of refrigeration temperature and its fluctuation range on the growth of psychrotrophic microorganisms and the quality of refrigerated foods such as apple, fish and oyster were evaluated to find optimum storage conditions for a domestic refrigerator. Refrigeration temperature was $2^{\circ}C$ or $4^{\circ}C$, and fluctuation ranges were varied: ${\pm}0.3,\;{\pm}1.0,\;{\pm}1.2,\;or\;{\pm}4.0^{\circ}C$. Changes in hardness of apples stored at $2{\pm}0.3^{\circ}C$ were much slower than those of apples stored at $4{\pm}1.2^{\circ}C$. Freshness of fish and oyster also lasted much longer at low temperature such as $2{\pm}0.3^{\circ}C$. The growth of Listeria monocytogenes inoculated on sliced ham was inhibited for 1 month at $2{\pm}0.3^{\circ}C$, but the cells at $4{\pm}1.2^{\circ}C$ began to grows as time elapsed. Therefore, it was expected that shelf-life of certain food stored in a domestic refrigerator could be extended by lowering temperature to $2^{\circ}C$ and by reducing fluctuation range of refrigerator.

• Economic and Environmental Geology
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• v.28 no.4
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• pp.351-367
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• 1995

The elemental geochemistry and oxygen isotopes of illite/smectite (I/S) have been studied in relationship to the mineralogical trend in the Reindeer D-27 well, Beaufort-Mackenzie Basin. The increase in concentrations of $K_2O$, Rb and rare earth elements (REE), the decrease in concentrations of tetrahedral elements such as Mg, Ti, Sc, Zn and Zr, and the increase in concentrations of tetrahedral elements such as Be and V can be related to I/S compositions that vary systematically with depth. Layer formulae of S- and I-layers are estimated as $[Al_{1.57}Fe_{.19}Mg_{.31}Ti_{.07}][Si_{3.84}Al_{.16}]O_{10}(OH)_2$ and $[Al_{1.84}Mg_{.16}][Si_{3.33}Al_{.67}]O_{10}(OH)_2$, respectively. The mobilization of REE appears to occur during illitization. The increase in concentrations of REE, especially La and Ce, with depth is probably linked to incorporation of ions with high valency (e.g. $V^{5+}$) in tetrahedral sites. The excess valency due to V is partly counter-balanced by ions with low valency (e.g. $Be^{2+}$) and, in turn, the local valency deficiency caused by $Be^{2+}$ could be compensated by high-charge interlayer cations such as REE (＋3). ${\delta}^{18}O$ values of I/S range from 2.91 to 15.72‰ (SMOW), and increase with depth, contrasting to trends observed in the Gulf Coast and elsewhere. The increase in ${\delta}^{18}O$ of I/S results from the rapid increase in ${\delta}^{18}O$ of pore water that overcomes the decrease in temperature-dependent fractionation values with increasing burial depth (${\delta}^{18}O_{pore\;water}>-d{\Delta}/_{I/S-water};\;d{\delta}^{18}O_{I/S}>0$). Calculated ${\delta}^{18}O$ values of pore water in equilibrium with I/S suggest that the original water was probably meteoric water. The stratification of pore water is postulated from the presence of an isotopically light interval, about 450m thick. The depth range of the isotopically light zone overlaps, but does not coincide with the interval of lowered I-content and $K_2O$ concentrations, suggesting that oxygens may have been exchanged independently of mineralogical and geochemical reactions.

• Journal of Bio-Environment Control
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• v.14 no.3
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• pp.155-159
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• 2005

This study was carried out to investigate the effects of cultivars and to establish the hydroponic cultivation method of spinach (Spinacia oleracea L.) f3r autumn season. Considering the rate of germination, plant height is 25 cm interior and exterior and leaf blade and petiole attitude is erect the best two cultivars 'Artlars', 'Dimple' were selected among the 19 cultivars tested. Seed germination was more than $90{\%}$ in both cultivars of 'Artlars', 'Dimple'. Seed rate of germination drops more or less, but it was cultivar that 'Mahoroba' cultivars is becoming in export standard production, and 'Premium', 'Platon' cultivar which plant height of leaf blade and petiole attitude is erect is about 20 cm was thought by suitable cultivars to domestic. Plant height relationship difference that follow to planting distances decreased according as planting distances growth than $12{\times}11$ cm to $12{\times}15$ cm. In the meantime, the increase of leaf area and fresh weight was increasing transplanting distance. The yield per ha of 14,890 kg in the $12{\times}11$ cm was $67{\%}$ increased than that in the $12{\times}9$ cm. Therefore, $12{\times}11$ cm spacing is considered optimum planting distance for spinach hydroponic cultivation in autumn season.

• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.1
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• pp.34-38
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• 2011

Purpose: The SUV is a widely used semi-quantitative index in PET for the estimation of radio-tracer accumulation in VOI. In this study, SUVs from three different PET/CT scanners were assessed, and differences between SUVs were evaluated. Materials and Methods: The PET/CT scanners which were assessed in this study were GEMINI, GEMINI TF 64 (Philips) and Biograph True Point True V 40 (Siemens). The NEMA PET phantom (Data Spectrum Corp., USA) was used to evaluate SUVs. The NEMA PET phantom has6.8 kg weight and three hot inserts. Two different activity distributions for the background and inserts were tested. The activity ratio were 3.7:3.7:7.4:11.1 MBq (1:1:2:3) and 1.85:7.4:9.25:11.1MBq (1:4:5:6) for each of background, insert 1, insert 2 and insert 3. Acquisition time was 2 minutes per bed position and NEMA PET phantom could be covered by two bed positions for all PET/CT scanners. The SUVs from each PET/CT scanner were compared with calculated true value. Results: For both activity ratios, all scanners showed similar results. The differences between each scanner were insignificant. Each scanner showed 91.2%, 85.9% and 87.2% of true SUV for GEMINI, GEMINI TF 64, Biograph True Point TrueV, respectively. Conclusion: For all scanners, SUVs were slightly lower than true value. However, the difference between scanners was insignificant. The SUVs from these scanners would be clinically meaningful if their consistent underestimation is kept in mind.

• 한국해양학회지
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• v.28 no.1
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• pp.1-16
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• 1993

The monthly mean sea levels at 48 stations located at the East and Yellow Seas coasts of Korea, Russia and Japan are processed to investigate seasonal sea level variations. The strong seasonal variations are found to be at the west coast of Korea (42.1 cm in Kunsan), in the region of the Korea strait and near the southern part of Primorye (30-33 cm); the weak ones near the southwestern coast of the Sakhalin Island (10-12 cm). Practically for the whole study area except the southwest Sakhalin, the general picture of the seasonal sea level changes is alike: the mean sea level rises in summer-autumn and falls in winter-spring. The spectral analysis of the records also shows that the seasonal oscillations strongly dominate in the sea level variations, more than 80% or total energy in the southern part of the investigated region and 50-70% in the northern part relate to these oscillations. The annal peak significantly prevails in spectra of the monthly sea levels for the majority of stations, the semiannual peak is also well manifested, but the seasonal peaks of higher order (corresponding to the periods of four and three months) reveal only at some records. The maximal amplitudes of annual component by a least square method are found at the Yellow Sea coast of Korea (20-21 cm) and also near the Japanese coast of the korea Strait (19-19 cm). The semiannual component has the maximal amplitudes (3-4 cm) near the south and southwestern coasts of the Sakhalin Island. The annual range of the sea levels is much weaker here than in the other regions, the relative investment of the seasonal oscillations in total energetic budget is only 35-40%, annual ($A_1$) and semiannual ($A_2$) components have nearly the same amplitude (seasonal factor $F=A_1/A_2=0.9-1.2$). On the basis of the present examination on sea level changes together with the results of Tomizawa et. al.(1984) the whole investigated area may be divided into 10 subregions, 2 of them are related to the Yellow Sea and Western part of the Korea Strait (Y1, Y2), the other ones (E1-E8) to the East Sea.

• Restorative Dentistry and Endodontics
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• v.28 no.1
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• pp.89-99
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• 2003

The purpose of this study was to investigate the bonding of resin- based root canal sealer, AH26 when the sealer was applied as a thin layer between dentine and gutta-percha surface. In this study forty non-caries extracted human molars and resin-based root canal sealer(AH 26, DeTrey/Dentsply, Germany) were used. Disks of gutta-percha, 6mm in diameter.6mm thick (Diadent/Dentsply, Korea) for thermoplastic obturation were used and dentin surfaces were treated with 2% NaOCl(Group 1) or 2%NaOCl+17% EDTA(Group 3). Disks of gutta-Percha, 6mm in diameter.6mm thick (Diadent/Dentsply, Korea) for conventional obturation were used and dentin surface were treated with 2% NaOCl(Group 2) or 2%NaOCl+17% EDTA(Group 4). Enamel was removed by a horizontal section 1mm below the deepest portion of the central occlusal groove by using a watercooled low speed diamond saw. A second horizontal section was done around cementoenamel junction. Exposed dentin surface was cut to approximately $8{\times}8{\;}mm$ rectangular shape and was ground against 320, 400, 600 grade silicon carbide abrasive paper serially. After grinding, the dentine surface were soaked in a solution of 2% NaOCl for 30 minutes and twenty of specimens were treated with 17% EDTA solution for 1 minute. The treated specimens were washed and dried, Root canal sealer, AH26 was prepared according to the manufacture's instructions The Gutta-percha and dentin surface were coated with a thin layer of the freshly mixed seal or. The specimens were left overnight at room temperature. After their initial set, they were transferred to an incubator at $37$^{\circ}C$ for 72 h. After 72 hours, resin blocks were made. The resin block was serially sectioned vertically into stick of $1{\cdot}1mm$. Twenty sticks were prepared from each group. After that, tensile bond strength f3r each stick was measured with Microtensile Tester Failure patterns of the specimens at the interface between gutta-percha and dentin were observed under the SEM(x1000) and Stereomicroscope (LEICA M42O, Meyer Inst., TX U.S.A) at 1.25 x25 magnification. The results were statistically analysed by using a One-way ANOVA and Tukey's test. The results were as follows; 1. Tensile bond strengths($mean{\pm}SD$) were expressed with ascending order as follows: Group 1, $3.09{\pm}$ 1.05Mpa : Group 2, $6.23{\pm}1.16MPa$ : Group 3, $7.12{\pm}1.07MPa$ : Group 4, $10.32{\pm}2.06MPa$. 2. Tensile bond strengths of the group 2 and 4 used disks of gutta-percha for conventional obturation were significantly higher than that of the group 1 and 3 used fir thermoplastic obturation. (p < 0.05). 3. Tensile bond strengths of the group 3 and 4 treated with 2% NaOC1+17% EDTA were significantly higher than that of the group 1 and 2 treated with 2% NaOCl. (p < 0.05). 4. In analysis of failure patterns at the interface between sealer and gutta-percha, there were observed 49 (61%)cases of adhesive failure patterns and 31 (39%) cases of mixed failures patterns.

• Economic and Environmental Geology
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• v.25 no.3
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• pp.259-273
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• 1992

The Seongsan mine is one of the largest dickite deposits in the southwestern part of the Korean Peninsula. The main constithent minerals of the ore are dickite and quartz with accessory alunite, kaolinite and sericite. The geology around the Seongsan mine consists mainly of the late Cretaceous felsic volcanic rocks. In the studied area, these rocks make a synclinal structure with an axis of E-W direction plunging to the east. Most of the felsic volcanic rocks have undergone extensive hydrothermal alteration. The hydrothermally altered rocks can be classified into the following zones: Dickite, Dickite-Quartz, Quartz, Sericite, Albite and Chlorite zones, from the center to the margin of the alteration mass. Such zonal arrangement of altered rocks suggests that the country rocks, most of which are upper part of the rhyolite and welded tuff, were altered by strongly acid hydrothermal solutions. It is reasonable to consider that initial gas and solution containing $H_2S$ and other compounds were oxidized near the surface, and formed hydrothermal sulfuric acid solutions. The mineralogical and chemical changes of the altered rocks were investigated using various methods, and chemical composition of fifty-six samples of the altered rocks were obtained by wet chemical analysis and X.R.F. methods. On the basis of these analyses, it was found that some components such as $SiO_2$, $Al_2O_3$, $Fe_2O_3$, CaO, MgO, $K_2O$, $Na_2O$ and $TiO_2$ were mobilized considerably from the original rocks. The formation temperature of the deposits was estimated as higher than $200^{\circ}C$ from fluid inclusion study of samples taken from the Quartz zone. On the basis of the chemical composition data on rocks and minerals and estimated temperatures, the hydrothermal solutions responsible for the formation of the Seongsan dickite deposits were estimated to have the composition: $m_{K^+}=0.003$, $m_{Na^+}=0.097$, $m_{SiO_2(aq.)}=0.008$ and pH=5.0, here "m" represents the molality (mole/kg $H_2O$).