• Journal of Animal Environmental Science
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• v.15 no.1
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• pp.9-16
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• 2009

This study, tasting 14 months, was conducted to investigate the effects of different pen size and group size on growing-fattening characteristics of Hanwoo steers. Forty-eight, 12-month-old Hanwoo steers($305.8{\pm}32.2\;kg$) were randomly assigned to three groups($35.28\;m^2$; n=4 heads, $70.56\;m^2$; n=8 heads, $105.84\;m^2$; n=12 heads) and reared in separate pens with a constant space allowance of $8.82m^2$ per head from 12 to 21 month of age and then regrouped to 4 heads per pen. A common diet including concentrate(limited) and forage(ad lib) was provided to all the animals. Images of live animal ultrasonic back fat thickness, longissimus muscle area and Marbling score were evaluated in three months interval from 12 months of age using an ultrasound equipment(HS-2000) at the 13th rib and lumber vertebra interface of left side. Significant differences of ADG was found mainly at $15{\sim}18$ month and $18{\sim}21$ month fattening stages(p<0.05). Marbling score(MS) was higher(p<0.05) in 12 heads group when compared with that of 4 and 8 heads groups after 18 months. Animals in 12 heads group had the lowest Average daily gain(ADG) but showed the highest longissimus muscle area(LMA) and marbling score(MS). In addition, Hanwoo steers in 12 heads group obtained a higher quality appearance(HQA) of 82.7% than that of other treatments. The results indicated that Hanwoo steers housed on large group size and pen size decreased their ADG but improved meat quality.

• Korean Journal of Environment and Ecology
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• v.32 no.2
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• pp.165-175
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• 2018

The purpose of this study is to provide the basic data such as distribution status, growth characteristics, and the structural characteristics of forest stands for the systematic conservation and management of relict forest trees (stem girth of 300cm or larger) established naturally in Gangwon Province, Korea. The survey showed that 434 individuals of 19 species (conifers: 228 individuals of 4 species, broad-leaved trees: 206 individuals of 15 species) were distributed in Gangwon Province, and Taxus cuspidata was the most abundant among them with 203 individuals or about 46.7 % of the total. The stem girth was average of 404cm (conifers: 373cm, broad-leaves: 421cm), and Tilia amurensis with multi-stemmed growing on Sorak mountain range had the largest stem girth at 1,113cm. The average height and the crown width of relict forest trees were 15.4m and 10.0m, respectively. Although the environments of relict forest trees showed a slight difference by species, the relative appearance frequencies of most trees were high in the environments where the altitude was higher than 1,000 m, slope degree was greater than $25^{\circ}$, the slope faced north, and microtopography was at the upper of slopes. Regarding the stand characteristics of relict forest trees per unit area ($/100m^2$), the average total coverage was 294% (max. 475%), the total average number of species was 36 species (max. 60 species), the average species diversity index (H') was 2.560 (max. 3.593), the average canopy closure was 84.8% (max. 94.6%), and the average basal area (/ha) was $52.7m^2$ (max. $116.4m^2$, relict trees $30.0m^2$, and other trees $22.7m^2$). The analysis of the dynamics of the forest stands where relict forest trees were growing showed four types of the maintenance mechanisms of relict forest trees depending on the supply pattern of succeeding trees: "Low-density but persistent type (Quercus mongolica, Abies holophylla, Tilia amurensis, and Pyrus ussuriensis)," "Long ago stopped type (Pinus densiflora)," "Recently stopped type (Abies nephrolepis, Quercus variabilis, and Betula schmidtii)," and "Periodically repeated types of supply and stop (Salix caprea and Quercus serrata).".

• The Korean Journal of Malacology
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• v.31 no.2
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• pp.93-101
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• 2015

The effects of different stocking densities on the growth and survival rate of the 3-year-old pacific abalone, Haliotis dicus hannai were investigated in marine net cage for a year. Stocking densities in net cage ($2.4{\times}1.2m$) was set 15, 30, 45 and 60 percentage (= per)/sq m (square meter, $m^2$) with share to cross-sectional area per shelter. The water temperature during the testing period was $8.2^{\circ}C-22.1^{\circ}C$, and salinity is $33.5{\pm}0.6psu$, and dissolved oxygen is $7.87{\pm}0.86mg/L$. In the shell length (initial size : $71.50{\pm}2.28mm$) growth and shell breadth (initial size : $46.43{\pm}2.28mm$) of the test abalones, the absolute growth rate (ARG), daily growth rate (DGR) and specific growth rates (SGR) of the 15 per/sq m and 30 per/sq m were higher than those of 45 per/sq m and 60 per/sq m density group (P < 0.05). Also in the weight (initial weight : $35.7{\pm}8.1g$), it showed the same results. In survival rates, it were that 15 per/sq m and 30 per/sq m is significantly higher than 45 per/sq m and 60 per/sq m. Therefore, it was that the 15 per/sq m is optimized stocking density in marine net cages about the 3-year-old pacific abalone over 70 mm size. The result shown that total cross-sectional area under the shelter is based on 15 per/sq m ($2.4{\times}2.4m$, 354 number in a net cage) is suitable for fast growth and survival. But if the economy consider, optimized stocking density would be appropriate to accept 30 per/sq m ($2.4{\times}2.4m$, 710 number in a net cage).

• KEPCO Journal on Electric Power and Energy
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• v.6 no.3
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• pp.305-313
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• 2020

The use of cable tunnels for electric power transmission as well as their construction in difficult conditions such as in subsea terrains and large overburden areas has increased. So, in order to efficiently operate the small diameter shield TBM (Tunnel Boring Machine), the estimation of advance rate and development of a design model is necessary. However, due to limited scope of survey and face mapping, it is very difficult to match the rock mass characteristics and TBM operational data in order to achieve their mutual relationships and to develop an advance rate model. Also, the working mechanism of previously utilized linear cutting machine is slightly different than the real excavation mechanism owing to the penetration of a number of disc cutters taking place at the same time in the rock mass in conjunction with rotation of the cutterhead. So, in order to suggest the advance rate and machine design models for small diameter TBMs, an EPB (Earth Pressure Balance) shield TBM having 3.54 m diameter cutterhead was manufactured and 19 cases of full-scale tunneling tests were performed each in 87.5 ㎥ volume of artificial rock mass. The relationships between advance rate and machine data were effectively analyzed by performing the tests in homogeneous rock mass with 70 MPa uniaxial compressive strength according to the TBM operational parameters such as thrust force and RPM of cutterhead. The utilization of the recorded penetration depth and torque values in the development of models is more accurate and realistic since they were derived through real excavation mechanism. The relationships between normal force on single disc cutter and penetration depth as well as between normal force and rolling force were suggested in this study. The prediction of advance rate and design of TBM can be performed in rock mass having 70 MPa strength using these relationships. An effort was made to improve the application of the developed model by applying the FPI (Field Penetration Index) concept which can overcome the limitation of 100% RQD (Rock Quality Designation) in artificial rock mass.

• The Journal of Korean Medicine
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• v.34 no.3
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• pp.13-24
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• 2013

Objectives: The aims of this study were to investigate the availability of diagnosis of Yin-deficiency in the elderly with xerostomia and factors influencing subjective oral dryness. Methods: We surveyed 50 patients recruited by the clinical trial, 'Efficacy of Yukmijihwang-tang on Xerostomia in the Elderly: A Randomized, Double-blind, Placebo-controlled, Two-center Trial'. The subjects were assessed on their subjective oral dryness using the Dry Mouth Symptom Questionnaire (DMSQ). Their salivary functions were measured by Unstimulated Salivary Flow Rate (USFR) measurements. In addition, the subjects were evaluated on their Qi-stagnation and Yin-deficiency conditions using the Qi-stagnation questionnaire and Yin-deficiency questionnaire. Results: There were statistically significant correlations between three variables (USFR, DMSQ score and Qi-stagnation score) and Yin-deficiency score. In the multiple regression analysis, the regression model was statistically significant (F = 10.273, p < .001). The factor most strongly influencing the subjective oral dryness was USFR (${\beta}$ = -0.386). Yin-deficiency had the next strongest impact on the subjective oral dryness (${\beta}$ = 0.371). Qi-stagnation affected the subjective oral dryness weakly (${\beta}$ = 0.075). In the simple regression analysis, Yin-deficiency had a statistically significant effect on each of six subscales of DMSQ (p < .01). Among the six subscales, DMSQ-1 ('Oral dryness at night or on awakening') was the most strongly influenced by Yin-deficiency. Conclusions: The results of this study show that the diagnosis of Yin-deficiency in the elderly with xerostomia was available and Yin-deficiency was an important factor influencing the subjective oral dryness. Therefore, the consideration of Yin-deficiency is significant for diagnosis and treatment in the elderly with xerostomia.

• Journal of the Korean Wood Science and Technology
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• v.44 no.5
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• pp.716-725
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• 2016

In this study, MCQ (Micronized copper Quat) which was copper-based wood preservative, was investigated on decay properties by difference of the its infiltration volume. After pressure-treatment with different MCQ concentration, test specimens (Japanese Red Pine) were exposed by a brown-rot fungus (Fomitopsis palustris). At the end of the 12 weeks exposure to the fungus, untreated specimen was showed the mass loss of more than 35%, and the value of preservative effectiveness of MCQ by indoor decay was $3.99{\pm}0.42kg/m^3$. Therefore, MCQ should be pressure-injected at least $3.99kg/m^3$. The three dimensional of the specimens were observed by using the light microscope and scanning electron microscope, Untreated and treatment specimens with low concentration generally had underwent serious decays and had a lot of fungal hyphae. Howere, the formation of bore hole by hyphae were not observed. Mass loss and decay properties of specimens were affected by amount of MCQ injection. Therefore, it is necessary to the review of the adequacy of the MCQ injection amount in domestic environments.

• Journal of the Korean Wood Science and Technology
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• v.44 no.1
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• pp.48-56
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• 2016

In this study, to develop the lattice materials with a low environmental load for restoring the destroyed forest, 7 types of wood-concrete hybrid laminated materials were manufactured with domestic four softwoods, three hardwoods and concrete, and the effects of density of wood species on static bending strength performances were investigated. Bending MOEs of wood-concrete hybrid laminated materials increased with increasing density of wood species on the whole, and the values were higher than that of concrete by hybrid-laminating woods on the concrete. It was found that the measure values of bending MOEs were slightly lower than the calculated values calculated using equivalent cross-section method from MOE of each laminae of hybrid laminated materials and the difference between them was less than 10%. Bending proportional limit stresses of hybrid laminated materials showed 1.2-1.6 times higher than that of concrete by hybrid-laminating. Bending strength (MOR) of hybrid laminated materials increased with the density of wood species. By hybrid-laminating, the MOR of concrete was considerably increased. Therefore, it is considered that wood-concrete hybrid laminated materials can be applied as a materials with a low environmental load and durability for ecological restoration.

• Journal of Korea Water Resources Association
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• v.42 no.8
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• pp.619-629
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• 2009

The objective of this study is to estimate bed-resistance in gravel-bed rivers using the equivalent roughness height($k_s$). We calculated the friction factor(f) with the measured data from 8 domestic gravel-bed rivers and investigated the size distributions of the bed materials. The averaged $k_s$ in each cross-section, which is determined under the hypothesis that the vertical velocity distribution follows the logarithmic law, is compared with the reach $k_s$ which is calculated with the cumulative grain diameter distribution curve of bed materials. Moreover, the applicability of existing formulae, such as Strickler type equations, is examined by comparing with Manning's n value converted from the $k_s$. According to the results, the reach $k_s$ proves to be a good indicator of representative characteristic of bed materials in a reach, and the Manning's n based on the reach $k_s$ is appropriate for practical estimation of the bed-resistance, for RMS errors between calculated and measured Manning's n is less than 0.003. The correlation between the $k_s$ and specified bed-material size($D_i$) is very low, so it is difficult to select a proper one among the existing empirical equations.

• Journal of Preventive Medicine and Public Health
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• v.32 no.3
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• pp.306-316
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• 1999

Objectives: In Korea, as in most countries, there will be a sharp increase in the number of dementia patients in the near future. However basic data on dementia prevalence, which is important in defining epidemiologic characteristics and in implementing preventive strategy, are limited. This study was conducted to estimate the prevalence rate of dementia in the urban elderly aged 65 or older in Kwangmyung, Korea. Methods: A two phase design was used for case finding and case identification. In phase I, a representative sample aged 65 or older was selected and interviewed by door-to-door survey with a Korean version of the Mini-Mental State Examination (K-MMSE). In phase II, Of the 946 subjects interviewed in phase 1,356 elderly were randomly selected disproportionately according to K-MMSE score. Of these elderly, 223 (61.5%) underwent standardized clinical evaluations, including psychiatric interview, neurological examination, and neuropsychological assessment. Dementia was diagnosed by the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria. The diagnosis of Alzheimer's disease (AD) was made by National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and feinted Disorders Association(NINCDS-ADRDA) criteria and vascular dementia (VD) by DSM-IV. Results: The overall weighted prevalence rate of all dementia among Kwangmyung residents aged 65 or older was 12,8%(age-adjusted rate: 13,0%, 95% Confidence Interval[CI]: 10.6-15.3%). Women had much higher prevalence rate than men even when age was controlled(15.9%[95% CI 12.6-19.2%] vs 7.5%[95% CI 4.0-10.4%]), The rates of dementia were 5.2%, 12.2%, 17.0%, and 34.3% for the age groups of 65-69, 70-74, 75-79 and 80 and over, respectively. The rate of AD appeared to be slightly higher than that of VD(5.2% vs 4.8%), though not statistically significant. Most of the cases(69%) were mild dementia according to CDR(<1) in these subjects. Conclusions : These results showed that the prevalence rate of dementia among urban elderly in Korea appears to be higher than those of other Asian countries.

• Journal of Korean Society of Forest Science
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• v.84 no.4
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• pp.437-446
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• 1995

This study was carried out to estimate the Korean Pine stand structure such as coefficient of variation of mean DBH, number of trees and volume per ha by Weibull distribution for each age class from I to V, based on photo measurement and timber cursing in Kangwon National University Experimental Forests. The results were summarized as follows: 1) Coefficient of variation of mean DBH for each age class from I to V, which was obtained by converting DBH estimated from crown diameter by photo measurement into quadratic mean DBH, was estimated as 28.88%, 24.13%, 23.29%, 20.27%, and 18.79%, respectively. 2) Number of trees per ha of each age class by Weibull distribution was obtained as 2875, 2100, 1875, 800, and 325, respectively. 3) Volume per ha of each age class was estimated as $22.9m^3$, $66.8m^3$, $101.3m^3$, $209.6m^3$, and $266.8m^3$, respectively. 4) Therefore, aerial photographs will be helpful to estimate the stand structure effectively.