• Journal of Korean Society of Forest Science
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• v.82 no.2
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• pp.188-194
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• 1993

A natural Quercus variabilis forest and a Populus alba${\times}$P. glandulosa plantation in Mt. Mohu area were studied to investigate aboveground biomass and net production. A $20m{\times}30m$ quadrat was set up in each stand, and 10 sample trees each of Quercus variabilis and Populus alba ${\times}$ P. glandulosa were cut for dimension analysis. There was little difference in accuracy among three biomass regression models of logWt=A+BlogD, $logWt=A+BlogD^2H$, and logWt=A+BlogD+ClogH, where Wt. D, and H were dry weight, DBH, and height, respectively. Aboveground total biomass of Quercus variabilis stand was 31,275kg/ha, and that of Populus alba ${\times}$ P. glandulosa was 55,581kg/ha. In both of Quercus variabilis stand and Populus alba ${\times}$ P. glandulosa stand, the proportion of each tree component to abovegound total biomass was high in order of stem wood, branches, stem bark, and leaves. Quercus variabilis stand was higher in the proportion of stem bark, branches and leaves than Populus alba ${\times}$ P. glandulosa stand, while the former was lower in that of stem wood than the latter. Aboveground total net production of Quercus variabilis stand was 4,267kg/ha/yr., and that of Populus alba ${\times}$ P. glandulosa stand was 3,903kg/ha/yr. The proportion of each tree component to aboveground total net production of Quercus variabilis stand was high in order of leaves, stem wood, branches, and stem bark. That of Populus alba ${\times}$ P. glandulosa stand was high in order of stem wood, leaves, branches, and stem bark. Net assimilation rate and efficiency of leaf to produce stem of Quercus variabilis stand were 2.121 and 0.840, respectively. Those of Populus alba ${\times}$ P. glandulosa stand were 3.376 and 2.085, respectively. Though Populus alba${\times}$P. glandulosa stand was lower in aboveground total net production than Quercus variabilis stand, the former was higher in aboveground total biomass than the latter. The reason was that Populus alba${\times}$P. glandulosa stand was higher in net production of stem wood of accumulation organs than Quercus variablis stand.

• 사료
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• s.15
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• pp.62-64
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• 2005

농림부가 자원 순환 형 친환경축산기반조성을 위한 지원에 나서고 있음에도 입지를 확보하지 못해 신청이 저조한 것으로 나타나고 있는 가운데 친환경축사시설설치사업 추진계획에 대해 궁금해 하는 축산 인이 적지 않다. 이에 농림부가 추진하고 있는 친환경축사시설설치사업 추진계획을 축산신문이 정리한 것을 전재한다.(편집자 주)

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.4
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• pp.367-372
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• 2010

Purpose: The purpose of this study was to provide useful information for evaluating the sensory function of patients with strabismus by identifying the distribution of anomalous retinal correspondence (ARC) and normal retinal correspondence (NRC) by the degree of refractive errors and deviation angles. Methods: Objective refraction (AR/K, Cannon RK-F1, Japan) and subjective refraction tests were performed on 56 subjects (male: 26, female: 30) by an examiner; objective deviation angle was measured using synoptophore (OCULUS Synoptophore, Germany) with subject' eyes fully corrected for distance, and then subjective deviation angle was measured. Results: In all groups with refractive errors, the number of ARC was larger than that of NRC(67%). Particularly, it was largest in groups with myopia (71%), and in all groups, the number of UARC was larger than that of HARC. In groups with anisometropia, although the numbers of NRC and ARC were same, the number of UARC was larger than that of HARC as in other groups. In the distribution of NRC and ARC by deviation angle, the number of NRC was larger than that of ARC (46%) only at microstrabismus (0 ~ ${\pm}10{\triangle}$). Conclusions: Normal retinal correspondence were the most emmetropia in the retinal response were much higher than in the more hyperopia than the retinal correspondence were more myopia. In addition, the smaller the angle of retinal correspondence Normal over many, but overall, respectively.

• Journal of Korean Society of Forest Science
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• v.90 no.5
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• pp.600-607
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• 2001

This study was conducted to estimate the capability of Populus alba ${\times}$ glandulosa and Betula schmidtii for the uptake of Pb from the lead-contaminated soil and their tolerance to lead. Rooted cuttings in the former species and germinated seedlings in the latter species were planted in pots and irrigated with Pb-containing water for 60 days. In both tree species, growth inhibition was observed in 800, and 1,500ppm of $Pb(NO_3)_2$. Most Pb was accumulated in plant roots and only a small portion was transported to the shoots. The translocation rates of Pb for B. schmidtii and P. alba ${\times}$ glandulosa were 1.6-2.6% and 1.2-1.6%, respectively. The maximum Pb content accumulated in shoots was 468.0mg/kg d.w. in P. alba ${\times}$ glandulosa, and 602.0mg/kg d.w. in B. schmidtii. Although tolerance to lead was generally higher in B. schmidtii than P. alba ${\times}$ glandulosa, the highest tolerance to lead was observed in P. alba ${\times}$ glandulosa clone, 72-16. Finally, we discussed the applicability of P. alba ${\times}$ glandulosa and B. schmidtii for phytoextraction based on their Pb uptake ability, high biomass production, and easiness in large-scale cultivation.

• Journal of Korean Library and Information Science Society
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• v.49 no.2
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• pp.25-58
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• 2018

This study analyzed the agriculutral book Gyemi Metal Type Sasichanyo which was produced in Jujaso(鑄字所), by early Joseon dynasty's king Taejo(太宗). It is the most advanced edition of Sasichanyo("四時纂要") among whole east-northern Asia, which contains miscellanies about monthly agricultural plan(月令式 農家雜錄) and the themes are; agriculture, production spin-off processing, sanitation and medicine, tool fixing and conservation, business management. This research divided all letters appeared in Gyemi metal type Sasichanyo("四時纂要") by three categories; small letters, smaller letters, smallest letters to define its' function and characteristics and estimated the value of Sasichanyo("四時纂要"). Also in the aspect of typeface of letters and typesettings, this study compared all editions of Sasichanyo("四時纂要") with Gyemi metal type Sasichanyo("四時纂要").

• Journal of The Korean Ophthalmological Society
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• v.58 no.11
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• pp.1260-1268
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• 2017

Purpose: Strabismus affects any age and represents various functional or non-functional eye problems. This population-based study was conducted to determine the prevalence of strabismus and nystagmus in South Korea according to various sociodemographic factors. Methods: We acquired data from the Korea National Health and Nutrition Examination Survey, a nation-wide cross-sectional survey and examinations of the non-institutionalized civilian population in South Korea (n = 30,538), conducted from July 2008 to December 2011. The prevalence of strabismus and nystagmus were verified, and associated sociodemographic factors was evaluated. Results: The overall prevalence of strabismic disorder in participants over 3 years of age was $1.4{\pm}0.1%$ (95% confidence interval [CI] 1.3-1.6%; $1.5{\pm}0.1%$ in males, $1.3{\pm}0.1%$ in females). The prevalence of exodeviation (15 or more prism diopters), esodeviation (10 or more prism diopters), vertical deviation, and other complicated strabismus and nystagmus was 1.0%, 0.2%, 0.2%, 0.1% and 0.1% respectively. The prevalence was highest in the 6 to 15-year age group ($1.9{\pm}0.3%$), and lowest in the 40 to 49 years age group ($0.8{\pm}0.1%$) (p = 0.005). There were no statistically significant differences for gender, region, residential area, household income, educational level and occupation. Conclusions: This nation-wide epidemiologic study demonstrated that the prevalence of strabismus and nystagmus according to various sociodemographic factors in South Korea was not statistically significant except for age group. Further investigations are required based on more surveys to better recognize the etiologic or risk factors that may be related to strabismus and nystagmus.

• The Korean Journal of Nuclear Medicine
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• v.12 no.1
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• pp.17-28
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• 1978

A simplified photoelectric apparatus producing graphic records of the free Achilles tendon reflex allowed us to study the reflex quantitatively in subjects with normal and abnormal thyroid function. In this study Achilles tendon reflex times were tested in 340 normal Korean persons, 89 hyperthyroid patients, 19 hypothyroid patients and 85 other thyroid disease patients who were euthyroid in thyroid function tests. In normal Korean persons, the Achilles tendon reflex time was delayed with increasing age and slower in female than in male. They showed good correlationship with various thyroid function tests which included ETR, $T_3RU,\;^{131}I$ thyroid uptake and serum TSH. Diagnostic accuracy of them was 71% in hyperthyroidism and 90% in hypothyroidism. Finally the serial measurements of them were very useful tests in evaluating the clinical coures of hyperthyroidism and hypothyroidism once treatment was begun.

• Journal of Korean Society of Forest Science
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• v.105 no.3
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• pp.309-314
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• 2016

A locally adapted plant population under harsh environmental changes might survive for a long generation through maintaining proper level of genetic diversity. When it happens losing the genetic diversity too much fast, the population could be declining and probably become extinct. An isolated small population of Populus davidiana was investigated to study out the genetic diversity and the fine-scale spatial genetic structure. The estimated number of adult trees in the population of Mt. Worak, South Korea, was 350 in the total area of $14,000m^2$. The number of adults in a study plot ($70m{\times}70m$) was 123. The average age was 16-year-old and a 32-year-old tree was the oldest. The distribution of individuals was slightly aggregated in the plot. Sixty-one among the 123 individuals were randomly sampled to estimate genetic variation using AFLP markers. One hundred fifty-one (77%) of total 196 amplicons were polymorphic from six AFLP primer combinations. The average number of loci per primer combination was 32.7 (S.D.=7.2). Expected heterozygosity ($H_e$) and Shannon's diversity index (S.I.) were 0.154 and 0.254, respectively. These values were extremely lower than those of other P. davidiana populations in South Korea. Genetic patchiness was showed within 21 meters by spatial autocorrelation analysis and the isolated small size of population might be mainly attributed to the formation of such small patch size.

• Korean Journal of Agricultural and Forest Meteorology
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• v.7 no.4
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• pp.296-302
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• 2005

We investigated changes in photosynthetic characteristics of P. davidiana in order to understand damage patterns to photosynthetic apparatus under drought stress. Root sprout saplings of P. davildiana were treated with $0\%,\;2\%,\;5\%,\;and\;10\%$ of 300ml polyethylene glycol (PEG) once a weer far one month. After one month, we measured photosynthetic parameters and analyzed the photochemical and $CO_2$ fixation systems. Photosynthetic rate, stomatal conductance, and respiration rate in the leaves of P. davildiana decreased according to increasing stress strength. In the photochemical system, quantum yield of PSII was reduced by the increment of PEG concentration, The decrease of apparent quantum yield was related to reduction of electron transport. Respiration rate decreased with an increase in PEG concentration, whereas photorespiration rate in the $CO_2$ fixation system increased. In conclusion, photosynthesis of P. davidiana responded sensitively under drought stress, and the sensitivity depended upon the strength of water stress. P. davidiana exhibited an increase of water use efficiency under water stress.

• Journal of the Korean Wood Science and Technology
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• v.23 no.2
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• pp.94-99
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• 1995

현사시나무의 목질부와 수피부를 아세톤-물(1:1)의 혼합용액으로 추출하고 Sephadex LH-20로 충진한 칼럼을 사용하여 4개의 후라보노이드, 즉 (+)-catechin, (+)-dihydroquercetin, eriodictyol 및 (+)-dihydrokaempferol을 단리하고 $^{13}C$-NMR과 $^1H$-NMR 스펙트럼을 이용하여 그 구조를 규명하였다. 단리된 화합물의 A-환은 모두 후로로그루시놀형으로, B-환은 카테콜형 또는 페놀형으로 구성되어 있으며 (+)-dihydroquercetin, (+)-dihydrokaempferol과 eriodictyol은 포플라속의 수종에서는 처음으로 단리 되었다.