• Journal of Ginseng Research
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• v.31 no.3
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• pp.154-158
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• 2007

In order to increase the content of germanium in ginseng adventitious roots, the effects of chelating agents on germanium content and root growth were investigated in the submerged cultures of ginseng adventitious roots. Chelating agents such as citric acid, oxalic acid, phosphoric acid, EDTA (Ethylenediamine tetraacetic acid) or EGTA (Ethylene glycol-bis $({\beta}-aminoethylether)-tetraacetic$ acid) were administrated in the submerged culture of ginseng root containing 50 ppm $GeO_2$. After 6 weeks of cultivation, fresh weight, germanium and saponin contents in the roots were analyzed. Among chelating agents, addition of 1.0mM phosphoric acid was found to be best for germanium accumulation. Under this condition, germanium content increased 1.4 times as compared to that of the control. The germanium content in the adventitious roots also increased with addition of EDTA or EGTA, while they inhibited the growth of ginseng adventitious root. Citric and oxalic acids were not effective for increasing germanium content in adventitious roots. As the results, it suggests that the phosphoric acid can be proved as the optimal agent for the enhancement of germanium accumulation in ginseng adventitious roots. These results can be served as a guideline for the mass production of ginseng adventitious roots containing germanium by large-scale production.

• Journal of the Korean Chemical Society
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• v.38 no.8
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• pp.585-589
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• 1994

The complexation of cadmium(II) with a well characterized local soil fulvic acid was investigated at different solution pH and fulvic acid concentration using ion selective electrode. The stability constants were determined using a continuous distribution model based on Scatchard Plot; this model takes into consideration the diversitv of cation binding sites on a naturally occurring organic macromolecules even if the nature of the binding sites may not be known. The mean value of $logKi(\mu)$ was found to increase at higher pH(pH 4.0: ${\mu}=3.79{\pm}0.74$ l\;mol^{-1}; pH 6.0: ${\mu}=4.51{\pm}0.78$ l\;mol^{-1}$), and in more dilute fulvic acid concentration([FA] = 50 mgl$^{-1}: {\mu}=4.16{\pm}0.60$ l\;mol^{-1}; [FA]=151 mgl$^{-1}:{\mu}=3.75{\pm}0.5\;l\;mol^{-1}$). The intrinsic constant(logKint) for binding at the strongest site was measured to be around $4.72\;l\;mol^{-1}$ at both pH4.0 and 5.0, but was found to be increased to $6.03\;l\;mol^{-1}$ when pH was 6.0.

• Korea journal of population studies
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• v.16 no.2
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• pp.65-83
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• 1993

The purpose of this study is estimate limits of Korean life expectancy at birth by 'Gompertz growth curse Model', 'Cause-Elimination Model' and Multidimensional models of Senescencee and Mortality'. Data used in Gompertz curve were obtained from all life tables published from 1905 to 1990 in Korea, and life expectancies at birth of eighteen groups were selected at five-year interval in consideration of time-series changes. Data used in Cause-Elimination Model are 'Cause of Death statistics in 1991' published in 1992 by National Bureau of Statistics of Korea and 'life table of 1989' published in 1990 by National Bureau of Statistics, Economic Planning Board of Korea. The materials are all classifiable death data, 119, 253 cases of male and 82, 420 cases of female, which is from 1991 Causes of Death statistics. The cases of death analyzed belong to one of 8 categories; i.e., Infectious and Parasitic Diseases(001-139; with notation of Infectious Diseases), Malignant Neoplasms(140-208), Hypertensive Diseases(401-405), Ischemic Heart Dieases and Diseases of Pulmonary Circulation and Other Forms of Heart Diseases(410-429;with notation of Heart Disease), Cerebrovascular Diseases(430-438), Chronic Liver Diseases and Cirrhosis(571; with notation of Liver Diseases), Injury and Poisoning(800-999) and all other disease. Data used in 'Multidimensional models of senescence and mortality' were life table of 1989 published by National Bureau of statistics, Economic Planning Board of Korea and life table of 1970, 1978-79, 1983, 1985 and 1987. The major findings may be summarised as follows: 1. Estimate equations of Gompertz growth curve using life expectancy at birth during the 1905-1990 period are as the following. Male : y = 88.047697 $\times$ $0.199690^{0.903381x}$ Female : y = 95.632828 $\times$ $0.199690^{0.903381x}$ Limits of life expectancy at birth, which were estimated by Gompertz growth curve, are 88.05 for male and 95.63 for female. 2. The effect on life expectancy at birth eliminationg all causes death is 14.04 years(for male) and 10.86 years(for female). Astonishingly, eliminating the malignant neoplasms increase life expectancy at birth by 2.85 years for male 2.03 years for female in 1991. In table 8 we show the effect on life expectancy at birth of separately eliminating each of the 8 categorical causes of death. The theoretical limit to life expectancy by Cause-Elimination Model is 80.96 for male and 85.82 for female. 3. If the same rate of delay [0.376 year(male), 0.435 year(femable) per calendar year] continued, then life expectancy at birth would reach 74.82(male) years and 84, 10(female) years in 2010. With 14.04-years(male) and 10.86-years(female) effect attributable in 2010 would be 88.86 years(male) and 94.96(femable) years. 4. 'Multidimensional models of senescence and death' permits calculations of the value of the attribution coefficient (B), percent of loss per year of physiologic function. The results of Ro and B during the 1970-1989 period are listed in table 9. Estimate of limit to Korean life expectancy at birth by 'Multidimensional models of senescence and death' is 99.47 years for male and 104.74 years for female in 1989.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.5
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• pp.435-444
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• 2017

The vehicle-track structure dynamic interaction analysis problem can be treated as sliding contact problem, and it is assumed that vehicle run at a constant speed over a rail modeled as beam elements. Unfortunately, Salome-Meca can not satisfy the compatibility condition for the beam master elements, which are consist of the elements with higher order polynomial shape function, in sliding contact problem. In this study, it is suggested to use more finer beam master element mesh as the remedy for incompatibility in sliding contact problem, and the accuracy of the solution is secured. For this, the effect of beam element mesh refinement consisting runway is analysed through simple examples, and the applicability to the dynamic interaction analysis is evaluated. Finally, the dynamic interaction analysis of railway skewed culvert transition problem is carried out to evaluate the effect of supporting stiffness due to backfill pattern changes and track irregularity due to uneven subgrade settlement.

• Membrane Journal
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• v.17 no.4
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• pp.338-344
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• 2007

Electro-electrodialysis of hydriodic acid with HI molality of ca. 9.5 $mol/kg-H_2O$ was examined in the presence of iodine using a commercial cation exchange membrane, CMB, as a separator. For the increase of the selectivity of proton permeation, the membrane was radiation-treated by accelerated electron radiation. The membrane properties (area resistance, ion exchange capacity, water content) of the radiation-treated membranes were measured. The area resistance in 2 $mol/dm^3$ KCl solution, ion exchange capacity and water content of the radiation-treated membranes at each dose rate dad almost the same value as that of the non-treated membrane (original of CMB membrane). Electro-electrodialysis of hydriodic acid with HI molality of ca. 9.5 $mol/kg-H_2O$ was examined at $75^{\circ}C$ with 9.6 $A/dm^2$. The radiation-treated cation exchange membrane by accelerated electron radiation had higher selectivity of the proton permeation by cross-linking structure of polymer than that of the non-treated membrane.

• The Korean Journal of Pesticide Science
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• v.12 no.2
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• pp.192-196
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• 2008

This study examined the acaricidal activity of a new compound, K16776 against honeybee mite, Varroa destructor which is ecto-parasite of Apis mellifera. Acaricidal activity was performed using six acaricides, two Chinese commercial acaricides and one newly synthesized K16776 against V. destructor in the small container and in the bee hive. K16776 and amitraz exhibited 100% acaricidal activity against V. destructor without insecticidal toxicity to A. mellifera in the small container. The other acaricide was not activity. Applied to the bee hives, K16776 showed acaricidal activity as 98.7% ($250{\times}$) and 88.6% ($500{\times}$) and amitraz showed as 100% ($500{\times}$) and 90% ($1,000{\times}$), respectively. Made in China, Cao Suan Sha Man Pian and Wangs showed acaricidal activity as 56.9% and 66.7%, respectively. The result indicates that K16776 can be potentially useful control agent against honeybee mite, V. destructor.

• The Journal of the Korea Contents Association
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• v.19 no.12
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• pp.593-603
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• 2019

The purpose of this study is to analyze the effect of early health status on income status as young old adults grow older. Using Korean Retirement & Income Study(KReiS), this study finally included 923 older adults who were fully present from the first wave (2005) to the sixth wave (2015) for 10 years. The results of descriptive analysis show that the difference of income occurs due to the difference of health status at the early old age. In other words, older adults with good health status at the early old age(56 ~ 60 years old) have a relatively higher income level for 10 years compared with older adults with poor healthy status. In multiple regression analysis, the results represent that the better the health condition in early age, the higher the gross individual income, controlling for gender, spouse, and education level. In addition, older adults with good health at early old age stage have higher income level than those with poor health at early old age stage. The difference by health status continues as they are getting old. Therefore, this study suggests several policies and practical alternatives to improve the early health condition and to reduce the negative impact of early health condition on old age income.

• Journal of Distribution Science
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• v.11 no.1
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• pp.55-63
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• 2013

Purpose - As the members of the baby boomer generation have retired in earnest, the start-up market has received more attention than ever before. According to recent statistical data, an increasing number of entrepreneurs are in their fifties. There has been a continuous increase in promotional materials on small business issues published by start-ups. This means that senior start-ups have increased in number. A number of support systems have been established for youth start-ups, but there are few government support policies in place for the senior start-up market. Thus, this study suggests a number of constructive alternatives from the perspective of government policy and marketing strategy for entrepreneurs, in order to generate competitiveness in the start-up process, through examining the current state of the senior start-up and by diagnosing extant problems. Research design, data, methodology - This study gives a number of options regarding the government's support policies and the securing of competitiveness in order to vitalize senior business start-ups. As for the government's support policies, funding support policy, publicizing business start-up policies, and operating systematic mentoring policies before retirement have all been covered. In particular, in order for senior business start-ups to become competitive, development through mutual relations with diverse policies is urgently needed. The aging population is becoming an issue in Korea, so businesses for the aged, and the creation of jobs for these people, will become a social issue. Senior business start-ups are playing an important role in expanding enterprise productivity, in addition to enhancing national competitiveness. Expanding senior business start-ups is important, because they also serve to expand the national infrastructure. Productivity increase through continuous expansion is thus recommended. Results - In order to expand the competitiveness of business start-ups, marketing-related observations and learning in regard to customers are necessary for the baby boomer generation, and competitiveness for seniors is urgently needed. Conclusions - Studies on the business start-up policies for the domestic baby boomer generation are almost non-existent, and systematic studies on small businesses are necessary. Only the government is providing statistical studies for small businesses, and such research remains at a general level for entrepreneurs. Therefore, a support system that can actually assist entrepreneurs is essential. Continuous business start-up studies with respect to the baby boomers should be vitalized, to invigorate studies on competition. In order to supplement and strengthen foundational support, senior business start-ups must develop various competitive capabilities with a focus on the customer. The government and the various stakeholder agencies and organizations involved with start-up businesses must find ways to offer support to founders. Such support should include access to knowledge and legal and consultancy services in order to incubate the rapid increase in start-ups founded by seniors. Government support projects should be expanded to meet this end.

• Korean Journal of Food Science and Technology
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• v.37 no.1
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• pp.84-89
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• 2005

Mongolian dandelion (Taraxacum mongolicum H.) extracted with solvents having different polarities were prepared to investigate protection activity of gastric mucosa. Ethanol extracts were successively reextracted with methylene chloride, and n-butanol. Concentrations of total flavonoids and luteolin in n-butanol extracts were 27.75 and 1.14%, respectively, much higher than those of other solvent extracts. Results of anti-microbial acitivity test against Helicobacter pylori and urease inhibition test revealed n-butanol extract exerted higher inhibition (13.16%) than other solvent extracts. Based on 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, n-butanol extract showed the highest efficiency of free radical-scavenger activity among the extracts ($SC_{50}\;47{\mu}g/mL$). Erythrocytic photohemolysis tests, for the protection of cell membrane showed that half-life of human erythrocytes was increased by the addition of n-butanol extract $({\tau}_{50}=172min;C=5.0{\mu}g/mL)$. These results indicate n-butanol extract of Mongolian dandelion may be useful as a adjuvant for gastric diseases.

• Korean Journal of Environment and Ecology
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• v.29 no.6
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• pp.819-841
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• 2015

To investigate the distribution of vascular plants growing at Halmibong(1,026m) and Gusibong(1,014m) in Baekdutrail, we surveyed from March in 2013 to March in 2014. The flora of Haimibong and Gusibong in Baekdu trail were found to be; 528 taxa; 95 families, 287 genus, 454 species, 4 subspecies, 59 varieties, 11 forma. Rare plants were found to be; 15 taxa, 10 families, 14 genus, 13 species, 2 varieties. Among them EN degree was found to be 1 species(Rhododendron tschonoskii Maxim.), VU degree; 2 species(Scorzonera albicaulis Bunge, Lilium cernuum Kom.), LC degree; 12 species(Abies koreana Wilson, Coreanomecon hylomeconoides Nakai, Viola albida Palib. etc.) respectively. In all surveyed areas, a total of 15 taxa(Heloniopsis koreana Fuse, N.S.Lee & M.N. Tamura etc.) were found to be endemic to Korea. Distribution of floristic special plants in the surveyed areas were found to be divided into five classes (class I~V). The floristic special plants found in surveyed areas were 2 taxa of grade V, 6 taxa of grade IV, 12 taxa of grade III, respectively. The naturalized plants were investigated as 23 taxa; Rumex crispus L., Amorpha fruticosa L., Veronica arvensis L. etc..