• Journal of Technology Innovation
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• v.25 no.3
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• pp.51-82
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• 2017

In terms of both economic growth and social welfare, this paper discusses the optimal proportion and size of basic research budget by adding knowledge stock to an endogenous growth model. On the basis of the modified endogenous growth model, this paper derived an equation that consists of kinds of parameters and suggested this equation as a criterion for determining whether allocated basic research budget has been appropriate. This paper also found that the theoretical optimal ratio between government investment spending and investment in basic research is equal to the ratio between the partial elasticity of output with respect of public capital stock and the partial elasticity of output with respect of knowledge stock. In addition, after the required parameters were specified based on precedent literatures, this paper estimated an optimum size of the basic research budget using the theoretical optimal ratio with official statistical records and compared the estimated size to its actual size. This paper therefore is expected to contribute to budget planning and allocation regarding establishing basic research policy, because the results of this paper presents a useful criterion for optimum level and an approximate size of investment in basic research. However, it should be noted that although the optimal solution is optimal in a economic sense, it may not be the best solution from a practical perspective.

• Journal of Physiology & Pathology in Korean Medicine
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• v.24 no.1
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• pp.134-142
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• 2010

Although BinSo-San(BSS), a mixed herbal formula consisted of 11 types of medicinal herbs and have been used as anti-inflammatory agent, In the present study, the acute toxicity (single oral dose toxicity) of lyophilized BSS aqueous extracts was monitored in male and female mice after oral administration according to Korea Food and Drug Administration (KFDA) Guidelines (2005-60, 2005). In order to observe the 50% lethal dose ($LD_{50}$), approximate lethal dosage (ALD), maximum tolerance dosage (MTD) and target organs, test articles were once orally administered to female and male ICR mice at dose levels of 2000, 1000, 500, 250 and 0 (control) mg/kg (body wt.) according to the recommendation of KFDA Guidelines (2005-60, 2005). The mortality and changes on body weight, clinical signs and gross observation were monitored during 14 days after dosing according to KFDA Guidelines (2005-60, 2005) with organ weight and histopathology of 12 types of principle organs. We could not find any mortality, clinical signs and changes in the body weights except for dose-independent increases of body weight and gains restricted in 1000 mg/kg of BSS extracts-dosing female group. Hypertrophic changes of lymphoid organs.thymus, spleen and popliteal lymph nodes were detectedat postmortem observation with BSS extracts dose-dependent increases of lymphoid organ weights, and hyperplasia of lymphoid cells in these all three lymphoid organs at histopathological observations. These changes are considered as results of pharmacological effects of BSS extracts or their components, immunomodulating effects, not toxicological signs. In addition, some sporadic accidental findings such as congestion spots, cyst formation in kidney, atrophy of thymus and spleen with depletion of lymphoid cells, and edematous changes of uterus with desquamation of uterus mucosa as estrus cycles were detected throughout the whole experimental groups including both male and female vehicle controls. The significant (p<0.01) increases of absolute weights of kidney and pancreas detected in BSS extracts 1000 mg/kg-treated female group are considered as secondary changes from increases of body weights. The results obtained in this study suggest that the BSS extract is non-toxic in mice and is therefore likely to be safe for clinical use. The LD50 and ALD of BSS aqueous extracts in both female and male mice were considered as over 2000 mg/kg because no mortalities were detected upto 2000 mg/kg that was the highest dose recommended by KFDA and OECD. In addition, the MTD of BSS extracts was also considered as over 2000 mg/kg because no BSS extracts-treatment related toxicological signs were detected at histopathological observation except for BSS or their component-related pharmacological effects, the immunomodulating effects detected in the present study.

• Toxicological Research
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• v.29 no.4
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• pp.263-278
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• 2013

The silkworm extract powder contain 1-deoxynojirimycin (DNJ), a potent ${\alpha}$-glycosidase inhibitor, has therapeutic potency against diabetes mellitus. Therefore, natural products containing DNJ from mulberry leaves and silkworm are consumed as health functional food. The present study was performed to evaluate the safety of the silkworm extract powder, a health food which containing the DNJ. The repeated toxicity studies and gentic toxicity studies of the silkworm extract powder were performed to obtain the data for new functional food approval in MFDS. The safety was evaluated by a single-dose oral toxicity study and a 90 day repeated-dose oral toxicity study in Sprague-Dawley rats. The silkworm extract powder was also evaluated for its mutagenic potential in a battery of genetic toxicity test: in vitro bacterial reverse mutation assay, in vitro chromosomal aberration test, and in vivo mouse bone marrow micronucleus assay. The results of the genetic toxicology assays were negative in all of the assays. The approximate lethal dose in single oral dose toxicity study was considered to be higher than 5000 mg/kg in rats. In the 90 day study, the dose levels were wet at 0, 500, 1000, 2000 mg/kg/day, and 10 animals/sex/dose were treated with oral gavage. The parameters that were monitored were clinical signs, body weights, food and water consumptions, ophthalmic examination, urinalysis, hematology, serum biochemistry, necropsy findings, organ weights, and histopathological examination. No adverse effects were observed after the 90 day administration of the silkworm extract powder. The No-Observed-Adverse-Effect-Level (NOAEL) of silkworm extract powder in the 90 day study was 2000 mg/kg/day in both sexes, and no target organ was identified.

• Journal of Preventive Medicine and Public Health
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• v.40 no.3
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• pp.197-204
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• 2007

Objectives : This study was conducted to evaluate the public's awareness of the importance of hand washing and to compare perceptions on the habit of hand washing with actual hand washing behavior. Methods : Data were collected by observing 2,800 participants washing their hands after using public restrooms in seven cities nationwide and by surveying 1,000 respondents (age > 14 years) through telephone interviews using a structured questionnaire. Results : Although 94% of the survey respondents claimed to mostly or always wash their hands after using public restrooms, only 63.4% of the observed participants did wash their hands after using public restrooms. Significant factors related to increased adherence to hand washing were female gender, approximate ages of 20 to 39 years by their appearance, and the presence of other people from the observation. About 79% of the survey respondents always washed their hands after using bathrooms at home, 73% washed their hands before handling food, and 67% washed their hands upon returning to their home. However, 93.2% and 86.3% of the survey respondents did not wash their hands after coughing or sneezing and after handling money, respectively. Although most of the survey respondents (77.6%) were aware that hand washing is helpful in preventing communicable diseases, 39.6% of the survey respondents did not do so because they were 'not accustomed' to washing their hands and 30.2% thought that washing their hands is 'annoying'. Conclusions : This is the first comprehensive report on hand washing behavior and awareness of the general population in Korea. The result of this study in terms of individual behavior and awareness of hand washing are comparable with similar studies conducted in other countries. However adherence to hand washing is still low and needs to be increased. The results of this study can be used as a baseline in setting up strategies and activities to promote adherence to hand washing.

• Journal of radiological science and technology
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• v.39 no.4
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• pp.483-491
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• 2016

The conditions after exposure to digital mammography and digital breast tomosynthesis were analyzed. The examinations for the ACR phantom were done using manual exposure, not auto exposure, to examine image discrimination and patient dose. As a result, the following results were derived: In the CC exposure, the kVp was 2kVp higher while mAs decreased to 58.6% for the 3D tomography. Such result showed an approximate decrease of 60mAs. At that time, the patients' Average Glandular Dose (AGD) was 1.65mGy in 2D and 1.87mGy in 3D; thus, AGD of 3D was shown to have about 1.13times higher. The result of the manual exposure revealed a reduced mAs of up to 80%; there was no effect in the assessment standard in terms of image discrimination, resulting in more than 10 points. When mAs was reduced to 80% in the manual exposure for ACR phantom, AGD was decreased to 0.66mGy. The diagnostic values of images were maintained and patients dose was reduced in the manual exposure in the AEC condition for 3D. Since the use of 3D has recently increased, using the manual exposure has been recommended in this study to improve the diagnostic value, while, simultaneously reducing patients dose.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.6
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• pp.587-593
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• 2016

Reliability-based design optimization (RBDO) requires a high computational cost owing to its reliability analysis. A surrogate model is introduced to reduce the computational cost in RBDO. The accuracy of the reliability depends on the accuracy of the surrogate model of constraint boundaries in the surrogated-model-based RBDO. In earlier researches, constraint boundary sampling (CBS) was proposed to approximate accurately the boundaries of constraints by locating sample points on the boundaries of constraints. However, because CBS uses sample points on all constraint boundaries, it creates superfluous sample points. In this paper, efficient constraint boundary sampling (ECBS) is proposed to enhance the efficiency of CBS. ECBS uses the statistical information of a kriging surrogate model to locate sample points on or near the RBDO solution. The efficiency of ECBS is verified by mathematical examples.

• Korean Journal of Food Science and Technology
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• v.45 no.3
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• pp.274-278
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• 2013

The aim of our study was to investigate the chemical composition of the Asian ginseng seed (Panax ginseng C.A. Meyer) and the American ginseng seed (Panax quinquifolium L.) grown in Korea (3 years, KGS3; 4 years, KGS4), China (4 years, CGS4), and USA (4 years, AGS4). AGS had the heaviest 100-seed weight ($4.21{\pm}0.31g$). The approximate compositions of the ginseng seeds were 13.66-17.00% crude protein, 2.21-8.65% crude ash, 19.06-24.06% crude lipid, and 43.21-47.49% crude fiber. The mineral contents of the ginseng seeds were greater in order of K>P>Ca>Mg>Fe>Na>Zn >Cu. The unsaturated fatty acid content was 96.71-96.94%, and the major fatty acids oleic acid and linoleic acid were present. Total sugar content was 15.00-26.17 mg glucose/g. The acidic polysaccharide content was 0.56-0.80 mg ${\beta}$-Dgalacturonic acid/g. These results showed the differences in the physicochemical characteristics of ginseng seeds with respect to cultivation location, cultivation year, and species.

• The Korean Journal of Applied Statistics
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• v.33 no.5
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• pp.527-540
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• 2020

While analyzing data, researching outliers, which are out of the main tendency, is as important as researching data that follow the general tendency. In this study we discuss the influence function for outlier discrimination. We derive sample influence functions of sample mean, sample variance, and sample standard deviation, which were not directly derived in previous research. The results enable us to mathematically examine the relationship between the empirical influence function and sample influence function. We can also consider a method to approximate the sample influence function by the empirical influence function. Also, the validity of the relationship between the approximated sample influence function and the empirical influence function is also verified by the simulation of random sampled data in normal distribution. As the result of a simulation, both the relationship between the two influence functions, sample and empirical, and the method of approximating the sample influence function through the emperical influence function were verified. This research has significance in proposing a method that reduces errors in the approximation of the empirical influence function and in proposing an effective and practical method that proceeds from previous research that approximates the sample influence function directly through empirical influence function by constant revision.

• KSTLE International Journal
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• v.7 no.2
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• pp.27-34
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• 2006

Knudsen number is the ratio of molecular mean free path versus mm thickness and the criterion to determine the flow form. When its value is lower than 0.01, the flow can be assumed to has no slip boundary condition. And in the case that the value is between 0.01 and 10, then the flow has slip boundary condition at both the adjacent walls. The condition of the air flow between the rotating journal and top foil in the air foil bearing is determined by the rotating speed and load, and the Knudsen number is also varied by those values. Because the molecular mean free path is variable to the pressure and temperature, more exact formulation is necessary to understand and analyze the flow regime. In this study, the analysis considering Knudsen number formulated with those variables (pressure, temperature and mm thickness) was executed. The approximate value was examined using the equation to confirm whether the flow has the slip or no-slip boundary condition. From the analytic investigation, it was decided to range approximately 0.01 to 1.0 and the flow can be supposed to have the slip boundary condition. Under the condition of the slip flow, the static characteristics of the air foil bearing were examined using modified Reynolds equations. The results were compared with those considering no slip condition. It shows that the slip condition makes the flow decelerates and the load carrying capacity decreases compared with no slip condition. And as the bearing number and eccentricity ratio increase, the load carrying capacity also increased at both the cases. From this result, it can be supposed that the bearing torque also increases. In the analysis of the dynamic characteristics, the perturbed Knudsen number was taken into consideration. Because the Knudsen number is expressed as the terms of each variable, the perturbed equation can be simply derived. The results of both cases considering and not considering Knudsen number were compared each other. In the case of the direct terms of the stiffness and damping coefficients, the difference between both cases was little and increased as the bearing number and eccentricity ratio increased. And the cross terms have less or more differences.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.4
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• pp.650-657
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• 2011

The object of this study was to obtain acute information (single oral dose toxicity) of Taraxaci Herba (Dried total parts of Taraxacum platycarpum. H.Dahlstedt (Compositae)), has been traditionally used in Korean medicine for treating various inflammatory diseases. In order to observe the 50% lethal dose (LD 50), approximate lethal dosage (ALD) and target organs, test articles were once orally administered to female and male ICR mice at dose levels of 2,000, 1,000, 500 mg/kg according to the recommendation of Korea Food and Drug Administration Guidelines. The mortality and changes on body weight, clinical signs and gross observation were monitored during 14 days after single oral treatment of Taraxaci Herba aqueous extracts according to KFDA Guidelines with organ weights and histopathological observations of 12 types of principle organs. After single oral treatment of Taraxaci Herba aqueous extracts, we could not find any mortality and toxicological evidences up to 2,000 mg/kg treated group, the limited dosages in rodents at body and organ weights, clinical signs, gross and histopathological observations. Except for slight soft feces, which were detected in male mice treated with 2,000 mg/kg of Taraxaci Herba aqueous extracts at 1 day after end of treatment. The results obtained in this study suggest that the LD 50 and ALD of Taraxaci Herba aqueous extracts in both female and male mice after single oral treatment were considered as over 2,000 mg/kg because no mortalities were detected up to 2000 mg/kg that was the highest dose recommended by KFDA and OECD. However, it also observed that the possibility of digestive disorders, like diarrhea when administered over 2,000 mg/kg of Taraxaci Herba aqueous extracts in the present study, but these possibilities of digestive disorders can be disregard in clinical use because they ate transient in the highest dosages male only.