• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2004년도 유체기계 연구개발 발표회 논문집
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• pp.546-551
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• 2004

An applying Thermodynamic method for the purpose of measuring hydraulic efficiency of pump-motor system, based on IEC60041 code, is not easy to adopt at field test. Even though there were splendid development in measuring technic in discharge measuring through the hydraulic machina lots of unsolved problems concerned in flow-rate are still remain in measuring hydraulic efficiency in hydraulic machine. The key point in measuring hydraulic efficiency is to measure exact flow-rate. So, Thermodynamic methode provides a good solution. This methode measures hydraulic efficiency by detecting the difference of temperature and pressure between the hydraulic process of machine, without measuring flow-rate of pump or turbine. By measuring temperature in mk level and absolute pressure in pascal, we can get a difference of thermodynamic specific energy in Moliere chart before and after of hydraulic process, md that difference is equal to hydraulic loses. Following the standard in proceeding Thermodynamic methode, I hope these trial and records make others be familiar to the thermal methode and make it easer to beginner for trial.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.759-764
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• 2004

In this study, the experiment was carried out to investigate and analyze the ready-mixed concrete production of ultra-high strength concrete with mixing strength of $100N/mm^2$ according to types of mineral admixtures. The main experimental variables were water/binder ratio $25.0\%$, water content $160kg/m^3$ and mineral admixtures such as fly ash, silica fume and meta kaolin. According to the test results, the principle conclusions are summarized as follows. 1) even if it secures similar slump, the viscosity appear to difference by mixing condition relatively. 2) The autogeneous shrinkage of ultra-high strength concrete is profitable that use admixture, and heat of hydration is desirable that apply considering countermeasure enough in the advance. 3) The concrete that use SF10+MK10 on 56days could confirm that it is possible that achieve compressive strength more than $100N/mm^2$ under mixing conditions that is appearing by compressive strength $102.7N/mm^2$.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 추계학술발표회논문집(2)
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• pp.669-674
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• 1996

The theory of quantum mechanics states that for any system there are a set of discrete physical states, quantum states, which corresponds a particular energy level of the system. The lowest energy the system can have, corresponding to its ground state, is not necessarily zero, but depends only on the precise microscopic nature of the system under consideration. At the absolute zero of temperature all systems will be in their lowest energy state (zero point energy) and as the system is warmed from OK, the higher energy states become occupied. The probability of occupancy of the excited states relative to that of the ground state is proportional to the absolute temperature. Therefore we can obtain nuclear dipole and quadrupole moment very accurately at ultra low temperature (<15mk) by NMR and from the destruction of anisotropy. The former is called LTNO/NMR and the latter is called LTNO (Low Temperature Nuclear Orientation). In this paper we discuss and introduce only an experimental apparatus with results of cooling power test, a helium dilution refrigerator, which can reache 8mK, and an actual technique for the experiment, a theory and results will be presented in another papers.

• 산경연구논집
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• 제13권2호
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• pp.45-57
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• 2022

Purpose: This paper examines whether or not universal banking operating in the asset management business tend to IPO underpricing when they are hosting IPOs in favor of their private interests. Previous studies suggest evidence which indicates that the universal banking operating in the asset management business tend to underestimate offering prices. This paper compares and analyzes the data before and after June 2007 to examine the influence of put-back option on IPO underpricing. Research design, data, and methodology: This paper compares the underwritten prices of IPOs of universal banking with and without asset management business in Korea in order to test such tendency actually exists. Result: We can find that such tendency is not correlated with first-day stock returns but correlated with put-back options. Our paper concludes that the hypothesis that "the universal banking's subsidiary asset management business influences the IPO underpricing" is found to be statistically insignificant. Conclusion: According to our analysis, it cannot be concluded that the interests of operating asset management do not conflict with the ones of underwriting business. However, it is so possible that the asset management companies try to harm the customers' interests, for instances churning and stuffing, it is necessary to scrutinize their behaviors and review the related regulations.

• 동아시아경상학회지
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• 제11권1호
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• pp.21-30
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• 2023

Purpose - The purpose of this study is to analyze the factors that influence Korean adults to acquire accounting knowledge. This study, which analyzes the characteristics of accounting knowledge of the general public, is expected to be used as basic data for the development of accounting curricula and education programs necessary for liberal arts courses and individual investor education in the future. Research design, data, and methodology -In this study, correct answer rates in the Economics and Business Literacy Test were analyzed across two rounds of tests. This study have the accounting scores of the applicants as a dependent variable and it aims to estimate key factors that affect accounting scores. Result - The results of regression analysis for individual variables that both the scores from the business administration and the economics, which were estimated to affect accounting performance, were found to have a positive effect. The results of the analysis of the relationship between major and accounting scores showed that the scores of all other majors were lower than those who majored in business. Conclusion - The results of this study suggest several implications in lecturing accounting as a basic or principle. Acquiring basic knowledge in economics and business administration was found to play an important role in understanding accounting ideas, indicating that such activities would be helpful when lecturing on accounting.

• Journal of Microbiology and Biotechnology
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• 제13권6호
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• pp.1013-1017
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• 2003

A thermophilic nonspore-forming rod isolated from hay compost in Korea was subjected to a taxonomic study. The microorganism, designated as $SC-1^T$, was identified as a nitrate-reducing and nonmotile bacterium. Although the strain was negatively Gram-stained, a KOH test showed that the strain $SC-1^T$ belonged to a Gram-positive species. Growth was observed between 45 and $70^{\circ}C$. The optimal growth temperature and pH were $60^{\circ}C$ and pH 7.5, respectively. The G+C content of the genomic DNA was 65 mol% and the major quinone types were MK-6 and MK-7. A phylogenetic analysis based on 16S rDNA sequences revealed that the strain $SC-1^T$ was most closely related to Symbiobacterium thermophilum. However, the level of DNA-DNA relatedness between strain $SC-1^T$ and the type strain for Symbiobacterium thermophilum was approximately 30%. Accordingly, on the basis of the phenotypic traits and molecular systematic data, the strain $SC-1^T$ would appear to represent a new species within the genus Symbiobacterium. The type strain for the new species is named $SC-1^T$ ($=KCTC\;0307BP^T;\;DSM15906^T$).

• Journal of Ginseng Research
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• 제24권4호
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• pp.196-201
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• 2000

흰쥐 소뇌로부터 과립신경세포를 배양하여 NaCN으로 유도되는 신경세포손상에 대한 ginsenosides의 보호효과를 검토하였다. NaCN(I~10 M)을 배양된 세포에 1시간 동안 처리하면 농도 의존적으로 신경세포사를 일으켰다. Ginsenosides(Rb$_1$, Rc, Re, Ri, Rg$_1$)(0.5, 5 $\mu\textrm{g}$/ml를 세포에 전처치하면 10 mM NaCN으로 유도되는 세포사가 현저히 감소되었다. Rb$_1$과 Rc(5$\mu\textrm{g}$/ml)는 5 mM NaCN에 의하여 배양액 중으로 유리되는 glutamate의 증가를 현저히 억제하였으며, 1 mM N3CN에 의하여 유발되는 세포내 $Ca^{2+}$농도의 증가를 억제하였다. NaCN으로 유발되는 세포독성은 또한 MK-801, verapamil, NAME에 의하여도 억제되었다. 따라서, NaCN으로 유도되는 신경세포사는 glutamate release를 통한 NMDA수용체의 활성화와 그에 따른 $Ca^{2+}$의 세포내유입에 의한 것임을 알수 있고, ginsenosides, 특히 Rb$_1$과 Rc는 $Ca^{2+}$의 유입을 억제하므로서 NaCN에 의한 신경세포사를 억제하는 것으로 생각된다.

• Korean Journal of Radiology
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• 제20권5호
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• pp.791-800
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• 2019

Objective: To compare various models of diffusion-weighted imaging including monoexponential apparent diffusion coefficient (ADC), biexponential (fast diffusion coefficient [D_f], slow diffusion coefficient [D_s], and fraction of fast diffusion), stretched-exponential (distributed diffusion coefficient and anomalous exponent term [α]), and kurtosis (mean diffusivity and mean kurtosis [MK]) models in the differentiation of renal solid masses. Materials and Methods: A total of 81 patients (56 men and 25 women; mean age, 57 years; age range, 30-69 years) with 18 benign and 63 malignant lesions were imaged using 3T diffusion-weighted MRI. Diffusion model selection was investigated in each lesion using the Akaike information criteria. Mann-Whitney U test and receiver operating characteristic (ROC) analysis were used for statistical evaluations. Results: Goodness-of-fit analysis showed that the stretched-exponential model had the highest voxel percentages in benign and malignant lesions (90.7% and 51.4%, respectively). ADC, D_s, and MK showed significant differences between benign and malignant lesions (p < 0.05) and between low- and high-grade clear cell renal cell carcinoma (ccRCC) (p < 0.05). α was significantly lower in the benign group than in the malignant group (p < 0.05). All diffusion measures showed significant differences between ccRCC and non-ccRCC (p < 0.05) except D_f and α (p = 0.143 and 0.112, respectively). α showed the highest diagnostic accuracy in differentiating benign and malignant lesions with an area under the ROC curve of 0.923, but none of the parameters from these advanced models revealed significantly better performance over ADC in discriminating subtypes or grades of renal cell carcinoma (RCC) (p > 0.05). Conclusion: Compared with conventional diffusion parameters, α may provide additional information for differentiating benign and malignant renal masses, while ADC remains the most valuable parameter for differentiation of RCC subtypes and for ccRCC grading.

• The Korean Journal of Physiology and Pharmacology
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• 제21권1호
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• pp.55-64
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• 2017

Progressive memory impairment such as that associated with depression, stroke, and Alzheimer's disease (AD) can interfere with daily life. In particular, AD, which is a progressive neurodegenerative disorder, prominently features a memory and learning impairment that is related to changes in acetylcholine and abnormal ${\beta}$-amyloid ($A{\beta}$) deposition in the brain. In the present study, we investigated the effects of dehydroevodiamine HCl (DHED) on cognitive improvement and the related mechanism in memory-impaired rat models, namely, a scopolamine-induced amnesia model and a $A{\beta}_{1-42}$-infused model. The cognitive effects of DHED were measured using a water maze test and a passive avoidance test in the memory-impaired rat models. The results demonstrate that DHED (10 mg/kg, p.o.) and Donepezil (1 mg/kg, p.o.) ameliorated the spatial memory impairment in the scopolamine-induced amnestic rats. Moreover, DHED significantly improved learning and memory in the $A{\beta}_{1-42}$-infused rat model. Furthermore, the mechanism of these behavioral effects of DHED was investigated using a cell viability assay, reactive oxygen species (ROS) measurement, and intracellular calcium measurement in primary cortical neurons. DHED reduced neurotoxicity and the production of $A{\beta}$-induced ROS in primary cortical neurons. In addition, similar to the effect of MK801, DHED decreased intracellular calcium levels in primary cortical neurons. Our results suggest that DHED has strong protective effects against cognitive impairments through its antioxidant activity and inhibition of neurotoxicity and intracellular calcium. Thus, DHED may be an important therapeutic agent for memory-impaired symptoms.

• 한국의류산업학회지
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• 제23권5호
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• pp.624-633
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• 2021

This study was intended to compare the comfort of wearing each type of commercially available bralette. The trial wearing experiment was conducted on five women in their 20s who wear an average Korean bra size of 70A. The experimental bralettes were of four types: a bralette with both hooks and pads and a bralette without both, a bralette with hooks but no pads, and a bralette with pads but no hooks. The wearing test results are as follows. First, in terms of functional satisfaction, the padded bralette provided the greatest satisfaction in supporting the chest from the bottom up and bringing it to the center, and the bralette without the pad provided the least satisfaction. In addition, the level of convenience of attaching/detaching was about twice as high in the bralette with hooks than those without hooks. Chest compression was found to be greater in bralettes without hooks than in those with hooks. In terms of the pressure on the shoulder strap and on the lower chest band, it was found that bralettes with hooks had a greater sense of pressure than those without. In the appearance characteristics test, the unpadded bralettes scored higher than the padded one in the matter of feeling embarrassed, because in unpadded bralettes, the nipples were exposed underneath the clothes . This study is meaningful in classifying the design of the bralette and evaluating the fit for each design in the absence of prior research on the bralette.