• Journal of Distribution Science
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• v.14 no.3
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• pp.39-44
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• 2016

Purpose - The purpose of this research is to investigate whether Korea's economic growth can be explained by the endogenous growth theory. Specifically, we test whether R&D expenditure has a positive and significant effect on the economic growth. Research design, data, and methodology - We hypothesize that R&D expenditure has a positive effect on the economic growth after adding control variables in the growth equation. Korean annual data from 1963 to 2011 from Science and Technology Annual of the Ministry of Education, Science and Technology, the Bank of Korea, etc. are used. We estimate the growth equation by GMM in addition to OLS. Results - We found that R&D expenditure has a positive and significant effect on the economic growth after adding the ratio of investment to GDP, the ratio of FDI to GDP, the ratio of government expenditure to GDP, inflation and the ratio of trade openness to GDP as control variables in the growth equation. Conclusions - Our results show that Korea's rapid economic growth for the past five decades can be explained by the R&D-based endogenous economic growth theory. Our results suggest that the policy attention of the Korean government be paid to R&D promotion.

• Journal of Korean Neurosurgical Society
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• v.59 no.4
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• pp.346-351
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• 2016

Objective : Early progressive infarction (EPI) is frequently observed and related to poor functional outcome in patients with middle cerebral artery (MCA) infarction caused by MCA occlusion. We evaluated the perfusion parameters of magnetic resonance imaging (MRI) as a predictor of EPI. Methods : We retrospectively analyzed patients with acute MCA territory infarction caused by MCA occlusion. EPI was defined as a National Institutes of Health Stroke Scale increment ${\geq}2$ points during 24 hours despite receiving standard treatment. Regional parameter ratios, such as cerebral blood flow and volume (rCBV) ratio (ipsilateral value/contralateral value) on perfusion MRI were analyzed to investigate the association with EPI. Results : Sixty-four patients were enrolled in total. EPI was present in 18 (28%) subjects and all EPI occurred within 3 days after hospitalization. Diabetes mellitus, rCBV ratio and regional time to peak (rTTP) ratio showed statically significant differences in both groups. Multi-variate analysis indicated that history of diabetes mellitus [odds ratio (OR), 6.13; 95% confidence interval (CI), 1.55-24.24] and a low rCBV ratio (rCBV, <0.85; OR, 6.57; 95% CI, 1.4-30.27) was significantly correlated with EPI. Conclusion : The incidence of EPI is considerable in patients with acute MCA territory infarction caused by MCA occlusion. We suggest that rCBV ratio is a useful neuro-imaging parameter to predict EPI.

• The Korean Journal of Nuclear Medicine
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• v.30 no.3
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• pp.315-324
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• 1996

The purpose of this study was to compare the specific binding ratio method with model-based methods in estimating the transporter parameter $k_3/k_4$ in normal controls and Parkinson's patients with [I-123]IPT SPECT and to evaluate the usefulness of [I-123]IPT SPECT. $6.5{\pm}1.1$ mCi ($239.0{\pm}40.3$ MBq) of [$^{123}I$]IPT was intravenouly injected as a bolus into six normal controls(age:$45{\pm}13$) and seventeen patients(age:$55{\pm}8$) with Pakinson's disease(PD). The transporter parameter $k_3/k_4$ was derived using the Ichise's graphical method($R_v$) and Lassen's area ratio method($R_A$) for the dynamic IPT SPECT data without blood samples. Then, the relationships between the transporter parameter $R-v,\;R_A$ and the ratio of (BG-OCC)/OCC at 115 minutes were evaluated by linear regression analysis. $R_vs$ by Ichise's graphical method for NC and PD were $2.08{\pm}0.29$ and $0.78{\pm}0.31$, respectively. $R_As$ by Lassen's area ratio method for NC and PD were $1.48{\pm}0.16$ and $0.65{\pm}0.24$, respectively. The correlation coefficients between (BG-OCC)/OCC and $R_v$, (BG-OCC)/OCC and $R_A$, and $R_v$ and $R_A$ were 0.93, 0.90, 0.99 and their corresponding slopes were 0.54, 0.34, and 0.65, respectively. The $R_v$ and $R_A$ of NC were significantly higher than the ones of PD. That is, the $k_3/k_4$ of NC was clearly separated from the one of PD. $k_3/k_4$ showed a good correlation with the ratio of (BG-OCC)/OCC. The results indicate that the noninvasive simplified quantitative methods may be useful to measure the transporter parameter $k_3/k_4$ and the specific binding ratio method can be used for quantitative studies of dopamine transporter with [I-123]IPT SPECT in humans brains.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.158-167
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• 2018

The role of S/W in weapon systems has been developed with various functions and complex structures. As the weapon system S/W is directly related to quick and accurate decision making of users, more accurate evaluation is required during the training. However, situation awareness of weapon system S/W users has only been assessed qualitatively such as by simple test or qualitative judgement. Therefore, this study suggests the 'Cognition Ratio' concept which represents the quantitative of users by combining ACT-R cognitive architecture to SA (Situation Awareness) and Fitts' Law based on the theory of cognitive engineering. The cognition ratio is a ratio of cognition among the whole cognitive behavior process including perception and psychomotor. Moreover, this study provides a systematic assessment process of situation awareness that will be applicable to various weapon system S/W for effective assessment.

• Journal of environmental and Sanitary engineering
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• v.15 no.3
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• pp.15-23
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• 2000

This study's purpose is the investigating the created liquid post-acid fermentation of usability of denitrification as exterior carbon sources by loading capacity of Organic matters. The time of acid fermentation of food waste, the slower loading capacity of organic matter, the faster decomposition fate, but the density of generation $VFA_S$ was weak and, $SBOD_5$ : ST-N rate and $SBOD_5/SCOD_{Cr}$ rate was low. Between TS and VS, VS was decreased to 6th day rast, and then was decreased slowly. Two days after stating the experiments, $SCOD_{Cr}$, $SBOD_5$, STOC and $VFA_S$ was decreased or increased slowly, and then increased fast. And after showing the highest density, it was tended to decreased fast. About 5 days after, because about 5 days later $CH_4$ bacteria activity due to the accumulation of $VFA_S$ was limited, $CH_4$ density was weak. When highest density in the acquisition of VFA, $R_1$ was $10,120mg/{\ell}$, $R_2$ was $11,380mg/{\ell}$, $R_3$was $13,720mg/{\ell}$. So $R_3$ only cut was highest generation. At the time of $SBOD_5$ with the highest density, at $SBOD_5$ : ST-N ratio, $R_1$ was 243:1, $R_2$ was 278:1, $R_3$ was 293:1. All of these were high $SBOD_5$ : ST-N ratios. And $R_3$ was the highest. After studying $SBOD_5$ : ST-N ratio and $SBCD_5/SCOD_{Cr}$ ratio, as a carbon source of biological denitrification it was profitable composition ratio.

• The Journal of the Society of Korean Medicine Diagnostics
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• v.9 no.2
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• pp.123-144
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• 2005

Objectives: Pulse-Respiration Ratio has been used for estimating subject's Han-Yeol [寒熱] status since it mentioned in suwen [素問]. In practicing Pulse-Respiration Ratio over 5 means the status of Yeol [熱], Pulse-Respiration Ratio below 3 means the status of Han [寒]. We performed this study to examine the Optimum Standard for Measuring Pulse-Respiration Ratio on the Basis of Repeatability and Reproducibility. Methods: After subject's 5 minutes rest we measured subject's ECG, respiration pattern, EEG, EMG simultaneously. In this research examiner's number is two, subject's number is four, and the number of repeat is two. We calculated Pulse-Respiration Ratio through dividing Respiration cycle average by Pulse cycle average according to each standard including time section, $EEG(relative-{\alpha}$ density, $relative-{\beta}$ density, ${\alpha}/{\beta}$ and EMG. We analyzed these data through Gage R&R study using MINITAB 13.20 program and considered the results of below 30 %R&R and over 4 Number of Distinct Categories to have a significance. Results: 1. In the applying of time standard, Pulse-Respiration Ratio from section 3, 4, 6, 8 had a significant meaning in the aspect of Repeatability and Reproducibility. 2. In the applying of $EEG({\alpha}$ I , ${\beta}$ I , ${\alpha}/{\beta})$, EMG(E I) standard, there was no significant results. 3. In the applying of time standard(section 5, 6, 7), $EEG({\alpha}$ I , ${\beta}$ I , ${\alpha}/{\beta})$ and EMG(E I) standard simultaneously, Pulse-Respiration Ratio from ${\alpha}/{\beta}$ in section 6, ${\beta}$ I in section 8 had a significant meaning in the aspect of Repeatability and Reproducibility. Conclusions: We can suggest the Optimum Standard for Measuring Pulse-Respiration Ratio on the basis of Repeatability and Reproducibility as followings; 1. Pulse-Respiration Ratio Measuring time should be at least 15 minutes. 2. Applying of time(section 6, 8) and $EEG({\beta}$ I, ${\alpha}/{\beta})$ standard simultaneously is recommended considering reliability and validity but more study is needed. 3. EMG(E I) may be helpful to detect the segment of physical rest and exclude artifacts but more study is needed.

• Journal of the Korean Data and Information Science Society
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• v.7 no.2
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• pp.289-294
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• 1996

This paper considers the limit of the ratio of two incomplete beta functions $I_{x}(p+s,q+r)\;to\;I_{x}(p,q)\;as\;p+q{\rightarrow}{\infty}$. The results show that the limits depend on r,s,x and the limit of p/(p+q).

• Proceedings of the Korea Concrete Institute Conference
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• 1996.10a
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• pp.283-289
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• 1996

In this paper, the mix design of the super flowing concrete is described with respcet to basic concept, confined water ratio($\beta_p$), volume ratio of water-binder(w/b), volume ratio of fine aggregates($S_r$) and coarse aggregates($G_v$). The primary purposes of this study are to evaluate the effects of cementitious materials(fly ash, slag cement, portland cement), mixing factors ($\beta_p$, w/b, $S_r$, $G_v$)., and to propose the mix design method of the super flowing concrete. As results of this study, confined water ratio($\beta_p$) of cementitious materials is very high (0.99~1.1), and then the ranges of the optimum mixing factors to be satisfied with the super flowing concrete are $S_r$ 47$\ell$ 2%, $G_v$ 52$\ell$ 1%.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.5
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• pp.46-53
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• 2001

To optimize the intake flow condition in the heavy-duty LPG SI engine, five different swirl ratios of intake port were investigated experimentally by oil spot method, LDV and single cylinder engine test. The flow characteristics near the piston surface were observed by oil spot method and magnitudes of swirl flow were measured quantatively by LDV method in the steady flow rig. The engine performances of various swirl flow were also tested with the heavy-duty LPG SI single cylinder engine. In the results, high swirl ratio, above $R_s$=2.3, was not suitable to develope a stable flame kernel and to produce high engine performance. Especially it was more serious under lean burn conditions, since turbulence intensity was smaller than bulk flow though those are increased together. These results were also confirmed by LDV measurement and oil spot method. On the contrary, low swirl ratio($R_s$=1.3) is not good to propagate a flame since the turbulence intensity and bulk flow are vanished during compression stroke and low swirl ratio has too weak initial energy for stable combustion. Therefore, the of optimized swirl ratio f3r the heavy-duty LPG engine in this work was found around $R_s$=2.0.

• Korean Journal of Ecology and Environment
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• v.55 no.4
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• pp.352-359
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• 2022

Recently, with the development of genetic technology, interest in environmental DNA (eDNA) to study biodiversity according to molecular biological approaches is increasing. Environmental DNA has many advantages over traditional research methods for biological communities distributed in the environment but highly depends on the established base sequence database. This study conducted a comprehensive analysis of the habitat status and classification at the genus level, which is mainly used in eDNA (12S rRNA, 16S rRNA, 18S rRNA, COI, and CYTB), focusing on Korean registration taxon groups (phytoplankton, zooplankton, macroinvertebrates, and fish). As a result, phytoplankton and zooplankton showed the highest taxa proportion in 18S rRNA, and macroinvertebrates observed the highest ratio in the nucleotide sequence database in COI. In fish, all genes except 18S rRNA showed a high taxon ratio. Based on the Korean registration taxon group, the gene construction of the top 20 genera according to bio density observed that most of the phytoplankton were registered in 18S rRNA, and the most significant number of COI nucleotide sequences were established in macroinvertebrates. In addition, it was confirmed that there is a nucleotide sequence for the top 20 genera in 12S rRNA, 16S rRNA, and CYTB in fish. These results provided comprehensive information on the genes suitable for eDNA research for each taxon group.