• Journal of Korea Trade
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• 제27권5호
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• pp.153-166
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• 2023

Purpose - This research empirically analyzes the influence of economic policy uncertainty and free trade agreements (FTAs) on bilateral trade volumes between Korea and its trading partners. The study investigates whether fluctuations in the Economic Policy Uncertainty Index (EPUI) for both Korea and its trading partners significantly impact trade volumes and whether the implementation of FTAs mitigates these effects. Design/methodology - The study employs dynamic panel data analysis using the system generalized method of moments (system GMM) estimation method to achieve its research objectives. It utilizes country-month-level panel data, including the EPUI, trade volume between Korea and its trading partner countries, and other pertinent variables. The use of system GMM allows for the control of potential endogeneity issues and the incorporation of country-specific and time-specific effects. Findings - The analysis yields significant results regarding the impact of economic policy uncertainty on Korea's exports and imports, particularly before the implementation of FTAs. An increase in the EPUI of trading partners leads to a notable increase in Korea's exports to them. Conversely, an increase in Korea's EPUI negatively affects its imports from trading partners. However, post-FTA implementation, the influence of each country's EPUI on trade volume is neutralized, with no significant difference observed. Originality/value - This research contributes to the existing literature by providing empirical evidence on the interaction effects between economic policy uncertainty and FTAs on bilateral trade volumes. The study's uniqueness lies in its examination of how FTAs mitigate the impact of economic uncertainty on trade relations between countries. The findings underscore the importance of trade agreements as mechanisms to address economic risks and promote international trade relations. In a world where global market uncertainties persist, these insights can aid policymakers in Korea and other countries in enhancing their trade cooperation strategies and navigating challenges posed by evolving economic landscapes.

• 한국학교수학회논문집
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• 제11권1호
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• pp.19-30
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• 2008

카발리에리는 아르키메데스의 구의 부피에 대한 연구결과를 재구성하는 과정에서 면적은 무한히 많은 평행한 선분으로, 부피는 무한히 많은 평행한 면적으로 구성된다고 하였다. 이것을 면적과 부피에 대한 불가분량이라 하고 이 원리를 발전시켜 카발리에리의 원리를 발견하였다. 본 연구에서는 영재학생들이 피라미드의 부피를 찾는 과정에서 카발리에리의 원리를 발견하고 이를 적용하고 일반화하는 교수 학습모형을 제시하였다.

• 한국도서관정보학회지
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• 제24권
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• pp.519-557
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• 1996

The purpose of this study is to suggest the strategic development model for the Taegu University Library preparing the 21st century. The results of the study are summarized as follows. 1. Size of collection aim to 697,000 volumes and 1,605 titles until 2000, 975,000 volumes and 3,224 titles until 2005, and 1,185,000 volumes and journals of 6,482 titles until 2010. 2. The library should have 36 professionals until 2000, 53 professionals until 2005, and 69 professionals until 2,010. And library should reorganize 3 departments and 14 sections up to 2,000, 6 departments and 22 sections up to 2,010. After that, the university should grope for a best way to combine the library and the CCC (Computing and Communication Center) into a single unit. 3. In case of space plan, it is necessary that library have to the total area of 31,478m$^{2}$. To find the recommended area, the library must improve the ratio of the net space 50 percent to 75 percent. 4. The model of scholarly information system should be designed to provide a total array of information services to the students and professors, envisioned as typically a user seeking information at a desk and workstation, regardless of format or computing capacity.

• 한국IT서비스학회지
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• 제11권3호
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• pp.191-203
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• 2012

In the stock market, the investors rely on stock information to trade. Good information may stimulate buying, raising the stock prices and the bad information may result in selling, decreasing the stock prices. In terms of the relationship between information and stock prices, stock prices can be viewed as reaction of investors to all the information flowing into the market. The significant increase of web stock news volume is often associated with the significant changes of stock prices. When the web stock news volume for a firm increases significantly, the stock price movement is often oscillatory. This paper attempts to investigate the relationship between volumes of information from Korean web IT and stock prices in Korean stock market. This research shows that when the web stock news volume increases significantly, volatility, trading volumes and rate of returns are increase too. The results of the study provide us with the new clues to the microstructure of the stock market from the perspective of the web news.

• 대한기계학회논문집A
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• 제29권3호
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• pp.418-424
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• 2005

We present the design, fabrication and experimental results of 4-bit digital microinjectors, whose ejected droplet volumes are adjusted by the digital operation of a 4-bit microheater array. We design the reference microinjectors as well as its comparative test structures. In the fabrication process, we use a five-mask micromachining process and the total chip size of the fabricated microinjector is $7,640{\mu}m{\times}5,260{\mu}m.$ We measure the ejected droplet volumes and velocities, which are adjusted from $12.1{\pm}1.0~55.6{\pm}14.7pl\;and\;2.3{\pm}0.1~15.7{\pm}0.8m/s.$ respectively, depending on the 15 possible combinations of 4-bit microheater array. We also experimentally characterize the effect of geometric variation including the microheater size, inter-microheater gap, microchannel width and sequential operation of microheater array on the ejected droplet volume and velocity. Among these parameters, we find that the microheater size is the most dominant parameter affected to the ejected droplet volumes and velocities. Thus, the present microinjector has a potential for application to the high-resolution inkjet printers with multiple gray levels or high-precision fluid injectors with variable volume control.

• Toxicological Research
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• 제11권2호
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• pp.199-203
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• 1995

The focus of this study was to investigate that cellular parameters and glucose uptake might be altered by extracellular calcium and starvation. Addition of 1 mM $Ca^{++}$ to hepatocytes (equalling to the free calcium concentration of blood) significantly increased intracellular $Na^+$ and decreased $Na^+$ & LDH leakage. This pertains to the hepatocytes of control rats as well as those of rats fasted for 24 and 48. hr. These effects might be come from the membrane-stabilizing effects of calcium. But calcium had no effects on cell volumes, superoxide-formation and glucose uptake. Actually hepatocytes of starved rats showed changes in several cellular parameters. Starvation increased LDH leakage, glucose uptake and the total concentration of $Na^+$ and $Na^+$ whereas it markedly decreased cell volumes. Since total tonicity remained unchanged, intracellular $Na^+$ and $Na^+$ could contribute to a higher share of total osmolarity in starvation. Starvation increased the cytoplasmic pH because $R-NH^{3+}$ions and their corresponding counterions disappeared. This increase may be related to suppress the protonization of amino groups in proteins. Starvation decreased hepatic glycogen, a major compound that affects cytosolic volume of hepatocytes. The data indicate that starvation increases the glucose transport activity. The possible molecular basis will be discussed.

• Annals of Clinical Neurophysiology
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• 제19권1호
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• pp.20-27
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• 2017

Background: We evaluated whether eye movements could reflect the efficacy of antiepileptic drugs in patients with epilepsy. Methods: Thirty patients with epilepsy of unknown cause as well as age- and sex-matched normal controls were enrolled in this study. We divided the patients into drug-controlled epilepsy (n = 22) and drug-resistant epilepsy (n = 8) groups according to their seizure controls. We analyzed the differences in the parameters of the eye movements in these two groups compared with normal controls using video-based electro-oculography. In addition, we investigated the differences in the cerebellar volumes of these two groups using whole-brain T1-weighted images. Results: The latency and accuracy of saccade in patients with epilepsy were significantly different from normal controls, but they were not different between patients with drug-controlled epilepsy and drug-resistant epilepsy. However, the gain of pursuit was significantly decreased in patients with drug-resistant epilepsy compared with normal controls (p = 0.0010), whereas it was not different between patients with drug-controlled epilepsy and normal controls (p = 0.9646). In addition, the patients with drug-resistant epilepsy had lower cerebellar volumes than normal controls (p = 0.0052), whereas the cerebellar volumes in patients with drug-controlled epilepsy were not different from normal controls (p = 0.5050). Conclusions: We demonstrated that pursuit eye movements could reflect the efficacy of antiepileptic drugs in patients with epilepsy, a finding that may be related to cerebellar dysfunction.

• 한국압력기기공학회 논문집
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• 제4권2호
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• pp.20-28
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• 2008

According to IAEA regulations, a transportation package of radioactive material should perform its intended function of containing the radioactive contents after the drop test, which is one of hypothetical accident conditions. Impact limiters attached to a transport cask absorb the most of impact energy. So, it is appreciated to determine properly the shape, size and material of impact limiters. A material data needed in this determination is a dynamic one. In this study, several materials considered as those of impact limiters were tested by a drop weight facility to acquire dynamic material characteristics data. Impact absorbing volume of the impact limiter was derived mathematically for each drop condition. A size optimization of impact limiter was conducted. The derived impact absorbing volumes were applied as constraints. These volumes should be less than critical volumes generated based on the dynamic material characteristics. The derived procedure to decide the shape of impact limiter can be useful at the preliminary design stage when the transportation package's outline is roughly determined and applied as input value.

• 한국조리학회지
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• 제10권4호
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• pp.165-177
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• 2004

This study was accomplished to examine possibilities to apply Korean medicine to breamaking. Extracts of Chungpesagan-tang prepared by the prescription of Korean medicine were used for baking, instead of water among ingredients of baking. Effects of addition of extracts of Chungpesagan-tang on various baking properties were analyzed during the process of baking. Changes in pH values and volumes of doughs during fermentation and pH values of bread showed no differences among samples. Loaf volumes and specific loaf volumes were increased somewhat on addition. The values of cohesiveness, springness, gumminess and brittleness of breads, which were measured by rheometer, were increased on addition while those of hardness were decreased a little. Lightness values of sections of loaves were decreased on addition, but their color differences were increased largely on color difference meter. There were nearly little differences among samples in all the values of parameters of external and internal characteristics and eating qualities of breads by sensory evaluation. Re-purchasing attitude of pullman bread added with Chungpesagan-tang had a high in the gender and age.

• 한국응급구조학회지
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• 제22권1호
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• pp.73-82
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• 2018

Purpose: The purpose of this study was to compare the tidal volumes and airway pressures of 3 mask-sealing methods (one hand C-E, two hands C-E, and one hand O-E) for ventilation treatment. Methods: The study subjects were 45 paramedic students. Tidal volume was measured for the three sealing methods by setting a ventilator, connecting it to the masks for 2 minutes, and using Respi-trainer software. Results: Regarding general characteristics, the group of men, in upper grades, and with practical training experience and experience and experience in the implementation of bag-valve-mask ventilation provided higher tidal volumes. Regarding physical characteristics, larger hands and greater grip strength correlated with higher tidal volume. Two hands C-E generated the highest tidal volume of $483.78{\pm}34.14mL$, one hand O-E generated $449.59{\pm}51.09mL$ and one hand C-E generated $394.31{\pm}68.95mL$. Conclusion: Means of tidal volumes were statistically significantly different based on mask sealing methods (p<.001). Two hand C-E was performed by the two-persons task and was suggested as the most effective method. For the one-person task, one hand O-E was the more effective method compared to the previous one hand C-E.