• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.2101-2101
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• 2001

Near-infrared spectroscopy is now being used in clinical diagnosis as a non-invasive monitor of tissue oxygenation state. However, due to lack of the optical pathlength information within tissues, it is still difficult to quantitate the hemoglobin concentration with present CW techniques. Time-resolved spectroscopy (TRS), which measures temporal profiles of emerging light from tissues, enables to estimate the pathlength distribution within tissues by converting time to distance. Consequently, quantitative measurement of tissue oxygenation is possible by analyzing the data with optical diffusion equation 1) or our Microscopic Beer-Lambert law2). Time-Resolved Spectroscopy System : TRS-1O3) Our TRS-10 system consists of a three-wavelength (759, 797, 833 nm) PLP as pulsed light source, a high speed PMT with high sensitivity and three signal-processing circuits for time-resolved measurement (CFD/TAC, A/D converter and histogram memory). Optical pulse train consisting of 759, 797 and 833nm is generated by PLP at 5㎒ repetition rate and irradiated a sample through a single optical fiber. The diffuse-reflected light from the sample is collected by a bundle fiber and then detected by the PMT for single photon measurement. After being amplified by a following fast amplifier, the electrical signals for each wavelength are picked out by CFD/TAC module. Then, a signal processing circuit integrated the TRS data for each wavelength individually. The simultaneous TRS measurement for three wavelengths achieved without any optical or mechanical switch. Experiment and Results Input and detection fibers of TRS-10 were attached at the human forehead with a fiber separation of 3cm. TRS measurements were continuously performed for about 20 minutes including 2 minutes hyper ventilation. It was observed that the total hemoglobin concentration was decreasing during the hyper ventilation and recovered until 2 minutes after hyper ventilation. On the other hand, the deoxy-hemoglobin concentration began to increase after hyper ventilation and had its peak at around 2 minute later, showing 502 drop from 75% to 60% due to inhibition of breathing by performing hyper ventilation. The results showed that this system might be able to quantitate the concentrations of oxy- and deoxy-hemoglobin in the human brain.

• Imaging Science in Dentistry
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• v.47 no.4
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• pp.227-231
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• 2017

Purpose: Sialolithiasis is one of the most prevalent large obstructive disorders of the submandibular glands. The aim of this study was to investigate submandibular sialolithiasis with computed tomography (CT) and scintigraphy, with a particular focus on the relationship between CT values of the submandibular glands and their excretion rate. Materials and Methods: Fifteen patients with submandibular sialolithiasis who underwent CT and salivary gland scintigraphy were included in this study. The relationship between the CT values of submandibular glands with and without sialoliths and salivary gland excretion measured using salivary gland scintigraphy was statistically analyzed. Dynamic images were recorded on the computer at 1 frame per 20 seconds. The salivary gland excretion fraction was defined as A (before stimulation test [counts/frame]) / B (after stimulation test [counts/frame]) using time-activity curves. Results: The CT values in the submandibular glands with and without sialoliths was $9.9{\pm}44.9$ Hounsfield units(HU) and $34.2{\pm}21.8HU$, respectively (P=.233). Regarding the salivary gland excretion fraction using scintigraphy, the A/B value in the submandibular glands with sialoliths ($1.09{\pm}0.23$) was significantly lower than in the submandibular glands without sialoliths($1.99{\pm}0.57$, P=.000). Conclusion: Assessments of the CT values and the salivary gland excretion fraction using scintigraphy in the submandibular glands seem to be useful tools evaluating submandibular sialolithiasis.

• Korean Journal of Construction Engineering and Management
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• v.9 no.6
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• pp.225-234
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• 2008

The engineering competitiveness of domestic construction companies is 70$\sim$80% of advanced countries. And Korean' companies fall behind China and South-East Asia in a competitive price. Recently, there are increased the amount of overseas order received in Korean construction companies. But, there is not enough the supporting policy of government. Therefore, this research compared and analyzed the competitiveness of domestic construction companies throughout benchmarking support system of overseas construction in advanced companies. Such research was obtained through business trip & consultation with related specialists for the difficulties of domestic companies in advancing into overseas market. This research provided governmental plans to advance into overseas market. First, this research provided assurance system and connected plan of ODA(Official Development Assistant) in construction. Second, this research suggested the improvement of overseas marketing survey and overseas construction marketing center. Third, this research provided the support system of bidding information and the training system of professionals.

• 한국초전도학회:학술대회논문집
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• v.10
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• pp.85-85
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• 2000

The normal state of high-Tc superconducting materials has been believed to contain important clues to finding the correct mechanism of the high-Tc superconductivity. One example is the existence of pseudogap in the normal state even above Tc, as observed in various measurements such as photoemission spectroscopy and tunneling conductance. In this pseudogap regime the existence of preformed pairs only with local phase coherence has been debated. Recently Choi, Bang, and Campbell[1] have proposed the occurrence of the zero-bias conductance enhancement due to Andreev quasiparticle reflection from the preformed pairs even with the local phase coherence. In this study we examine the zero-bias enhancement of the differential conductance near or slightly above Tc, using c-axis tunneling in mesa structure of Bi2Sr20a0u208+d single crystals. In slightly overdoped samples zero-bias conductance enhancement (ZBCE) has been observed over a range of 2 K above Tc. In contrast, in underdoped samples with Tc${\sim}$72K the ZBCE appears over a range of 5-6 K above Tc, a much wider temperature range than in overdoped samples. This result may pose as positive signs of the existence of prefurmed pairs in the normal state of high- Tc superconducting materials.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.161-161
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• 2010

n-type 반도체 특성을 띄는 $SnO_2$ 나노선은 가스 센서, 투명 소자, 태양광 전지 등으로 널리 사용되고 있다. 본 연구에서는 화학기상증착법으로 성장한 $SnO_2$ 나노선으로 폴리이미드 (PMDA-ODA: PI) 박막을 게이트 절연막으로 이용한 전계효과트랜지스터를 플렉서블 기판에 제작하고 전기적 특성을 분석하였다. 전자 전달 특성 곡선으로부터 n-형의 반도체 특성을 확인하였으며, 대부분의 산화금속 나노선에서와 같이 매우 큰 전기적 히스테리시스가 관찰되었다. 산화금속계통 나노선 소자의 히스테리시스는 나노선 표면에 산소 및 물 분자가 흡착되어 생기는 전자 갇힘 현상이 가장 큰 원인으로 알려져 있는데, 이러한 히스테리시스를 조절하거나 없애는 것은 소자의 특성 향상에 있어 매우 중요하다. 한편 PI 절연막에는 느린 분극 현상을 만드는 OH 반응기가 존재하기 때문에 나노선과는 반대 방향의 히스테리시스를 보일 것으로 예상된다. 본 연구에서는 제작된 $SnO_2$ 나노선 FET에서 PI 게이트 절연막의 경화 정도에 따른 히스테리시스를 조사하였다. FT-IR 측정에 따르면, PI 필름에 존재하는 OH 반응기는 PI를 경화시킴에 따라 감소하였으며 전기적인 히스테리시스도 감소하였다. 따라서, 절연막을 경화시키지 않았을 때는 PI 내부에 다량의 OH 반응기가 존재하여, PI의 히스테리시스가 나노선 히스테리시스보다 더 크게 작용하여, 전체적으로는 PI의 특성인 반시계 (counterclockwise) 방향의 히스테리시스를 나타내었다. 한편, 절연막을 완전히 경화시키면, OH 반응기는 대부분 사라지고 나노선의 히스테리시스만 발현되어 소자는 시계방향의 히스테리시스를 보였다. 이러한 실험결과를 통해, PI 박막을 $250^{\circ}C$ 에서 약 7분간 경화시켰을 때 나노선과 절연막의 히스테리시스가 가장 이상적으로 상쇄되어 전체적으로 히스테리시스가 매우 작아진 것을 관찰할 수 있었다. 이는 향후 나노선 FET의 안정적인 응용에 매우 유용한 결과로 활용될 것으로 예측된다.

• Journal of Korean Society of Rural Planning
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• v.24 no.3
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• pp.137-144
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• 2018

The purpose of this study is to measure the cost-benefit of a road construction project in Vietnam through international development cooperation, which includes private grants and Official Development Assistance(ODA). In developing countries, it is difficult and costly to use data on markets, the CVM(Contingent Valuation Method) to measure the WTP(Willingness-to-Pay) as the benefits of road construction are used. A total of 232 villagers in 16 villages of Lao Cai Province in Northern Vietnam have been surveyed. It is found that the Benefit-Cost Ratio(B/C) in all 3 models are found to be well over 1.0, ranging from 2.8 to 3.64 with the discount rate of 0.06. These BC ratios imply the road construction project in Lao Cai can be justified. Also, it is found that the shortened travel time is the most relevant factor for WTP among direct benefits and the enhanced academic achievement of the children is the most relevant factor among indirect benefits, due to easier and faster access to schools, which in turn increase the school attendance rate. The result of this study can be used to justify other similar projects in Vietnam, even though the benefits may have to be reassessed in other countries.

• Journal of the Korean association of regional geographers
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• v.23 no.1
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• pp.62-88
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• 2017

Global polarization at different scales has been more intensified than ever before. So, more complicated geographies are associated with global poverty and inequality, and their subsequent problems such as famine, disease, environmental degradation, and asylum seekers. These problems are apparently confined to specific countries and regions. However, they are a consequence of historical-geographic (post)colonial interconnectedness. In this sense, since the early 1960s, international development cooperation has significantly contributed to resolve or alleviate them. Especially, in 2015, the Millenium Development Goals(MDGs) project is finished and Sustainable Development Goals(SDGs) are newly set up as a global project to end human poverty. It is assumed that donor's IDC to accomplish SDGs will be more complicatedly implemented because SDGs contain more expanded and diversified forms of project targets than before. They are both possibilities and limits in the sense of development geography.

• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.3
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• pp.238-244
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• 2015

Three growing wethers were used to investigate the differences in nitrogen (N) retention, blood plasma metabolite concentration and energy-yielding nutrient supply to muscle and adipose tissue. The wethers were fed one of three diets: timothy hay with concentrate (THD), Italian ryegrass with concentrate (IRD), and rice straw with concentrate (RSD) for 11 days. The experimental diets were adjusted to the animals to provide 100 g of daily gain. The triglyceride (TG) concentration of blood plasma in arterial and portal veins was higher with THD and IRD than with RSD. Conversely, the available amount of TG in tissues was higher with IRD. The daily amount of glucose and non-esterified fatty acids (NEFA) supplied to muscle tissue and adipose tissue was numerically higher with THD than IRD or RSD. Although N retention did not differ among the diets, it was numerically higher with THD than with IRD or RSD. The results suggest that the difference in the amount of glucose and NEFA delivered to muscle tissue may reflect the N retention in response to forage based diets.

• Journal of the Korean Society for Library and Information Science
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• v.45 no.2
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• pp.61-74
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• 2011

The author analyses the challenging activities of Japanese libraries in this decade by launching two keywords; "product-sharing" and "outcome generation." "Product-sharing" means that libraries share knowledge, skills, and records which are produced as the result of the services or in the process of activities. And "outcome generation" means that libraries generate any efficiency or effectiveness through their services to users. Using these concepts, reported are the current situation and aspects of Japanese libraries which try to make various contributions to the society; research and learning of the people, and education and training for professional librarians, and so on. In the analysis, the author shows some examples of "product-sharing" at first, including the records of reference transaction and the multi-functioned online public access catalogue. Especially, focused is on the various possibility and adoptability of the Collaborative Reference Database System of the National Diet Library of Japan. This system is one of digital reference service in Japan, and the database of reference transaction records is expected to be useful for research and academic studyies as knowledge-base of professional librarians. And the system is also expected to be a platform for LIS education and professional development in the e-learning environment. Secondly, as the examples of "outcome generation", explained are the problem-solving-type activities, and provision of the collection about books on struggling against disease and illness. A few examples of outcome in the problem-solving-type activities are these; increase of sales in the services for shop managers, business persons, and entrepreneurs, contribution to affluent daily life by providing the local information services to residents and neighbourhoods, and etc. And for both the patients with serious cases and their family or those who nurse them, books about other persons' notes or memorandum are the greatest support, and sometime healing. The author discuss the 'raison d'etre' of these activities focusing on public libraries in Japan.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.5
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• pp.437-444
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• 2010

Extracts of the marine microalgae Nannochloropsis oculata were obtained using 80% methanol (MeOH) and water. The 80% MeOH extract was further fractionated with n-hexane, chloroform, ethyl acetate (EtOAc), n-butanol (n-BuOH), and water to isolate the active fraction. Seven samples were prepared and their angiotensin converting enzyme (ACE), $\alpha$-glucosidase, and cancer cell growth inhibitory activities in vitro were determined. The most profound ACE inhibitory activity was observed in the chloroform fraction, while the others had moderate effects. By contrast, greater $\alpha$-glucosidase inhibitory activity was found in the EtOAc fraction, n-hexane fraction, and water extract of N. oculata. The antiproliferative effects of the extracts and fractions against HL-60, U937, CT-26, and SK-Hep1 cancer cells were also determined. The n-BuOH fraction had the strongest antiproliferative effects on CT-26 cells in a time-dependant manner (P<0.05). These results suggest that the extracts and fractions from N. oculata could be used as a potential functional food or as pharmaceutical ingredients.