• The Korean Journal of Financial Management
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• v.21 no.2
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• pp.125-151
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• 2004

This study tests the price discovery from US Treasury bond markets to Korean bond markets using the daily returns of Korean bond data (CD, 3-year T-note, 5-year T-note, 5-year corporate note) and US treasury bond markets (3-month T-bill, 5-year T-note 10-year T-bond) from July 1, 1998 to December 31, 2003. For further research, we divide full data into two sub-samples on the basis of the start-up of bond valuation system in Korean bond market July 1, 2000, employing uni-variate AR(1)-GARCH(1,1)-M model. The main results are as follows. First the volatility spillover effects from US Treasury bond markets (3-month T-bill, 5-year T-note, 10-year T-bond) to Korean Treasury and Corporate bond markets (CD, 3-year T-note, 5-year T-note, 5-year corporate note) are significantly found at 1% confidence level. Second, the price discovery function from US bond markets to Korean bond markets in the sub-data of the pre-bond valuation system exists much stronger and more persistent than those of the post-bond valuation system. In particular, the role of 10-year T-bond compared with 3-month T-bill and 5-year T-note is outstanding. We imply these findings result from the international capital market integration which is accelerated by the broad opening of Korean capital market after 1997 Korean currency crisis and the development of telecommunication skill. In addition, these results are meaningful for bond investors who are in charge of capital asset pricing valuation, risk management, and international portfolio management.

• Journal of Oral Medicine and Pain
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• v.31 no.3
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• pp.199-210
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• 2006

The epidemiological researches on the inpatients hospitalized at the oral medicine ward have been continuously carried out since 1970, and most researches have been performed by centering around the oral medicine wards of college hospitals. Numerous specialists have been produced after the establishment of oral medicine, and they have been active in various fields. As dental clinics have gotten bigger, the function of oral medicine in the secondary clinics is being brought out. As admissive channel, case features, case composition and otherwise have not been researched for a long time, the related researches should be carried out from now on. Hereupon, this study was carried out by targeting the 100 inpatients hospitalized at the oral medicine ward of Sun Hospital located in Daejeon Korea, through questionnaire. As the result, the following results were derived. 1. The ages of the inpatients in Sun Hospital were $29.21{\pm}11.31$ on the average; 71 females' mean average was $29.63{\pm}11.29$ and 29 males' mean average was $28.17{\pm}11.48$. In regard of school career, the patients who finished high-school course or higher accounted for 78%; the patients' school career seemed to be relatively high. The patients who complained of temporomandibular pain accounted for the highest proportion with 65%. In motivation to visit this hospital, internet surfing was 11%, mass media was 10%, acquaintance's introduction was 38%. The patients, who were hospitalized at another hospital due to the same symptom, accounted for 56%. The dental clinics, which made the patients visit this hospital, accounted for 20%. The patients, who were previously aware that the present symptom should be treated by oral medicine, accounted for 38%. The patients, who were not aware of the fact in advance, were 62%. The respondents of 51% answered that they were aware of the fact one month or below before hospitalization. 2. The patients, who complained of craniocervical ache, accounted for 58%; the patients, whose ache aches affect dailylife, were 22%. Continuous ache was 14% and intermittent ache was 68%, and dull pain was 23%. 3. Life variations were compared with each other by using SRRS (Social Readjustment Rating Scale). In consequence, the variation within 3 years indicated a significant difference in the both groups but the variation within 6 months did not indicate any differences. 4. In regard of the questionnaire on the incidents happened for a week, the ache-group was compared with the group free from the ache. As the result, the number of strain arisen for a week, the decrease of favorite works and sudden fear indicated a significant difference. Pleasant feeling and the decrease of interests in looks did not indicate a significant difference, but came close to the significance. 5. In the questionnaire on impatience, the ache-group indicated higher value but there was not a significant difference. 6. In the questionnaire on the symptoms caused by stress, the two groups indicated significant differences in the item of 'the teethridge itches and feels a tooth rising' and 'the occiput or the nape is stiff.' In the item 'the inside of the cheek or the teethridge are widely peeled off, accompanied with ache and hemorrhage', 'the face has acne or pimple' and 'headache frequently attacks', a significant difference was not observed but the two groups came close to the significance.

• The Korean Journal of Air & Space Law and Policy
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• v.24 no.2
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• pp.47-67
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• 2009

In recent years, greenhouse gas (GHG) reduction has become high priority issue in international aviation. GHG emissions from the aviation sector only accounts for approximately 2 percent of total GHG emissions in the world. However, as with GHG gases in other sectors, it has been pointed out as a contributing factor to global warming and there is an ongoing conversation in the aviation community to establish international framework for emissions reductions. In the case of international aviation, effects of aviation activities of a State go beyond the airports and airspace of that State. This makes compiling of GHG emissions data very difficult. There are also other legal and technical issues, namely the principle of “Common but Differentiated Responsibility (CBDR)” under the United Nations Framework Convention on Climate Change (UNFCCC) and “Fair Opportunity” principle of the Chicago Convention. For all these reason, it is expected that it will not be an easy job to establish an internationally agreed mechanism for reducing emissions in spite of continuing collaboration among States. UN adopted the UNFCCC in 1990 and the Kyoto Protocol in 1997 to impose common but differentiated responsibility on emissions reductions. In international aviation, ICAO has been taking the lead in measures for the aviation sector. In this role, ICAO held the High-level Meeting on International Aviation and Climate Change on 7 to 9 October 2009 at its Headquarters in Montreal and endorsed recommendations on reducing GHG from international aviation which will also be reported to the 15th Meeting of the Conference of the Parties (COP15). Key items include basic principle in global aviation emissions reduction: aspirational goals and implementation options: strategies and measures to achieve goals: means to measure and monitor the implementation; and financial and human resources. It is very likely that the Republic of Korea will be included among the Parties subject to mandatory limitation or reduction of GHG emissions after 2013. Therefore, it is necessary for Korea to thoroughly analyze ICAO measures to develop comprehensive measures for reducing aviation emissions and to take proactive actions to prepare for future discussions on critical issues after COP15.

• Journal of Chest Surgery
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• v.30 no.9
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• pp.920-926
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• 1997

Remarkable effect of pain relief and prevention of the postoperative Complications after thoracotomy has been achieved by continuous intravenous analgesia. This study was carried out with thirty patients who underwent posterolateral thoraco tony. The patients were divided into three groups: Group I(n= 10), the patients with intermittent intramuscular analgesia(piroxicam 20 mg), Group II(n=10), the patients with continuous epidural analgesia(0.5% bupivacaine 30m1 + normal saline 30 ml + morphine 10 mg), and Group III(n= 10) the patients with controlled intravenous infusion of analgesics(fentanyl 2500 mfg +normal saline 10 ml). The results w re as follows; 1) There were no significant changes of vital signs, between groups. 2) Tidal volume and FVC were significantly improved in the group II and III compared with the group I during the first postoperative day. 3) A significant reduction of immediate post-thoracotomy pain was achieved in the group II and III compared with the group I. 4) The limitation of motion in the operative side was less in the group II and III compared with the group I. 5) A signi(icant reduction of the postoperative analgegics consumption was noticed in group II and III. 6) Significant complications were not occured during follow-up period in all groups.

• Korean Journal of Ecology and Environment
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• v.33 no.4 s.92
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• pp.366-373
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• 2000

Toxin production and low digestibility of cyanobacteria are known to cause low exploitability of cyanobacteria by zooplankton. In this study, we compared relative tolerance and compatibility of zooplankton taxa in eight eutrophic lakes, exposed to frequent cyanobacterial blooms, uring the summer season of 1999. Microcystis, Anabaena, Oscillatoria and Phormidium were common cyanobacteria in all lakes. with relatively lower $NO_3-N$ concentration (<0.2 mgN/l) and TN/TP ratio (<20), compared with other lakes where colonial cyanobacteria dominated. Rotifers were dominant zooplankton in most lakes, and among them, Keratella, Polyarthra and Hexathra were common. The laboratory feeding experiment showed that relative copepods that greatly decreased (90%) after 4 day when cyanobacteria were used as the food source of zooplankton, while rotifers gradually increased with the change of dominant taxa from Keratella through Pompholyx to Monostyla. These results suggest that rotifers may be capable of coexisting with cyanobacteria by exploiting them for the food source.

• Economic and Environmental Geology
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• v.35 no.1
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• pp.43-54
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• 2002

The Chonju and Samchun streams are palling though Chonju City and several contamination sources are located along these streams. The Samchun stream joins the Chonju stream in the Gosapyeong waste disposal site and the Chonju stream finally joint to the Mankyeong River. The Chonju and Samchun streams are now contaminated with BOD, COD, T-N and T-P and the amounts of each contamination are increasing from upper stream to downstream. At the downstream the amounts of COD. T-N.T-P are several times higher than fifth grade of water quality thor lacustrine. Sewage from Chonju provides BOD, COD,T-N and T-P into the Chonju and Samchun streams and Chonju Waste Water Treatment Plant il a main source of COD, T-N and T-P contamination. Gosapyeong waste disposal site may be the source of BOD and COD contamination. T-N is higher than fifth grade of water quality for lacustrine at the upper stream indicationg that the rivers are contaminated with T-N before inflowing into Chonju by agricultural activity. The Chonju stream asffects the contamination of the Mankyeong river with BOD. COD, T-N,T-P. Other branch steams of the Mankyeong river also affects the contamination of the Mankyeong river by BOD, COD, T-N and T-P, Among the branch streams, the Ikasn stream is a main contamination source. Amounts of concentrations inflowing from the Chonju and Sanchun Streams on Aug. 1999 are calculated by using yeasured flow rate find concentrations of contaminants The result are as fikkiws; 1) the amounts of influent from the Gosan Stream are 0.49, 0.86, 1.61 and 0.01 ton/day for BOD, COD, T-N and T-P, respectively, 2) compared to the amounts of influent from the Gosan Stream, BOD, COD,T-N,T-P supplied from the Chonju river are higher by about 5, 7, 7. 36 times, respectively, and those supplied from the Iksan stream are higher by about 13, 10, 10, 147 times, respectively.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.3
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• pp.217-226
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• 2015

To investigate the distributions of BVOCs (Biogenic Volatile Organic Compounds) from mountain near mega city and their role in forest atmospheric, BVOCs and their oxidized species were measured at a 41 m tower in Mt. Taehwa during May, June and August 2013. A proton transfer reaction-mass spectrometer (PTR-MS) was used to quantify isoprene and monoterpenes. In conjunction with BVOCs, $O_3$, meteorological parameters, PAR (Photosynthetically Active Radiation) and LAI (Leaf Area Index) were measured. The average concentrations of isoprene and monoterpenes were 0.71 ppbv and 0.17 ppbv, respectively. BVOCs showed higher concentrations in the early summer (June) compared to the late summer (August). Isoprene started increasing at 2 PM and reached the maximum concentration around 5 PM. In contrast, monoterpenes concentrations began to increase 4 PM and stayed high at night. The $O_3$ maximum was generally found at 3 PM and remained high until 5 PM or later, which was concurrent with the enhancement of $O_3$. The concentrations of BVOCs were higher below canopy (18 m) than above canopy, which indicated these species were produced by trees. At night, monoterpenes concentrations were negatively correlated with these of $O_3$ below canopy. Using MEGAN (Model of Emissions of Gases and Aerosols from Nature), the emissions of isoprene and monoterpenes were estimated at 1.1 ton/year and 0.9 ton/year, respectively at Mt. Taehwa.

• Journal of Korean Society of Forest Science
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• v.86 no.1
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• pp.105-111
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• 1997

Root dynamics of a pine stand at Hongcheon, Korea was assayed with two kinds of soil samplers which had been tentatively manufactured to renovate the routine soil sampler, Oakfield soil sampler. Root-mixed soil samples were collected on December of 1995, March, May, August and December of 1996 within each randomly selected 8 plots. The amount of roots collected by the two kinds of soil samplers were not significantly different at the 5% level, which indicated that the renovated sampler was more desirable to be used since the sampler showed efficiencies in time for collection and quantification than the routine sampler. The quantities of total root in 100g soils were 469mg on December of 1995, and 352mg, 473mg, 461mg, 522mg on the following March, May, August and December, respectively. That is, total amount of roots showed the smallest in Spring and reached maximum in early Winter, although the differences were not significant among each season. By the way, the alive roots and dead roots showed significant differences among season, the alive roots took about 90% from May to early December while they decreased down to some 65% from late December to March. The roots of Pinus densiflora S. et Z. took about 46% of total roots although the species comprised 70% of crown layer, and the ratio of fine-roots of the species were higher than that of other species. By the way, the dynamics of total roots and that of alive roots were quite different. Thus, the study for root dynamics such as fine roots which take a major role for mycorrhizae formation or nutrient uptake should not be inferred from the data of total root dynamics but be investigated in detail by dividing them into each class.

• Journal of Nutrition and Health
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• v.52 no.5
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• pp.435-448
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• 2019

Purpose: This study examined the changes in the nutrient intake and the prevalences of obesity and metabolic syndrome according to the eating alone behavior in middle-aged men and women. Methods: The data from the 2013 ~ 2017 Korean National Health and Nutrition Examination Survey were analyzed. A total of 7,728 adults (3,404 male, 4,324 female) aged 40 ~ 64 years old were included. The subjects were classified into three groups according to the number of times eating alone per day (0, 1 ~ 2, and 3 times/day). Dietary data were collected by a 1-day 24-h recall. The nutrient intakes were compared among the three groups. Survey logistic regression analyses were conducted to examine the association of the eating alone behavior with obesity and metabolic syndrome, adjusting for the related confounding variables. Results: In men, eating alone was associated significantly with a lower intake of potassium (p-for-trend = 0.048) and lower intake of calories from protein (p-for-trend = 0.04). In women, the proportion of subjects consuming energy less than 75% of the estimated energy requirement (p = 0.001) and less than the estimated adequate requirement of riboflavin (p < 0.001) differed significantly according to the eating alone behavior. The eating alone behavior was positively associated with an increased risk of developing metabolic syndrome (p-for-trend = 0.033), increased blood pressure (p-for-trend < 0.001), and increased waist circumference (p-for-trend = 0.004). On the other hand, in women, however, the eating alone behavior was associated with a decreased risks of developing obesity (p-for-trend = 0.02). No association was found between the eating alone behavior and the risk of metabolic syndrome in women. Conclusion: These results suggest that the eating alone behavior is a risk factor for the development of metabolic syndrome in middle-aged Korean men.

• Economic and Environmental Geology
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• v.55 no.5
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• pp.477-495
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• 2022

This study examined the sustainability of CO₂-rich water by analyzing the water level and water quality change pattern with the amount of its use in Angseong area, Chungju. The origin and supply of CO₂ component were discussed in consideration of ⁸⁷Sr/⁸⁶Sr ratio, occurrence of CO₂-rich fluid inclusions in nearby W-Mo deposits and other surrounding geological characteristics. According to the data from 1986 to 2017, the depth of the water level of CO₂-rich water was significantly lowered in the late period (2009-2015) than in the early period (1986-1992) of the development of hot spa wells, and the optimal yields for pumping tests also showed a tendency to gradual decrease. Concentrations of CO₂ component also decreased continuously in the later stages compared to the early stages of development, but it has been stable since 2012. It is inferred that the geological environment related to forming W-Mo quartz vein deposits (0.5×1.5×several km) around the study area are largely involved in the origin and supply of CO₂ component, and the supply of CO₂ component is not infinitely supplied from deep current magma activity. Rather, since it is finitely supplied from a restricted subsurface region formed in the past geological period, it is necessary to efficiently control its use in order to maintain the sustainability of CO₂-rich water in the study area.