• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.1229-1234
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• 2005

Since the 20th century, the business of railway was invaded by the invention of airplanes and vehicles in the field of the transportation of passenger and commercial products, however, in the 21st century, the fervent development of a high speed railway made possible the huge capacity of transporting passengers and commercial freight, so the railway industry is facing a new era of railway revolution. The 200 years old railway tradition includes the history of railway bridges built in areas of river, valley and metropolitan region and in that, the number of constructions of railway bridges that is composed of cable-stayed bridges is increasing as one of the most optimal bridges considering the quality of materials and the span of continuous-welded long rail. Thanks to the minimized effects of the fixed load on the stiffening girder section by delivering the fixed load which is applied to the pylon with the composition of elastic supporting points by using cables and the effective structural system that can throughly resist extra loads in addition to fixed load, the long-extended span of a bridge becomes possible. In this structural system, the load that is applied to the stiffening girder section forms a now pattern and in the process of these load delivery, there will be a necessity to examine the concentration of stress occurred in the cable-anchor system of the cable.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.552-557
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• 2006

Since the 20th century, the business of railway was invaded by the invention of airplanes and vehicles in the field of the transportation of passenger and commercial products, however, in the 21st century, the fervent development of a high-speed railway made possible the huge capacity of transporting passengers and commercial freight, so the railway industry is facing a new era of railway revolution. The 200 years old railway tradition includes the history of railway bridges built in areas of river, valley and metropolitan region and in that, the number of constructions of railway bridges that is composed of cable-stayed bridges is increasing as one of the most optimal bridges considering the quality of materials and the span of continuous-welded long rail. Thanks to the minimized effects of the fixed load on the stiffening girder section by delivering the fixed load which is applied to the pylon with the composition of elastic supporting-points by using cables and the effective structural system that can throughly resist extra loads in addition to fixed load, the long-extended span of a bridge becomes possible. In this structural system, the load that is applied to the stiffening girder section forms a flow pattern and in the process of these load delivery, there will be a necessity to examine the concentration of stress occurred in the cable-anchor system of the cable.

• 대한음성학회지:말소리
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• 제60호
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• pp.67-84
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• 2006

The purpose of this study is to find some acoustic parameters on frequency domain to distinguish the Korean nasals, $/m,\;n,\;{\eta}/$ from each other. The new parameters are devised on the basis of LTAS (Long Term Average Spectrum). The maximum peak amplitude and the relevant formant frequency are measured in low and high frequency range, respectively. The frequency of spectral valley and its energy level are also obtained in the specific frequency range of the spectrum. Spectral slope, total energy value in specific frequency range, statistical distribution of spectral energy like centroid, skewness, and kurtosis are suggested as new parameters as well. The parameters that show statistically significant differences across nasals are summerized as follows. 1) in syllable initial positions: the total energy value from 1,500 to 2,200 Hz(zeroENG); 2) in syllable final positions: the peak amplitude of the first formant(peak1_a), the formant frequency with maximum peak amplitude from 4,000 to 8,000 Hz(peak2_f), the maximum peak amplitude of the formant frequency from 4,000 to 8,000 Hz(peak2_a), and the total energy value from 1,500 to 2,200 Hz(zeroENG).

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회
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• pp.519-526
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• 2010

The construction site for $\bigcirc\bigcirc$ transformer substation was located at a mountain valley. In order to prepare the site, the valley was first filled with crushed rock debris up to 63m. Since the main concern of this project is to minimize differential settlement of the foundation of transformer facilities, dynamic compaction was performed every 7m followed by reinforcement with EMP(Ez-Mud Piling). The EMP is one of bored piling methods, in which a hole is bored by means of air percussion and maintain by injecting Ez-Mud. Then a PHC pile (Pretensioned spun High strength Concrete pile) is embedded and finalized with a hammer. In this study, bearing capacities and long term behavior of a pile installed by EMP were investigated. To achieve these objectives, a series of tests such as static and dynamic load tests were conducted. In addition, a construction quality control standard was proposed based on the test results.

• Nutrition Research and Practice
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• 제7권1호
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• pp.34-42
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• 2013

This study investigated the effects of magnetized water supplementation on blood glucose, DNA damage, antioxidant status, and lipid profiles in streptozotocin (STZ)-induced diabetic rats. There were three groups of 4-week-old male Sprague-Dawley rats used in the study: control group (normal control group without diabetes); diabetes group (STZ-induced diabetes control); and magnetized water group (magnetized water supplemented after the induction of diabetes using STZ). Before initiating the study, diabetes was confirmed by measuring fasting blood glucose (FBS > 200 dl), and the magnetized water group received magnetized water for 8 weeks instead of general water. After 8 weeks, rats were sacrificed to measure the fasting blood glucose, insulin concentration, glycated hemoglobin level, degree of DNA damage, antioxidant status, and lipid profiles. From the fourth week of magnetized water supplementation, blood glucose was decreased in the magnetized water group compared to the diabetes group, and such effect continued to the 8th week. The glycated hemoglobin content in the blood was increased in the diabetes group compared to the control group, but decreased significantly in the magnetized water group. However, decreased plasma insulin level due to induced diabetes was not increased by magnetized water supplementation. Increased blood and liver DNA damages in diabetes rats did significantly decrease after the administration of magnetized water. In addition, antioxidant enzyme activities and plasma lipid profiles were not different among the three groups. In conclusion, the supplementation of magnetized water not only decreased the blood glucose and glycated hemoglobin levels but also reduced blood and liver DNA damages in STZ-induced diabetic rats. From the above results, it is suggested that the long-term intake of the magnetized water over 8 weeks may be beneficial in both prevention and treatment of complications in diabetic patients.

• 한국토양비료학회지
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• 제45권5호
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• pp.738-743
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• 2012

Topographic conditions of agricultural fields work as a important factor to identify different soil properties. This study was conducted to investigate the selected soil chemical properties and the concentrations of heavy metals, Cd, Cr, Pb, Cu, Ni, and Zn, in the paddy fields of different topographic areas at four year intervals from 1999 to 2011. Three-hundred soil sampling sites in the paddy fields were selected from the different topographic areas that were local valley and fans, fluvio-marine deposits, alluvial plains, and diluvial terraces. The mean values of soil pH ranged 5.7~5.8 that were within optimal range for rice cultivation. The mean values of other properties such as soil organic matter (SOM) content, the concentrations of exchangeable cations, $K^+$, $Ca^{2+}$, and $Mg^{2+}$, and available silicate concentration were lower or close to the optimal values, but the mean concentrations of available phosphorus were exceeded the range of optimal value, $80{\sim}120mg\;kg^{-1}$, in many paddy fields. In particular, The concentrations of available phosphorus in the paddy fields of local valley and fans, alluvial plains, and fluvio-marine plains were mostly declined. However, in diluvial terrace areas, the phosphorus concentrations unexpectedly increased; furthermore, they were significantly higher than those in other topographic areas. The mean concentrations of 0.1 M HCl-extractable heavy metals, Cd, Cr, Pb, Cu, Ni, and Zn, in the paddy fields were slightly and gradually declined during the study years, but the Pb concentrations were not statistically changed. In addition, the concentrations of heavy metals were widely ranged depending on the different sampling sites. Nevertheless, the concentrations of heavy metals were significantly lower than the levels of Soil Contamination Warning Standard (SCWS) for agricultural lands (1-region) presented in Soil Environment Conservation Law (SECL).

• 한국전자통신학회논문지
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• 제7권3호
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• pp.485-490
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• 2012

본 논문에서는 선박의 진동에 의하여 수명이 짧은 필라멘트를 사용하는 조명기구를 대체하기 위하여 선박용 LED 조명등 구동회로를 설계 및 구현하였다. 구동회로는 부피를 줄이고 비용을 절감하기 위하여 변압기가 없는 스위칭 회로로 설계되었다. 스위칭 회로는 입력 교류전압 220 V에 PWM 제어를 함으로써 안정적으로 LED를 구동할 수 있도록 설계하였다. 스위칭 회로의 펄스성 전류에 대하여 Valley-fill 방식의 역률 보상회로를 채용함으로써 역률를 개선하였다. 장기간 운항하는 선박에서의 조명등 교체 주기를 줄여 관리를 효율적으로 할 수 있도록 직병렬 배열로 LED 모듈 회로를 설계하여 LED의 일부가 손상되더라도 LED 모듈이 조명등 기능을 할 수 있도록 하였다. 개발한 구동회로를 포함한 조명기구는 전력소모와 역률이 각각 39 W, 0.925 로 선박 조명에 적합함을 확인하였다.

• Journal of Ecology and Environment
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• 제30권1호
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• pp.17-21
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• 2007

The organic carbon (OC) distribution of Pinus densiflora forest in Songgye valley at Mt. Worak National Park were studied as a part of the National Long-Term Ecological Research in Korea. In order to investigate the OC distribution, OC in plant biomass, litterfall, litter layer on forest floor, and soil were estimated. The density of P. densiflora forest was 1,300 trees/ha, average DBH was $15.2{\pm}6.17\;cm$ and average tree height was $10.7{\pm}2.56\;m$. The shrub layer was dominated by shrubby Quercus variabilis, Fraxinus sieboldiana and lndigofera kirilowii with low frequency, and herb layer was dominated by Pteridium aquilinum and Miscanthus sinensis. Total amount of OC stored in this pine forest was 142.78 ton C/ha. Organic carbon stored in soil and plant biomass accounted for 59.2% and 37.8%, respectively. Amount of OC distributed in trees, shrubs, herbs and litter layer in this pine forest was 51.79, 2.03, 0.12 and 4.29 ton C/ha, respectively. Amount of OC returned to forest floor via litterfall was $1.50\;ton\;C\;ha^{-1}\;yr^{-1}$. Soil organic carbon (SOC) decreased along the soil depth. Total amount of SOC within 50cm soil depth was $84.55\;ton\;C\;ha^{-1}\;50\;cm-depth^{-1}$.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2001년도 추계정기 학술발표회 초록집
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• pp.25-32
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• 2001

Potatoes have been recognized for a long time as one of the major food crops as well as horticultural crops. Potato production as a table food has been decreased in developed countries, while it has been steadily increased in the third world countries for it importance as food source. It is a new trend to look for the food, not only as a feeding crop but also healthy food. It is also time for the potato producers to look for the potato having high economic value as found in medicinal plants. There are great diversities in potato species, indicating that valuable compounds can be found in different amounts, depending on potato species. We screened the cultivars, breeding clones, and germplasms based on the vitamin C, Vitamin E, antioxidant compounds, diverse sugar types, important amino acids, and other valuable compounds. We could select the breeding clones KC003, 98Wl17, 99j717, and Vally 8 (A group) due to their high levels of antioxidant compounds, and it can be said that most of the red and purple colored potato clones belong to the A group. In the contents of essential amino acids, ‘Taebook Valley’,‘Summer Valley’ and other breeding clones were found to be high in amount. We also made crosses between breeding clones with high biological function and low agronomic traits and low biological function with high quality in agronomic characteristics . The patterns of genetic trends of these offsprings in comparison with their parents will be reported as well. And the potential of using potato as antibody production of anti-cancer will be discussed.

• Journal of Ecology and Environment
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• 제29권5호
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• pp.439-443
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• 2006

Soil properties of Quercus variabilis forest on Youngha valley at Mt. Worak National Park were studied as a part of Korea National Long-Term Ecological Research. Soil sampling was carried out along the 50 cm soil depth with 10cm intervals at every quarter from May 2005 through July 2006. Fresh soil was used for $NH_4{^+}-N,\;NO_3{^-}-N$, and soil water content determination. Remaining soils were air dried in the shade, and then used for determination of soil pH, T-N, T-P and exchangeable cation. Average soil organic matter in top soil was $8.5{\pm}1.2%$ and decreased with soil depth. Bulk density of top soil was $0.82{\pm}0.07g/cm^3 $and increased with soil depth. Soil organic matter and bulk density showed a negative linear correlation ($R^2=0.8464$). Soil pH in top soil and subsoil was similar. T-N, $NH_4{^+}-N,\;NO_3{^-}-N$ and T-P in top soil were $1.9{\pm}0.5mg/g,\;7.3{\pm}1.0mg/kg,\;2.0{\pm}0.4mg/kg\;and\;0.2{\pm}0.05mg/g$, respectively. $K^+,\;Ca^{2+}\;and\;Mg^{2+}$ in top soil were $84.6{\pm}24.4,\;408.8{\pm}137.8\;and\;93.4{\pm}23.0mg/kg$, respectively. They decreased with soil depth. Amounts of organic matter, T-N, $NH_4{^+}-N,\;NO_3{^-}-N$, T-P, $K^+,\;Ca^{2+}\;and\;Mg^{2+}$ in 50 cm soil depth were 250.9, 3.45, 0.025, 0.003, 0.639, 0.181, 0.845 and 0.302 ton $ha^{-1}\;50cm-depth^{-1}$, respectively.