• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.62-62
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• 2000

비접촉식 온도센서는 물체에서 방출하는 적외선 등의 복사신호를 열에너지로 전환하고 이를 다시 전기신호로 2차 에너지 변환하여 온도를 감지하는 센서로 인체 검지를 응용한 다양한 상품 및 교통, 방재, 빌딩 시스템 등의 분야에 널리 응용되고 있다. 비접촉식 적외선 센서는 열에너지를 전기에너지로 변환하는 방법에 따라 양자형과 열형으로 구분되며, 이중 양자형은 광전도나 광기전력 효과 등을 이용하여 감도 및 응답성이 우수하다는 장점을 지니고 있지만, 소자부를 80K 이하 온도로 유지시키는 냉각을 필요로 하므로 대형 제작이 불가피하고 그 용도가 제한적이다. 열형은 냉각이 필요 없고 소형으로 제작가능한 장점을 지니고 있어 써모 파일이나 초전체를 이용한 번용 센서가 보급되고 있다. 그러나 써모파일의 경우 출력되는 전기 신호가 미약하여 감도 및 응답성을 향상하기 위해 구조가 복잡하고, 특히 모터초퍼나 저항을 전압으로 변환시키는 전력기 등이 필요로 하는 단점을 지니고 있다. 따라서 이러한 문제점을 보완하기 위해 열전재료 박막을 이용한 적외선 센서를 개발하려는 노력이 진행중에 있다. 열전박막을 이용한 적외선 센서는 열전재료의 Seebeck 현상을 이용하여 열에너지에서 전기에너지의 변환이 자가발전으로 이루어져 offset과 외부 바이어스를 필요로 하지 않는다. 또한 작은 온도 변화에도 그 감도와 응답성이 높고, 출력신호가 커서 증폭기 등이 불필요한 장점을 지니고 있다. 특히 초전형 센서가 상온에서도 기판에 대한 열 확산을 제어해야 하는 문제점을 갖는 반면, 열전박막형 적외선 센서는 고온에서도 안정된 출력 신호를 얻을 수 있어 그 활용 온도 범위가 크게 확대될 것으로 기대된다. 본 실험에서는 우수한 열전특성을 갖는 (Bi1-xSbx)2Te3 박막을 얻기 위해 열팽창계수가 작고 알칼리 원소가 0.3% 이하로 포함되어 있는 corning glass(# 7059)를 기판으로 사용하였다. 또한 최적의 열전특성을 나타내는 조성을 실험적으로 구하기 위해 (Bi0.2Sbx)2Te3 조성의 합금 타？ 위에 Bi2Te3 및 Sb2Te3 chip을 올려놓고 그 면적을 변화시켜 다양한 조성의 열전박막을 증착하였다. 열전박막의 증착시 산화와 오염에 의한 열전특성 변화를 최소화하기 위해 초기진공도를 1$\times$10-6 Torr로 하였으며, Ar 가스를 흘려주어 2$\times$102 Torr 의 증착진공도를 유지하였다. 열전박막을 증착하기 전에 기판을 10분간 200W의 출력으로 RF 처리하였으며, 30$0^{\circ}C$에서 33 /sec의 속도로 (Bi1-xSbx)2Te3 박막을 증착하였다. 이와 같이 제조된 (Bi1-xSbx)2Te3 박막의 미세구조를 SEM으로 관찰하고 EDS로 조성을 분석하였으며, XRD를 이용하여 결정성을 관찰하였다. 또한 (Bi1-xSbx)2Te3 박막의 Seebeeck 계수 및 전기비저항을 측정하고 증착된 박막조성, 결정상, 미세구조와 열전특성간의 상관관계를 고찰하였다.

• Current Research on Agriculture and Life Sciences
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• v.5
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• pp.106-111
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• 1987

The susceptibility of 8 chrysanthemum varieties to Apelenchoides ritzemabosi, Shuhonothikara and Sagakiku were resistant by 11.7% and 14.5% each infested leaf, Sinrokusiogio, Dangonanako and Sintoa were susceptible as above 50%, Gold wave and Tenju were modertae by 24 to 26%. Percentage of infested leaf was positively correlated with the number of epidermal hair but not with leaf area, leaf thickness, stomatal size, number of stomata and length of epidermal hair. In effect of watering method, Polyethylene film cover plot was lowest by 9.4%, next conventional watering plot by 50%, Conventional watering and spray plot was the highest by 62%. The infested leaf rate was closely related with a number of rainy days than the amount of rainfall. Effect of chemical soil treatment, Temik showed the lowest infested leaf rate by 5%. There was no significant difference between the chemicals except Temik, but these are markedly effective in compare to control.

• Journal of Korean Society of Forest Science
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• v.113 no.1
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• pp.31-39
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• 2024

This study was performed to determine the effects of Four seedling age classes ageon the characteristics of growth and nutrient uptake in Chamaecyparis obtusa container seedlings. Seedlings (1-1, 2-0, 2-1, and 2-2 seedlings) of C. obtusa grown in containers were harvested to measure specific leaf area, height (H)/root collar diameter (D) ratio, dry mass of aboveground (T)/root dry mass (R) ratio, and seedling quality index of seedlings. The specific leaf area was highest in 1-0 seedlings (30.48 cm² g^-1), whereas it decreased (from 28.62 cm² g^-1 to 23.59 cm² g^-1) with increasing seedling age. The H/D ratio increased with increasing seedling age (from 4.41 in 1-0 seedlings to 8.35 in 2-2 seedlings). The T/R ratio decreased as the seedling age increased (from 4.29 in the 1-0 seedling to 2.13 in the 2-1 seedling). The seedling quality index increased with increasing seedling age (from 0.10 for the 1-0 seedling to 3.06 for the 2-2 seedling). The carbon concentrations of seedling components (leaf, branches, stem, and roots) did not differ significantly with seedling age, whereas the nitrogen concentration of seedling components was the lowest in 2-1 seedlings, as no fertilizer was applied to discourage excessive growth of the seedlings. Phosphorus, potassium, and magnesium concentrations in 2-1 seedling components were not affected by the lack of fertilizer application. These results can be applied to determine the optimum morphological characteristics and nutrient management by seedling age in container- grown C. obtusa.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.1
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• pp.62-69
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• 2012

Purpose: The present study has an objective of effectively separating and making observations on a portion of radiopharmaceutical excreted via digestive organ to remain in the organ and invade a heart shadow. Materials and methods: When heart shadow is blocked by the organ in tests during a resting phase and a loaded phase, additional images were obtained using immobilization device. The immobilization devices were used to tilt the upper body forward from supine position. Results: In the reconstructed image for the separated case, as compared with the case where a part of organ is overlapped with heart, in terms of an overall mean value for each parameter, the end-diastolic volume increased by 2.75 mL, the end-systolic volume decreased by 3.16 mL, the left ventricle cardiac coefficient increased by 3.58%, and the area of defect region decreased by 3.58 and 3.92 cm for loading and resting phase, respectively. Conclusions: In the present study with myocardial perfusion SPECT, overlapped areas of heart and other organs could be effectively separated and visualization by the use of an immobilization device.

• Journal of the Korean Society of Radiology
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• v.5 no.6
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• pp.401-407
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• 2011

The purpose of this study is to know the differences of MR spectra, obtained from normal volunteers by variable TE value, through the quantitative analysis of brain metabolites by peak integral and SNR between 1.5T and 3.0T, together with PRESS and STEAM pulse sequence. Single-voxel MR proton spectra of the human brain obtained from normal volunteers at both 3.0T MR system (Magnetom Trio, SIEMENS, Germany) and 1.5T MR system (Signa Twinspeed, GE, USA) using the STEAM and PRESS pulse sequence. 10 healthy volunteers (3.0T:3 males, 2 females; 1.5T : 3 males, 2 females) with the range from 22 to 30 years old (mean 26 years) participated in our study. They had no personal or familial history of neurological diseases and had a normal neurological examination. Data acquisition parameters were closely matched between the two field strengths. Spectra were recorded in the white matter of the occipital lobe. Spectra were compared in terms of resolution and signal-to-noise ratio(SNR), and echo time(TE) were estimated at both field strengths. Imaging parameters was used for acquisition of the proton spectrum were as follow : TR 2000msec, TE 30ms, 40ms, 50ms, 60ms, 90ms, 144ms, 288ms, NA=96, VOI=$20{\times}20{\times}20mm3$. As the echo times were increased, the spectra obtained from 3.0T and 1.5T show decreased peak integral and SNR at both pulse sequence. PRESS pulse sequence shows higher SNR and signal intensity than those of STEAM. Especially, Spectra in normal volunteers at 3.0T demonstrated significantly improved overall SNR and spectral resolution compared to 1.5T(Fig1). The spectra acquired at short echo time, 3T MR system shows a twice improvement in SNR compared to 1.5T MR system(Table. 1). But, there was no significant difference between 3.0Tand 1.5T at long TE It is concluded that PRESS and short TE is useful for quantification of the brain metabolites at 3.0T MRS, our standardized protocol for quantification of the brain metabolites at 3.0T MRS is useful to evaluate the brain diseases by monitoring the systematic changes of biochemical metabolites concentration in vivo.

• Journal of Bio-Environment Control
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• v.4 no.1
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• pp.59-67
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• 1995

This study was conducted to develope the automatic insulation system which control inside temperature of the greenhouse. For this purpose, the double- wall greenhouse and system which could automatically supply and discharge styrene pellets were constructed and abrasion of the pellets, blower ability, insulating property, transmittance and shading effect were analyzed by the experiments. The results obtained from this study can be summarized as follows : 1. It took an hour and fifteen minutes to supply and discharge about 2㎥ pellets in the experimental greenhouse. However, it is possible to reduce the operation time by proper selection of the blower and exhaust port, and by proper control of the supply and return pipe. 2. It was founded that the indirect delivery way was more profitable than the direct one in the supply and return of pellets. 3. When the transmittance was measured between 10 a.m. and 3 p.m., the average light transmissivity rate was 67%. 4. In winter nighttime, the inside temperature of the double- wall greenhouse with out the pellets was higher than the outside temperature by 3.4$^{\circ}C$ on an average. However, the inside temperature of the double - wall greenhouse with insulated area 73% was higher than the outside by one 6.6$^{\circ}C$ on an average, and the inside temperature of the greenhouse with insulated area 100% was higher than outside one by 13.5$^{\circ}C$ on an average. Therefore, it was proved that the insulating ability of the double - wall greenhouse in nighttime was excellent. 5. When the outside temperature was 36.9$^{\circ}C$ on an average, the inside temperature of the double- wail greenhouse with insulated area 100% was 3$0^{\circ}C$ on an average. As the inside temperature was lower than the outside one by 7$^{\circ}C$ on an average, we could know that the shading effects of the double- wall greenhouse were excellent in summer daytime.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.3
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• pp.357-368
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• 1987

The productivity of cropping systems with corn and soybean were tested in field layouts such as monocultures of each, I-row alternation(l：1), 1-row corn with 2-rows soybean(l：2), and 1-row corn with 3 rows soybean(l : 3). Increasing soybean rows in alternative row croppings modified corn plant short and thick stalk. Decreasing soybean rows induced lodging of soybean plants because of lengthy stem. Although LAI in alternative row croppings increased by 2-8% over monocultures, light transmition into canopy was improved in alternative rows with rearrangement of leaf area and top dry wt.. Top/root ratio of corn plants in alternative rows was decreased as increasing soybean rows. The amount of total nitrogen uptake was increased by 4-22% in alternative row croppings over monocultures. Grain yield of corn plants was increased and that of soybean was decreased as rows of soybean increased in alternative row croppings. Land equivalent ratios were ranged from 0.96 to 1.01, but grain yields, amount of total nitrogen, and dry matter yields were increased by 17-20, 10-25, and 17-20%, respectively, in alternative rows. The 1 : 1 alternative row of corn and soybean was concluded the best cropping system for production of grain and dry matter.

• Journal of the Korean Society of Groundwater Environment
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• v.6 no.3
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• pp.152-157
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• 1999

Oil leaked from underwound storage tanks and leachate from sanitary landfills have been known as contaminant sources of the high-quality groundwater resources. The mobility of contaminants in the aquifer largely depends on the groundwater flow and the determination of associated hydraulic parameters is essential for a proper remediation of contaminated grnundwater. This study aimed at determining an optimum set of hydraulic parameters for an unconfined sandy aquifer of a laboratory scale through comparison of various methods. Results showed that the specific yield obtained from gravity drainage experiment was an average of 0.20 with minor variations in aquifer depths. and the permeabilities obtained from Dupuit approximation and slug test gave similar values of 5.33 cm/min and 5.85 cm/min but the constant head method gave 0.17 cm/min, which is much ion than the other methods. This experimental evidence reveals that the permeability of the unconfined sandy aquifer could be accurately determined by Dupuit assumption or slug tut rather than by constant head method conducted for a disturbed separate soil column.

• Journal of Korean Society of Forest Science
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• v.111 no.3
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• pp.365-373
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• 2022

We compared carbon stocks in tree biomass and soils of Quercus acutissima, Q. mongolica, Q. serrata, and Q. variabilis stands. A total of 531 plots (Q. acutissima: 110 plots, Q. mongolica: 177 plots, Q. serrata: 96 plots, Q. variabilis: 148 plots) were examined between 2016 and 2021 to determine the tree biomass and soil carbon stocks throughout the country. The carbon stocks of tree biomass were significantly higher in Q. mongolica (mean stand age, 57 years, 144.9 Mg C ha^-1) than in Q. variabilis (mean stand age, 43 years, 123.7 Mg C ha^-1), Q. serrata (mean stand age, 43 years, 120.1 Mg C ha^-1), and Q. acutissima (mean stand age, 36 years, 113.2 Mg C ha^-1) stands. The soil carbon concentration was significantly higher in Q. mongolica (A: 43.1 mg C g-1) than in Q. serrata (31.0 mg C g-1), Q. variabilis (25.31 mg C g-1), and Q. acutissima (24.4 mg C g-1) stands. The soil carbon stocks were significantly higher in Q. mongolica (116.8 Mg C ha^-1) than in Q. acutissima (49.3 Mg C ha^-1) stands. Total carbon stocks of tree biomass and soil were highest in Q. mongolica (262 Mg C ha^-1), followed by Q. serrata (218 Mg C ha^-1), Q. variabilis (211 Mg C ha^-1), and Q. acutissima (163 Mg C ha^-1) stands. Multiple linear regressions were performed to estimate the total carbon stocks of the four Quercus spp., and results showed that total carbon stocks increased with increasing elevation, mean diameter at breast height, and basal areas. Basal area and elevation of Quercus spp. stands were important explanatory variables based on multiple linear regressions for estimating carbon stocks.

• Journal of the Earthquake Engineering Society of Korea
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• v.1 no.1
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• pp.69-77
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• 1997

An intensity survey on the 13 December 1996 Yeogweol earthquake has mode for 262 locations throughout southern part of Korean peninsula, then we investigated attenuation properties in the south Korean region as well as intensities distribution. In this study, intensities are estimated to be from II to possibly VIII. The iso-seismal intensity map we obtained shows general pattern of intensity distribution in the south korean region quite clearly despite the inherent uncertainties included in the process of intensity estimation. In case of intensity larger than VI, considerable damages such as fracturing walls are frequently reported. One of the significant feature of this intensity map is, considering its magnitude 4.5 reported by KMA, the felt area is unusually large covering most of the Korean Peninsular except Cheju island. This result indicates either the magnitude is under estimated or the focal depth is much deeper than expected. Assuming indicates either the magnitude is under estimated or the focal depth is much deeper than expected. Assuming shallow earthquake whose focal depth is by iso-seismal contour lines for intensity IV to VII, respectively. To resolve this ambiguity, more reliable estimation of focal depth and magnitude by using telesesmic instrumental records should be made in the future.