• Journal of the Korean Applied Science and Technology
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• v.34 no.4
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• pp.1076-1084
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• 2017

For analyzing the qualitative and quantitative analysis of fuel marker in petroleum products, the applicability of HPLC was studied. For the qualitative analysis of fuel marker in kerosene and automotive diesel, optimal analytical conditions(ratio of mobile phase solvent, flow rate, etc) in HPLC were selected and calibration curve for quantitative analysis of fuel marker was prepared based on the result of qualitative analysis. In particular, the correlation coefficient of calibration curve in kerosene and automotive diesel was shown to be 0.999 in a certain concentration range and it could be applied to the quantitative analysis. The results of analysis using the UV/Vis spectrometer, which is the current analysis method of fuel marker, were compared with the analysis results using the HPLC. The kerosene showed a low deviation of about 7 % and the automotive diesel showed a somewhat large deviation of about 20 %.

• Korean Journal of Remote Sensing
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• v.24 no.6
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• pp.559-569
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• 2008

The Geostationary Ocean Color Imager (GOCI) on board the Communication Ocean Meteorological Satellite (COMS), the first geostationary ocean color sensor, requires accurate atmospheric correction since its eight bands are also affected by atmospheric constituents such as gases, molecules and atmospheric aerosols. Unlike gases and molecules in the atmosphere, aerosols can interact with sunlight by complex scattering and absorption properties. For the purpose of qualified ocean remote sensing, understanding of aerosol-radiation interactions is needed. In this study, we show micro-physical and optical properties of aerosols using the Optical Property of Aerosol and Cloud (OPAC) aerosol models. Aerosol optical properties, then, were used to analysis the relationship between theoretical satellite measured radiation from radiative transfer calculations and aerosol optical thickness (AOT) under various environments (aerosol type and loadings). It is found that the choice of aerosol type makes little different in AOT retrieval for AOT<0.2. Otherwise AOT differences between true and retrieved increase as AOT increases. Furthermore, the differences between the AOT and angstrom exponent from standard algorithms and this study, and the comparison with ground based sunphotometer observations are investigated. Over the northeast Asian region, these comparisons suggest that spatially averaged mean AOT retrieved from this study is much better than from standard ocean color algorithm. Finally, these results will be useful for aerosol retrieval or atmospheric correction of COMS/GOCI data processing.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.40-40
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• 2019

는쟁이냉이는 전국 각지 산지의 응달이나 물가에서 자생하는 여러해살이풀이다. 3월 경 눈을 뚫고나와 가장 이른 봄나물로 식용하기도 한다. 특유의 매운 맛이 있어 식용작물로 발전가능성이 높은 식물종이다. 따라서 본 연구는 는쟁이냉이 재배기술 정립을 위한 기초자료 수집의 일환으로 수행되었다. 차광에 따른 는쟁이냉이 생육특성을 비교 분석하기 위해 경북 봉화군 소재 국립백두대간수목원 양묘장 노지에 무차광, 40% 차광, 55%차광, 65%차광 처리구를 배치 후, 실험을 진행하였다. 생육특성의 비교를 위해 초장, 초폭, 엽 수, 엽길이, 엽너비, 엽병길이, SPAD 값 총 7가지 항목에 대해 생장기(6월), 휴면기(9월) 두 차례 측정하였다. 측정 결과, 모든 측정값이 차광구가 무차광구보다 높게 나타났다. 또한 무차광구는 6월 조사 이후, 7월 말까지 생장량이 줄어들다가 전량 지상부 고사가 발생하여 는쟁이냉이 재배를 위해서는 차광처리가 필수적으로 필요하다는 것을 확인할 수 있었다. 측정항목 중 초장, 초폭, 엽길이, 엽너비, 엽병길이는 차광율이 높을수록 증가하는 경향을 보였다. 그러나 엽록소함량을 추정할 수 있는 SPAD 값은 40% 차광구가 가장 높았고 55%차광구, 65%차광구에서는 오히려 감소하는 경향을 보였다. 또한 엽 수도 40% 차광구가 가장 높았다. 위 결과를 종합해볼 때, 는쟁이냉이 재배 시 55% 이상의 차광율을 적용하면 잎 자체의 크기 증대를 기대할 수 있으며, 40% 수준의 차광율을 적용하면 잎 수와 혁질의 잎을 생산할 수 있을 것으로 여겨진다. 다만, 본 실험은 는쟁이냉이 재배 생산량에 대한 부분에 집중하였고 상품화를 위해서는 품질에 관한 연구가 추가적으로 이루어져야 할 것으로 판단된다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.108-111
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• 2009

In this paper, the development of unmanned vehicle systems to analysis applicable communications and alternative IEEE 802.11a. IEEE 802.11b/g uses the 2.4GHz. So, using the 5GHz OFDM in IEEE 802.11a interference phenomenon better. IEEE 802.11a has a maximum speed of 54Mbps. Indoors and apartment parking on experiment to soft roaming, hard roaming. Test equipments are AP four units(RSU), reliable results for the AP one unit Bridge, Switch one unit, one server notebook, one notebook(OBU), one car. Use Softwares are Wireshark, Jperf, Ping and million second transfer was used to develop the program. So the actual car was similar to the environment. With the results of the experiment for the unmanned vehicle systems will provide the best method.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.4 s.54
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• pp.343-347
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• 2005

As aging occurs, ow skin gets more wrinkles, becomes drier and loses its elasticity. Validating the evaluation of skin elasticity is especially important, because it is not as visible as other signs of aging such as wrinkles. Here, we identified the correlation between age and the Parameters given by Cutometer, and (we present) the parameters of that reflect the decreases in skin elasticity along with ages (Ur/Uf, Ua/Uf, Ur/Ue, Ua, $r=0.687{\sim}0.725$). Also we developed an evaluation method to quantify the difference of skin by viewing or touching. A five-grade standard of Moire topographic photo scale on face was prepared using sensory evaluation of 20 to 61 year - old women. Based on this photo standard, scoring was performed using (a) 5-grade system by three specialists to obtain the consensus score. Significant negative correlations between age and results of Cutometer $(r=-0.687{\sim}-0.725)$, Moire topography scores (r=-938) were found. Finally we have shown the significance of the correlation between the result of Cutometer and the score of Moire topography (r=0.711). Our studies using Moire topography on face have confirmed that instrumental measurements reflect the decrease in shin elasticity, which is perceived visually.

• Korean Journal of Optics and Photonics
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• v.14 no.3
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• pp.331-337
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• 2003

This paper represents 50 ㎓ narrow band pass filters for fiber optical communication fabricated by dual ion beam sputtering method. We have analyzed the characteristics of the TA$_2$ $O_{5}$ and $SiO_2$ single layers in order to optimize the process conditions for the 50 ㎓ narrow band pass filters, and controlled the film thickness uniformity to less than 0.1 nm deviation by dual peak spike filter pre-deposition. We designed and fabricated 50 ㎓ narrow band pass filters that consist of 216 layers including 4 cavities based on quarter wave optical thickness. Class substrates with high thermal expansion coefficients were used to reduce the film stress. Anti-reflection coating at the rear side of the substrate was also needed to reduce the optical thickness errors of the Optical Monitoring System caused by multiple beam interference between the front side and the rear side of substrate. The optical characteristics of this 50 ㎓ narrow band pass filters are insertion loss of 0.40 ㏈, pass band ripple of 0.20 ㏈, and pass bandwidth at -0.5 ㏈ of 0.20 nm. and isolation bandwidth at -25 ㏈ of 0.6 nm, which satisfy specifications of dense WDM system in fiber optical communications.tions.

• Food Science and Preservation
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• v.18 no.3
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• pp.414-422
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• 2011

The optimum condition for phenolics contents extraction from purple sweet potato was 12 hrs. in 50% ethanol. The electron donating scavenging activities (DPPH), ABTS radical cation decolorization (ABTS) and antioxidant protection factor (PF) of Jami, Yeonjami and Shinjami were higher than general sweet potato, and thiobarbituric acid reaction substance (TBARs) was below 30%. The minimum inhibitory concentration (MIC) against Staphylococcus aureus and Escherichia coli on skin were each 5,000 and 2,500 ppm in all purple sweet potatoes, and MIC of Jami was the lowest as 2,500 ppm against Staphlococcus epidermidis. The whitening (tyrosinase inhibitory) activity of purple sweet potatoes was the highest as 62.5% and 48.7% in Jami water and ethanol extracts. The anti-inflammation (hyaluronidase inhibitory) activity of purple sweet potatoes was the highest as 25.3% and 94.4% in Jami water and ethanol extracts. The safety of cosmetic with Jam; extracts was assessed by various safety profiles. pH and viscosity change of essence for 90 days was not detected. Cosmetic was stable to temperature and light for 90 days. The result to measure changes of skin color and pore size of the skin was that an aged skin was more effective than young skin.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1144-1149
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• 2011

The occurrence of Korean pine (Pinus koraiensis) advance growth has been noticed in the deciduous oak forest being adjacent to the mature Korean pine plantation. the korean pine seedlings in the forest were regenerated naturally from harvested and transported Korean pine seeds and cones by rodents, mainly red squirrels. Mongolian oak (Quercus bariabilis), which formed dominant overstory, had close-to-normal distributions of height, diameter and age classes. Korean pine, which dominated the understory, had the reverse J-shaped height, diameter and age distributions that are expected of a shade tolerant species. Growing in the summer shade of the oak, Korean pine seedling had slow, but steady height growth during the past four decades. Total biomass of Korean pine seedling ranged from $2,835-8,541kg\;ha^{-1}$ and biomass allocation of Korean pine seedling was follows : stem (with bark) > foliage > branches > roots. Korean pine seedlings allocated more biomass to foliage and branches compare to planted Korean pine. The smaller root/shoot ratio of Korean pine seedling in the site is to believed to be result of competition for light. Contents of N and K for Korean pine seedling were greatest in foliage follow by branches, stem ad roots, while content of P was greater in the order of foliage > roots > stem > branches.

• Journal of Korean Society of Forest Science
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• v.110 no.4
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• pp.543-553
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• 2021

This research focused on the investigation of isoprene and terpene emissions from 30 major urban tree species. We conducted sampling using a specific dynamic enclosure system between August and September 2020. Seedlings less than three years old were enclosed in a chamber consisting of a 400 L transparent Tedlar bag. The air-flows from the chamber's outlet were sampled using Tenax-filled sorbent tubes in the presence of standard conditions (temperature: 30℃, PAR: 1,000 μmol/m²/sec). A thermal desorption GC/MS system was used to analyze 38 BVOC compounds (isoprene, monoterpene, sesquiterpene, oxygenated monoterpene, and sesquiterpene). Isoprene emitters included Phyllostachys bambusoides, Quercus serrata, Daphniphyllum macropodum, and Buxus Koreana. Monoterpene emitters included Pinus rigida, Acer pictum subsp. mono, Larix kaempfer, Magnolia denudata, Metasequoia glyptostroboides, Pinus koraiensis, Pinus densiflora, and Abies holophylla. The monoterpene emission profiles were dominated by α-pinene, myrcene, limonene, β-pinen, and sabinene, while caryophyllene and farnesene were the prominent sesquiterpenes. Predominant oxygenated monoterpene compounds were also discovered as pulegone, borneol, menthol, eucalyptol, and nerol, while caryophyllene oxide were the prominent oxygenated sesquiterpenes. Sesquiterpenes and oxygenated sesquiterpenes had relatively lower contributions for all species.

• Journal of Broadcast Engineering
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• v.26 no.4
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• pp.409-418
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• 2021

Conformal coating is a technology that protects PCB(Printed Circuit Board) and minimizes PCB failures. Since the defects in the coating are linked to failure of the PCB, the coating surface is examined for air bubbles to satisfy the successful conditions of the conformal coating. In this paper, we propose an algorithm for detecting problematic bubbles in high-risk groups by applying image signal processing. The algorithm consists of finding candidates for problematic bubbles and verifying candidates. Bubbles do not appear in visible light images, but can be visually distinguished from UV(Ultra Violet) light sources. In particular the center of the problematic bubble is dark in brightness and the border is high in brightness. In the paper, these brightness characteristics are called valley and mountain features, and the areas where both characteristics appear at the same time are candidates for problematic bubbles. However, it is necessary to verify candidates because there may be candidates who are not bubbles. In the candidate verification phase, we used convolutional neural network models, and ResNet performed best compared to other models. The algorithms presented in this paper showed the performance of precision 0.805, recall 0.763, and f1-score 0.767, and these results show sufficient potential for bubble test automation.