• Title/Summary/Keyword: Reflectivity

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Design of Echo Classifier Based on Neuro-Fuzzy Algorithm Using Meteorological Radar Data (기상레이더를 이용한 뉴로-퍼지 알고리즘 기반 에코 분류기 설계)

  • Oh, Sung-Kwun;Ko, Jun-Hyun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.63 no.5
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    • pp.676-682
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    • 2014
  • In this paper, precipitation echo(PRE) and non-precipitaion echo(N-PRE)(including ground echo and clear echo) through weather radar data are identified with the aid of neuro-fuzzy algorithm. The accuracy of the radar information is lowered because meteorological radar data is mixed with the PRE and N-PRE. So this problem is resolved by using RBFNN and judgement module. Structure expression of weather radar data are analyzed in order to classify PRE and N-PRE. Input variables such as Standard deviation of reflectivity(SDZ), Vertical gradient of reflectivity(VGZ), Spin change(SPN), Frequency(FR), cumulation reflectivity during 1 hour(1hDZ), and cumulation reflectivity during 2 hour(2hDZ) are made by using weather radar data and then each characteristic of input variable is analyzed. Input data is built up from the selected input variables among these input variables, which have a critical effect on the classification between PRE and N-PRE. Echo judgment module is developed to do echo classification between PRE and N-PRE by using testing dataset. Polynomial-based radial basis function neural networks(RBFNNs) are used as neuro-fuzzy algorithm, and the proposed neuro-fuzzy echo pattern classifier is designed by combining RBFNN with echo judgement module. Finally, the results of the proposed classifier are compared with both CZ and DZ, as well as QC data, and analyzed from the view point of output performance.

A Study on Performance for Camouflage of Domestic and Foreign Combat Uniforms (국내·외 전투복의 카무플라주(Camouflage) 성능 연구)

  • Kang, Jinwoo;Lee, Minhee;Hong, Seongdon;Moon, Sunjeong
    • Journal of the Korean Society of Clothing and Textiles
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    • v.40 no.6
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    • pp.1025-1033
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    • 2016
  • It is important to compare and analyze digital camouflage from different countries to promote the continuous development of a camouflage combat uniform. This effort should lead to developing a camouflage pattern suitable for the domestic environment and expand its performance of night camouflage. This study investigates digital camouflage by comparing camouflage fabrics sampled from Korea and eight other countries (USA, UK, Singapore, Croatia, Colombia, and Mongolia) in terms of textile, near-infrared reflectivity of colors, and color distribution. First, the fabric construction of camouflage from Korea, UK, US, Singapore, Span, and Croatia were all characterized by derivative plain weaves, while derivative twill weaves were generally used in Croatia and Mongolia. It is assumed that derivative plain weaves are adopted to improve the tearing strength of fine yarns. However, twill weaves enhance the flexibility of coarse yarn fabrics. Next, reflectivity change was analyzed based on camouflage color. The reflectivity of a combat uniform in Korea, Colombia, Croatia, and UK increased before 780nm in the visible light range, but remained consistent from 800nm which falls under the near-infrared range. In contrast, camouflage samples in Mongolia, Span, Singapore and USA showed a gradual increase of reflectivity in the near-infrared range. Finally, the color distribution analysis of digital camouflage found that camouflage of countries with desert or woodland combat settings dominantly contained brown colors. It indicates the color pattern consideration of different geographic regions is important to determine camouflage performance. This research involves basic study that will have implications for developing patterns and colors suitable for the South Korean environment and expand its use as night camouflage that helps achieve continuous improved camouflage performance.

Analysis of Spectral Reflectance Characteristic Change during Growing Status of Rice Plants using Spectroradiometer (스펙트로레디오메터를 이용한 벼 생장시기의 분광반사 특성 변화 분석)

  • Jang, Se-Jin;Suh, Ae-Sook;Kim, Pan-Gi;Yun, Jin-Il
    • Journal of the Korean Association of Geographic Information Studies
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    • v.3 no.3
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    • pp.12-19
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    • 2000
  • Knowledge for reflectance characteristic of interesting targets will provide us with actual application of remote sensing on agriculture. In this study, we have measured and analyzed reflectivity characteristics based on growing status from transplanting time to harvesting time. Rice paddies transplant into 3 fields at 20, May, 1999. Measurement of reflectivity characteristics were carried out with a portable spectroradiometer for frequencies from 300nm to 1100nm during the time period from 11:00 AM to 01:00 PM of clear sky and calm a day. The measurements for a day repeated 3 times(also, 3 times to each measurement)for reliable values. In result, we found that averaged reflectivity of visible range has about 2.34% - 2.55% in blue region(400nm-498nm), about 5.05% - 6.01% in green region(500nm-598nm) and about 4.21% - 5.24% in red region(600nm-698nm). It must be noted that the more rice canopy grows, the more spectral reflectivity decreases in visible region. Also, we separated infrared region into two cases - One case is increasing region with 700nm-780nm, the other is fixed region with 800nm-1100nm. Averaged reflectivity of these regions has about 22.3% - 23.0% in increasing region, about 29.4% - 33.1% in fixed region. It must be noted that more rice canopy grows, the more spectral reflectivity also increases up to 23, Aug. in infrared region. After 23, Aug, the reflectivity has a tendency toward decrease.

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A Proposal of the Evaluation Method of Toner Particle Type Display (토너입자형 디스플레이의 평가방법 제안)

  • Kim, Cheol-Woo;Kim, Young-Cho
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.23 no.9
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    • pp.691-695
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    • 2010
  • A measurement method of the particle-based reflective display is proposed, estimated, and compared with reported method. The reflectivity measurement by previous studies is simply obtained by integrating sphere, but it has a limitation for the estimation of real moving particles because its data include surface reflection and incomplete attachment on electrodes. To get the number of real moving particles, the area by attached particles on the electrodes is calculated at microscopic signals. The moving particles on subthreshold voltage are observed and this fluctuational variation of surface on subthreshold voltage gives a tip to understand the driving mechanism. By this measurement we ascertained the relationship of a particle layer and real driving particles, and the feasibility of observation and estimation for moving color particles, which were measured by the reflectivity and CIE (Commission Internationale de I'Eclairage) system of color specification at previous studies.

Reflectivity Improvement by Particle Neutralization in a Charged Particle-Type Electronic Display

  • Kim, Young-Cho
    • Transactions on Electrical and Electronic Materials
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    • v.14 no.1
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    • pp.36-38
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    • 2013
  • Eight sample panels using an indium tin oxide(ITO)-coated glass substrate were fabricated, with barrier ribs formed of 55 ${\mu}m$ height and 10 ${\mu}m$ width. The upper and lower substrates were designed with the same panel condition, so a cell gap of 110 ${\mu}m$ was obtained. The charged particles in a cell consisted of $TiO_2$ (for white color) or carbon black (black color), negative or positive charge control agents, and a polymer. The average diameter of the two types of particles was commonly 10 ${\mu}m$, and their q/m value was -4.5 ${\mu}C/g$ and +4.5 ${\mu}C/g$, respectively. The electrically opposite particles mixed by an agitator were loaded into their cells by a simple particle-loading method. The discharging process proceeded at a humidity of 80% and a temperature of $30^{\circ}C$. Reflectivity was measured depending on discharging time, and a hysteresis curve by bias voltage obtained for comparison between the neutralized and non-neutralized panel, in which the superior optical property of the neutralized panel was ascertained.

Synchrotron X-ray Reflectivity Studies on Nanoporous Low Dielectric Constant Organosilicate Thin Films

  • Oh, Weon-Tae;Park, Yeong-Do;Hwang, Yong-Taek;Ree, Moon-Hor
    • Bulletin of the Korean Chemical Society
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    • v.28 no.12
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    • pp.2481-2485
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    • 2007
  • Spatially resolved, quantitative, non-destructive analysis using synchrotron x-ray reflectivity (XR) with subnano-scale resolution was successfully performed on the nanoporous organosilicate thin films for low dielectric applications. The structural information of porous thin films, which were prepared with polymethylsilsesquioxane and thermally labile 4-armed, star-shaped poly(ε-caprolactone) (PCL) composites, were characterized in terms of the laterally averaged electron density profile along with a film thickness as well as a total thickness. The thermal process used in this work caused to efficiently undergo sacrificial thermal degradation, generating closed nanopores in the film. The resultant nanoporous films became homogeneous, well-defined structure with a thin skin layer and low surface roughness. The average electron density of the calcined film reduced with increase of the initial porogen loading, and finally leaded to corresponding porosity ranged from 0 to 22.8% over the porogen loading range of 0-30 wt%. In addition to XR analysis, the surface and the inner structures of films are investigated and discussed with atomic force and scanning electron microscopy images.

Analysis of Quality Control Technique Characteristics on Single Polarization Radar Data (단일편파 레이더자료 품질관리기술 특성 분석)

  • Park, Sora;Kim, Heon-Ae;Cha, Joo Wan;Park, Jong-Seo;Han, Hye-Young
    • Atmosphere
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    • v.24 no.1
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    • pp.77-87
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    • 2014
  • The radar reflectivity is significantly affected by ground clutter, beam blockage, anomalous propagation (AP), birds, insects, chaff, etc. The quality of radar reflectivity is very important in quantitative precipitation estimation. Therefore, Weather Radar Center (WRC) of Korea Meteorological Administration (KMA) employed two quality control algorithms: 1) Open Radar Product Generator (ORPG) and 2) fuzzy quality control algorithm to improve quality of radar reflectivity. In this study, an occurrence of AP echoes and the performance of both quality control algorithms are investigated. Consequently, AP echoes frequently occur during the spring and fall seasons. Moreover, while the ORPG QC algorithm has the merit of removing non-precipitation echoes, such as AP echoes, it also removes weak rain echoes and snow echoes. In contrast, the fuzzy QC algorithm has the advantage of preserving snow echoes and weak rain echoes, but it eliminates the partial area of the contaminated echo, including the AP echoes.

Peak Power Reflectivity and Phase Conjugation Fidelity in a Pulse Compression Process by Stimulated Brillouin Scattering (유도 브릴루앙 산란에 의한 펄스 압축 과정에서의 Peak Power 반사율과 위상공액도)

  • 조민식;최병일;남창희
    • Korean Journal of Optics and Photonics
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    • v.5 no.1
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    • pp.37-44
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    • 1994
  • The characteristics of stimulated Brillouin scattering wave for applications to high power laser was experimentally investigated. The peak power reflectivity and the phase conjugation fidelity of Stokes wave with respect to the focal length of lens were measured, and the phase conjugation fidelity for a compressed part of the Stokes wave was also investigated. For the long focal length of lens.(f=100 cm), the peak power of the Stokes wave amounts to about twice as high as that of incident wave. The phase conjugation fidelity for the compressed leading pulse is up to 90%, better than that for other temporal parts of the Stokes pulse. In spatial distribution, the Stokes pulse from the axial region has the largest SBS gain, and it has been ascertained as a best candidate to the application due to excellent pulse compression, peak power reflectivity, and good phase conjugation fidelity.

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Label-Free Real-Time Monitoring of Reactions Between Internalin A and Its Antibody by an Oblique-Incidence Reflectivity-Difference Method

  • Wang, Xu;Malovichko, Galina;Mendonça, Marcelo;Conceição, Fabricio Rochedo;Aleixo, José AG;Zhu, Xiangdong
    • Journal of the Optical Society of Korea
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    • v.20 no.1
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    • pp.165-168
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    • 2016
  • Surface protein internalin (InlA) is a major virulence factor of the food-borne pathogen L. monocytogenes. It plays an important role in bacteria crossing the host's barrier by specific interaction with the cell adhesion molecule E-cadherin. Study of this protein will help to find better ways to prevent listeriosis. In this study, a monoclonal antibody against InlA was used to detect InlA. The reaction was label-free and monitored in real time with an oblique-incidence reflectivity-difference (OI-RD) technique. The kinetic constants kon and koff and the equilibrium dissociation constant Kd for this reaction were also obtained. These parameters indicate that the antibody is capable of detecting InlA. Additionally, the results also demonstrate the feasibility of using OI-RD for proteomics research and bacteria detection.

The Effect of Coloring Condition on the Surface Characteristic of 304 Stainless Steel (304 스테인리스강의 착색 처리 조건이 표면 특성에 미치는 영향)

  • Kim, Ki-Ho
    • Journal of the Korean institute of surface engineering
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    • v.44 no.5
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    • pp.220-225
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    • 2011
  • 304 stainless steel plate was colored by hot dip and electrochemical treatment in a solution containing sulphuric and chromic acids. In the process, treatment variables such as operating time and methode were changed. The surface characteristics that changed by the treatment of the samples such as surface composition, oxide film thickness, color, surface roughness and reflectivity were studied. Surface composition was varied as follows. Fe was decreased, but Cr and O were increased. Ni was increased until 20 min, but reveals decreasing tendency as time passed after that. These means the surface film becomes chrome rich oxide phase as the treatment times increase. The thickness of film was about 220 nm at 30 min by dip treatment and it reduced as the treatment times increased. On the other hand, the thickness was about 150 nm at 10 min by electrochemical method and it doesn't increased with time. Surface color changed from metallic white of the base plate to gray, black, red, and green-blue, gradually, as the treating time increased. The reflectivity of colored surface measured by UVVIS-NIR spectrophotometer was reduced from max 38% of basis metal to min 3.5%.