• Title/Summary/Keyword: Dispersion index

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Application of Dispersion Number for Analysis of Tracer test in Sedimentation Basin (침전지 추적자 실험을 위한 Dispersion Number의 적용)

  • Kim, Young-Il;Park, No-Suk;Jung, Nam-Jung;Kim, Seong-Su;Bae, Byung-Uk
    • Journal of Korean Society of Water and Wastewater
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    • v.21 no.2
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    • pp.187-193
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    • 2007
  • Reynolds and Froude numbers, along with tracer tests, have been widely used to estimate hydrodynamics in full-scale horizontal sedimentation basin in water treatment plants (WTPs). In spite of this, the former numbers do not reflect actual operating conditions, instead most often being based on the dimensions of the structures. The index and graphic analyses most often used were found to be too subjective to accurately analyze tracer test results. In order to overcome these limitations, dispersion number was applied for analysis of tracer test results. Tracer tests were conducted in eight full-scale sedimentation basins in six WTPs, and then analyzed by index and graphic analyses as well as by dispersion number. The dispersion number was more useful as an indicator of the hydrodynamic behavior in the basin. It was also found that as dispersion number decreased, flow approached the ideal for plug flow in which case, higher sedimentation efficiency could be expected.

Optical Constants and Dispersion Parameters of CdS Thin Film Prepared by Chemical Bath Deposition

  • Park, Wug-Dong
    • Transactions on Electrical and Electronic Materials
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    • v.13 no.4
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    • pp.196-199
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    • 2012
  • CdS thin film was prepared on glass substrate by chemical bath deposition in an alkaline solution. The optical properties of CdS thin film were investigated using spectroscopic ellipsometry. The real (${\varepsilon}_1$) and imaginary (${\varepsilon}_2$) parts of the complex dielectric function ${\varepsilon}(E)={\varepsilon}_1(E)+i{\varepsilon}_2(E)$, the refractive index n(E), and the extinction coefficient k(E) of CdS thin film were obtained from spectroscopic ellipsometry. The normal-incidence reflectivity R(E) and absorption coefficient ${\alpha}(E)$ of CdS thin film were obtained using the refractive index and extinction coefficient. The critical points $E_0$ and $E_1$ of CdS thin film were shown in spectra of the dielectric function and optical constants of refractive index, extinction coefficient, normal-incidence reflectivity, and absorption coefficient. The dispersion of refractive index was analyzed by the Wemple-DiDomenico single-oscillator model.

Change in Spatial Dispersion of Daphnia magna(Cladocera: Daphniidae) Populations Exposed to Organophosphorus Insecticide, Diazinon (유기인계 살충제 (다이아지논)에 대한 물벼룩, Daphnia magna (Cladocera: Daphniidae) 개체군의 공간분산 변이)

  • Lee, Sang-Hee;Ji, Chang-Woo;Chon, Tae-Soo
    • Environmental Analysis Health and Toxicology
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    • v.24 no.3
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    • pp.231-240
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    • 2009
  • We explored collective behaviors of indicator species to elucidate the effect of the chemical stress. After the treatments of an insecticide, diazinon, at low concentrations (1.0 and 10.0 ${\mu}g/L$), spatial dispersion patterns of Daphnia magna were checked in a test chamber. The I-index was used to characterize the movement data before (0~1 h) and after (1~2 h) the treatments in laboratory conditions. The slopes of the frequency distribution of I-index in semi-log scale decreased significantly, and the test populations appeared to be more dispersed with a lower degree of aggregation after the treatments. The index was feasible in indicating decrease in the ability of the specimens to keep desirable distances with neighbor individuals under chemical stress and showed a possibility of monitoring presence of toxic chemicals in environment through group behavior measurement.

A Study on the Internet Intrusion Detection and Prediction by IDC (Index Dispersion for Count를 이용한 인터넷에서의 침입탐지예측)

  • Lee, Kyunghee
    • Proceedings of the Korea Information Processing Society Conference
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    • 2009.04a
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    • pp.1069-1070
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    • 2009
  • 본 논문에서는 실시간 학습기능을 갖는 다층 신경회로망과 주어지는 인터넷 트래픽 데이터에서의 IDC(Index dispersion for count) 정보를 이용하여 인터넷에서의 공격(침입)을 탐지 예측 할 수 있는 모델을 제안하고 컴퓨터 모의실험을 통한 결과를 보인다.

Design of quadruple-clad, dispersion-flattened optical fibers with ultra-low dispersion at ${\lambda}=1.55{\mu}m$ (${\lambda}=1.55{\mu}m$에서 극저분산을 갖는 사중-클래드 평탄분산 광섬유의 설계)

  • 정석원;김창민
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.32A no.8
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    • pp.140-152
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    • 1995
  • Derived was the scalar wave equation of optical fibers. Based on the derived equation, the dispersion characteristics of arbitrarily profiled fibers were analyzed. We applied the 1-D FEM employing quadratic interpolation fucntions to solve the scalar wave equation. To find the optimum index distribution of a fiber that has the ultra-low total dispersion, we analyzed QC fibers as objects. Adding 2$_{nd}$ and 3$_{rd}$ clads to DC fiber, we investigated the change of dispersion characteristics. We found the QC fiber parameters for which the dispersion was ultra-low flattened, less than 0.5 ps/km.nm for ${\lambda}=1.4~1.6{\mu}m$, and the dispersion value was as low as 0.20 ps/km.nm at ${\lambda}=1.55{\mu}m$.

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EVALUATION 01 OIL DISPERSION AGENT BY ASSESSMENT 01 COLOR STRENGTH 01 ORGANIC PIGMENT

  • H., Young-Chan;R., Seo-Joon;L., Dong-Wook;H., Soon-Taek
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.24 no.3
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    • pp.73-80
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    • 1998
  • This Study was performed to get the suitable oil dispersion agent by assessment of color strength of organic pigment in non-aqueous systems. Organic pigment is used as a color expression material with other body pigments in the make-up products. But occasionally aggregation or agglomeration occurs for the lack of affinity with medium, This function is the cause of disturbing homogeneous dispersion, and then bring about an instability of products. Our study, research of dispersion mechanism between the pigment and oil phase, has been executed to solve this problem, and find a oil dispersion agent having optimum dispersion condition. Generally dispersion is related to between the solid-liquid mutual properties and electrical phenomena associated with solid-liquid interface. This factor is determined to input energy, milling time, optical properties, particle size, rheological properties, etc. Ideal dispersion state is told that coloring primary solid particle is homogeneously dispersed in medium. Good dispersed colorants are strongly and clearly appeared. We are already known that the particle size of organic pigment, chemical properties and viscosity of medium, refractive index. Consequently We determine the affinity of medium and organic pigment by measuring of color strength in the same mechanical condition. UV-VISIBLE RECORDING SPECTRO PHOTOMETER is used for measuring apparatus. We can decided the dispersion level of oil dispersion agent by measuring absorbance of color strength in the visible range that diluted medium for colloid colorant particles.

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Refractive Index Dispersion of Sputter-Deposited Silicon-Rich Silica Thin Films (스퍼터링 방법으로 증착된 실리콘 과잉 실리카 박막의 굴절률 분산)

  • Jin, Byeong-Kyou;Choi, Yong-Gyu
    • Journal of the Korean Ceramic Society
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    • v.46 no.1
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    • pp.10-15
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    • 2009
  • We have fabricated silicon-rich silica thin films via RF magnetron sputtering using a SiO target. Thickness evolution and microstructure change of such $SiO_x$ (1$SiO_x$ thin films turned out to be mainly responsible for the increase of refractive index.

New Growth Power, Economic Effect Analysis of Software Industry (신성장 동력, 소프트웨어산업의 경제적 파급효과 분석)

  • Choi, Jinho;Ryu, Jae Hong
    • Journal of Information Technology Applications and Management
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    • v.21 no.4_spc
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    • pp.381-401
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    • 2014
  • This study proposes the accurate economic effect (employment inducement coefficient, hiring inducement coefficient, index of the sensitivity of dispersion, index of the power of dispersion, and ratio of value added) of Korea software industry by analyzing the inter-industry relation using the modified inter-industry table. Some previous studies related to the inter-industry analysis were reviewed and the key problems were identified. First, in the current inter-industry table publishedby the Bank of Korea, the output of software industry includes not only the output of pure software industry (package software and IT services) but also the output of non-software industry due to the misclassification of the industry. This causes the output to become bigger than the actual output of the software industry. Second, during rewriting the inter-industry table, the output is changing. The inter-industry table is the table in the form of rows and columns, which records the transactions of goods and services among industries which are required to continue the activities of each industry. Accordingly, if only an output of a specific industry is changed, the reliability of the table would be degraded because the table is prepared based on the relations with other industries. This possibly causes the economic effect coefficient to degrade reliability, over or under estimated. This study tries to correct these problems to get the more accurate economic effect of the software industry. First, to get the output of the pure software section only, the data from the Korea Electronics Association(KEA) was used in the inter-industry table. Second, to prevent the difference in the outputs during rewriting the inter-industry table, the difference between the output in the current inter-industry table and the output from KEA data was identified and then it was defined as the non-software section output for the analysis. The following results were obtained: The pure software section's economic effect coefficient was lower than the coefficient of non-software section. It comes from differenceof data to Bank of Korea and KEA. This study hasa signification from accurate economic effect of Korea software industry.

The Naturalization Index of Plant Around Abandoned Military Camps in Civilian Control Zone (민통선 지역 폐 군생활관 주변 식물의 입지별 귀화율 연구)

  • Oh, Choong-Hyeon;Kim, Yong-Hoon;Lee, Ho-Young;Ban, Su-Hong
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.12 no.5
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    • pp.59-76
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    • 2009
  • This study was conducted to supply basic data for restoration and management of forests in Civilian Control Zone, with surveying naturalized plants around abandoned military camps. The total study sites are 72 abandoned military camps, from Gosung in east region to Paju in west region of Civilian Control Zone. The naturalized index of total area is 12.6%, and naturalized index of east and middle regions are 12.1% and 8.4%. But its index of west region is 15.9%. These results are due to geographical characteristics. The east and middle regions are in steep mountainous districts, and so but west region is flat district, and so naturalized plants was imported by only army. But west region is in flat districts, and so imported method of naturalized plants is very various. The main naturalized plants are Ambrosia trifida and Ambrosia artemisiifolia var. elatior in Civilian Control Zone. The main dispersion pattern of naturalized plants are gravity dispersion pattern ($D_4$) and wind and water dispersion pattern ($D_1$). The all naturalized plants are photophilic plants in survey sites. And so, if abandoned military camps are recovered to forests, the naturalized plants are disappeared because of the change of sunlight condition. So it is necessary to manage and recover forests, even if that area is Civilian Control Zone.

Design of double-clad, dispersion-compensating single-mode fiber with parabolic-index profile for $\lambda$=1.55 $\mu$m ($\lambda$=1.55 $\mu$m에서 포물선분포-이중클래드, 분산보상 단일모드 광섬유의 설계)

  • 김동각;김창민;이상배;강희전
    • Korean Journal of Optics and Photonics
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    • v.8 no.2
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    • pp.134-141
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    • 1997
  • We design the single mode dispersion-compensating fibers (DCF) which may be necessary for upgrading the previously installed 1.31 ${\mu}{\textrm}{m}$ optical communication system to the 1.55 ${\mu}{\textrm}{m}$ system. To obtain the optimum index profile that allows large negative dispersion at 1.55 ${\mu}{\textrm}{m}$, parabolic-index, double-clad fibers are analyzed by applying the 1-D FEM to the scalar wave equation of optical fibers. In constideration of macro-bending loss, the fibers are designed so that the cutoff wavelength of the $LP_{01}$ mode is greateer than 1.80 ${\mu}{\textrm}{m}$. The computer simulations show that the lower bound of the dispersion at 1.55 ${\mu}{\textrm}{m}$ is limited to about -120 ps/nm . km for the fiber index profiles satisfying the $LP_{01}$'s cutoff condition.

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