• Title/Summary/Keyword: Characterization,

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Characterization of Coagulation on Synthetic Polymerization Al(III) Inorganic Coagulants for Water Treatment (상수처리용 합성 무기고분자 Al(III)계 응집제의 응집특성)

  • Han Seung-Woo;Jung Chul-Woo;Kang Lim-Seok
    • Journal of Environmental Science International
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    • v.8 no.6
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    • pp.717-724
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    • 1999
  • This experiment was performed on three parts with prepared coagulants. (1) The characterization of coagulation for PACI coagulants. (2) Comparison of the characterization of coagulation with PAS and PACI coagulants. And (3) Comparison of the characterization of coagulation for the addition of calcium with PACI. Coagulation experiments were conducted with several dosages and pH for each coagulants. For the characterization of coagulation with PACI coagulants, coagulation of Nakdong river waters with three PACls (r=2.0, 2.2, 2.35) showed that the effectiveness of the three coagulants can be considered as r=2.2 > 2.0 > 2.35 which are also the order of higher polymeric aluminum contents. For the comparison of the characterization of coagulation for PAS and PACI coagulants, PAS (r=0.75) coagulants was more effective than other coagulant for the removal of organic matters by sweep floc mechanism with $A;(OH)_{3(S)}$. For comparison of the characterization of coagulation for the addition of calcium with PACI, the presence of divalent cation like $Ca^{2+}$ was supposed to influence the complex formation of organic anions. From the result of test on coagulation at various pH ranges, the PACI was least affected by the coagulation pH, and the addition of calcium to PACI was very effective for the removal of turbidity and organic materials over broader pH range (pH 4-9).

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A Case Study on the Sharing System of Scientific and Technical Information through the Characterization of Academic Libraries in France (대학도서관의 특성화를 통한 학술정보 공동이용 방안: 프랑스 사례를 중심으로)

  • Kim, Sun-Ae
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.15 no.2
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    • pp.141-159
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    • 2004
  • This paper investigated the introduction background, the role a nd the functioning of the CADIST which is operated in France in order to emphasize the necessity of characterization of academic libraries. The objective of this policy is to collect and to diffuse scientific and technical information, and to establish its sharing system. The result of the policy shows that the sharing system is brought an activation of research and a discrimination or characterization of universities. And the discrimination and characterization of academic libraries is played an important role in area industry.

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Accurate Characterization of T/R Modules with Consideration of Amplitude/Phase Cross Effect in AESA Antenna Unit

  • Ahn, Chang-Soo;Chon, Sang-Mi;Kim, Seon-Joo;Kim, Young-Sik;Lee, Juseop
    • ETRI Journal
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    • v.38 no.3
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    • pp.417-424
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    • 2016
  • In this paper, an accurate characterization of a fabricated X-band transmit/receive module is described with the process of generating control data to correct amplitude and phase deviations in an active electronically scanned array antenna unit. In the characterization, quantization errors (from both a digitally controlled attenuator and a phase shifter) are considered using not theoretical values (due to discrete sets of amplitude and phase states) but measured values (of which implementation errors are a part). By using the presented procedure for the characterization, each initial control bit of both the attenuator and the phase shifter is closest to the required value for each array element position. In addition, each compensated control bit for the parasitic cross effect between amplitude and phase control is decided using the same procedure. Reduction of the peak sidelobe level of an array antenna is presented as an example to validate the proposed procedure.

Strategy of the Fracture Network Characterization for Groundwater Modeling

  • Ji, Sung-Hoon;Park, Young-Jin;Lee, Kang-Kun;Kim, Kyoung-Su
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2009.06a
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    • pp.186-186
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    • 2009
  • The characterization strategy of fracture networks are classified into a deterministic or statistical characterization according to the type of required information. A deterministic characterization is most efficient for a sparsely fractured system, while the statistics are sufficient for densely fractured rock. In this study, the ensemble mean and variability of the effective connectivity is systematically analyzed with various density values for different network structures of a power law size distribution. The results of high resolution Monte Carlo analyses show that statistical characteristics can be a necessary information to determine the transport properties of a fracture system when fracture density is greater than a percolation threshold. When the percolation probability (II) approaches unity with increasing fracture density, the effective connectivity of the network can be safely estimated using statistics only (sufficient condition). It is inferred from conditional simulations that deterministic information for main pathways can reduce the uncertainty in estimation of system properties when the network becomes denser. Overall results imply that most pathways need to be identified when II < 0.5 statistics are sufficient when II $\rightarrow$ 1 and statistics are necessary and the identification of main pathways can significantly reduce the uncertainty in estimation of transport properties when 0.5$\ll$1. It is suggested that the proper estimation of the percolation probability of a fracture network is a prerequisite for an appropriate conceptualization and further characterization.

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Issues with the electrical characterization of graphene devices

  • Lee, Byoung-Hun;Lee, Young-Gon;Jung, Uk-Jin;Kim, Yong-Hun;Hwang, Hyeon-Jun;Kim, Jin-Ju;Kang, Chang-Goo
    • Carbon letters
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    • v.13 no.1
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    • pp.23-28
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    • 2012
  • Graphene is an attractive material for device applications, but device characteristics are very unstable because the graphene is very sensitive to environmental factors such as charges nearby the graphene, metal contacts, defects, contaminants and other adsorbates. Since the interactions between graphene and environmental factors affect the electrical characteristics of graphene devices, the interpretation of electrical characteristics as simple as current-voltage curves is non-trivial, despite the common practice of using well known electrical characterization methods that have been used in silicon MOSFET. This paper addresses major obstacles in the electrical characterization of graphene devices and offers countermeasures to improve the accuracy of electrical characterization methods.

A Study on the Antibacterial Properties of Ag Electropulsed Anodized Aluminium Alloy (Pulse도금법에 의한 Ag주입 양극산화 알루미늄 합금의 항균특성에 관한 기초연구)

  • Lim, Ki-Young;Ki, Joon-Seo;Jang, Yong-Seok;Lee, Woo-Min;Yoon, Jeong-Mo
    • Korean Journal of Materials Research
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    • v.16 no.10
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    • pp.639-646
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    • 2006
  • Over the last two decades, microbiologically influenced corrosion (MIC) of metallic materials has received considerable attention due to its serious effects on industrial field. In this context, it is important to devise control methods which inhibit biofilm formation on various metallic compounds and are compatible with environment. It was change of various conditions (duty cycle, current density, $AgNO_3$ concentration and pH) for injection of Ag particles in anodized Aluminum alloy pore using pulsed current. Optimal condition was obtained by means of FE-SEM, ICP analysis etc. The antibacterial metal's specimen were manufactured under optimal condition and this specimen were tested the antibacterial characterization and anticorrosion characterization. In result of test, we can confirmed that the antibacterial characterization and anticorrosion characterization of the specimens of injected Ag particles in anodized Aluminum alloy pore using pulsed current were better than the anodized Aluminum alloy specimens.

A NEW CHARACTERIZATION OF ALTERNATING AND SYMMETRIC GROUPS

  • ALAVI S. H.;DANESHKHAW A.
    • Journal of applied mathematics & informatics
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    • v.17 no.1_2_3
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    • pp.245-258
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    • 2005
  • In this paper we prove that the alternating groups A_n, for n = p, p+1, p+2 and symmetric groups $S_n$, for n = p, p+1, where p$\ge$3 is a prime number, can be uniquely determined by their order components. As one of the important consequence of this characterization we show that the simple groups An, where n = p, p+1, P+2 and p$\ge$3 is prime, satisfy in Thompson's conjecture and Shi's conjecture.

A simple proof of analytic characterization theorem for operator symbols

  • Chung, Dong-Myung;Chung, Tae-Su;Ji, Un-Cig
    • Bulletin of the Korean Mathematical Society
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    • v.34 no.3
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    • pp.421-436
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    • 1997
  • In this paper we first give a simple proof of the analytic characterization theorems of the operator symbols by using the characterization theorem for white noise functionals. We next give a criterion for the convergence of operators on white noise functionals in terms of their symbols and then use this result to give a proof for the Fock expansion theorem of operators on white noise functionals.

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QUOTIENT MOMENTS OF THE ERLANG-TRUNCATED EXPONENTIAL DISTRIBUTION BASED ON RECORD VALUES AND A CHARACTERIZATION

  • Kumar, Devendra
    • Journal of applied mathematics & informatics
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    • v.32 no.1_2
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    • pp.7-16
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    • 2014
  • Erlang-truncated exponential distribution is widely used in the field of queuing system and stochastic processes. This family of distribution include exponential distribution. In this paper we establish some exact expression and recurrence relations satisfied by the quotient moments and conditional quotient moments of the upper record values from the Erlang-truncated exponential distribution. Further a characterization of this distribution based on recurrence relations of quotient moments of record values is presented.