• Title/Summary/Keyword: (2,M)-filters

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(L,M)-NEIGHBORHOOD SPACES

  • Kim, Y.C.;Ramadan, A.;Usama, M.A.
    • Korean Journal of Mathematics
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    • v.15 no.2
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    • pp.121-133
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    • 2007
  • We introduce the notions of (L,M)-neighborhood spaces and (2,M)-fuzzifying neighborhood spaces. We investigate the relations among (L,M)-neighborhood spaces, (L,M)-topological spaces and (2,M)-fuzzifying neighborhood spaces.

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Implementation of Programmable Multiplierless FIR Filters with Powers-of-Two Coefficients (곱셈기가 필요없는 2의 누승 계수를 사용한 프로그램 가능한 FIR필터의 구현)

  • 오우진;이용훈
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.19 no.11
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    • pp.2249-2254
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    • 1994
  • An observation which is useful for hardware implementation of programmable FIR filters with powers-of two coefficients (2PFIR filters) is made. Specifically, it is shown that the exponents of filter coefficients representable by the canonical signed digit(CSD) code with M ternary digits can be chosen from some subsets of {0, 1, $\cdots$, M-1}. This observation naturally leads to 2PFIR filters with shorter shifters whose length is strictly less than M and, as a consequence, leads to an efficient hardware structure fo programmable 2PFIR filtering. In addition, we present some experimental results indicating that the shifters of 2PFIR filters can be shortened further in some cases.

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Study on Metal Microfilter Coated with Ceramics by Using Plasma Thermal Spray Method (플라즈마 용사를 이용한 복합세라믹 미세필터 연구)

  • Song, In-Gyu;Lee, Young-Min;Shin, Hyun-Myung;Choi, Hae-Woon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.35 no.9
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    • pp.1035-1040
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    • 2011
  • This research was performed on a microfilter made of a hybrid material (ceramic + metal) that was coated with ceramics on the metal-filter surface by using the thermal spray method. The ceramic powders used were $Al_2O_3+40TiO_2$ powder with a particle size of $20{\mu}m$ and $Al_2O_3$ (98%+)powder with a particle size of $45{\mu}m$. The metal filters were filter-grade $20{\mu}m$, $30{\mu}m$, and $50{\mu}m$ sintered metal powder filters (SIKA-R 20 IS, 30 IS, 50 IS; Sinter Metals Filters) and filter-grade $75{\mu}m$ sintered mesh filter with five layers. Ceramic-coated filters that were coated using the thermal spray method had a great influence on powder material, particle size, and coating thickness. However, these filters showed a fine performance when used as micro-filters.

Forward Gene Mutation Assay of Seven Benzophenone-type UV Filters using L5178Y Mouse Lymphoma Cell

  • Jeon, Hee-Kyung;Sarma, Sailendra Nath;Kim, Youn-Jung;Ryu, Jae-Chun
    • Molecular & Cellular Toxicology
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    • v.3 no.1
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    • pp.23-30
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    • 2007
  • The effects of high energy short wave solar radiation on human skin have received much publicity as the major cause of accelerated skin ageing and of skin cancers. To meet public demand, the cosmetic industry has developed sun protection factor products, which contain a variety of so-called "UV filters", among others benzophenone (BP) and its metabolites are the widely used UV filters. UV filters are also used to prevent UV light from damaging scents and colors in a variety of cosmetics products and to protect of plastic products against light-induced degradation. There are many variants of BP in use. In this respect, to regulate and to evaluate the hazardous effect of BP-type UV filters will be important to environment and human health. The genotoxicity of 7 BP-type UV filters was evaluated in L5178Y $(tk^{+/-})$ mouse lymphoma cells in vitro. BP, benzhydrol, 4-hydroxybenzophenone 2-hydroxy-4-methoxybenzophenone and 2, 4-dihydroxybenzophenone did not induce significant mutation frequencies both in the presence and absence of metabolic activation system. 2, 2'-Dihydroxy-4-methoxybenzophenone appeared the positive results at the highest dose, i.e. 120.4 ${\mu}g/mL$ only in the absence of metabolic activation system. And also, 2, 3, 4-trihydroxybenzophenone revealed a significant increase of mutation frequencies in the range of 138.1-207.2 ${\mu}g/mL$ in the absence of metabolic activation system and 118.3-354.8 ${\mu}g/mL$ in the presence of metabolic activation system. Through the results of MLA with 7 BP-type UV filters in L5178Y cells in vitro, we may provide the important clues on the genotoxic potentials of these BP-type UV filters.

Evaluation of Single and Binary Mixture Toxicity of Organic UV-Filters Using H295R Cells (H295R 세포를 활용한 유기 UV-Filters의 단일 및 혼합독성 평가)

  • Bomee Lee;Inhye Lee;Kyunghee Ji
    • Journal of Environmental Health Sciences
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    • v.50 no.3
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    • pp.201-211
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    • 2024
  • Background: Organic ultraviolet (UV) filters are widely used in sunscreen products and have been identified as an emerging contaminant. Organic UV filters co-exist with multiple components, but their mixture toxicity remains largely unknown. Objectives: We investigated the toxicity of single and binary mixtures of commonly used UV-filters using the human adrenocarcinoma (H295R) cell line. Methods: After exposure to non-cytotoxic concentrations of avobenzone (AVO), homosalate (HS), octisalate (OS), octinoxate (OMC), and octocrylene (OC), the levels of testosterone (T) and 17β-estradiol (E2) were measured. The median effective concentration (EC50) values for the E2 of the individual substances were used to determine the mixture effect of four binary combinations: OMC+AVB, OMC+HS, OMC+OS, and OMC+OC. The synergistic, additive, and antagonistic effects of the mixture were determined by calculating toxic units (TU). To examine the mechanism of mixture toxicity, eight genes involved in steroidogenesis were analyzed using the real-time polymerase chain reaction. Results: The significant increase in E2 in H295R cells exposed to AVO, HS, OS, OMC, and OC suggest an estrogenic effect of the tested UV-filters. A significant decrease in T was observed in cells exposed to HS and OS. EC50 values for E2 increase were 105 nM for AVO, 110 nM for HS, 120 nM for OS, 55 nM for OMC, and 80 nM for OC. Both binary mixtures consisting of OMC+HS and OMC+OS have synergistic effects. Conclusions: Our results showed that five types of UV-filter substances increase E2 in H295R cells. We examined the mixture toxicity in terms of increased estrogenicity and confirmed that E2 significantly increased when OMC was mixed with a salicylate-based UV-filters. These findings highlight the importance of determining the impact of UV filter mixtures.

FILTERS OF BE-ALGEBRAS WITH RESPECT TO A CONGRUENCE

  • RAO, M. SAMBASIVA
    • Journal of applied mathematics & informatics
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    • v.34 no.1_2
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    • pp.1-7
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    • 2016
  • Some properties of filters are studied with respect to a congru-ence of BE-algebras. The notion of θ-filters is introduced and these classes of filters are then characterized in terms of congruence classes. A bijection is obtained between the set of all θ-filters of a BE-algebra and the set of all filters of the respective BE-algebra of congruences classes.

FUZZY TRANSITIVE FILTERS OF BE-ALGEBRAS

  • Rao, M. Sambasiva
    • Journal of the Chungcheong Mathematical Society
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    • v.30 no.2
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    • pp.213-226
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    • 2017
  • The concept of fuzzy transitive filters is introduced in BE-algebras. Some sufficient conditions are established for every fuzzy filter of a BE-algebra to become a fuzzy transitive filter. Some properties of fuzzy transitive filters are studied with respect to fuzzy relations and cartesian products.

Rigorous Design of Optical Directional Filters using MTLT (MTLT를 이용한 광 방향성 필터의 설계)

  • Park, Jai-Seo;Hong, Kwon-Eui;Ho, Kwang-Chun
    • Journal of IKEEE
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    • v.5 no.2 s.9
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    • pp.128-135
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    • 2001
  • Optical wavelength filters based on directional couplers are rigorously designed and analyzed by Modal Transmission-Line Theory (MTLT). The conventional parallel directional coupler is utilized to implement a narrow-band filter, and it takes up the coupler with tapered structure as a wide-band filter. The power transfers of TE/TM modes in narrow-band filters are maximized at ${\lambda}=1.303{\mu}m\;and\;1.1496{\mu}m$, and the optical bandwidths are then 30nm and 10nm, respectively. Furthermore, when the coupling lengths of TE/TM modes in wide-band filters operating at ${\lambda}=1.55{\mu}m$ are selected as $183{\mu}m\;and\;178{\mu}m$, those are operated as the stop-band and pass-band filters, respectively.

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A Study of High Temperature Filtration Performance Test on Low Density Cylindrical Ceramic Filters (저밀도 원통형 세라믹 필터의 고온 여과 성능시험 연구)

  • 이동섭;홍민선;최종인
    • Journal of Korean Society for Atmospheric Environment
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    • v.17 no.2
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    • pp.213-222
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    • 2001
  • Cylindrical type ceramic filers, that is 60 O.D$\times$10t$\times$600L and 60 O.D$\times$10t$\times$1,000L were manufactured by vacuum forming processes using ceramic ray materials. For cylindrical type ceramic filters, porosity and bulk density were measured for, 80 to 90% and 0.3 to 0.4 g/㎤, respectively at uniform pore size of 41 to 45${\mu}{\textrm}{m}$. Bench scale candle filters (60$\psi$ $\times$10t$\times$600L) were tested using different dusts collected from many industries including chemical processing, glass processing and metal manufacturing pants. Collection efficiencies found out to range from 99.87% to 99.90%, while resistance coefficients from 1.1$\times$10(sup)11/$m^2$ to 1.7$\times$10(sup)11/$m^2$ . Full scale low density ceramic filters (60$\psi$ $\times$10t$\times$1,000L) were also tested at 1 atm, $600^{\circ}C$ to reveal the filtration efficiency, conditioning, and resistance coefficients using two different types of dust as chemical processing and metal refined processing. Darcys law resistance coefficients were measured to range 1.44$\times$10(sup)11/$m^2$ to 2.74$\times$10(sup)11/$m^2$, and collection efficiencies on the range 99.84 to 99.96%, Finally, results of long term performance test showed that filters were conditioned after 170hrs. Experimental conditions for effective filtration were examined under the condition 10 cm/sec face velocity, 3kg/$\textrm{cm}^2$ pulsing pressure, 5 min filtration cycle, and 300msec pulse opening time.

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An Adaptive Active Noise Cancelling Model Using M-Channel Subband QMF Filter Banks (M-채널 서브밴드 QMF 필터뱅크를 이용한 적응 능동소음제거 모델)

  • 허영대;권기룡;문광석
    • Journal of Korea Multimedia Society
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    • v.2 no.1
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    • pp.30-37
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    • 1999
  • A wideband active noise cancelling system involves adaptive filters with hundreds of taps. The computational burden required with these long adaptive filters. This paper presents active noise cancelling system using M-channel QMF filter banks in which the adaptive weights are computed in subbands. The analysis and synthesis filter banks use cosine-modulated pseudo QMF filters. The reference signal for on-line identification of error path transfer characteristics is used to difference signal between the output of adaptive filters and the output of lowpass subband filters. The proposed adaptive subband filter bank suggests robust active noise cancelling system retaining the computational complexity and convergence speed advantaged of subband processing.

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