• 제목/요약/키워드: DF-b

검색결과 121건 처리시간 0.028초

Laser-Induced Fluorescence Spectroscopy of the $S_1-S_0 (^1B_2-^1A_1)$ Transition of Dimethyldiazirine

  • 김택수;김상규;Choi, Young S.;곽일환
    • Bulletin of the Korean Chemical Society
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    • 제19권10호
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    • pp.1042-1047
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    • 1998
  • The fluorescence excitation (FE) spectrum of the S1-S0 (1B2-1A1) transition of dimethyldiazirine cooled in supersonic jet expansions has been obtained. Dispersed fluorescence (DF) spectra have also been taken for some prominent features of the FE spectrum. Vibrational analyses of the FE and DF spectra with the help of an ab initio molecular orbital calculation lead to some new vibrational assignments and refined fundamental frequencies.

Amplify-Forward Relay Network의 인터리버에 근거한 협동 다이버시티와 그 효과적 알고리즘 (Cooperative Diversity Based on Interleavers and Its efficient Algorithm in Amplify-And-Forward Relay Networks)

  • 얀이얼;조계문;발라카난;이문호
    • 대한전자공학회논문지TC
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    • 제46권6호
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    • pp.94-102
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    • 2009
  • 참고문헌 [1]에서 full diversity를 달성할 수 있을 뿐만 아니라 각 relay node에서의 시간 지연을 제거하기 위해서 새로운 기법을 제안했다. 그러나 복호 후 전달 (DF) 모델 연산 모드는 relay에 더욱 많은 처리 부담을 준다. 본 논문에서는 [2],[3]에서 제안한 증폭 후 전달 (AF) model로 확장할 뿐만 아니라 source-relay link와 relay-destination link로 이루어진 모든 채널의 결합 채널 계수의 순서를 정하고 다음 복호 절차에서 이전의 복호된 심벌을 지우는 효율적인 복호 알고리즘을 제안한다. 컴퓨터 모의실험 결과를 통하여 제안한 알고리즘을 이용하면 높은 SNR 영역에서 참고문헌 [1]과 비교하여 상대적으로 2-3dB의 이득을 가져오기에 효율적으로 성능을 향상시킬 수 있다는 것을 알 수 있었다. 또한 제안한 알고리즘이 원래의 알고리즘과 비교하여 상대적으로 3dB 이상의 이득을 얻을 수 있는 복호 후 전달 (DF)에 유용하다는 것을 알 수 있었다.

기초의 근입깊이를 고려한 지오그리드 보강 사질토지반의 지지력 (Bearing Capacity of Strip Foundation on Geogrid-Reinforced Sand with Embedment Depth)

  • 신은철
    • 한국지반공학회논문집
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    • 제16권3호
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    • pp.57-65
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    • 2000
  • 다층의 지오그리드로 보강된 사질토 지반에 축조된 줄기초의 극한 지지력을 결정하기 위하여 실내모형실험을 실시하였다. 한가지 종류의 사진토와 지오그리드를 사용하였으며, 시험은 기초의 근입깊이(Df)가 없을 때와 근입깊이(Df)가 있을 때로 분류하여 시행되었다. 기초의 근입깊이(Df)는 기초의 폭(B)보다 작도록 제한되었다. 시험결과, 주어진 보강깊이의 두께에 대하여 지지력비(BCR)는 기초의 근입깊이(Df)가 0보다 클 때 증가하였다.

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Synthesis and Biological Activities of the Alternating Copolymers Containing Cyclic Ether Rings along with Carboxyl or Hydroxyl Groups on Their Backbones

  • Man Jung Han;Shin Duk Kang;Won Young Lee
    • Bulletin of the Korean Chemical Society
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    • 제11권2호
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    • pp.154-156
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    • 1990
  • The alternating copolymers of dihydropyran(DP)-maleic anhydride(MA), dihydrofuran(DF)-MA and DF-vinylene carbonate(VC) were prepared by free radical copolymerization of DP or DF with MA or VC. The reactivity ratios for poly(DF-VC) were found to be less than unity (0.05, 0.04) and its alternating sequences were obtained by feeding an equimolar amount of the comonomers at the onset of copolymerizations. The copolymers were hydrolyzed to give poly(TP-CE), poly(TF-CE) and poly(TF-HE), whose cytotoxicities against normal and tumor cells (3LL, B16) were measured in vitro.

Acid green-25 removal from wastewater by anion exchange membrane: Adsorption kinetic and thermodynamic studies

  • Khan, Muhammad Imran;Ansari, Tariq Mahmood;Zafar, Shagufta;Buzdar, Abdul Rehman;Khan, Muhammad Ali;Mumtaz, Fatima;Prapamonthon, Prasert;Akhtar, Mehwish
    • Membrane and Water Treatment
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    • 제9권2호
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    • pp.79-85
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    • 2018
  • In this work, batch adsorption of anionic dye acid green-25 (AG-25) from aqueous solution has been carried out at room temperature using anion exchange membrane (DF-120B) as a noval adsorbent. The effect of various experimental parameters such as contact time, membrane dosage, ionic strength and temperature on the adsorption of dye were investigated. Kinetic models namely pseudo-first-order, pseudo-second-order, Elovich, liquid film diffusion, Bangham and modified freundlich models were employed to evaluate the experimental data. Parameters like adsorption capacities, rate constant and related correlation coefficients for every model are calculated and discussed. It showed that adsorption of AG-25 onto DF-120B followed pseudo-first-order rate expression. Thermodynamic study indicates that adsorption of AG-25 onto DF-120B is an exothermic and spontaneous process.

Cooperative Nano Communication in the THz Gap Frequency Range using Wireless Power Transfer

  • Samarasekera, A. Chaminda J.;Shin, Hyundong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제13권10호
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    • pp.5035-5057
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    • 2019
  • Advancements in nanotechnology and novel nano materials in the past decade have provided a set of tools that can be used to design and manufacture integrated nano devices, which are capable of performing sensing, computing, data storing and actuation. In this paper, we have proposed cooperative nano communication using Power Switching Relay (PSR) Wireless Power Transfer (WPT) protocol and Time Switching Relay (TSR) WPT protocol over independent identically distributed (i.i.d.) Rayleigh fading channels in the Terahertz (THz) Gap frequency band to increase the range of transmission. Outage Probability (OP) performances for the proposed cooperative nano communication networks have been evaluated for the following scenarios: A) A single decode-and-forward (DF) relay for PSR protocol and TSR protocol, B) DF multi-relay network with best relay selection (BRS) for PSR protocol and TSR protocol, and C) DF multi-relay network with multiple DF hops with BRS for PSR protocol and TSR protocol. The results have shown that the transmission distance can be improved significantly by employing DF relays with WPT. They have also shown that by increasing the number of hops in a relay the OP performance is only marginally degraded. The analytical results have been verified by Monte-Carlo simulations.

Energy Metabolism and Methane Production in Faunated and Defaunated Sheep Fed Two Diets with Same Concentrate to Roughage Ratio (70:30) but Varying in Composition

  • Chandramoni, Chandramoni;Jadhao, S.B.;Tiwad, C.M.;Haque, N.;Murarilal, Murarilal;Khan, M.Y.
    • Asian-Australasian Journal of Animal Sciences
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    • 제14권9호
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    • pp.1238-1244
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    • 2001
  • Two calorimetric experiments were performed to investigate the effects of two diets with same concentrate: roughage ratio (70:30) but varying in composition on energy metabolism and methane production in faunated (F) and defaunated (DF) Muzaffarnagari sheep. For experiment I, ten animals were divided equally into two groups of which one was kept normally F as such while other was DF using 10% sodium lauryl sulphate. All the animals were offered diet I which comprised of oat hay and concentrate mixture I (CM I) containing maize grain (93%) as a major ingredient in 70:30 ratio. Similarly, the experiment II was conducted for which four F and four DF sheep (same as used for experiment I) were switched to diet II that consisted of maize hay and CM II (maize grain 59% + molasses 36%). Through diet II, DM intake in DF sheep was significantly (p<0.05) lower. Intake of GE through both the diets was similar in F and DF sheep. Digestibility of DM, OM, CP and GE and also metabolisability (ME/GE) was similar in F and DF sheep on both the diets. Total urinary energy loss did not differ in F and DF on both the diets, but methane energy loss as a percent of GE in DF was significantly (p<0.05) lower on diet I (3.75 vs 2.48), while it did not differ on diet II (3.20 vs 3.60). Heat production was significantly (p<0.01) reduced in DF on both the diets. Although, efficiency of utilisation of ME for maintenance calculated as per ARC (1984) did not differ in F and DF on both the diets, efficiency for maintenance and growth was higher (0.60 vs 0.672) on diet I in DF. It was inferred that methane production in DF sheep reduces on good quality hay-based diet supplemented with slowly fermentable carbohydrate (maize grain) but supplementation of molasses (rapidly fermentable CHO) nullify this effect when sheep were fed diets with concentrate: roughage ratio of 70:30.

Expression patterns of innate immunity-related genes in response to polyinosinic:polycytidylic acid (poly[I:C]) stimulation in DF-1 chicken fibroblast cells

  • Jang, Hyun-Jun;Song, Ki-Duk
    • Journal of Animal Science and Technology
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    • 제62권3호
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    • pp.385-395
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    • 2020
  • Polyinosinic:polycytidylic acid (poly[I:C]) can stimulate Toll-like receptor 3 (TLR3) signaling pathways. In this study, DF-1 cells were treated with poly(I:C) at various concentrations and time points to examine the comparative expression patterns of innate immune response genes. The viability of DF-1 cells decreased from 77.41% to 38.68% when cells were treated different dose of poly(I:C) from 0.1 ㎍/mL to 100 ㎍/mL for 24 h respectively. The expressions of TLR3, TLR4, TLR7, TLR15, TLR21, IL1B, and IL10 were increased in dose- and time-dependent manners by poly(I:C) treatment. On the contrary, the expression patterns of interferon regulatory factors 7 (IRF7), Jun proto-oncogene, AP-1 transcription factor subunit (JUN), Nuclear Factor Kappa B Subunit 1 (NF-κB1), and IL8L2 were varied; IRF7 and IL8L2 were increasingly expressed whereas the expressions of JUN and NF-κB1 were decreased in a dose-dependent manner after they were early induced. In time-dependent analysis, IRF7 expression was significantly upregulated from 3 h to 24 h, whereas JUN and NF-κB1 expressions settled down from 6 h to 24 h after poly(I:C) treatment although they were induced at early time from 1 h to 3 h. Poly(I:C) treatment rapidly increased the expression of IL8L2 from 3 h to 6 h with a plateau at 6 h and then the expression of IL8L2 was dramatically decreased until 24 h after poly(I:C) treatment although the expression level was still higher than the non-treated control. These results may provide the basis for understanding host response to viral infection and its mimicry system in chickens.

전력 및 대역폭 효율성있는 무선센서네트워크협력 전송에 관한 연구 (Power-and-Bandwidth Efficient Cooperative Transmission Protocol in Wireless Sensor Networks)

  • ;공형윤;최정호;정휘재
    • 정보처리학회논문지C
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    • 제13C권2호
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    • pp.185-194
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    • 2006
  • 단 논문에서 먼저 LEACH (Low-Energy Adaptive Hierarchy)를 사용한 무선센서네트워크에서 하나의 센서 노드가 다른 두 센서노드의 클러스터 헤드를 향한 데이터 전송을 도와주는 전력 및 대역폭에 효율성있는 협력 통신 프로토콜을 제안하고, 제안한 프로토콜의 closed-form BER(Bit Error Ratio)을 유도한다. 또한 이것이 복호 후 전송 프로토콜의 일반적인 BER 임을 보이고, 제안한 시스템이 기존의 복호 후 전송 프로토콜보다 더 높은 주파수 효율을 가지면서 동일한 성능을 나타내는 것을 보인다. 많은 수학적인 결과를 통해 직접 전송일 경우 BER이 $10^{-3}$에서 11dB까지 네트워크의 전력이 절약되는 것을 확인할 수 있다.

Blind Signal Processing for Medical Sensing Systems with Optical-Fiber Signal Transmission

  • Kim, Namyong;Byun, Hyung-Gi
    • 센서학회지
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    • 제23권1호
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    • pp.1-6
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    • 2014
  • In many medical image devices, dc noise often prevents normal diagnosis. In wireless capsule endoscopy systems, multipath fading through indoor wireless links induces inter-symbol interference (ISI) and indoor electric devices generate impulsive noise in the received signal. Moreover, dc noise, ISI, and impulsive noise are also found in optical fiber communication that can be used in remote medical diagnosis. In this paper, a blind signal processing method based on the biased probability density functions of constant modulus error that is robust to those problems that can cause error propagation in decision feedback (DF) methods is presented. Based on this property of robustness to error propagation, a DF version of the method is proposed. In the simulation for the impulse response of optical fiber channels having slowly varying dc noise and impulsive noise, the proposed DF method yields a performance enhancement of approximately 10 dB in mean squared error over its linear counterpart.