• 제목/요약/키워드: branch point

검색결과 406건 처리시간 0.026초

WEAK CONVERGENCE THEOREMS FOR 2-GENERALIZED HYBRID MAPPINGS AND EQUILIBRIUM PROBLEMS

  • Alizadeh, Sattar;Moradlou, Fridoun
    • 대한수학회논문집
    • /
    • 제31권4호
    • /
    • pp.765-777
    • /
    • 2016
  • In this paper, we propose a new modied Ishikawa iteration for finding a common element of the set of solutions of an equilibrium problem and the set of fixed points of 2-generalized hybrid mappings in a Hilbert space. Our results generalize and improve some existing results in the literature. A numerical example is given to illustrate the usability of our results.

Synthesis of 1,2,3-and 1,2,4-Triazole Isonucleosides as Potential antiviral agents

  • Jeong, Soon-Yong;Kim, Myong-Jung;Chun, Moon-Won
    • 대한약학회:학술대회논문집
    • /
    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
    • /
    • pp.181.2-181.2
    • /
    • 2003
  • Inosine monophosphate dehydrogenase(IMPDH) catalyzes the $NAD^+$-dependent oxidation of IMP to XMP, the rate limiting step in the de novo biosynthesis of guanine nucleotide. Its critical role at the metabolic branch point in purine nucleotide biosynthesis makes it a useful target in the development of drugs for antiviral and anticancer chemotherapy and in immunosupressant area. Several compound with antiviral activity have been found to be inhibitors of IMPDH. For example, ribavirin, a competitive inhibitor of IMPDH, has broad spectrum antiviral activities against DNA and RNA viruses. (omitted)

  • PDF

ON CONTROLLABILITY FOR FRACTIONAL VOLTERRA-FREDHOLM SYSTEM

  • Ahmed A. Hamoud;Saif Aldeen M. Jameel;Nedal M. Mohammed;Homan Emadifar;Foroud Parvaneh;Masoumeh Khademi
    • Nonlinear Functional Analysis and Applications
    • /
    • 제28권2호
    • /
    • pp.407-420
    • /
    • 2023
  • In this manuscript, we study the sufficient conditions for controllability of Volterra-Fredholm type fractional integro-differential systems in a Banach space. Fractional calculus and the fixed point theorem are used to derive the findings. Some examples are provided to illustrate the obtained results.

중주파 전류의 주파수가 감각 역치에 미치는 영향 (The Influence of Medium Frequency Currents According to Frequency on Sensory Threshold)

  • 유진호;황태연;정진규
    • 대한임상전기생리학회지
    • /
    • 제7권1호
    • /
    • pp.23-27
    • /
    • 2009
  • Purpose : The purpose of this study was to examine the effects of different medium frequency currents on afferent fibers. Methods : Thirty healthy volunteers who had no known history of neurological disorders were equally assigned to one of three groups; 2500Hz, 4000Hz, and control and each group was applied to the left wrist in palmer cutaneous branch of radial nerve by different medium frequency currents for 15 min. We measured the changes of thresholds for tactile, two-point discrimination, and thresholds for pain. Results : The results showed that the medium frequency currents stimulation increased thresholds for tactile, two-point discrimination, and thresholds for pain. However, there is no statistically significant difference between group 2500Hz and group 4000Hz. Conclusion : This may explain thresholds for tactile, two-point discrimination, and thresholds for pain plain medium frequency currents stimulation inhibits the excitability of afferent fibers, but the effect of the frequency difference within medium frequency currents is not demonstrated.

전개확산제트화염과 정체점 확산화염과의 유사성 (Similarity between a stagnant point diffusion flame and an evolving jet diffusion flame)

  • 박정;신현동
    • 대한기계학회논문집B
    • /
    • 제21권4호
    • /
    • pp.494-502
    • /
    • 1997
  • Experiments on corresponding jet flames with stagnant point diffusion flames have been carried out in initial injection periods. A compensated measurement of maximum flame temperature, which is based on the ion signal, has been employed to inspect flame responses to time-varying strain rates. The flame responses are obtained at two conditions for the slowly time-varying strain rate and the case of flame extinction, and analyzed to confirm similarity between a stagnant point diffusion flame and an evolving jet diffusion flame. Nonsteady effects are addressed via the comparison between several time scales. The time variation with low strain rates, in which illustrates the flame behavior of the upper branch far from extinction in the well-known S-curve, is confirmed to produce a quasi-steady flame response through the nonsteady experiments. The time variation with strain rates in the case of flame extinction indicates an unsteady effect of flame response. It is therefore found that the flame responses near jet tip depend on time histories of characterized strain rates in the developing process.

소도읍의 재래시장 활성화를 위한 환경개선에 대한 연구 -충북 옥천재래시장을 중심으로- (Environment Improvement for the Traditional Market Activation of the Small Capital - Focused on Okcheon Traditional Market-)

  • 한상호;최효승
    • 한국농촌건축학회논문집
    • /
    • 제6권3호
    • /
    • pp.1-14
    • /
    • 2004
  • Around the rural village area the traditional markets which are center the small capital it was active at the strong-point and the possibility the fact that it is developed. With this the same small capital currently as the city and the area where the quality of the rural village coexists, has the regional quality which belongs in guard of the capital region or strong-point city. With relative estrangement from the support process against this result past falling behind farming village it does not illustrate the possibility of knowing the fact that the duplex point who is falling behind as guard territory of reverse appears. Selects the small capital of the each area from like this point of view and the possibility of knowing center role of traditional market the possibility which is various is the possibility of doing in the process which propels an activation. Currently it is planned from the multi local self-governing group and the result which investigates the traditional market activation contents which are in the process of propelling, it will be able to discover the multi branch problem points against a traditional market activation.

  • PDF

Spatial Point-pattern Analysis of a Population of Lodgepole Pine

  • Chhin, Sophan;Huang, Shongming
    • Journal of Forest and Environmental Science
    • /
    • 제34권6호
    • /
    • pp.419-428
    • /
    • 2018
  • Spatial point-patterns analyses were conducted to provide insight into the ecological process behind competition and mortality in two lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) stands, one in the Lower Foothills, and the other in the Upper Foothills natural subregions in the boreal forest of Alberta, Canada. Spatial statistical tests were applied to live and dead trees and included Clark-Evans nearest neighbor statistic (R), nearest neighbor distribution function (G(r)), and a variant of Ripley's K function (L(r)). In both lodgepole pine plots, the results indicated that there was significant regularity in the spatial point-pattern of the surviving trees which indicates that competition has been a key driver of mortality and forest dynamics in these plots. Dead trees generally showed a clumping pattern in higher density patches. There were also significant bivariate relationships between live and dead trees, but the relationships differed by natural subregion. In the Lower Foothills plot there was significant attraction between live and dead tees which suggests mainly one-sided competition for light. In contrast, in the Upper Foothills plot, there was significant repulsion between live and dead trees which suggests two-sided competition for soil nutrients and soil moisture.

OFDMA 상향 링크 시스템에서 PAPR 저감을 위한 선택적 DFT Spreading 기법의 설계와 성능 평가 (Design and Performance Evaluation of Selective DFT Spreading Method for PAPR Reduction in Uplink OFDMA System)

  • 김상우;유흥균
    • 한국전자파학회논문지
    • /
    • 제18권3호
    • /
    • pp.248-256
    • /
    • 2007
  • 본 논문에서는 OFDMA(Orthogonal Frequency Division Multiple Access) 상향 링크 시스템에서 발생하는 높은 PAPR(Peak to Average Power Ratio) 문제를 해결하기 위한 방법으로 선택적 DFT(Discrete Fourier Transform) spreading 기법을 새롭게 제안한다. 제안된 방법은 기존의 DFT spreading 기법에 선택적 특성을 추가한 것으로, SLM(Selective Mapping) 기법과 DFT spreading 기법이 혼합된 형태를 갖는다. 그러나 제안된 기법은 copy branch를 사용함에 있어 그 복잡도의 증가를 최소화하기 위해 하나의 DFT만을 사용하고, DFT출력 신호에 여러 개의 각기 다른 matrix를 곱함으로써 여러 개의 copy branch를 생성한다. 여기서 사용된 matrix는 DFT 앞에서의 입력 데이터 위상 회전을 선형 변환함으로써 얻어진 것으로, 각각의 matrix는 그 복잡도가 하나의 DFT보다 매우 낮게 설계된다. 성능 분석을 위해 QPSK 변조 및 512 point IFFT의 사용을 가정하고 한 사용자에게 할당된 sub-carrier 수는 각각 75, 100인 두 가지 경우를 고려하였다. 성능 분석 결과에서, 제안된 선택적 DFT spreading 기법은 copy branch 수가 4일 때 약 5.2 dB 이상의 PAPR 저감 효과를 가지며, 이는 기존의 DFT spreading만을 사용하는 경우 보다 약 1.8 dB 이상, 그리고 32 copy branch를 사용하는 SLM보다도 약 0.95 dB 이상의 뛰어난 PAPR 저감 성능이다. 또한 복잡도의 비교에서도 사용자에게 할당된 sub-carrier의 수가 100일 때, 제안된 기법은 기존의 DFT spreading 기법 보다는 증가되었으나 제안된 기법의 성능에 가장 근접하는 32 copy branch의 SLM보다 약 91.79 % 저감된 곱셈 량을 갖는다. 제안된 기법의 효율성을 확인할 수 있으며, 사용자에게 할당된 sub-carrier의 수가 증가되어 단일 사용자가 모든 sub-carrier를 사용하는 경우, 즉 일반적인 OFDM과 같은 상황에서도 유사한 성능적 이득을 예상할 수 있다.

VHDL 모델의 효율적인 검증 방법 (Efficient Strategies to Verify VHDL Model)

  • 김강철
    • 한국정보통신학회:학술대회논문집
    • /
    • 한국해양정보통신학회 2003년도 춘계종합학술대회
    • /
    • pp.526-529
    • /
    • 2003
  • 논 논문에서는 VHDL 모델을 검증하기 위하여 정지법을 사용할 때 클럭 사이클을 줄일 수 있는 2가지 방법을 제안한다. 첫 번째 방법은 세미랜덤변수를 정의하고, 정지법이 동작 중에 세미랜덤변수의 영역에 존재하는 데이터를 생략하여 정지점(stopping point)을 줄이고, 두 번째 방법은 정지법의 페이즈가 변화시에 베이지안 파라미터의 기존 간을 그대로 유지하여 클럭 사이클을 줄이는 방법이다. 제안된 방법의 효율성을 입증하기 위하여 12개의 VHDL 모델에 대하여 분기검출률에 관한 모의실험을 하였다.

  • PDF

스위칭 소자를 사용한 편파 다이버시티 개구결합 원편파 패치 안테나 (Aperture Coupled Circularly Polarized Patch Antenna for Polarization Diversity using Switching Elements)

  • 윤천수;박동국;양규식
    • 한국전자파학회논문지
    • /
    • 제15권5호
    • /
    • pp.461-466
    • /
    • 2004
  • 본 논문에서는 스위칭 소자를 사용한 새로운 형태의 편파 다이버시티 개구 결합 원편파 패치 안테나를 제안하였다. 제안된 안테나의 구조는 정사각형 패치의 모서리를 왜곡시킨 단일 패치이며, 급전은 전력 분배기 형태의 마이크로스트립 급전에 Schottky 다이오드를 삽입시킨 형태이다. 스위칭 소자인 Schottky 다이오드는 급전의 전력 분배 지점에서 $\lambda$/4 떨어진 위치에 삽입하였으며, Schottky diode의 ON/OFF 동작으로 방사체인 패치의 급전이 변화를 이루어 좌$.$우 선회 원편파로 변화되는 구조로 설계하였다. 스위칭 동작에 의해 측정되어진 안테나의 3 dB 축비 대역폭은 약 2 %로 측정되어졌다.