• 제목/요약/키워드: wilson

검색결과 555건 처리시간 0.028초

ON THE STABILITY OF PEXIDER TYPE TRIGONOMETRIC FUNCTIONAL EQUATIONS

  • Kim, Gwang Hui
    • Korean Journal of Mathematics
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    • 제16권3호
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    • pp.369-378
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    • 2008
  • The aim of this paper is to study the stability problem for the pexider type trigonometric functional equation f(x + y) − f(x−y) = 2g(x)h(y), which is related to the d'Alembert, the Wilson, the sine, and the mixed trigonometric functional equations.

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EINSTEIN EQUATIONS IN NUMERICAL RELATIVITY

  • Park, Seok-Jae
    • 천문학논총
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    • 제5권1호
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    • pp.17-25
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    • 1990
  • Rapid progress in modern computer industries now enables us to solve the Einstein equations numerically. In the first part of this paper we briefly review how to deal with those equations in relativistic astrophysics and cosmology. In the second part we introduce two examples-the Centrella and Wilson's cosmology and the Shapiro and Teukolsky's relativistic stellar cluster.

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Development of daily solar flare peak flux forecast models for strong flares

  • Shin, Seulki;Lee, Jin-Yi;Chu, Hyoung-Seok;Moon, Yong-Jae;Park, JongYeob
    • 천문학회보
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    • 제40권1호
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    • pp.64.3-64.3
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    • 2015
  • We have developed a set of daily solar flare peak flux forecast models for strong flares using multiple linear regression and artificial neural network methods. We consider input parameters as solar activity data from January 1996 to December 2013 such as sunspot area, X-ray flare peak flux and weighted total flux of previous day, and mean flare rates of McIntosh sunspot group (Zpc) and Mount Wilson magnetic classification. For a training data set, we use the same number of 61 events for each C-, M-, and X-class from Jan. 1996 to Dec. 2004, while other previous models use all flares. For a testing data set, we use all flares from Jan. 2005 to Nov. 2013. The best three parameters related to the observed flare peak flux are weighted total flare flux of previous day (r = 0.51), X-ray flare peak flux (r = 0.48), and Mount Wilson magnetic classification (r = 0.47). A comparison between our neural network models and the previous models based on Heidke Skill Score (HSS) shows that our model for X-class flare is much better than the models and that for M-class flares is similar to them. Since all input parameters for our models are easily available, the models can be operated steadily and automatically in near-real time for space weather service.

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Periventricular nodular heterotopia in a child with a mild Mowat-Wilson phenotype caused by a novel missense mutation of ZEB2

  • Kim, Young Ok;Lee, Yun Young;Kim, Myeong-Kyu;Woo, Young Jong
    • Journal of Genetic Medicine
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    • 제16권2호
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    • pp.71-75
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    • 2019
  • Periventricular nodular heterotopia (PNH) is a malformation of cortical development in which normal neurons inappropriately cluster in periventricular areas. Patients with Mowat-Wilson syndrome (MWS) typically present with facial gestalt, complex neurologic problems (e.g., severe developmental delay with marked speech impairment and epilepsy), and multiple anomalies (e.g., Hirschsprung disease, urogenital anomalies, congenital heart defects, eye anomalies, and agenesis of the corpus callosum [CC]). MWS is mostly caused by haploinsufficiency of the gene encoding zinc-finger E-box-binding homeobox 2 (ZEB2) due to premature stops or large deletions. We present a case report of a 9-year-old girl with PNH, drug-responsive epilepsy, severe intellectual disability, and facial dysmorphisms only in whom we performed whole-exome sequencing and found a de novo heterozygous missense mutation (c.3134A>C; p.His1045Pro) of ZEB2 (NM_014795.3; NP_055610.1). This mild case of MWS caused by a rare novel missense mutation of ZEB2 represents the first report of MWS with isolated PNH.

Toluene, Methylcyclohexane, n-heptane 그리고 Ethylbenzene 이성분 혼합계에 대한 101.3 kPa에서의 인화점 측정 (Measurement of Flash Point for Binary Mixtures of Toluene, Methylcyclohexane, n-heptane and Ethylbenzene at 101.3 kPa)

  • 황인찬;인세진
    • 한국화재소방학회논문지
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    • 제31권3호
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    • pp.19-24
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    • 2017
  • 인화점은 산업현장에서 화재 및 폭발의 위험성을 결정하는데 사용되는 중요한 지표의 하나로 안정성 평가 시 많이 사용되고 있다. 따라서 본 연구는 고무제조 공정에서 주로 쓰이는 이성분계 혼합물 중 {toluene+ethylbenzene}, {methlycyclohenxane+ethylbenzene} 그리고 {n-heptane+ethylbenzene} 대한 인화점을 101.3 kPa에서 SETA 밀폐식 인화점 측정기를 이용하여 측정하였다. 각 이성분계에 대하여 Raoult's의 법칙, Wilson, NRTL 및 UNIQUAC 파라미터를 이용하여 혼합물에 대한 인화점 예측하고 실험 결과와 비교하였다. 비교 결과 모든 예측값과 실험값은 유사한 값을 보였고 편차가 1.74 K이내의 결과를 보였다.

대구경 타원관을 적용한 건조기용 핀-관 열교환기의 성능특성 (Performance Characteristics of Fin-Tube Heat Exchanger having Large Diameter Oval Tube for Dryer)

  • 배경진;차동안;권오경
    • 설비공학논문집
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    • 제27권1호
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    • pp.8-13
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    • 2015
  • The objective of this paper is to provide design data of fin-tube heat exchanger which have a large diameter oval tube for dryer application. In this study, the heat transfer and pressure drop performance characteristics of the fin-tube heat exchanger were compared with Dittus-Boelter and a new correlation equation using Wilson plot method. The simulation results based on section by section method were compared with experimental results. These results showed that a new correlation equation using Wilson plot method provided better prediction, about 3 to 12%, than the Dittus-Boelter equation, from the experiment comparison. Also, the pressure drop of simulation results showed much more deviation with the experimental results.