• 제목/요약/키워드: ${\beta}-limit\

검색결과 216건 처리시간 0.023초

Error Rate for the Limiting Poisson-power Function Distribution

  • Joo-Hwan Kim
    • Communications for Statistical Applications and Methods
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    • 제3권1호
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    • pp.243-255
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    • 1996
  • The number of neutron signals from a neutral particle beam(NPB) at the detector, without any errors, obeys Poisson distribution, Under two assumptions that NPB scattering distribution and aiming errors have a circular Gaussian distribution respectively, an exact probability distribution of signals becomes a Poisson-power function distribution. In this paper, we show that the error rate in simple hypothesis testing for the limiting Poisson-power function distribution is not zero. That is, the limit of ${\alpha}+{\beta}$ is zero when Poisson parameter$\kappa\rightarro\infty$, but this limit is not zero (i.e., $\rho\ell$>0)for the Poisson-power function distribution. We also give optimal decision algorithms for a specified error rate.

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쌀의 아밀로펙틴 분자구조와 밥의 텍스쳐 (Relationship between Molecular Structure of Rice Amylopectin and Texture of Cooked Rice)

  • 강길진;김관;김성곤
    • 한국식품과학회지
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    • 제27권1호
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    • pp.105-111
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    • 1995
  • 밥의 식미가 다른 일반계와 통일계 쌀을 대상으로 아밀로펙틴과 그 베타-한계덱스트린의 분자구조적 특성을 조사하고 밥의 텍스쳐와의 관련성을 검토하였다. 쌀 전분의 아밀로펙틴 분자구조는, 아밀로펙틴과 베타-한계 덱스트린의 사슬분포로 보아, $\overline{DP}$ 12.4의 A 사슬, $\overline{DP}$ 20.6의 짧은 B 사슬, $\overline{DP}$ 26.3의 중간 B 사슬, $\overline{DP}$ 45의 긴 B 사슬과 $\overline{DP}$ 55 이상의 초장쇄로 이루어진 polymodal이었다. 아밀로펙틴의 초장쇄는 긴 직쇄를 가진 사슬로서 아밀로펙틴의 평균 사슬길이, 고유점도, 베타-아밀라아제 분해한도와 정의 상관을 보이나 요오드 복합체의 최대흡수파장과는 부의 상관을 보였다. 아밀로펙틴과 베타-한계 덱스트린의 분자구조적 성질은 일반계와 통일계 쌀 시료간 차이를 보였다. 아밀로펙틴의 A 사슬에 대한 B 사슬의 비율은 일반계가 통일계 보다 약간 높았으나 초장쇄의 분포 비율은 일반계가 통일계 보다 더 낮았다. 아밀로펙틴의 분자구조와 밥의 텍스쳐와의 관계에서, 고유점도, 베타-아밀라아제 분해한도와 사슬길이 그러고 초장쇄는 밥의 경도와 정의 상관을, 부착성과는 부의 상관을 보였다. 따라서 밥의 식감은 아밀로펙틴의 긴 사슬이 적고 짧은 사슬이 많이 분포할 수록, 밥의 경도가 낮고 부착성이 높았다. 이러한 결과는 아밀로펙틴의 분자구조가 밥의 텍스쳐와 밀접한 관계가 없음을 나타내고 있다.

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Mg-Li-Al합금의 가공성 및 시효거동 (Workability and Aging Behavior of Mg-Li-Al alloys)

  • 강민철;김순호;정해용;이정무;김경현;김인배
    • 한국재료학회지
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    • 제2권6호
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    • pp.389-397
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    • 1992
  • Li의 양과 Al의 양을 달리한 $\alpha$(HCP) 단상 및 $\alpha$(HCP)+${\beta}$ (BCC) 2상 조직인 Mg-Li-Al합금을 시료로 하여 이 합금의 가공성과 시효경화륵성을 조사한 결과 $\alpha$단상보다는 $\alpha$+${\beta}$ 2상 조이,$\alpha$+${\beta}$ 2상조직에서는 Al양이 많을수록 가궁성이 증가하였으며 Mg-8.08Li-4.26Al의 경우 가공한계값은 62%였다. 이와같이 가공성이 증가한 이유는 basal plane뿐만 아니라 pyramidal plane과 prism plane에서도 슬립이 일어났기 때문이다. $\alpha$단상의 경우 MgL$i_2$ Al(${\theta}$)의 석출이 일어나지 않았으나 $\alpha$+${\beta}$ 2상 조직의 곁우 ${\beta}$상 내에서 ${\theta}$의 석출에 의한 피크경도같이 나타났으며, 2상 조직의 경우 경도값은 Al양이 많을수록 증가하였는데 이것은 Al양의 증가에 따른 Al Partition에 의한$\alpha$ 상의 강화와 ${\beta}$상에서의 석출물 증가에 의한 것으로 생각된다.

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Reversed-Phase High Performance and Liquid Chromatographic Separation of the Enantiomers of Terbutaline by Derivatization with 2,3,4-Tetra-o-acetyl-\beta-glucopyranosyl Isothiocyanate

  • Kim, Kyeong-Ho;Kim, Dong-Sig;Hong, Seon-Pyo;Keon, Oh-Seung
    • Archives of Pharmacal Research
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    • 제23권1호
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    • pp.26-30
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    • 2000
  • The enantiomers of the bronchodilator terbutaline were separated by reversed-phase high performance liquid chromatograhy after derivatization with 2,3,4,6-tetra-O-acetyl-\beta-D-glucopyranosyl isothiocyanate(GITC) reagent. The derivatization proceeded quantitatively within 1 h at room temperature. The corresponding diastereomeric thiourea derivatives were well resolved on an ODS column with acetonitrile-acetate buffer as a mobile phase. Elution orders of the diastereomers were confirmed by derivatization of R-(-)-terbutaline and S-(+)-terbutaline which were collected by semi-preparative chiral HPLC using Sumichiral OA-4700 column. The native fluorescence of terbutaline was quenched by derivatization with GITC. The detection limit was 25ng when monitored at UV 278 nm.

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Radish $\beta$-amylase에 관한 연구 (Studies on $\beta$-Amylase of Radish)

  • 우원식
    • 약학회지
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    • 제6권2호
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    • pp.18-22
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    • 1962
  • Purified preparation of .betha.-amylase is obtained from radish root by the means of fractional precipitation with ammonium sulfate. Purified preparation saccharifies the starch, .betha.-maltose being formed. Dextrinization in the true sense does not take place. Hydrolysis ceases when approximately 50% of the theoretical yield of maltose is obtained and there remains a substance (to be .betha.-limit dextrin) which gives a blue-violet with iodine, no glucose being formed. Stability of preparation is optimal at pH 4-9 and more completely inactivated at 65.deg. in fifteen minutes. .betha.-Amylase of radish exhibits optimal activity at and near pH 5.0, which varied depending upon the buffer. Calcium and chloride ions do not effect the activities of enzyme. The results of experiments with oxidizing, alkylating and mercaptide-forming reagents which have been reported to be specific for sulfhydryl groups confirm that free sulfhydryl groups are essential to the activity of .betha.-amylase from radish.

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Release of AKARI/FIS Bright Source Catalogue ${\beta}-2$

  • 정웅섭
    • 천문학회보
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    • 제35권1호
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    • pp.41.2-41.2
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    • 2010
  • The infrared astronomy satellite AKARI/FIS (Far-Infrared Surveyor) performed all-sky survey in 4 Far-IR bands (50 - 200${\mu}m$ range). It observed around 94% of the whole sky twice or more with a higher spatial resolution and a wider wavelength coverage than that of previous all-sky mission, IRAS. The AKARI/FIS bright source catalogue ${\beta}-2$ is the second released version which included around 290,000 point sources. It provides us with more reliable position and flux information, and around 4 times larger number of sources compared with the first version of catalogue. The sensitivity limit at $90{\mu}m$ band is 0.6 Jy and the estimated flux uncertainty is 20-35% for bright sources. The catalogue will be open to public in this year after the improvement of accuracy, reliability and completeness.

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Testing of Poisson Incidence Rate Restriction

  • Singh, Karan;Shanmugam, Ramalingam
    • International Journal of Reliability and Applications
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    • 제2권4호
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    • pp.263-268
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    • 2001
  • Shanmugam(1991) generalized the Poisson distribution to capture a restriction on the incidence rate $\theta$ (i.e. $\theta$$\beta$, an unknown upper limit), and named it incidence rate restricted Poisson (IRRP) distribution. Using Neyman's C($\alpha$) concept, Shanmugam then devised a hypothesis testing procedure for $\beta$ when $\theta$ remains unknown nuisance parameter. Shanmugam's C ($\alpha$) based .results involve inverse moments which are not easy tools, This article presents an alternate testing procedure based on likelihood ratio concept. It turns out that likelihood ratio test statistic offers more power than the C($\alpha$) test statistic. Numerical examples are included.

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공명형광과 레이저광과의 4차 간섭 (Fourth-Order Interference Between Fluorescent Photon and a Laser Field)

  • 김태수;홍순철;나상균;김갑진
    • 한국광학회지
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    • 제2권4호
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    • pp.214-218
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    • 1991
  • 레이저로 여기된 원자에서 방출하는 형광과 여기용 레이저 빛이 중첩 되었을 때 일어나는 4차 간섭현상을 조사하였다. 간섭무늬 선명도(visibility)가 50% 이상의 비고전적 효과가 나타나는 조건을 검토하였으며 2차 간섭무늬 선명도와 비교하였다. 여기레이저를 원자에 입사시킨 후 오랜 시간이 경과하면 $\Omega/\beta$>>1 일 때 2차 간섭현상을 소멸하는 데 반하여 4차 간섭은 존재함을 알 수 있다.

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Chiral Purity Test of Bevantolol by Capillaryelectrophoresis and High Performance Liquid Chromatography

  • Long, Pham Hai;Trung, Tran Quoc;Oh, Joung-Won;Kim, Kyeong-Ho
    • Archives of Pharmacal Research
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    • 제29권9호
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    • pp.808-813
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    • 2006
  • Two methods for the chiral purity determination of bevantolol were developed, namely capillary electrophoresis (CE) using carboxymethyl-${\beta}$-cyclodextrin (CM-${\beta}$-CD) as a chiral selector and high-perfomance liquid chromatography (HPLC) using a chiral stationary phase. In the HPLC method, the separation of bevantolol enantiomers was performed on a Chiralpak AD-H column by isocratic elution with n-hexane-ethanol-diethylamine (10:90:0.1, v/v/v) as mobile phase. In the CE method, bevantolol enantiomers were separated on an uncoated fused silica capillary with 50 mM amonium phosphate dibasic adjusted to a pH 6.5 with phosphoric acid containing 15 mM CM-${\beta}$-CD as running buffer. Validation data such as linearity, recovery, detection limit, and precision of the two methods are presented. The detection limits of S-(-)-bevantolol were 0.1% and 0.05% for CE and HPLC method, respectively and R-(+)-bevantolol were 0.15% and 0.05% for CE and HPLC method, respectively. There was generally good agreement between the HPLC and CE results.

Determination of Terbutaline Enantiomers in Human Urine by Capillary Electrophoresis Using $Hydroxypropyl-{\beta}-cyclodextrin$ as a Chiral Selector

  • Kim, Kyeong-Ho;Seo, Sang-Hun;Kim, Hyun-Ju;Jeun, Eun-Young;Kang, Jong-Seong;Mar, Woong-Chon;Youm, Jeong-Rok
    • Archives of Pharmacal Research
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    • 제26권2호
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    • pp.120-123
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    • 2003
  • A method for the determination of terbutaline enantiomers in human urine by capillary elctrophoresis has been developed. Optimum resolution was achieved using 50 mM phosphate buffer, pH 2.5, containing 15 mM of hydroxypropyl-$\beta$-cyclodextrin as a chiral selector. Urine samples were prepared by solid-phase extraction with Sep-pak silica, followed by CE. The assay was linear between 2-250 ng/mL (R = 0.9998 for (S)-(+)-terbutaline and R = 0.9999 for (R)-(-)-terbutaline) and detection limit was 0.8 ng/mL. The intra-day variation ranged between 6.3 and 14.5% in relation to the measured concentration and the inter-day variation was 8.2-20.1%. It has been applied to the determination of (S)-(+)-terbutaline and (R)-(-)-terbutaline in urine from healthy volunteer dosed with racemic terbutaline sulfate.