• 약학회지
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• 제50권1호
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• pp.8-14
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• 2006

A 1 : 1 mixture of acriflavine (ACF; CAS 8063-24-9) and guanosine is currently being evaluated as a possible antitumor agent in preclinical studies. Guanosine is known to potentiate the anticancer activity of some compounds. However, the distributions of trypaflavine (TRF) or proflavine (PRF) have not been investigated in mammals. We, therefore, investigated the distribution of TRF and PRF after i.m. administration of the combination mixture (ACF and guanosine) at a dose of 30 mg/kg ACF in rats. to analyze TRF and PRF levels in biological samples, we used an HPLC-based method. The calibration curves for TRF and PRF in the samples were linear over the concenration range of $0.05{\sim}200\;{\mu}g/ml$. The intra- and inter-day assay accuracies of this method were within ${\pm}15\%$ of norminal values and the precision did not exceed $15\%$ of relative standard diviation. The lower limits of quantitation were 50 ng/ml for both TRF and PRF. The distribution of TRF or PRF was determined by 48 h after i.m. administration of the combination mixture at a dose of 30 mg/kg ACF. TRF and PRF were distributed as the following order; kidney>lung>liver>small intestine>muscle. Of the various tissues, TRF and PRF were mainly distributed to the kidney and lung. The concentrations of TRF or PRF in the tissues 24 h after i.m. administration decreased to undetectable levels. The concentrations of TRF or PRF in the blood cells were comparable to those for the plasma. However, the concentrations of TRF or PRF in the both plasma and blood cells 12 h after i.m. administration were not detected. The number of the platelets in the 1 ml of the blood was calculated to be $0.183{\times}10^8/ml$ of blood. The PRF concentration in platelets was higher than that of TRF at initial times after i.m. administration of the combination mixture. However, both the TRF and PRF concentrations in the plateles 24 h after i.m. administration of the combination mixture were below the quantifiable limit. In conclusion, the concentrations of TRF or PRF in the various tissues, plasma, blood cells, and plateles decreased to undetectable levels 24 h after i.m. administration of the combination mixture at a dose of 30 mg/kg ACF.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2007년도 추계학술대회 및 정기총회
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• pp.469-473
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• 2007

For the quantitative analysis of inclusion using OES data, separating of noise and inclusion is needed. In previous methods assuming that noises come from a normal distribution, intensity levels beyond a specific threshold are determined as inclusions. However, it is not possible to classify inclusions in low intensity region using this method, even though every inclusion is an element of some chemical compound. In this paper, we assume that distribution of OES data is a Gaussian mixture and estimate the parameters of the mixture model using EM algorithm. Then, we calculate mixing ratio of noise and inclusion using these parameters to separate noise and inclusion.

• 한국자동차공학회논문집
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• 제11권3호
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• pp.7-12
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• 2003

Mixture formation in the cylinder of a lean bum engine has been observed by Laser Induced Fluorescence technique. XeCl laser (308nm) was used to produce a laser sheet. 3-pentanone has been added to iso-octane fuel to produce fluorescence, the intensity of which is proportional to the concentration of the fuel. The laser sheet was introduced through the piston window and the fuel distribution in the vertical plane was observed through a side window. Comparison has been made for the cases of selected fuel injection timing as 0, 360, 405, and 450 CA. For the case of 0 and 360 CA injection, uniform fuel distribution in the combustion chamber has been obtained at the ignition time which is favorable for the high load mode. And the late injection cases, 405 and 450 CA, revealed the stratified formation of rich mixture around the spark plug. That extends the lean misfire limit and reduces cyclic variation in the low load mode.

• 응용통계연구
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• 제24권2호
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• pp.425-433
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• 2011

Reject inference in credit scoring is a statistical approach to adjust for nonrandom sample bias due to rejected applicants. Function estimation approaches are based on the assumption that rejected applicants are not necessary to be included in the estimation, when the missing data mechanism is missing at random. On the other hand, the density estimation approach by using mixture models indicates that reject inference should include rejected applicants in the model. When mixture models are chosen for reject inference, it is often assumed that data follow a normal distribution. If data include missing values, an application of the normal mixture model to fully observed cases may cause another sample bias due to missing values. We extend reject inference by a multivariate normal mixture model to handle incomplete characteristic variables. A simulation study shows that inclusion of incomplete characteristic variables outperforms the function estimation approaches.

• 품질경영학회지
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• 제27권1호
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• pp.80-90
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• 1999

In this paper, reliability estimation using Gibbs sampler is considered for the mixture model with Gamma family, Gibbs sampler is derived to compute the features for the posterior distribution. By simulation study, the maximum likelihood estimator and the Gibbs estimator are obtained. A numerical study with a simulated data is provided.

• Journal of applied mathematics & informatics
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• 제6권2호
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• pp.661-668
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• 1999

Reliability estimation using Gibbs sampler considered for modeling mixture exponential reliability problems. Gibbs sampler is developed to compute the features of the posterior distribution. Bayesian estimation of complicated functions requires simpler esti-mation techniques due to the mathematical difficulties involved in the Bayes approach. The Maximum likelihood estimator and the Gibbs estimator of reliability of the system are derived. By simula-tion risk behaviors of derived estimators are compared. model de-termination based on relative error is considered. A numerical study with a simulated data set is provided.

• Communications for Statistical Applications and Methods
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• 제9권1호
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• pp.1-11
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• 2002

This paper discusses problems of the Poisson Mixture model which Is widely used to decide the effective words in judging relevant document. Gamma Distribution model and Gauss Patterns model as an alternative of the Poisson Mixture model are studied. Classification experiments by using TREC sub-collection, WSJ[1,2] with MGQUERY and AidSearch3.0 system are discussed.

• 정보과학회 컴퓨팅의 실제 논문지
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• 제22권11호
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• pp.567-575
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• 2016

스마트폰의 대중화로 이용자의 위치정보를 이용한 모바일 앱이 늘어나면서 위치정보에 대한 관심이 증가하고 있다. 본 논문에서는 위치정보를 이용한 사용자의 이동속도를 나타내는 간단한 분포함수를 찾고자 한다. 스마트폰에서 제공하는 위치정보는 경우에 따라 큰 오차가 발생할 수 있기 때문에 이를 제거하는 과정이 필요하다. 또한 이동속도 분포의 경우 교통수단에 따라 여러 가지 다른 분포들의 혼합분포로 표현할 수 있다. 속도의 분포함수를 찾기 위하여 혼합분포를 이용하여 꼬리부분에 해당하는 분포를 찾고 이부분을 설명할 수 있는 모수 분포모형을 찾는다.

• Communications for Statistical Applications and Methods
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• 제18권3호
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• pp.343-355
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• 2011

두 분포함수의 혼합모형을 가정한 자료에서 적절한 분류점을 찾고 평가하는 것은 중요한 문제이다. 분류정확도 측도로 많이 사용하는 아홉 종류의 MVD, Youden지수, (0,1)까지 최단기준, 수정된(0,1)까지 최단 기준, SSS, 대칭점, 정확도면적, TA, TR에 대하여 설명하고, 이 측도들의 관계를 발견하면서 정확도 측도들의 조건을 몇 개의 범주로 군집화한다. 정규혼합분포를 가정하여 군집된 측도들에 기반하는 분류점들을 구하고, 그 분류점에 대응하는 제I종 오류율과 제II종 오류율 그리고 두 종류의 오류율합을 구하여 크기를 비교하고 토론하다. 추정된 혼합분포에 대하여 어떤 분류 정확도 측도의 제I종과 II종 오류율 또는 오류율합이 최소인지를 탐색할 수 있으며 자주 인용하는 정확도 측도의 장점과 단점을 파악할 수 있다.

• 한국연소학회지
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• 제15권1호
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• pp.43-49
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• 2010

Co-combustion of syngas in an existing boiler can be one of the options for replacing conventional fossil fuel with alternative fuels such as waste and biomass. This study is aimed to investigate effects of syngas cocombustion on combustion characteristics and boiler efficiency. An experimental study was performed for a pilot-scale furnace with 4 oil burners. Tests were conducted with mixture-gas as a co-combustion fuel and heavy oil as a main fuel. The mixture-gas was composed of 15% CO, 7% $H_2$, 3% $CH_4$ and 75% $N_2$ for simulating syngas from air-blown gasification. And LHV of the mixture-gas was 890 kcal/$Nm^3$. Temperature distribution in the furnace and flue gas composition were measured for various heat replacement ratio by the mixture gas. Heat loss through the wall was also carried out through heat & mass balance calculation, in order to obtain informations related to boiler efficiency. Experimental results show that similar temperature distribution and flue gas composition can be obtained for the range of 0~20% heat replacement by syngas. NOx concentration is slightly decreased for higher heat replacement by the syngas because fuel NOx is decreased in the case. Meanwhile, heat loss is a bit decreased for higher heat replacement by the syngas, which implies that boiler efficiency can be a bit decreased when syngas co-combustion is applied to a boiler.