• 한국환경보건학회지
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• 제24권1호
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• pp.112-119
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• 1998

The objective of this study was to investigate the effect of bulking agents including cow manure, saw dust and rice straw in the ripening of leather sludge for vermistabilization. The changes of the waste properties for ripening time for 50 days were observed according to the various mixture ratios of leather sludge and bulking agents. The pH values of the mixture wastes were decreased from 7.5-8.0 to 6.4-7.3 with the ripening time for 50 days, and it was indifferent of the mixture ratio and type of the bulking agent. The initial value of oxidation-reduction potential(Eh) of the mixture waste was a negative(-)value indicating an unfavorable condition for earthworm life, but the values of Eh were increased with the ripening time. The increase rate of Eh value was proportional to the mixture ratio of bulking agents, but the increase rate for saw dust was higher than that of the cow manure and the rice straw. The value of alkalinity was also changed into the favorable range for earthworm after 50 days except for 10% of the mixture ratio of the bulking agents. When the mixture ratios of the bulking agents were increased from 10% to 40%, the growth characteristics of earthworms were increased from 31.7% to 95% for the survival rate, 103% to 225% for the liveweight increase rate and 32% to 91% for hatching rate of the cocoons. It can be concluded that the proper content of the bulking agents in the leather sludge to ensure effective vermistabilization was over 30%, when the mixture was ripened during 50 days. The contents of heavy metals in the ripened sludge were lower than the other regulatory standards for compost.

• International Journal of Reliability and Applications
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• 제6권2호
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• pp.101-115
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• 2005

This article provides a new class of multivariate linear failure rate distributions where every component is a mixture of linear failure rate distribution. The new class includes several multivariate and bivariate models including Marslall and Olkin type. The approach in this paper is based on the introducing a linear failure rate distributed latent random variable. The distribution of minimum in a competing risk model is discussed.

• Journal of Pharmaceutical Investigation
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• 제20권4호
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• pp.193-198
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• 1990

To increase the dissolution rate of furosemide, cogrinding or coprecipitating of furosemide with povidone was carried out. The ground mixture of furosemide with povidone was prepared by cogrinding in a ceramic ball mill and the coprecipitate was prepared by solvent method using methanol. The povidone ground mixture and the coprecipitate showed a faster and more enhanced dissolution rate than the physical mixture or intact furosemide. The IR, DTA and TGA studies showed the physicochemical modifications of furosemide from the ground mixture and the coprecipitate. An interaction, in the ground mixture and in the coprecipitate, such as association between the functional groups of furosemide and povidone might occur in the molecular level. The coprecipitating and cogrinding techniques with povidone provided a promising way to increase the dissolution rate of poorly soluble drugs.

• 한국조경학회지
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• 제23권2호
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• pp.113-123
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• 1995

This study was conducted to find out appropriate rates of seed mixture of both native and foreign plants in order for stabilization of early afforestation and proper vegetation on road slope. The results are summarized as follows: 1. Characteristics of germination : After seeding, 2 weeks for both Lespedeza bicolor and Lespedeza cuneata, and 4 weeks for both Arundinella hirta and Zoysia japonica were needed for vigorous germination, and 1-4 wee17s for 3 cool-season grasses were spent for gradual germination. 2. Plant height : There was no difference between Lespedeza cuneata and Lespedeza bicolor in plant height by 7 treatments. As mixture rates of cool-season grasses were lowered, plant height of Arundinella hirta became longer. Descending order of co81-season grasses for plant height was Tall fescue, Perennial ryegrass and Creeping redfescue. 3. Number of tillers : The number of tillers tended to increase in the experimental plots where competition was low. 4 Ground cover rate : Ground cover rate was the highest in Mixture IV (96.7%) and was fluctuated from 13.3% on Sept. 13 to 45% on Nev. 3 in Mixture III. Descending order of gronud cover rates in 7 treaments was Mixture IV, Mixture III. Mixture II, Mixture Ⅶ, Mixture V, Mixture Ⅵ, Mixture I, and Mixtur III when measured on Oct. 13 5. Visual assessment: High preferences were observed on Mixture IV and Ⅶ In sun the best seed mixtures were Mixture IV and Ⅶ. It meant that (1) either mixture of 70% the native plants with 30% cool-season graaes or (2) mixture of 80% the native plants with 20% cool-season glasses was best for this study.

• 디지털융복합연구
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• 제13권10호
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• pp.219-224
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• 2015

본 연구는 우리나라 가계저축률의 정규분포혼합을 추정한다. 2014년 마이크로데이터인 MDSS를 이용하였고 추정방법으로는 깁스알고리즘을 이용하였다. 실증분석결과의 주요내용은 다음과 같다. 첫째, 정규분포혼합을 추정하기 위한 방법으로 깁스알고리즘은 잘 작동하였다. 즉 주요 모수추정치는 모두 정상적 분포를 갖는 것으로 나타났다. 둘째 저축률 자료는 적어도 2개의 성분, 즉 저축률이 평균 0%인 성분과 평균 29.4%인 성분으로 이루어져 있는 것으로 보인다. 즉 우리나라의 가계는 고저축률 집단과 저저축률 집단으로 나누어질 수 있다는 뜻이다. 셋째 정규분포혼합모형 자체는 어떤 가계가 첫째 성분 또는 둘째 성분에 속하는가를 설명할 수 없다. 이에 본 연구는 추가적인 분석을 수행하였지만 소득수준과 가구주 연령은 이에 대한 설명력을 지니지 못하는 것으로 판단된다.

• 전기학회논문지
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• 제66권3호
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• pp.500-506
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• 2017

In 2014, ISO 55000s has been enacted and the power plant asset management is becoming a hot issue for all over the world. The asset management system is being developed as a combination of CBM(Condition Based Maintenance) and RCM(Reliability Centered Maintenance). Therefore, the research on the calculation of the failure rate which is the most basic index of RCM is actively carried out. The failure rate calculation has been going on for a long time, and the most widely used probability distribution is the Weibull distribution. In the Weibull distribution, the failure rate function is determined in three types according to the value of the shape parameter. However, the Weibull distribution has a limitation that it is difficult to apply it when the trend of failure rate changes-such as bathtub curves. In this paper, the failure rate is calculated using the mixture Weibull distribution which can appropriately express the change of the shape of the failure rate. Based on these results, we propose the necessity and validity of applying mixture Weibull distribution.

• 한국농공학회지
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• 제42권5호
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• pp.125-132
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• 2000

This study was performed to evaluate the physical properties of reinforced soil mixture powder. Soil sample was prepared by passing into the standard sieve of No. 200 and reinforcement materials were calcium carbonate, quicklime and portland cement. Fineness, setting time, and compressive strength test for reinforced soil mixture powder were performed and analyzed to investigate their physical properties. The main results were summarized as follow. The compressive strength of soil mixture powder itself and most reinforced was reinforced according to increasing in the mixture rate of reinforcement and the rate of increase was remarkably higher in the cement reinforced soil moisture powder. It was appeared that the early compressive strength is considering higher in the cement reinforced soil moisture powder with 2% of moisture rate of accelerator.

• Journal of Pharmaceutical Investigation
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• 제16권1호
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• pp.36-41
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• 1986

The ground mixtures of ketoprofen with chitin or chitosan were prepared by grinding in a ball mill to increase the dissolution rate. The ground mixture showed a faster and more enhanced dissolution rate than the physical mixture or intact ketoprofen. The X-ray diffraction peaks indicated the production of the amorphous form of ketoprofen in the ground mixture. An interaction, in the ground mixture, such as association between the functional groups of ketoprofen and chitin or chitosan might occur in the molecular level. The endothermic peak due to the fusion of ketoprofen disappeared in the ground mixture indicating the different thermal property. The co-grinding technique with chitin or chitosan provided a promising way enhancing the dissolution rate of practically insoluble drug.

• 한국초지조사료학회지
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• 제12권4호
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• pp.211-217
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• 1992

This experiment was conducted over a 3-year period (1990-1992) to evaluate the production and quality of orchardgrass (Potomac)-red clover (Kenland) mixture when orchardgrass + red clover mixture was sown at seed rates of 20+0. 18+2, 16+4, 14+6 and 12+8 kg/ha. Total herbage dry matter, crude protein and digestible organic matter production and organic matter intake were markedly affected by increasing rcd clover seed rate, those increased with increasing red clovcr seed rate due to the cnhancernent of red clover percentage of total herbagc in all 3-year. but significant differences occured between the orchardgrass alone and orchardgrass-red clover mixture with a seed rate of 4,6 and 8 kg/ha red clover (P<0.01). But on the other hand increasing red clover seed rate increased red clover percentage in total herbage, the mean red clover percentage of total herbage at the last cutting ranged from 54 to 65% in first year. 58 to 60% in second year, and 62 to 69% in third year, particularly it was observed that red clover was sown at seed rates of 6 and 8 kg/ha for red clover sown dominated strongly as the cutting times were progressed. Considering the maintenance of good botanical composition balance and the enhancement of production and quality of herbage, the optimized seed rate for orchardgrass-red clover mixtures, 16 kg/ha orchardgrass and 4 kg/ha red clover seems to be considered adequate.

• 한국전기전자재료학회논문지
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• 제17권3호
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• pp.299-304
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• 2004

In recent years, silicon carbide has emerged as an important material for MEMS application. In order to fabricate an SiC film based MEMS structure by using chemical etching method, high operating temperature is required due to high chemical stability Therefore, dry etching using plasma is the best solution. SiC film was deposited by thermal CVD at the temperature of 100$0^{\circ}C$ and pressure of 10 torr. SiC was dry etched with a reactive ion etching (RIE) system, using SF$_{6}$/O$_2$ and CF$_4$/O$_2$ gas mixture. Etch rate has been investigated as a function of oxygen concentration in the gas mixture, rf power, working pressure and gas flow rate. Etch rate was measured by surface profiler and FE-SEM. SF$_{6}$/O$_2$ gas mixture showed higher etch rate than CF$_4$/O$_2$ gas mixture. Maximum etch rate appeared at RF Power of 450W. $O_2$ dilute mixtures resulted in an increasing of etch rate up to 40％, and the superior anisotropic cross section was observe