• International Journal of Reliability and Applications
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• 제5권4호
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• pp.155-162
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• 2004

A new class of life distributions is studied. This class is defined based on comparing the residual life to the whole life in the moment generating function order giving "the new better than used in the moment generating function order ageing class ($NBU_{mgf}$)". Some new results of this class are given including some closere properties and characterizations. Finally testing exponentially against the $NBU_{mgf}$ class is also addressed.

• International Journal of Reliability and Applications
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• 제7권1호
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• pp.13-25
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• 2006

A new class of life distributions is studied. This class is defined based on comparing the residual life time to the whole life in the moment generating function order giving 'the new better than used in the moment generating function order ageing class $(NBU_{mgf})$'. Fundamental properties of this class are given including some closure properties and characterizations. Finally, we consider new results about comparisons of age and block replacement policies when the underlying distribution belongs to $NBU_{mgf}$ aging classes.

• International Journal of Reliability and Applications
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• 제7권1호
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• pp.79-87
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• 2006

In this paper, some characterization results of the NBUCA class of life distributions are obtained. Behavior of the life distributions of the present class is developed in terms of the monotonicity of the residual life of k-out of-n systems given that the (n-k)th failure has occurred at time $t{\geq}0$. Similar conclusions based on the residual life of parallel system are also presented. Next, we focus upon the aging process of a system with independent but not necessarily identical NBUCA components. Finally, it is proved that if the lifetimes of a series systems with a random number of identical components have the NBUCA property then its units also have the same property.

• International Journal of Reliability and Applications
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• 제16권1호
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• pp.27-34
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• 2015

Based on increasing concave ordering a new class of life distribution is introduced. The new class of life distribution is named used better than aged in increasing concave ordering and is denoted by UBAC(2). The implication of our proposed class of life distribution with other classes is given. The properties of UBAC(2) under convolution, discrete mixture and formation of a coherent system are studied. Finally a characterization of the proposed class of life distributions by Laplace transform is discussed.

• 대한기계학회논문집
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• 제18권3호
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• pp.729-737
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• 1994

A three-dimensional finite element model of a 20-pin plastic dual-in-line package(PDIP) plugged into a PCE has been developed by using the finite element code ANSYS. The model has been used for thermal characterization of the package during its normal operation under natural convection cooling. Temperature distributions in the package and PCB are obtained from numerical analysis and compared with experimentally measured data. Various cases are assumed and analyzed to study the effects of package and PCB materials on thermal characteristics of PDIP with and without aluminum heatspreader. Thermal dissipation capability of PDIP is greatly increased due to copper die pad/lead frame and heatspreader. However, thermally induced stresses in the package and fatigue life of chip are improved for PDIP with Alloy 42 die pad/lead frame and no heatspreader. It is also found that the role of PCB on thermal characteristics of PDIP is very imporatant.

• Mycobiology
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• 제50권2호
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• pp.150-154
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• 2022

Rhytisma lonicericola was identified as a tar spot fungus on Lonicera sp. in 1902, and has since been recorded on several species of Lonicera in China, Japan, and Korea. Most of the previous records of R. lonicericola have been based on a list of disease occurrences in the absence of any formal morphological identification or molecular analyses. Using six newly obtained specimens collected in the past 2 years, we confirmed the tar spot fungus found on L. japonica in Korea as R. lonicericola based on morphological examinations and molecular phylogenetic analyses. This fungus was distinguished from R. xylostei, another tar spot fungus on Lonicera, by ascospore size and geographical distributions. We present detailed mycological information and, for the first time, DNA sequence data useful for the identification of R. lonicericola.

• 한국발생생물학회지:발생과생식
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• 제14권4호
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• pp.261-268
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• 2010

As in the O. mykiss electrophoretic profiles of RNA, the signals of each RNA sample from 9 individual tissues such as liver, muscle, brain, heart, pituitary gland, kidney, intestine, spleen and gill similar to positive control were obtained. The tissue distributions of the complimentary DNA (cDNA) of O. mykiss four genes were analyzed using quantitative real-time PCR with primer sets for tissue expression analysis. In this rainbow trout species, author obtained bands of various sizes, ranged from 700 bp to 1,400 bp. A dissociation curve was made at the end of each run to make sure that there was no non-specific amplification. Supplementarily, the Ct of each DNA was compared. The Ct values of vinculin with rainbow trout tissues were determined in a manner similar to those for agouti-related protein (AgRP) and melanocortin receptors (MC4R I and MC4R II). Further, obtained Cts for standard curve of each DNA were affected by specific product (vinculin, AgRP and MC4R II genes). After several experiments with four individual genes of rainbow trout, author estimated a variation ratio of the mean Ct value of the DNA extracted using the comparative CTt method was 37.27, and the standard deviation was 5.33. The correlation coefficient between the Ct values and the concentration of cDNA was -0.98, -0.99, -0.91 and -0.86, respectively (vinculin, AgRP, MC4R I and MC4R II genes). Since this correlation showed high linearity, the straight line obtained was used as a standard for the O. mykiss tissues reared in aquarium. A PCR efficiency of 100% is ideally achieved when the slopes are close to the theoretical value of -3.31. According to quantification method, the results of quantification are strongly affected by the DNA fragmentation. The size of most DNA fragments obtained from various tissues of rainbow trout used in the experiment was approximately 100 bp. According to the four slopes, an efficiency of nearly 100% was estimated for four genes detection methods. Additionally, further analysis with more individuals and primers will be required to fully establish optimization in rainbow trout.

• 환경위생공학
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• 제14권4호
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• pp.85-92
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• 1999

Indoor air quality tends to be the dominant contributor to personal exposure because most people spend over 90% of their time indoors. For some contaminants, exposure to indoor air poses a potentially greater health threat than outdoor air exposures. Indoor nitrogen dioxide ($NO_2$) levels are mainly affected gas range, flue gas spillage, kerosene heaters, wood-burning appliances and cigarette smoke. In addition, indoor $NO_2$ levels are influenced by such house characterization as surface reaction and air exchange rate. In this study, the measurements of indoor and outdoor $NO_2$ concentrations were taken using identical protocols, and information was collected on housing characteristics using identical questionnaires in 14 houses out of 15 houses for daily 30 daily 30 days in Brisbane, Australia.The usage of gas range was the most contributing factor in indoor $NO_2$ concentration in relation to house characteristics. Average indoor and outdoor ratios of NO2 concentration in electronic and gas cooking houses were $0.6{\pm}0.1$ and $0.9{\pm}0.2$, respectively. The frequency distributions of $NO_2$ concentration in each house were approximately log-normal Geometric mean of indoor $NO_2$ concentrations of electronic and gas cooking houses for daily 30 days ranged from 2.5 ppm to 11.5 ppm with a mean 6.8 and from 4.7 ppm to 28.6 ppm with a mean 15.6 ppm, respectively. The $NO_2$ concentrations between electronic and gas cooking houses were significantly different (p<0.05). Since each house has different life-style and house characteristics, sampling interval to measure the $NO_2$ levels was recommended above 7 days.

• 생명과학회지
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• 제27권3호
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• pp.275-282
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• 2017

부산지역 급성호흡기감염증으로 내원한 환자에서 호흡기바이러스 검사를 시행하여 아데노바이러스 및 보카바이러스의 특징적인 임상증상 및 유행양상을 알아보고자 하였다. 3,230명의 환자에서 총 1,485건(46.0%)의 호흡기바이러스가 검출되었고 이 중 아데노바이러스 257건(8.0%), 보카바이러스 68건(2.1%)을 확인하였다. 성별 발생양상은 남자가 여자보다 아데노바이러스, 보카바이러스로 인한 호흡기감염증에 취약하였으며, 모두 1~5세 연령군에서 높은 검출률을 보여 영 유아의 주요 감염요인임을 확인할 수 있었다. 주요 임상증상으로 아데노바이러스는 발열, 두통이 보카바이러스는 천명음이 통계적으로 유의하였다. 아형분석결과, 아데노바이러스는 1~6, 8형의 혈청형을 확인하였고 기존 분리주와 97% 이상의 상동성을 보였다. 연도별 유행 혈청형은 2011년 아데노바이러스 1형, 2012년 3형과 4형, 2013년에는 3형이 우점적으로 유행하였다. 아데노바이러스 3형의 경우, 대유행을 유발하는 아형으로 보인다. 보카바이러스는 모두 1형으로 나타났다.