• 대한후두음성언어의학회지
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• 제13권1호
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• pp.45-51
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• 2002

The purpose of this study is to examine the effects of vowel type on the nasalance score. Twenty one male adults without VPI produced 5 types of vowels (/a/, /e/, /i/, /o/, /u/) in two conditions-normal and simulated VPI condition. Nasalance scores were measured for each vowel. These data were compared between conditions and among vowel types. The results were as follow : For all vowels, nasalance scores were significantly higher in simulated VPI condition than in normal condition. The two conditions yielded different patterns in terms of the degree of nasalance across the 5 vowels. In normal condition, nasalance scores were higher in front vowels than in medial or back vowels. But in simulated VPI condition, nasalance scores were higher in high vowels than in mid or low vowels.

• Tribology and Lubricants
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• 제14권3호
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• pp.74-80
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• 1998

The morphologies of the wear particles are directly indicative of wear process occuring in the machine. The analysis of wear particle morphology can therefore provide very early detection of a fault and can also ofen facilitate a dignosis. For this work, the neural network was applied to identify friction coefficient through four shape parameters (50% volumetric diameter, aspect, roundness and reflectivity) of wear debris generated from the machine. The averages of these parameters were used as inputs to the network. It is shown that collect identification of friction coefficient depends on the ranges of these shape parameters learned. The various kinds of the wear debris had a different pattern characteristics and recognized relation between the friction condition and materials very well by neural network. We discuss how the network determines difference in wear debris feature, and this approach can be applied for machine condition monitoring and fault diagnosis.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제23권1호
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• pp.19-30
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• 2019

In this paper, we develop an accurate explicit finite difference method for the two-dimensional Black-Scholes equation with a hybrid boundary condition. In general, the correlation term in multi-asset options is problematic in numerical treatments partially due to cross derivatives and numerical boundary conditions at the far field domain corners. In the proposed hybrid boundary condition, we use a linear boundary condition at the boundaries where at least one asset is zero. After updating the numerical solution by one time step, we reduce the computational domain so that we do not need boundary conditions. To demonstrate the accuracy and efficiency of the proposed algorithm, we calculate option prices and their Greeks for the two-asset European call and cash-or-nothing options. Computational results show that the proposed method is accurate and is very useful for nonlinear boundary conditions.

• Structural Monitoring and Maintenance
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• 제8권4호
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• pp.361-378
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• 2021

While the pavement rating system is being utilized for periodic road condition assessment in the Eastern Region municipality of Saudi Arabia, the condition assessment is costly, time-consuming, and not comprehensive as only few parts of the road are randomly selected for the assessment. Thus, this study is aimed at developing a condition assessment model for a specific sample of a residential road network in Dammam City based on an individual road and a road network. The model was developed using the Analytical Hierarchy Process (AHP) according to the defect types and their levels of severity. The defects were arranged according to four categories: structure, construction, environmental, and miscellaneous, which was adopted from sewer condition coding systems. The developed model was validated by municipality experts and was adjudged to be acceptable and more economical compared to results from the Eastern region municipality (Saudi Arabia) model. The outcome of this paper can assist with the allocation of the government's budget for maintenance and capital programs across all Saudi municipalities through maintaining road infrastructure assets at the required level of services.

• International Journal of Automotive Technology
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• 제7권6호
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• pp.757-762
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• 2006

Reliability of automotive parts has been one of the most interesting fields in the automotive industry. Especially, a small DC motor was issued because of the increasing adoption for passengers' safety and convenience. For several years, small DC motors have been studied and some problems of a life test method were found out. The field condition was not considered enough in the old life test method. It also needed a lot of test time. For precise life estimation and accelerated life test, new life test procedure was developed based on measured field condition. The vibration condition on vehicle and latent force on fan motor shaft were measured and correlated with each other. We converted the acceleration data into the load data and calculated the equivalent load from integrated value. We found the relationship which can be used for accelerated life test without changing the severity by using different loading factors.

• International Journal of Fluid Machinery and Systems
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• 제5권4호
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• pp.143-151
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• 2012

Predicting the future condition of machine and assessing the remaining useful life are the center of prognostics. This paper contributes a new prognostic method based on grey model and survival probability. The first step of the method is building a normal condition model then determining the error indicator. In the second step, the survival probability value is obtained based on the error indicator. Finally, grey model coupled with one-step-ahead forecasting technique are employed in the last step. This work has developed a modified grey model in order to improve the accuracy of prediction. For evaluating the proposed method, real trending data of low methane compressor acquired from condition monitoring routine were employed.

• 동력기계공학회지
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• 제13권1호
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• pp.53-58
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• 2009

The emergency diesel generator(EDG) of the nuclear power plant is designed to supply the power to the nuclear reactor on Station Black Out(SBO) condition. The operation reliability of onsite emergency diesel generator should be ensured by a conditioning monitoring system designed to monitor and analysis the condition of diesel generator. For this purpose, we have developing the technologies of condition monitoring for the wolsong unit 3&4 standby diesel generator including diesel engine performance. In this paper, technologies of condition monitoring for the wolsong standby diesel generator are described about three step. First is for selection of operating parameter for monitoring. Second is for technologies of online condition monitoring, Third is for monitoring of engine performance.

• Asian-Australasian Journal of Animal Sciences
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• 제13권4호
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• pp.435-439
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• 2000

Records of weight, age, body condition at calving and udder characteristics scores of 425 beef cows and birth weights and periodical weights of their offspring from birth to weaning were analyzed to study the effect of body weight, condition and udder characteristic scores of dams on birth weight and Preweaning growth of their offspring. Dam's body condition (fat reserve) at calving were scored on a scale of 1 to 5 (1=extremely thin and 5=extremely fat) and dam's udder characteristics were scored on a scale of 1 to 7 (l=udder well attached with small teats and 7=at least one quarters not functional). Dams were from three distinct breed groups and were mated in single sire mating groups within each breed group for 45 days. Within each breed group and year, the dams were classified into high, medium and low based on their weights at the time of parturition. The data were analysed using covariance analysis. In general, calves born to heavier dams were heavier at birth and had higher rate of Preweaning growth. The effect of dam's body condition score on the calf birth weight was not significant. However, cows with average body condition score of 2.5 or 3.0 gave birth to calves that had higher pre weaning growth rates up to weaning than those born to calves with higher body condition score. The udder characteristics score did not affect calf birth weight as expected; however, cows with udder score of 3 (udder well attached with large teats) produced calves with higher preweaning growth rate than those with smaller teats. Based on the results, it can be concluded that maintaining animals with average body condition and weight would result in more efficient calf production. In addition, cows with well attached udder and large teats would provide a better maternal environment for Preweaning growth rates of their calves.

• 한국항공운항학회지
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• 제22권4호
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• pp.56-64
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• 2014

There were a total of 65 accidents of helicopers between 1990 and 2013. The overall accidents rate has remained around 8 accidents per 100,000 flight hours, and the fatal rate has stayed at about 8 accidents per 100,000 flight hours. In this study, we conduct a series of statistical analyses to investigate the significance of latent failure of groups that operate the helicopter. Analysis of variance demonstrated significant differences in the latent condition score for the 3 groups, with the lower accidents rate groups reporting better scores of latent condition. Results indicated that there are the significant differences of latent condition in accidents between groups of high accidents rate and groups of low accidents rate.

• 펄프종이기술
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• 제31권2호
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• pp.50-57
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• 1999

This study was carried out to compare a conventional alkaline flotation deinking conditions with neutral deinking conditions with and without enzyme addition with respect to the ink removal efficiency and theflotation deinking filtrate quality such as chemical oxygen demand, cationic demand, suspended solids. Based on ink removal rate the neutral deinking condition without enzyme was better than the alkaline deinking condition, and the neutral deinking with enzyme addition turned out to be the best. The brightness of the deinked pulp was found to be the same trend as the ink removal rate. Flotation reject rate for the neutral deinking condition without enzyme was higher than that of the alkaline deinking condition, but that of the neutral deinking condition with enzyme was lower than that of the alkaline and the neutral deinking condition without enzyme. On the freeness of the deinked pulp, the neutral deinking condition with enzyme had the highest value and the alkaline deinking condition had the lowest value among the conditions tested. On the filtrate of the flotation stage, the cationic polymer demand of the neutral deinking condition with enzyme was much lower than the other conditions. Suspended solids and chemical exygen demand for the neutral flotation deinking filtrate was lower than those of the alkaline flotation deinking filtrate.