• Speech Sciences
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• v.15 no.3
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• pp.39-51
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• 2008

Formant measurements are one of the most important factors to objectively test cross-linguistic differences among vowels produced by speakers of any given languages. However, many speech analysis softwares present erroneous estimates and some researchers use them without any verification procedures. The purposes of this paper are to examine formant measurements of complex waves which were synthesized from the average formant values of five Korean vowels using three default methods in Praat and to verify the measured values of the five vowels produced by 20 students using one of the methods. Variances along the time axis are discussed after determining absolute difference sum from the 1/3 vowel duration point. Results show that there were smaller measurement errors by the burg method. Also, greater errors were observed in the sl or lpc methods mostly caused by the inappropriate formant settings. Formant measurement deviations were greater in those vowels produced by the female students than those of the male students, which were mostly attributed to the settings for the vowels /o, u/. Formant settings can best be corrected by changing the number of formants to the number of visible dark bands on the spectrogram. Those results suggest that researchers should check the validity of the estimates from the speech analysis software. Further studies are recommended on the perception test of the original sound with the synthesized sound by the estimated formant values.

• Journal of the Korean Society of Visualization
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• v.3 no.2
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• pp.71-78
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• 2005

Uncertainty introduced by a cross-correlation algorithm based on FFT has been investigated using PIV standard images. The standard images were generated by the Monte Carlo simulation method. Both bias and random errors from the velocity vector have been analyzed with regard to the particle diameter, displacement, and the number of particles. The uncertainty of velocity is evaluated based upon the IS0/IEC standard. As a result, a total error of $0.26\%$ is included in the PIV cross-correlation algorithm. In addition, the uncertainty budget is presented, where the effect of the above three variables is examined. According to the budget, the variation of the number of particles within the interrogation window mainly contributes to the combined standard uncertainty of the real measured velocity field when excluding the effect of errors by the experiments itself. Finally, the expanded uncertainty is found to be about $12\%$ at the $95\%$ confidence level.

• Journal of the Korean Dietetic Association
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• v.21 no.1
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• pp.25-36
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• 2015

In this study, we attempted to improve hospital food delivery service quality and customer satisfaction by using FMEA (Failure Mode and Effect Analysis), which is applied to the quality control of products in manufacturing plants. Subjective food delivery service quality improvement was judged based on a 5-point likert scale. Traditional FMEA uses an RPN (Risk priority number) to evaluate the risk level of a component or process. The RPN index was determined by calculating the product of severity, occurrence, and detection indexes. In our results, total RPN value (P<0.01) significantly decreased after FMEA introduction, whereas customer satisfaction (P<0.001) and food delivery service quality (P<0.001) significantly increased. Specifically, foodservice errors (P<0.01) and loss cost (P<0.01) were significantly improved by FMEA introduction. Taken together, we suggest that FMEA reduces critical activities and errors in foodservice delivery caused by simple priority selection.

• KIPS Transactions on Software and Data Engineering
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• v.2 no.6
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• pp.369-376
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• 2013

Finance Information System is critical national infrastructure. Therefore it is important to select variables of defect causal factor for the system defect management effectively. We research and analyze detected errors in A Company's Finance Information System for three years. In the result of research and analysis, we have selected 9 variables of defect factor: the trading volume, the fluctuation of KOSDAQ index, and the number of public announcements, etc. Then we have assumed that these variables affect real system errors and analyzed correlation between the hypothesis and the detected system errors. After analyzing, we have extracted the trading volume, the number of orders and fills, changing tasks, and the fluctuations of NASDAQ index as valid variables of defect factor. These variables are proposed for failure prediction model as the variables to manage defects in the finance information system afterward.

• ETRI Journal
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• v.42 no.5
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• pp.700-711
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• 2020

Because of the rapid increase of mobile traffic, flexible broadband supportive unmanned aerial vehicle (UAV)-based 6G mobile networks using free space optical (FSO) links have been recently proposed. Considering the advancements made in UAVs, big data processing, and artificial intelligence precision control technologies, the formation of an additional wireless network based on UAV aerial platforms to assist the existing fixed base stations of the mobile radio access network is considered a highly viable option in the near future. In this paper, a combined time bound optimization scheme is proposed that can adaptively satisfy the control and communication time constraints as well as the processing time constraints in FSO-based 6G UAV aerial networks. The proposed scheme controls the relation between the number of data flows, input data rate, number of worker nodes considering the time bounds, and the errors that occur during communication and data processing. The simulation results show that the proposed scheme is very effective in satisfying the time constraints for UAV control and radio access network services, even when errors in communication and data processing may occur.

• 재활복지
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• v.20 no.4
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• pp.229-246
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• 2016

The aim of this study is to conduct superordinate word selection task to compare their performance and reaction time, and superordinate word writing task to compare the differences in their performance and error pattern in 40 elderly adults and 43 young adults. As a result, first, in both tasks, elderly adults had a smaller number of correct responses. Second, elderly adults showed slower reaction time than young adults. Third, in superordinate word writing task, elderly adults showed more relevant errors than irrelevant errors. The reason elderly adults had a smaller number of correct responses in both tasks was that the links among the pieces of information in the semantic lexicon weakened or deteriorated due to normal aging. Slower reaction time was based on neurophysiological changes of the brain and cognitive processing speed. In addition, the relevant errors showed that they could access the lexicon for target words and produce explanation the relevant characteristics, even though they could not retrieve the target words.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.6 s.165
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• pp.988-1000
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• 1999

An experimental study is presented for the effect of number of terms of a pewee series type stress function on stress analysis around a hole in tensile loaded plate. The hybrid method coupling photoelastsic data inputs and complex variable formulations involving conformal mappings and analytical continuity is used to calculate tangential stress on the boundary of the hole in uniaxially loaded, finite width tensile plate. In order to measure isochromatic data accurately, actual photoelastic fringe patterns are two times multiplied and sharpened by digital image processing. For qualitative comparison, actual fringes are compared with calculated ones. For quantitative comparison, percentage errors and standard deviations with respect to percentage errors are caculated for all measured points by changing the number of terms of stress function. The experimental results indicate that stress concentration factors analyzed by the hybrid method are accurate within three percent compared with ones obtained by theoretical and finite element analysis.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.171-174
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• 2006

A large number of service providers in countries all over the world have established GNSS reference station networks in the last years and are using network software today to provide a correction stream to the user as a routine service. In current GNSS network processing, all the geometric related information such as ionospheric free carrier phase ambiguities from all stations and satellites, tropospheric effects, orbit errors, receiver and satellite clock errors are estimated in one centralized Kalman filter. Although this approach provides an optimal solution to the estimation problem, however, the processing time increases cubically with the number of reference stations in the network. Until now one single Personal Computer with Pentium 3.06 GHz CPU can only process data from a network consisting of no more than 50 stations in real time. In order to process data for larger networks in real time and to lower the computational load, a federated filter approach can be considered. The main benefit of this approach is that each local filter runs with reduced number of states and the computation time for the whole system increases only linearly with the number of local sensors, thus significantly reduces the computational load compared to the centralized filter approach. This paper presents the technical aspect and performance analysis of the federated filter approach. Test results show that for a network of 100 reference stations, with the centralized approach, the network processing including ionospheric modeling and network ambiguity fixing needs approximately 60 hours to process 24 hours network data in a 3.06 GHz computer, which means it is impossible to run this network in real time. With the federated filter approach, only less than 1 hour is needed, 66 times faster than the centralized filter approach. The availability and reliability of network processing remain at the same high level.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1077-1083
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• 2011

Turnout is one of railroad track components. The turnout is used to change train routes to near other sections when keeping the train speed. There are many accidents in the section including the turnout. The number of accidents and errors is 363 for ten years in the section including the turnout and annual average is 36.3. To ensure safety of the turnout, it is necessary to install monitoring systems. By using the monitoring systems, it is able to accumulate related information, develop maintenance and take a step for accidents in advance. Hence, The number of accidents and errors is decreased in the section including the turnout. So, when new turnout is installed, it is needed to use monitoring systems. Therefore, combined turnout management system is needed in Korea. It is possible to perform efficient maintenance because real-time monitoring system by using sensors and data-base management system. In this paper, accidents in the section including domestic turnout are analyzed and foreign combined turnout management system is presented. Hence, articles for installing the combined turnout management system in Korea are proposed.

• The Transactions of the Korea Information Processing Society
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• v.4 no.5
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• pp.1267-1276
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• 1997

In this paper, the optimal model for specific test data was selected autimatically among sofware reliability growh models bassed on NAPP(Non Homogeneous Posission Preocess), and in result the tool for the reliability estimating scales was implemented.Whith the implemented tool, software optimal rekiability estimating scales(total expected number errors, error detection rate, expected number of errors remaining in the sortware, reliability, ete) could be predicted. By the reliability estimating scales gained form this, sofware development and projecr management could be applied. In order to test the optimal of the implemented tool, the comparicon with other paper and analization was done by using actual error data.