• Journal of Welding and Joining
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• v.21 no.3
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• pp.40-45
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• 2003

The high-speed rotating arc process forms a flat bead surface with decreased penetration depth because the molten droplets are deflected by centrifugal force. Therefore the rotating arc welding for horizontal fillet welding increases the leg length with the increase of rotation frequency and prevents the deflection of weld bead and overlap. In this study, the relationship between the welding parameters and the weld bead shape - leg length and undercut - are investigated experimentally. Consequently, the weld quality could be improved by rotating arc welding, and sound weld bead was achieved when applied to horizontal fillet welding with 4mm gap by avoiding the undercut which is inevitable for the conventional GMA welding methods.

• Speech Sciences
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• v.10 no.3
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• pp.29-36
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• 2003

The purposes of this study was to conduct a correlational analysis among $F_^{0}$, Jitter, Shimmer, and NHR (HNR), and NNE estimated by three speech analysis softwares, MDVP, Praat and Dr. Speech. Thirty females and 15 males with normal voice participated in the study. We used Sound Forge 6.0 to record their voice. MDVP, Praat and Dr. Speech were used to measure the acoustic parameters. The Pearson correlation coefficient was determined through a statistical analysis. The results came out as follows: Firstly, there was a strong correlation between $F_^{0}$ and Shimmer of both instruments. However, there was no correlation between Jitter of both instruments. Secondly, Shimmer showed a stronger correlation with HNR, NHR, and NNE than Jitter. Therefore, Shimmer was considered to be more useful and sensitive parameter to identify dysphonic voice compared to jitter.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.370-370
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• 2000

In this paper, we design a Multi-Fuzzy model by means of HCM clustering and genetic algorithms for a nonlinear system. In order to determine structure of the proposed Multi-Fuzzy model, HCM clustering method is used. The parameters of membership function of the Multi-Fuzzy ate identified by genetic algorithms. A aggregate performance index with a weighting factor is used to achieve a sound balance between approximation and generalization abilities of the model. We use simplified inference and linear inference as inference method of the proposed Multi-Fuzzy mode] and the standard least square method for estimating consequence parameters of the Multi-Fuzzy. Finally, we use some of numerical data to evaluate the proposed Multi-Fuzzy model and discuss about the usefulness.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.26 no.4
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• pp.412-419
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• 2016

The firing noise produced at artillery test range or military training ground is impulsive burst noise which energy is generated within tens of milliseconds and distributed an isolated burst of sound energy separated to one by one noise. The long range propagation of this noise is affected by a caliber of gun, amount of propellant, distance between source and receiver, ground and meteorological condition. In this paper, main influence parameters have been described based on experimental analysis of measured data. It is considered that this analysis result can be used as useful materials for study of effective firing noise management and development of propagation model.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.874-878
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• 2003

Acoustic materials are used for the purpose of absorbing noise and reducing transmission of sound into the receiving room. The purpose of this research is to predict the performance of absorbent materials with respect to absorbing behavior and transmission loss as possible as accurately. The performance of the absorbent materials are carried out systematically as follows: The Biot parameter are measured, first. Then using above parameters as input, LMS's SYSNOISE and VIOLINS programs are used to predict absorption coefficient and transmission loss values, which magnitudes are compared with experimental results. As an sample acoustic material, SK SKY VIVA and PET are selected.

• KIEAE Journal
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• v.7 no.3
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• pp.63-70
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• 2007

It is known that early reflections, their energy and delay times after the arrival of direct sound are important factors for speech intelligibility. In this basis, acoustical parameters like D50 and C80 had been proposed and are widely used for assessing the listening condition of rooms. These parameters are focused on the fraction of the early energy to the total, regardless of the spatial characteristics of the early reflections. This means that all the early reflections, arrived in certain time boundary. from front, behind, down and upside have the same impact on speech intelligibility. From the questionable simplicity, the influence of the direction of early reflections on speech intelligibility is examined in this study. A computer simulation speech intelligibility test, conducted for 22 university students, found that the reflection of vertical direction with method of the Paired comparison also the preference of 0.746 degree was visible an increase.

• Speech Sciences
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• v.8 no.1
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• pp.7-19
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• 2001

The acoustic parameters of nine Korean numbers were analyzed by Praat, a speech analysis software, and synthesized by SenSynPPC, a Klatt formant synthesizer. The overall intensity, pitch and formant values of the numbers were modified dynamically by a step of 1 dB, 1 Hz and 2.5% respectively. The study explored the sensitivity of listeners to changes in the three acoustic parameters. Twelve subjects (male and female) listened to 390 pairs of synthesized numbers and judged whether the given pair sounded the same or different. Results showed that subjects perceived the same sound quality within the range of 6.6 dB of intensity variation, 10.5 Hz of pitch variation and 5.9% of the first three formant variations. The male and female groups showed almost the same perceptual ranges. Also, an asymmetrical structure of high and low boundary was observed. The ranges may be applicable to the development of a speaker identification system while the method of synthesis modification may apply to its evaluation data.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.148-151
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• 2009

This paper presents an experimental study of deep-drawing and rubber-pad forming process using titanium alloy sheet. The process and results of the work carried out to investigate the capability of the process and to optimize th process parameters to ensure a sound forming. Room and high temperature tensile tests were carried out at various process conditions and microstructural evaluation was investigated. The experimental investigation was done using 150 ton hydraulic press to produce a deep-drawn part. Both graphite lubricant and polyethylene sheet were essential for defect-free product. Regarding the rubber-pad forming, reasonable formability was obtained only for pure-Ti not for Ti-6Al-4V.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.10a
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• pp.116-119
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• 2007

The application of light weight materials, such as aluminum alloy, has been limited due of their poor formability. Especially, aluminum alloy tube has limited expansion capability at most 15% at room temperature. New manufacturing process, called hot air forming, is introduced to apply aluminum tube to the automotive suspension components which have complex shape and require high expansion ratio about 40%. The process is carried out at the elevated temperature above $500^{\circ}C$, so numerous material properties and process parameters related to the high temperature should be investigated and determined to get a sound product. In this study, the effect of thermal properties and forming parameters such as the temperature of tool, axial feeding and gas pressure are analyzed by using explicit finite element method.

• Journal of Distribution Science
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• v.11 no.1
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• pp.7-14
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• 2013

Purpose - This study focuses on an empirical analysis of the factors affecting the behaviors of consumers who are extremely attached to branded products, and who commit themselves to renting them. Research design, data, methodology - The survey was conducted on college students enrolled in marketing classes. In total, 240 questionnaires were distributed. A total of 226 were returned. Questionnaires, excluding those that were void, were used for empirical analysis. We confirmed that the research model is sound by using a covariance structural analysis, and estimated its parameters. To estimate these parameters, a maximum likelihood method was used. Results - This study confirms that prominence and self-expressiveness positively affect brand attachment. Further, positive beliefs about, and the practicality of renting branded goods, influence attitudes toward their rental. In addition, commitment to renting branded goods is positively affected by attachment to the brand and attitude towards goods rental. Conclusions - Marketers should manage positive beliefs in and the practicability of renting branded goods, as well as the self-expressiveness and prominence of such products.