• Phonetics and Speech Sciences
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• v.1 no.2
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• pp.85-94
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• 2009

The purpose of this study was to see the effects of pitch and length patterns on spoken word recognition. In Experiment 1, a syllable monitoring task was used to see the effects of pitch and length on the pre-lexical level of spoken word recognition. For both Seoul dialect speakers and Daegu dialect speakers, pitch and length did not affect the syllable detection processes. This result implies that there is little effect of pitch and length in pre-lexical processing. In Experiment 2, a lexical decision task was used to see the effect of pitch and length on the lexical access level of spoken word recognition. In this experiment, word frequency (low and high) as well as pitch and length was manipulated. The results showed that pitch and length information did not play an important role for Seoul dialect speakers, but that it did affect lexical decision processing for Daegu dialect speakers. Pitch and length seem to affect lexical access during the word recognition process of Daegu dialect speakers.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.1
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• pp.43-48
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• 2013

In this study, the performance of an impeller according to blade length and pitch angle was studied experimentally by building a variable pitch impeller while changing blade length to review the effect of blade length and pitch angle on a fan's performance. The pitch angle was changed in six steps from $20^{\circ}{\sim}45^{\circ}$ at intervals of $5^{\circ}$ while the blade lengths were changed to 90 mm, 100 mm, 110 mm and 120 mm with an identical airfoil shape while carrying out the experiment. The results are summarized as follows: The air flow per static pressure of axial fans increased linearly with increase of pitch angle, but the high static pressure showed a decrease at a pitch angle of $35^{\circ}$. The shaft power increased proportionally to the pitch angle at all blade lengths; the larger the pitch angle, the larger the measured increase of shaft power. This is because the drag at the fan's front increases with the pitch angle. In the axial fans considered in this research, the flow and increase of static pressure amount increased up to a pitch angle of $30^{\circ}$ but decreased rapidly above $35^{\circ}$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.7
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• pp.3170-3176
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• 2013

In this study, the performance of an impeller according to blade length and pitch angle was studied experimentally by building a variable pitch impeller while changing blade length to review the effect of blade length and pitch angle on a fan's performance and sound characteristics. The pitch angle was changed in six steps from $20^{\circ}{\sim}45^{\circ}$ at intervals of $5^{\circ}$ while the blade lengths were changed 80 mm, 90 mm, 100 mm, 110 mm and 120 mm with an identical airfoil shape while carrying out the experiment.

• Journal of Biosystems Engineering
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• v.26 no.2
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• pp.177-188
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• 2001

This research was carried out to examine the optimum design conditions of a vertical small-scale milling machine where the rough rice is processed directly into the white rice in one pass. Effects of the main spindle speed, feed screw pitch and ceramic coating length of the roller on various milling characteristics such as white rice processing capacity, electric energy consumption, rice temperature increase, broken rice ratio, moisture reduction, outlet force and crack ratio increase were studied. The results are as follows. 1. The maximum white rice processing capacity and the lowest crack ratio increase, were obtained from a machine with specification: main spindle speed of 970rpm having a feed screw pitch of 19㎜. 2. The minimum electric energy consumption was obtained with the main spindle speeds of 900 and 970rpm respectively having a feed screw pitch of 19㎜. 3. The rice temperature was increased as the feed screw pitch decreased and the main spindle speed increased. 4. Broken rice ratio was relatively low with the range of 0.8∼1.3%. 5. Moisture content loss was with the range of 0.05∼0.4%. 6. The highest outlet force was 0.72kg$\_$f/ with 900rpm of the main spindle speed and 19㎜ of the feed screw pitch and the lowest outlet force was 0.18∼0.34kg$\_$f/ with 970rpm of the main spindle speed and 16㎜ of the feed screw pitch. 7. The optimum design conditions for the vertical small-scale milling machine were obtained at 970rpm of the main spindle speed, 19㎜ of the feed screw pitch and 20㎜ of the ceramics coating length.

• Phonetics and Speech Sciences
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• v.2 no.3
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• pp.11-22
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• 2010

The present study attempts to investigate declination in Korean and its relevant aspects to the length of utterance, the clause boundary, and focus. More specifically, I examine the relation of declination with the length of utterance, the declination reset at the clause boundary, and the effect of focus on declination. Results showed that the length of utterance had no relation with the first and last pitch values of the utterance but that they were consistent regardless of the length of utterance. However, the declination slope changed to be relatively gentle from the fourth accentual phrase to the end of the whole intonational phrase. There was a reset of declination in such a way that the first pitch in the second phrase was always lower than that of the first phrase, but the first pitch in the third phrase was not always lower than that of the second phrase when the whole utterance was composed of three phrases. Finally, the pitch values of the focusing words decreased as their position went back in a sentence. One declination line was formed in the case of focused utterance, but in the case of an utterance that contained a clause boundary, a new declination line was formed at the start of each new clause. These findings can be applied to developing a Korean speech synthesizer that contains natural prosody; they can be also utilized for teaching Korean prosody.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.7
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• pp.377-385
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• 2013

In this study, the performance of an impeller according to blade length and pitch angle was studied experimentally by building a variable pitch impeller while changing blade length to review the effect of blade length and pitch angle on a fan's performance. The pitch angle was changed in six steps from $20^{\circ}{\sim}45^{\circ}$ at intervals of $5^{\circ}$ while the blade lengths were changed to 90 mm, 100 mm, 110 mm and 120 mm with an identical airfoil shape while carrying out the experiment. The results are summarized as follows : The air flow per static pressure of axial fans increased linearly with increase of pitch angle, but the high static pressure showed a decrease at a pitch angle of $35^{\circ}$. The shaft power increased proportionally to the pitch angle at all blade lengths; the larger the pitch angle, the larger the measured increase of shaft power. This is because the drag at the fan's front increases with the pitch angle. In the axial fans considered in this research, the flow and incre.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.2
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• pp.94-104
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• 2013

A numerical analysis has been conducted to determine the pitch thrust vectoring characteristics of a two-dimensional convergent divergent exhaust nozzle for supersonic aircraft application. The numerical analysis was done by using Fluent and verified by the experimental test results. Analysis was performed with pitch angle of $0^{\circ}$ and $20^{\circ}$ each at the ambient temperature condition. To see the effect of a ratio of pitch flap length and pitch flap height, the ratio was varied from 0.5 to 2.5. The numerical analysis shows that pitch thrust is changed greatly with pitch flap length. The big difference of the pitch thrust with pitch flap length is due to the shock interactions in the nozzle.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.264-267
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• 2003

Pitch measurements of 150 nm pitch one-dimensional grating standards were carried out using an contact mode atomic force microscopy(C-AFM) with a high resolution three-axis laser interferometer. It was called as 'Nano-metrological AFM' In Nano-metrological AFM, Three laser interferometers were aligned well to the end of AFM tip. Laser sources of the three-axis laser interferometer in the nano-metrological AFM were calibrated with an I$_2$-stablilzed He-Ne laser at a wavelength of 633 nm. So, the Abbe error was minimized and the result of the pitch measurement using the nano-metrological AFM has a traceability to the length standard directly. The uncertainty in the pitch measurement was estimated in accordance with the Guide to the Expression of Uncertainty in Measurement(GUM). The Primary source of uncertainty in the pitch-measurements was derived from repeatability of pitch-measurement, and its value was approx 0.186 nm. Expanded uncertainty(k=2) of less than 5.23 nm was obtained. It is suggested that the metrological AFM is a useful tool for the nano-metrological standard calibration.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.17 no.1
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• pp.14-16
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• 2006

Background and Objectives: The purpose of this study is to investigate the change of vocal tract length according to the level of the pitch by the singers. Materials and Methods: Fifteen tenors were asked to produce successive /a/ sound in G4(382Hz) for the head register, C3(131Hz) for the chest register and usual speaking sound. The control group consisted of 15 males of an similar age who are not professional singers. The length of vocal tract was calculated by applying the formula of Fn=(2n-1) c/4L(F : formant frequency, c : the speed of sound in the vocal tract(350m/sec), L : length of vocal tract, $n=1,2,3,4,{\ldots}{\infty}$). Results: In singer's group, there showed no significant statistical difference of length among head and chest register and usual speaking sound. However in the control group, there showed statistically significant difference of length. Comparison of the absolute difference in the length of vocal tract by changing level of pitch in phonation, between the control group and the singers group. Changing from G4 phonation to C3 phonation and C3 phonation to usual speaking sound showed statistically difference of vocal tract length was less in the singers group than the control group. Conclusion: The change of vocal tract length, in either speaking or singing, was less in singers than the control group. We could assume that the singers maintain their larynx position constantly throughout the pitch range when phonation.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.6 s.183
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• pp.96-103
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• 2006

To establish of standard technique of nano-length measurement in 2D plane, new AFM system has been designed. In the long range (about several tens of ${\mu}m$), measurement uncertainty is dominantly affected by the Abbe error of XY scanning stage. No linear stage is perfectly straight; in other words, every scanning stage is subject to tilting, pitch and yaw motion. In this paper, an AFM system with minimum offset of XY sensing is designed. And XY scanning stage is designed to minimize rotation angle because Abbe errors occur through the multiply of offset and rotation angle. To minimize the rotation angle optimal design has performed by maximizing the stiffness ratio of motion direction to the parasitic motion direction of each stage. This paper describes the design scheme of full AFM system, especially about XY stage. Full range of fabricated XY scanner is $100{\mu}m\times100{\mu}m$. And tilting, pitch and yaw motion are measured by autocollimator to evaluate the performance of XY stage. As a result, XY scanner can have good performance. Using this AFM system, 3um pitch specimen was measured. The uncertainty of total system has been evaluated. X and Y direction performance is different. X-direction measuring performance is better. So to evaluate only ID pitch length, X-direction scanning is preferable. Its expanded uncertainty(k=2) is $\sqrt{(3.96)^2+(4.10\times10^{-5}{\times}p)^2}$ measured length in nm.