• Speech Sciences
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• v.9 no.3
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• pp.35-45
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• 2002

A simple algorithm for discriminating voiced sounds in a speech is proposed. In addition to low-frequency energy and zero-crossing rate (ZCR), both of which have been widely used in the past for identifying voiced sounds, the proposed algorithm incorporates pitch variation to improve the discrimination rate. Based on TIMIT corpus, evaluation result shows an improvement of 13% in the discrimination of voiced phonemes over that of the traditional algorithm using only energy and ZCR.

• 한국가시화정보학회:학술대회논문집
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• 2001.12a
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• pp.1-5
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• 2001

A particle image velocimetry (PIV) was applied to a flow measurement in a transonic centrifugal impeller. A phase locked measurement technique every $20\%$ blade pitch enabled a reconstruction of a velocity field over one blade pitch. The measured velocity field at the inducer of impeller clearly showed a shock wave generated on the suction surface of a blade.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.2
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• pp.1059-1065
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• 2014

Wind turbine system can obtain the maximum wind energy using torque control under the rated wind speed, and wind turbine power is controlled as the rated power using pitch control over the rated wind speed. In this paper, we present a method for wind turbine pitch controller using neural networks. The purpose of the pitch control is to control generator speed and power in the above rated wind speed. To improve the neural network pitch controller, the difference between a rated and current speed of generator has been used for another input of neural networks as well as wind speed. Error back-propagation algorithm is used for training the neural network pitch controller and simulation and Matlab/Simulink is used for verifying that this system is controlled well.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.04a
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• pp.121-124
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• 2005

This paper was about experimental test properties by mechnical joint of CF1263/Epoxy Al honeycomb panels. In case of mechanical joint using screw, nut shall be secured over than minimize third screw pitch. In case of insert backsheet for increase of joint force, increase weight for assemble by screw pitch. In case of insert backsheet with CF1263/Epoxy, predominant save weight and minimazer of displacement by tensile weight moreover predominant strength. In case of mechanical joint by rivet, rivet of Monobolt has over-hole in hole of CF1263/Epoxy but rivet of PROTRUDING has predominant of mechanical joint.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.1
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• pp.111-118
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• 2000

Over tightening experiments of the tension-controlled bolts are carried out and the stripping mechanism is reviewed base on the observed results. There are two modes of bolt failure due to the over tightening : one the fracture of the bolt the other the thread stripping Bifurcation between these two modes is rather delicate but it seems being related with the elastic flexibility of the bolt which depends upon the unused thread length. The fracture mode occurs in the bolts with good flexibility while the latter with bad one. According to the ISO Standard some meter coarse threads like M20 and M22 have the same pitch which causes bigger fastener to less resistance in shear and bending compared with the smaller one. however since UNC thread system adapts different pitch for different nominal diameter unified coarse threads show better stripping resistance than their corresponding meter threads.

• Journal of the Optical Society of Korea
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• v.9 no.4
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• pp.140-144
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• 2005

In this paper we have investigated the guiding properties of photonic crystal fibers (PCFs) with a square-lattice of air-holes in the cladding. We have shown numerical results of PCFs with various air hole sizes and hole-to-hole spacings over a wide wavelength range. The group velocity dispersion, effective area and effective refractive index of PCF have been calculated numerically. The waveguide dispersion has greatly affected the group velocity dispersion when hole-to-hole spacing is about $1{\mu}m$. The effective area is quite flat over the wide spectral range whether the hole-to-hole spacing is large or ratio of diameter to pitch is large. From the field distribution, we found that the field is tightly confined within the core region of PCF when the pitch is $3{\mu}m$ and the air-filling fraction is 0.9.

• Proceedings of the KSPS conference
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• 2003.05a
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• pp.43-47
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• 2003

This paper is phonetic study of $F_{0}$ range and boundary tone in Mandarin Chinese. The production data from 6 Chinese speakers show that there are declination, pitch resetting and tonal variation of boundary tone. In declarative sentence, $F_{0}$ declines gradually over the utterance but mid-sentence boundary prevents $F_{0}$ of following syllable from declining because of pitch resetting. $F_{0}$ range of syllable is expanded before the mid- and final sentence boundaries. In interrogative one, $F_{0}$ ascends gradually over the utterance and mid-sentence boundary makes $F_{0}$ of following syllable rise more. $F_{0}$ range of sentence final syllable is expanded and $F_{0}$ contour shows rising curve.

• Journal of Korean Foot and Ankle Society
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• v.11 no.1
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• pp.67-71
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• 2007

Purpose: To evaluate clinical results of the 5th proximal metatarsal intraarticular fracture (Zone I) with displacement treated operatively and to evaluate predisposing factors of the 5th proximal metatarsal fracture (Zone I). Materials and Methods: 11 patients treated for the 5th proximal metatarsal fracture (Zone I) operatively and 10 patients treated conservatively between Jan 2003 and Dec 2005, were followed for more than one year. Functions were graded by AOFAS foot scoring system and union time and postoperative complications were also evaluated. Calcaneal pitch angle was also evaluated. Results: Clinically there were no much difference in results. Clinical points were 94.5 in the operative group and 92.3 in the conservative group. At the last follow-up, the radiographic results showed union in all cases. During the follow-up period, there were no significant complications. But in the conservative group, displaced fracture with calcaneal pitch angle over 30 degree tends to show delayed union and time to loss of pain tends to be prolonged. Conclusion: Calcaneal pitch angle is thought to predisposing factor for 5th metatarsal base fracture. Operative treatment is viable option for the 5th proximal metatarsal intraarticular fracture with displacement and with calcaneal pitch angle over 30 degree. In cases of cavovarus foot deformity, we think operative treatment should be considered with deliberation and long term follow-up study for peroneal tendinopathy should be needed.

• Journal of Sasang Constitutional Medicine
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• v.19 no.2
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• pp.40-52
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• 2007

1. Objectives and Methods The purpose of this study was to objectify the diagnosis of Sasang Constitution. 63 Male Juvenile's and 151 Female Juvenile's sentences were analyzed into 73 factors like Pitch, APQ, Shimmer, Octave and Energy, etc. Juvenile's sentences were classified into 6 categories: total Male Juvenile group, under 12 years old Male Juvenile grout, over 13 years old Male Juvenile group, total Female Juvenile group, under 12 years old Female Juvenile group and over 13 years old Female Juvenile group. 2. Results 1) In Total Male Juvenile group, there were no significant differences among constitutional groups in APQ and Octave segment. Taeumin's Center freq.(3) was significantly high compared with Soyangin group. Soeumin's Center freq.(5) was significantly high compared with Soyangin and Taeumin groups. Taeumin's Octave3 Shimmer was significantly high compared with Soeumin group. Soeumin's Octave6 Shimmer was significantly high compared with Taeumin group. Solyangin's D# Tot E was significantly high compared with Taeumin group. 2) In Under 12 years old Male Juvenile group, there were on significantly among constitutional groups in Pitch, APQ, Octave and Energy segment. Taeumin's Octave3 Shimmer and G Shimmer(1) were significantly high compared with Soeumin group. 3) In Over 13 years old Male Juvenile group, there were no signigicant differences among constitutional groups in Pitch, APQ and Shimmer segment. Soyangin's and Soeumin's Octave6 were significantly high compared with Taeumin group. Soyangin's $0k{\sim}2k$ Total Sum, $0k{\sim}2k$ Dev., $2k{\sim}4k$ Total Sum, $2k{\sim}4k$ Dev., A Dev.(1), D# Dev.(1) and G# Dev.(1) were significantly high compared with Taeumin group. Soyangin's and Soeumin's G# Tot E were significantly high compared with Taeumin group. 4) In Total Female Juvenile group, there were no significant differences among constitutional groups in Pitch and APQ segment. Soeumin's Octave4 Shimmer was significantly high compared with Soyangin group. Soyangin's Octave6 was significantly high compared with Soeumin group. Solyangin's 2k-4k Total Sum and B Tot E were significantly high compared with Soeumin group. 5) In Under 12 years old Female Juvenile group, there were no significant differences among constitutional groups in APQ and Energy segment. Soeumin's and Taeumin's Center Pitch and Pitch were significantly high compared with Soyangin group. Soyangin's Center freq.(1) and Center freq.(7) were significantly high compared with Soeumin and Taeeunin groups. Soyangin's and Taeumin's B Shimmer(1) and F# Shimmer(1) were significantly high compared with Soeumin group. Soeumin's D Shimmer(1) was significantly high compared with Soyangin group. Taeumin's and Soeumin's G# Shimmer(1) were significantly high compared with Soyangin group. Soyangin's and Taeumin's Octave2 were significantly high compared with Soeumin group. 6) In Over 13 years old Female Juvenile group, there were no significant differences among constitutional groups in Pitch, APQ and Octave segment. Soeumin's Octave4 Shimmer was significantly high compared with Soyangin group. Soyangin's B Dev.(1) and F Dev.(1) were significantly high compared with Soeumin group. 3. Conclusions In juvenile groups, some sound factors are regarded as useful. PSSC are thought to be the objertive way to diagnose the Consitution and more participants are needed to get more efficiencies using PSSC.

• Journal of Sensor Science and Technology
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• v.22 no.1
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• pp.28-37
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• 2013

This paper presents a fault-tolerant control technique for wind turbine systems with sensor and actuator faults. The control objective is to maximize power production and minimize turbine loads by calculating a desired pitch angle within their limits. Any fault with a sensor and actuator can cause significant error in the pitch position of the corresponding blade. This problem may result in insufficient torque such that the power reference cannot be achieved. In this paper, a fault-tolerant control technique using a robust dynamic inversion observer and control allocation is employed to achieve successful pitch control despite these faults in the sensor and actuator. The observer based detection method is used to detect and isolate sensor faults by checking whether errors are larger than threshold values. In addition, the control allocation technique is adopted to tolerate actuator fault. Control allocation is one of the most commonly used fault-tolerant control techniques, especially for over-actuated systems. Further, the control allocation method can be used to achieve the power reference even in the event of blade actuator fault by redistributing the lost torque due to erroneous pitch position into non-faulty blade actuators. The effectiveness of the proposed method is demonstrated through simulations with a benchmark model of the wind turbine.