• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.105-108
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• 1999

TTS(Text-To-Speech) 시스템 합성음성의 자연감을 개선하기 위해 하나의 언어에 대해 존재하는 운율 법칙을 정확히 구현해야 한다. 존재하는 운율 법칙을 추출하기 위해서는 방대한 분량의 언어 자료 구축이 필요하다. 그러나 이 방법은 존재하는 운율 현상이 포함된 언어자료에 대해 완벽한 운율을 파악할 수 없으므로 합성음성의 질을 좋게 할 수 없다. 본 논문은 한국어 음성의 운율을 학습하기 위해 2개의 인공 신경망을 제안한다. 하나의 신경망으로 문장의 각 음소에 대한 피치 변화를 학습시키는 것이며, 다른 하나는 에너지 변화를 학습하도록 하였다. 신경망은 BP 신경망을 이용하며 11개의 음소를 나타내기 위해 11개의 입력과, 중간 음소의 피치와 에너지 변화곡선을 근사하는 다항식 계수를 출력하도록 하였다. 신경망시스템의 학습과 평가에 앞서, 음성학적 균형잡힌 고립단어를 기반으로 의미있는 문장을 구성하였다. 문장을 남자 화자로 하여금 읽게 하고 녹음하여 음성 DB를 구축하였다. 음성 DB에 대해 각 음소의 운율 정보를 수집하여 신경망에 맞는 목표 패턴과 훈련 패턴을 작성하였다. 이 목표 패턴은 회귀분석을 통한 추세선을 이용해 피치와 에너지에 대한 2차 다항식계수로 구성하였다. 본 논문은 목표패턴에 맞는 신경망을 학습시켜 좋은 결과를 얻었다.

• Tribology and Lubricants
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• v.28 no.1
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• pp.27-32
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• 2012

Oval gears are typical kinds of non-circular gears and are widely used in flow meters. This paper presents a tooth profile design of an oval gear according to the curvature of the pitch curve. The length of the pitch oval is divided by the number of teeth and the curvature of the divided points is obtained. The tooth profile is designed on the circle of the curvature as if it is the pitch circle of a gear. The teeth of the oval gear have the same module and pressure angle, but the pitch circle of each tooth differs in size. Thus, the teeth on the divided points of the pitch oval are different in shape. This type of oval gear will improve the meshing properties.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.861-866
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• 1996

The Non-Circular Gears is more advantage than other machinery using link and cam in the automation equipment. We designed Non-Circular Gears for a velocity of inequalty rotational equipment according to the variation of pressure angle, radius of curvature etc., and studied about pitch curve.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.5
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• pp.96-101
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• 1999

This study suggests an algorithm for tooth profile generation of free from curve involute gear, a special gear of which the pitch line is a free curve instead of a circular one. For the first, a methodology for calculation of the tooth curve is developed and formulated Then the formulated algorithm, is programmed for manufacturing and verified by computer graphics. Next the calculated results as changed in to NC codes to apply to wire electric discharge machine(WEDM). Finally, the machined gear is examined in engagement with a standard involute gear.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.19-22
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• 2000

Noncontact measuring methodology of 3-dimensional profile using CCD camera are very attractive because of it's high measuring speed and its's high sensitivity. Especially, when projecting a grid pattern over the object the captured image have 3 dimensional information of the object. Projection moire extract 3-D information with another grid pattern in front of CCD camera. However phase measuring profilometry(PMP) obtain similar results without additional grid pattern. In this paper, new method for grid pattern generation system by polygonal mirror and Laser Diode. This system is applied the projection moire and the PMP.

• Phonetics and Speech Sciences
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• v.5 no.2
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• pp.59-69
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• 2013

The purpose of this study is to examine the variation of pitch contour observed in the reading of Korean sentences produced by Chinese Korean-learners. In the reading context, Korean sentence intonation can be described by considering accentual phrases' pitch pattern and intonational phrases' boundary tone. But when APs and IPs connect to each other to form sentences, another aspect of speech production must be considered, that is declination of pitch contour. So, in order to examine how Chinese speakers produce Korean sentence intonation, we have analysed the sentences' pitch contours produced by fourteen Chinese speakers differing in proficiency, and compared them to pitch contours produced by six Korean native speakers. The results show that Chinese speakers tend to decline the pitch contour in shorter sentences, but for longer sentences, the declination was not observed. Moreover, even though Chinese speakers produced sentences with declination, internal tonal modulation differs from native speakers.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.6
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• pp.52-63
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• 1997

Non-circular gear has a good velocity ratio in high speed and heavy load without any slip, moreover, it can transmit various motion, using simpler structure than link and cam, automation mechainism. In case of designing and manufacturing non-circular gear. I suggest one of references in applying non-circular gear to industrial plant, and suitable range of application by pressure angle curvature and angle ratio

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.11
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• pp.964-972
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• 2007

Wind turbine experiment was carried out for the horizontal axis wind turbine with the aerodynamically optimized blade. From the comparison of aerodynamic performance between upwind and downwind type wind turbine rotor, the measured torque fluctuation of the latter is larger than that of the former. This phenomenon is owing to the interaction of wake generated from support column and blades. The wind turbine model satisfies the design condition in that the measured result of the power coefficient at zero pitch angle shows maximum peak at the designed tip speed ratio, λ = 6. It also shows that the decrease in aerodynamic power due to negative pitch change is more sensitive than that of the same positive pitch change.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.12 s.177
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• pp.108-116
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• 2005

Transplanting accuracy of a rice transplanter mainly depends on the trajectory of the hoe for picking, conveying and transplanting of seedlings as well as the return motion. The trajectory can be decided and prescribed to be suitable in treating seedlings fur a prevailing soil condition. For the purpose of the transplanting accuracy, the design of a transplanting mechanism would be carried out using a planetary-gear-train system instead of the four bar linkage system. In this study, a design method of transplanting mechanism is theoretically proposed by synthesizing a noncircular planetary-gear-train system fur the tool (hoe) to trace a prescribed trajectory. The method utilizes an optimization approach to decide the lengths of an arm and a tool, the inverse kinematics to figure out the configuration angles of the two links, the roll contact condition in transmitting motion between the gears, and a linearization approach to obtain the shapes of the gears. Based on the proposed method, the shapes of the gears and the lengths of the tools of the planetary-gear-train system are determined fur three prescribed trajectories. A kinematical simulation with a commercialized package program is also carried out to confirm that the gear-train system synthesized with the proposed method is able to trace the prescribed trajectory.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.3
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• pp.13-18
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• 2011

This study deals with the effect of the honing in SCM420H planetary gears. The hardness, tooth profile, lead and roughness of the gear surface can be improved by honing. Therein, the honing techniques are welcomed especially as one of the physical surface improvement methods. As a result, gear honing reduces vibration and noise, and will increase the life of gear. And gear honing also changes the surface of gear tooth in a short time and price, so it is a very important method in manufacturing industry. But nowadays, it is hard to find the detail information of gear honing. The test gear is a planetary gear which is used in the automotive industry. It is manufactured by the hobbing, shaving, carburizing and honing. This study investigates the effect of honing in surface shape of SCM420H planetary gears, including fatigue strength test and characteristics of honing of SCM420H planetary gears.