• Proceedings of the Acoustical Society of Korea Conference
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• 1994.06a
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• pp.984-990
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• 1994

In this paper a new speech synthesis method in the time domain using mono-syllables is proposed. It is to overcome the degradation of the synthetic speech quality by the synthesis method in the frequency domain and to develop an algorithm in the time domain for the prosodic control. In particular when we use a method in a time domain with mono-syllable as a synthesis unit it will be the main issues which are to control th pitch period and to smooth the energy pattern. As a solution to the pitch control, a method using Lagrange interpolation is suggested. As a solution to the other problem, an algorithm which can control the amplitude envelop shape of mono-syllable is proposed. As the results of experiments it was possible to synthesize unlimited Korean speeches including the prosody control. Accoding to the MOS evaluation the quality and the naturality in them was improved to be a good level.

• The International Journal of Costume Culture
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• v.4 no.1
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• pp.44-60
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• 2001

The purpose of this study is to present suggestions to improve the problems the domestic department stores face by analyzing and comparing the status of the development of PB which is absolutely critical for the specialized domestic department stores to survive, and to search for the future course which may lead to boosting sales and profit by developing the strategic PB products. Selected for this study were atotal of 20 PB's out of domestic as well s foreign PB's in the 4 big department stores. The data were analyzed with SAS package employed as per the by items frequency, percent, mean and standard deviation. From the above study, following viewpoints can be taken into account for the future development of PB ; First, the active will of the excutive is basically necessary for successful development of PB, by relying on long-term investment. Second, the existing mid or low-price goods should be in line with the mid or high price one's development for domestic merchandising with focus on middle or high class society. Third, the stock burden, biggest problem of PB, can be solved by discount policy at optimum prices and success rate of merchandising prediction.

• Journal of Electrical Engineering and Technology
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• v.13 no.2
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• pp.838-848
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• 2018

This paper proposes a single-phase buck-boost AC-AC converter. It consists of three legs with six switching units (each unit is composed of an active switch and a diode) and its input and output ports share a common ground. It can provide buck-boost voltage operation and immune from shoot-through problem. Since only two switching units are involved in the current paths, the conduction losses are low, which improves the system efficiency. The operation principle of the proposed circuit is firstly presented, and then, various operation conditions are introduced to achieve different output voltages with step-changed frequencies. Additionally, the parameters design and comparative analysis of the power losses are also given. Finally, experimental results verify the correctness of the proposed converter.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1999.10a
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• pp.257-266
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• 1999

This paper presents a method of seismic analysis for a cylindrical liquid storage structure on/in horizontally layered half.space considering the effects of the interior fluid and exterior soil medium in the frequency domain. To capture the essence of fluid-structure-soil interaction effects effectively, a mixed finite element with two-field (u, p) approximation is employed to model the compressive inviscid fluid, while the structure and soil medium are presented by the 3-D axisymmetric finite elements and dynamic infinite elements. The present FE-based method can be applied to the system with complex geometry of fluid region as well as with inhomogeneous near-field soil medium, since it can directly model both the fluid and the soil. For the purpose of verification, dominant peak frequencies in transfer functions for horizontal motions of cylindrical fluid storage tanks with rigid massless foundation on a homogeneous viscoelastic half.space are compared with those by two different added mass approaches for the fluid motion. The comparison indicates that the Present FE-based methodology gives accurate solution for the fluid-structure-soil interaction problem. Finally, as a demonstration of versatility of the present study, a seismic analysis for a real-scale LNG storage tank embedded in layered half.space is carried out, and its member forces along the height of the structure are compared with those by an added mass approach developed by the present writers.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.15 no.4
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• pp.599-607
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• 2002

During the shape optimization, relocations of nodes happen successively. However, excessive movement of nodes often results in the mesh distortion and eventually deteriorates the accuracy of the optimum solution. To overcome this problem, an efficient method lot the shape optimization has been developed. The method starts from the design domain which is large enough to hold the possible shape of the structure. The design domain has pre-defined uniform fine meshes. In each cycle, the method allots real properties to the elements inside the structure and nearly zero to ones outside. The performance of the method is evaluated through two examples with displacement and frequency constraints.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.17 no.3
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• pp.126-130
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• 2004

Oculomotor nerve palsy presents itself with sudden onset unilateral ptosis and inability to turn the eye upward, downward, or inward, which causes visual disturbances. Strabismus caused oculomotor nerve palsy refers to muscle imbalance that results in improper alignment of the visual axes of the two eyes It may be divided into paralytic and non paralytic strabismus. paralytic strabismus is primarily a neurologic problem. Characteristic clinical disturbances result from lesions of the third, fourth, and sixth cranial nerves. Lesions of the third nerve result in a paralysis of lateral or outward movement and a crossing of the visual axes. Objective: This study was designed to evaluate the effects of oriental medicine therapy on a peripheral oculomotor nerve palsy. Methods & Result: The clinical data was analyzed on a patient with oculomotor nerve palsy whose main symptoms were right side ptosis and inability to turn the eye inward. The patient was treated by the electroacupucture(4Hz frequency, intensity was adjusted so that localized muscle contractions could be seen). As the result, symptoms are improved remarkably. Conclusion: The patient showed right eye ptosis and unilateral deviation of the right eye ball in neutral position. After acupuncture treatment and electroacupuncture treatment, the ptosis and deviation of the patient's right eye was recovered six weeks after the onset. The study suggests that oriental medicine therapy is significantly effective on the treatment of peripheral oculomotor nerve palsy.

• Journal of the Semiconductor & Display Technology
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• v.19 no.1
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• pp.42-48
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• 2020

As global warming accelerates, eco-friendly electric cars are being developed to reduce carbon dioxide emissions, and power conversion inverters are used to drive motors. Among inverter components, DC-link capacitor is heated by high current usage, which causes problems such as performance and life-saving of inverter. Although metal cases with good thermal performance have been used to solve this problem, it is difficult to apply them in practice due to insulation problems with other parts. In this paper, the Heat-Generation influence factor of DC-link capacitor is analyzed. Variables on heat-generation are set at 3 levels for film width, inductance, and film thickness. Box-Behnken to 13 tests using the design and minimal deviations, e.g. through the experiment three times by each level. The surface of the film k type by attaching the sensor current is measured temperature. Capacitance was set to a minimum level of 200 ㎌ and had a frequency of 16 kHz with Worst case, ambient temperature of 85℃ and a ripple current of 50 Ams was applied. The temperature at the measurement point was collected in the data logger after sampling at 1 minute intervals for 2 hours after saturation with the ambient temperature. This experiment confirmed that setup factors are correlated with heat-generation.

• The Mathematical Education
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• v.53 no.3
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• pp.329-355
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• 2014

The purpose of this study is to understand the difference of cognitive structure depending on the level of the 6th graders' problem-solving abilities about the division of fraction and to propose a method for improving the 6th graders' understanding about the division of fraction through the word association test. The following is the findings from this study. 1)The lower level students' is, the lower the step that the chunk appeared in cognitive structure is. 2)The basic level students' association frequency between any two concepts was less than the excellent level students and the ordinary level students' it. 3)The basic level students' connection number between concepts was far less than the excellent level students and the ordinary level students' it. 4)The connection between natural number and unit fractions, subtraction of fraction and division of fraction, division of fraction and reduction to common denominator, and division of fraction and common multiple that expected in this study did not appear in the three groups.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.1
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• pp.165-176
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• 2013

This paper introduces the high density discrete wavelet transform using quincunx sampling, which is a discrete wavelet transformation that combines the high density discrete transformation and non-separable processing method, each of which has its own characteristics and advantages. The high density discrete wavelet transformation is one that expands an N point signal to M transform coefficients with M > N. The high density discrete wavelet transformation is a new set of dyadic wavelet transformation with two generators. The construction provides a higher sampling in both time and frequency. This new transform is approximately shift-invariant and has intermediate scales. In two dimensions, this transform outperforms the standard discrete wavelet transformation in terms of shift-invariant. Although the transformation utilizes more wavelets, sampling rates are high costs and some lack a dominant spatial orientation, which prevents them from being able to isolate those directions. A solution to this problem is a non separable method. The quincunx lattice is a non-separable sampling method in image processing. It treats the different directions more homogeneously than the separable two dimensional schemes. Proposed wavelet transformation can generate sub-images of multiple degrees rotated versions. Therefore, This method services good performance in image processing fields.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.85-87
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• 2008

The demand of a three phase PWM inverter for the purpose of power control or grid-connecting is increasing. This inverter is connected to a grid through an L-filter or LCL-filter to reduce the harmonics caused by switching. An LCL-filter can reduce the harmonic of a low switching frequency and generate a satisfactory level of grid side current with a relatively low-inductance than an L-filter. But the additional poles caused by the LC part affects a stability problem due to induced resonance of the system. This paper presents a compensation method using a power theory to improve performance, the designed LCL-filter system and to reduce the stability problems caused by resonance. The effectiveness of the proposed algorithm is verified by simulations.