• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.10
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• pp.138-145
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• 1990

This paper present a rule-based speech synthesis method for improving the naturalness of synthetic speech and using the small data base based on demisyllable units. A 12-pole Linear Prediction Coding method is used to analyses demisyllable speech signals. A syllable and vowel concatenation rule is developed to improve the naturalness and intelligibility of the synthetic speech. in addiion, phonological structure transform rule using neural net and prosody rules are applied to the synthetic speech.

• 한국전산유체공학회:학술대회논문집
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• 2006.10a
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• pp.120-125
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• 2006

Piezoelectric actuators have been investigated for flow control in the field of fluid dynamics. Numerical simulation for a single diaphragm piezoelectric actuator operating in quiescent air is performed to investigate the complex flow field around the slot exit. A periodic velocity transpiration condition is applied to simulate the effect of the moving diaphragm. The computational results for the flow field around the slot exit agree well with the experimental data. The results also show that low pressure regions due to the vortex pairing cause non-monotonic variations in the vertical velocity.

• Journal of the Korean Society of Visualization
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• v.14 no.2
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• pp.46-51
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• 2016

In this study, a Masked Omni-Directional Integration(MODI) method for pressure calculation is proposed using the Particle Image Velocimetry (PIV) data. To obtain the velocity field, the Affine PIV method was adopted. Synthetic images were generated for a solid body rotation. Calculation on the pressure was based on the Navier-Stokes equation. The results obtained by the MODI were compared with those obtained by theoretical pressure and by the Omni-Directional Integration(ODI) method. It was shown that the minimum error by the proposed MODI method was attained when the mask size was 1.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2003.05a
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• pp.595-600
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• 2003

This paper presents the applicability of low caloric synthetic gas from coal gasification to a gas engine system. A commercial LPG engine is modified to use the low caloric synthetic gas from coal gasification as the gas engine fuel. The modification is focused on the fuel supplying system, which includes air flowrate adjusting orifice, gas mixer, vaporizer, preheater, regulators, and fuel tank. The electrical system and others for the alternative fuel are also redesigned and replaced. From the results of engine performance data, we have demonstrated that the engine modified by using coal gasification gas is well operated from idle to wide open throttle conditions although the engine power is somewhat reduced relative to LPG fueled engine. This paper addresses the need to determine the practical potential for such a concept and to identify further research and development efforts that may be necessary.

• Journal of the Korea Institute of Building Construction
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• v.11 no.6
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• pp.557-566
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• 2011

The surfactants facilitate the formation of foam bubbles under a proper condition and provide stability of foam bubbles by decreasing the surface tension of solutions and increasing the viscosity of foam surface. However, there have been almost no practical data of foam concrete in this regard so far. This study aims to understand the effects of foaming agents such as anionic synthetic surfactant and anionic natural material surfactant on the low density foamed concrete. From the experiment, the vegetable soap of anionic natural material surfactants showed a higher foaming rate, more open pores, slightly lower compressive strength, and a higher permeability coefficient compared to the vegetable soap of anionic synthetic surfactants. It is believed that the natural material surfactants make not only the surface tension of the solution low but also the viscosity of slurry high.

• Journal of Ocean Engineering and Technology
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• v.22 no.5
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• pp.83-86
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• 2008

This paper deals with the experimental works for the correlations of ice resistance for icebreaker with synthetic(model) ice in general towing tank and with refrigerated ice in ice tank. In order to find out the correlation, the density variation is mainly focused in the present study. The model of Terry-Fox ice breaker has been used for the present correlation study because many data are available to be compared. According to the increase of density, the correlation becomes better quantitatively as well as qualitatively. Other parametric studies such as an ice size, a friction coefficient, a bending moment, etc., are also expected to be carried out to have better correlation in a near future. This research could be the basis for the possibility of resistance test using a synthetic ice in a general towing tank instead of an expensive ice tank.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.7
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• pp.717-722
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• 2007

Inverse synthetic aperture radar(ISAR) images represent two-dimensional(2-D) spatial distribution of electromagnetic scattering phenomenology against a target. Hence, they are usually used in the areas of automatic target recognition (ATR) or non-cooperative target recognition(NCTR), identifying a target using radar in a long distance. This paper makes use of Korea Miniature Synthetic Aperture Radar(KOMSAR) to generate ISAR images of a real and maneuvering aircraft. The data obtained from KOMSAR are processed to eliminate phase errors due to motion of a target, with the use of entropy-based ISAR autofocusing technique. Results show that we can successfully obtain ISAR images of a real aircraft, and the success of experiments implies that a significant step toward ATR using radar has been established.

• Korean Journal of Clinical Pharmacy
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• v.11 no.2
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• pp.68-77
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• 2001

Herbal medicines have been used since ancient times as medicines to treat and relieve the symptoms of many different human diseases. However, so far, relatively few herbal medicines have been evaluated scientifically to prove their safety, potential benefits and effectiveness. This study was conducted to provide the groundwork for improving the current registration regulations for herbal medicines in distinction from synthetic medicines. The study was performed based on the literature research and individual interviews with 5 experts who had extensive experience in registration of herbal medicines. When compared with synthetic drugs, herbal medicines exhibit some marked differences, namely the active principles are frequently unknown, standardization, stability and quality control are not easy, they are usually mixtures of complex compounds. Second, the current regulations for herbal medicines are reviewed by comparison of foreign regulation systems like the one in China. The regulation requirements of herbal medicine in China are in distinction from synthetic drugs. The authors conclude that new registration requirements for the herbal medicines should be changed as follows; the toxicity and efficacy data should be submitted as mixed herbal preparation and the documents and other research on the reproduction and generation toxicity need to be shown for the proof of reproduction and generation toxicity, if needed.

• Journal of Korean Society on Water Environment
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• v.26 no.3
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• pp.532-539
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• 2010

The synthetic unit hydrograph is developed and verified using Nash model and characteristic velocities considering geomorphological dispersion in this present study. Application watersheds are selected 5 subwatersheds of Bocheong basin. The mean and variance of hillslope and stream path length are estimated in each watershed with GIS. Characteristic velocities are calculated using estimated path lengths and moment characteristics of rainfall-runoff data. Characteristic velocities of random devised 7 ungauged watersheds are estimated through regional analysis of chracteristic velocities in guaged watershed. And Nash model parameters and IUH are derived using characteristic velocities and path length in the gauged and ungauged watershed. The result to compare of IUH about gauged watershed and random devised ungauged watershed in application watershed presents coherently hydrologic response characteristics that peak discharge is reduced and peak time is extended. In conclusion, Developed synthetic unit hydrograph in this study expects that it is useful method to estimate runoff discharge for managing of water pollution in ungauged watershed.

• Development and Reproduction
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• v.20 no.2
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• pp.127-133
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• 2016

Purine metabolism is known factor for nuclear maturation of oocytes through both follicle cells and oocyte itself. However, it is largely unknown the roles of purine metabolism in the oocyte competence for fertilization and early development. In this study, the effects of adenosine in oocyte competence for development were examined using adenosine and its synthetic inhibitors. Adenosine treatment from GV intact stage for 18 hr (fGV) caused of decrease the fertilization rate but of increase the cleavage rate compared from the other stage treatment groups. Hadacidin did not effect on fertilization rate but increased cleavage rate without stage specificity. Adenosine did not block the effects of hadacidin with the exception of fGV group. Inhibition of purine synthetic pathways the fertilization rate was decreased in the fGV and fGVB groups but increased in the fMII group. Exogenous adenosine caused of decrease fertilization rate in the fGVB group but increase in the fMII group. Cleavage rate was dramatically increased in the adenosine treatment with synthetic inhibitors. It means that the metabolism of purine has stage specific effects on fertilization and cleavage. Exogenous adenosine had only can improve oocyte developmental competence when it treated at GV intact stage. On the other hand, endogenous synthesis in all maturation stage cause of increase the cleavage rate without effects on fertilization. These data suggest that adenosine at GV stage as a paracrine fashion and inhibitions of endogenous adenosine in all stage improve oocyte developmental competence.