• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.7A
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• pp.520-528
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• 2003

This paper proposes a method of implementing synthetic stereo and an acoustic echo cancellation algorithm for multiple participant conference system. Synthetic stereo is generated by HRTF and two loudspeakers. A robust adaptive algorithm for synthetic stereo echo cancellation is proposed to reduce the weight misalignment due to near-end speech signals and ambient noises. The proposed adaptive algorithm is modified version of SMAP algorithm and the coefficients of adaptive filter is updated with cross correlation of input and estimation error signal normalized with sum of the autocorrelation of input signal and the power of the estimation error signal multiplied with projection order. This is more robust to projection order and ambient noise than conventional SMAP. Computer simulation show that the proposed algorithm effectively attenuates synthetic stereo acoustic echo.

• Journal of the Optical Society of Korea
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• v.20 no.2
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• pp.239-244
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• 2016

Mugshot face images, routinely collected by police, usually contain both frontal and profile views. Existing automated face recognition methods exploited mugshot databases by enlarging the gallery with synthetic multi-view face images generated from the mugshot face images. This paper, instead, proposes to match the query arbitrary view face image directly to the enrolled frontal and profile face images. During matching, the 3D face shape model reconstructed from the mugshot face images is used to establish corresponding semantic parts between query and gallery face images, based on which comparison is done. The final recognition result is obtained by fusing the matching results with frontal and profile face images. Compared with previous methods, the proposed method better utilizes mugshot databases without using synthetic face images that may have artifacts. Its effectiveness has been demonstrated on the Color FERET and CMU PIE databases.

• Transactions of the Korean hydrogen and new energy society
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• v.10 no.4
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• pp.233-243
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• 1999

Combustion characteristics of synthetic gas from flame pyrolysis gasification of polymetric wastes are reported and the applicability of synthetic gas from flame pyrolysis gasification to a gas engine system is presented. Engine power is easily predicted by the volume percentage of the synthetic gas. Measurements have been made to obtain the range of flame existence in the function of volume percentage of CO and $H_2$ gases in the synthetic gas. In order to clarify the emission of the flames, NOx measurements by chemiluminescent analyser are taken in flames with different equivalent ratios. From the results of the engine performance data we also have demonstrated that the output of the gas engine modified from a LPG engine is about 5 ps at normal rating. We conclude that synthetic gas from flame pyrolysis gasification of polymetric wastes is applicable to a gas engine system.

• Journal of computational fluids engineering
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• v.12 no.2
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• pp.1-7
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• 2007

To develop an aerodynamic performance, two groups of studies have been achieved widely. One is about the geometric design of vehicles and the other is about aerodynamic devices. Geometric design is a credible and stable method. However, it is not flexible and each part is related interactively. Therefore, if one part of geometry is modified, the other part will be required to redesign. On the other hand, the flow control by aerodynamic devices is flexible and modulized method. Even though it needs some energy, a relatively small amount of input makes more advanced aerodynamic performance. Synthetic jet is one of the method in the second group. The device repeats suctions and blowing motions in constant frequency. According to the performance, the adjacent flow to flight surface are served momentum. This mechanism can reduce the aerodynamic loss of boundary layer and separated flow. A synthetic jet actuator has several parameters, which influences the flow control. This study focuses on the parameter effects of synthetic jet - orifice geometry, frequency, jet speed and etc.

• Journal of computational fluids engineering
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• v.15 no.4
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• pp.46-52
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• 2010

In the present work, the aerodynamic characteristics of elliptic airfoils which have a 12% thickness ratio are numerically investigated based on Reynolds-averaged Navier-Stokes equations and a transition SST model at a Reynolds number 8.0$\times$105. The numerical simulation of a synthetic jet actuator which is a well-known zero-net-mass active flow control actuator located at x/c = 0.00025, was performed to control massive flow separation around the leading edge of the elliptic airfoils. Four cases of non-dimensional frequencies were simulated at an angle of attack of 12 degree. It is found that the size of the vortex induced by synthetic jets was getting smaller as the jet frequency becomes higher. Comparison of the location of synthetic jets between x/c = 0.00025 (around the leading edge) and x/c = 0.9 (near the separation) shows that the control near the leading edge induces closed recirculation flow regions caused by the interaction of the synthetic jet with the external flow, but the control applied at 0.9c (near the trailing edge) induces a very small and weak vortex which quickly decays due to weak intensity.

• The Journal of the Acoustical Society of Korea
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• v.19 no.4
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• pp.77-83
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• 2000

The previous synthetic aperture techniques have been investigated to increase signal gain, improve angular resolution and peak-to-sidelobe level ratios for towed line array sonar systems. The synthetic aperture method in this paper is performed for conformal array systems by mapping real elements on an axis to control like a linear array. The proposed method for the conformal array performs coherent processing of subaperture signals at successive time intervals in the beam domain via FFT transformations. This was confirmed by the simulation results and compared to the results from use of the synthetic aperture technique under the conformal array.

• 한국전산유체공학회:학술대회논문집
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• 2007.04a
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• pp.72-78
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• 2007

To develop the aerodynamic performance, there are widely two group of studies are achieved. The first one is about design of the vehicles geometry and the second one is about aerodynamic devices. Geometry design is highly credible and stable method. But it is not flexible and each parts are related interactively. So if one part geometry are modified, the other parts are required to be redesigned. The other hand, flow control by aerodynamic device is flexible and modulized method. Though it needs energy, relatively little input makes far advanced aerodynamic performance. Synthetic Jet is one of the second group method. The device repeats suction and blowing motion in constant frequency. According to the performance, the flow which are near the flight surface are served momentum. This mechanism can reduce the aerodynamic loss by boundary layer and separated flow. Synthetic jet actuator has several parameters, that influence the flow control. This study focus the parameters effects of the synthetic jet - orifice geometry, frequency, jet speed and etc.

• Applied Chemistry for Engineering
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• v.4 no.2
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• pp.254-263
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• 1993

The industry of amino acids has developed for the synthetic methods, zymotechnics from the methods of extraction. In the present, part of amino acids (L-cystine, L-tyrosine, etc.) is manufactured by the methods of extraction, but most of amino acids is produced by synthetic methods, zymotechnics. Among the methods, the synthetic methods use of cyanic acid, which generate a large of waste water by acid or alkali in hydrolysis. In this point of view, improved new synthetic methods are demanded for being the influence of environment. This article Introduces new synthetic methods of phenyl alnine, further more, the recent of research results are introduced to prepare the derivative ${\alpha}-keto$ acids of precursor for preparing more than particular amino acids.

• Journal of Veterinary Clinics
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• v.21 no.4
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• pp.349-354
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• 2004

The effectiveness of a synthetic solution of sodium carboxymethy1cellulose (SCMC) and dextran in the prevention of adhesion formation following intestinal anastomosis of intestine in dogs was elucidated and compared with Interceed. Following induction of adhesion on jejunum of dogs by resection and intestinal anastomosis, the dogs were infused with a synthetic solution of 1% SCMC and 10% dextran in saline in the abdominal cavity at the dose of 5ml/kg of body weight or treated with Interceed membrane. Fourteen days after operation, all the dogs showed adhesion of anastomotic sites to surrounding tissues. The average score of adhesion was 0.50, 0.60 and 0.80 in the dogs infused with the synthetic solution, Interceed membrane and saline solution, respectively. The synthetic solution showed better result of adhesion prevention than Interceed or saline solution. No significant change of body weight, vital signs, hematological values and side effects after operation was found in each group. Therefore, a synthetic solution which is combined with 1% SCMC and 10% dextran in saline can be effectively used for the prevention of adhesion formation comparable to Interceed membrane following intestinal anastomosis in the dogs.

• English Language & Literature Teaching
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• v.13 no.2
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• pp.47-61
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• 2007

The purpose of this paper is to survey the major elements that have changed English from a synthetic language to an analytic one. Therefore, this paper has looked at the differences between synthetic languages and analytic ones. In synthetic languages, the relation of words in a sentence is synthetically determined by means of inflections, while in analytic languages, the functions of words in a sentence are analytically determined by means of word order and function words. Thus, Old English with full inflectional systems shows the synthetic nature. However, in the course of time, Old English inflections came to be lost by phonetic changes and operation, which made English dependent on word order and function words to signal the relation of words in a sentence. The major phonetic changes that have shifted English are the change of final /m/ to /n/, the leveling of unstressed vowels, the loss of final /n/, and the decay of schwa in final syllables. These changes led to reduction of inflections of English as well as the loss of grammatical gender. The operation of analogy, the tendency of language to follow certain patterns and to adapt a less common form to a more familiar one, has also played an important role in changing English.