• The Journal of the Acoustical Society of Korea
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• v.14 no.1E
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• pp.46-55
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• 1995

In this paper, we present a new wavelet transform-based CELP coder, called band selection wavelet transform CELP (BS-WTCELP) operated at 4.8 kbps. The proposed algorithm uses a band selection scheme of frequency bands of wavelet transform and selective vector quantization (VQ). The band selection and selective VQ structure is implemented by using a classified VQ structure. The proposed algorithm has about 0.5-1.0 dB improvement in segmental SNR compared with the conventional CELP that uses the random codebook search, while is has significantly reduced computational and storage complexity. Many experimental results have shown that the proposed algorithm is more suitable for most real-applications than the conventional CELP and wavelet transform CELP.

• Explosives and Blasting
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• v.22 no.1
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• pp.67-74
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• 2004

Blasting in urban area has become a serious issue in our living because it causes inconvenience to the resident living by construction area. Therefore, the practical solution and the better method for reducing blasting noise are highly required. However, finding practical solutions for the blasting noise is very difficult due to the lack of basic data and insufficient existing research. In order to overcome the limitation of existing sound barrier, we applied a new material to multi-layer soundproof system in the construction site, Kuksabong Tunnel in Yang Nyung-Ro. The statistical method was used to analyze blasting noise data. Through all these processes, it was verified that the soundproof system in this study was very effective method to decrease blasting noise.

• Journal of Educational Research in Mathematics
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• v.27 no.3
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• pp.581-598
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• 2017

The early Renaissance artist Albrecht $D{\ddot{u}}rer$ is an amateur mathematician. He published a book on geometry. In the second part of that book, $D{\ddot{u}}rer$ gave compass and straight edge constructions for the regular polygons from the triangle to the 16-gon. For mathematics education, I extracted base constructions of polygon constructions. And I also showed how to use $D{\ddot{u}}rer^{\prime}s$ idea in constructing divergent forms with compass and ruler. The contents of this paper can be expected to be the baseline data for mathematics education.

• Journal of Korea Multimedia Society
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• v.8 no.4
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• pp.544-553
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• 2005

In this paper, the research has been done to develop the inclination test items to form the desirable online learning community in which social interaction may be maximized, dropout rate lowered and learners' feeling of isolation eliminated. Once developed, the inclination test items have been classified into homogeneous ones and heterogeneous ones. And on the basis of the results of this research, Intelligent agent based Inclination Test Grouping e-learning System(IIGS) has been developed, which can perform automatic grouping of online leaning community by intelligent agent. The results of this research with 1,000 teachers in reality by means of developing the grouping system have shown that 151 groups are automatically formed. Among them, 34% have shown very high degree of learning satisfaction and intended to maintain the groups in the future.

• The Korean Journal of Nuclear Medicine
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• v.26 no.1
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• pp.124-126
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• 1992

Interleukin-2 (IL-2)는 많은 immunoenhancing lymphokine의 한 종류로서 lymphokine activiated killer (LAK) cell의 생성을 자극시켜 흑종의 종양세포를 죽인다고 알려져 있다. 최근 간종양에서 비장동맥 또는 간동맥으로 투여한 IL-2가 비장의 임파계를 자극하여 LAK cell을 생성하여 어느정도효과가 있음이 밝혀지면서, 여러가지의 투여 방법이 시도되고 있다. 그러나 각종의 투여 방법에서 실제로 투여한 IL-2의 인체내 분포에 관한 연구는 없다. 저자들은 비정맥과 간문맥에 이상이 없는 증례의 비동맥에 IL-2와 $^{99m}Tc-phytate$ 혼합물을 투여하고, IL-2의 생체에서의 비장과 간에 어떻게 분포하는지 알아보기 위하여 $^{99m}Tc$의 radioactivity를 계측하여 보았다. 6예의 간세포암과 3예의 위암으로부터의 전이성간암에서 동맥조영술적방법을 이용하여 초선택적 비장동맥에 투여한 IL-2와 $^{99m}Tc-phytate$ 혼합물이 비장 27%, 간73%의 분포를 보여 비장을 거쳐온 $^{99m}Tc$의 방사능이 간에 많이 침착함을 확인하였고 간과 비장이외의 부위 즉 골수, 복수 또는 폐장이나 늑막에는 전혀 방사능 분포가 없음을 알 수 있었다. 따라서 비정맥이나 간문백에 이상이 없는 증례에서 IL-2의 비장동맥 투여는 목적하는 바 IL-2의 생체내 분포를 이룩할 수 있을 것으로 사료된다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.10
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• pp.1094-1102
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• 2010

In this paper, the problem of electromagnetic transmission via slits in a cavity inside conducting screen of finite thickness is considered for the case that the TE(to the slit axis) polarized plane wave is incident on the slit in conducting screen. Using the method of moments the variations of the transmitted power through the slits are obtained and compared with those computed from an equivalent circuit constructed using an equivalent slit admittance. It is found that the effective slit width of a narrow slit, at resonance, becomes $1/{\pi}$ wavelengths independently of the actual slit width. The transmission resonance phenomena in the proposed geometry are explained in connection with the variations of an equivalent admittance of the slit in the cavity.

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.224-227
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• 2010

In the present study, the characteristics of blood flow inside a carotid artery numerically investigated with shear rate specific blood viscosity. To simulate the blood flow with a patient-specific arterial geometry, the geometry of a carotid artery was constructed from 2D rain MRA data. The measured data of blood flow velocity at the common carotid artery were used as boundary conditions of the simulation. For the blood rheology data to be used in the simulation, the patient specific blood viscosity over the whole ranges of shear rate was obtained using $BioVisco^{TM}$. From the numerical results of the blood flow in the carotid artery, the increase of blood viscosity and the decrease of wall shear stress could be found in the carotid bifurcated region, more specifically at the post-plaque dilated region. These characteristics of blood viscosity and wall shear stress can be used more precisely and efficiently to predict the region vulnerable to plaque growht or thrombosis on top of the plaque.

• Journal of Advanced Navigation Technology
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• v.12 no.6
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• pp.574-582
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• 2008

This paper shows the research about the development of software receiver processing Galileo E1B signal. it is introduced the structure of Galileo receiving software using sampled IF data as a program input. And the performance of SDR(Software Defined Radio) embodied using MATLAB tool is analyzed. Embodied SDR is modulated according to their roll and function.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.12 no.2
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• pp.219-226
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• 1994

When a route is planned, the distance of route and earthwork volume have an important role as an economic factor. In this paper, an investigation is made on the selection of optimum route with respect to two factors above mentioned. For this investigation, a numerical test is also executed to two different types of terrain, i.e. terrain with constant slope and no undulation and terrain with slope and undulation. The results show that the shortest route is determined by the degree of undulation with no relation to the slope of topographic model, and the earthwork volume is affected by the amount of undulation and interpolation function.

• The Korean Journal of Nuclear Medicine
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• v.27 no.1
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• pp.18-21
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• 1993

이상에서 $^{99m}Tc$-MAA 도관스캔을 고찰하여 보면 다음과 같이 요약할 수 있다. 1) $^{99m}Tc$-MAA 도관스캔은 반복 시행할 수 있고, 그 방법이 간단하나 도관의 위치를 알아내는데 매우 정확하다. 2) 방사선학적 방법인 혈관조영술은 조영제 주입시 실제 항암제를 주입하는 속도보다 매우 빠르게 주입하므로써 야기될 수 있는 동맥의 연축(spasm), 층류 등의 원인에 의하여 항암제를 주입할 때와 다른 양상을 보여 암종의 헐류분포나 주변의 다른동맥으로 항암제가 주입 되는지의 여부를 정확히 알 수 없는 반면, $^{99m}Tc$-MAA 도관스캔은 항암제 주입속도와 동일하게 주입하므로써 보다 정확하게 암종의 혈류분포나 부작용을 예측할 수 있다. 3) 골반내 종양의 경우와 같이 도관을 양측의 동맥에 삽입하여야 하는 경우에는 암종에 대한 각 동맥으로부터의 혈류분포를 비교하여 항암제의 투여량을 변화시키므로써 치료효과의 상승과부작용의 감소를 꾀할 수 있다. 나아가서 둔부동맥으로의 혈류가 많은 경우에는 둔부동맥을 색전화하여 부작용을 극소화할 수도 있다. 4) 여러 종류의 종양, 특히 간종양의 경우에는 폐의 방사능섭취를 측정하여 종양내 동정맥단락을 정량화 할 수 있어 치료후 그 변화를 관찰하여 치료효과를 추측할 수도 있다.