• The Journal of the Korea Contents Association
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• v.6 no.2
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• pp.162-168
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• 2006

This paper presents a high performance CORDIC circuit based on redundant numbers yielding a minimal number of iteration stages. The minimal number of iteration stages reflects the iteration number yielding a smaller computation error than the truncation error. The minimal number of iterations is found n-4 for $n\geq16$, where n is the number of input angle bits. The CORDIC circuit is based on a redundant number system with a constant scale factor The circuit performs sine and cosine calculations with a delay of {5 (n-4)+ 2[$log_{2}n$]}$\DeltaT$.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.5
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• pp.1117-1122
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• 2005

This paper is studied the high-repetition rate optical-pulse stream generation using optical loop mirror coupler. With the recent development of the ultrahigh-speed optical time division multiplexed system, hish-repetition rate optical-pulse stream generation is necessary. This is different from conventional approaches, which use fiber or integrated waveguide delay line circuits. The high-repetition-rate optical-pulse multiplication phenomenon occurs when the optical pulse's spectral width is greater than the transfer bandwidth of the coupler used. From the analysis, the output repetition rate can be controlled by using fiber couplers with different equivalent transfer bandwidths. The pulse separation spacing is controlled by number of cascaded coupler in optical loop mirror coupler scheme.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.2
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• pp.186-191
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• 2011

Ramp metering has been used to solve recurrent or non-recurrent congestion on many highways. However, the existing ramp metering methods cannot control non-recurrent congestion like incident and don't have any methods to solve congestion after congestion. In addition, the methods cannot solve congestion quickly because ramp metering operates independently for each ramp. In this study, we developed SARAM which is ramp metering technique with shockwave theory in order to solve the problems. In simulation from Jangsoo IC to Joongdong IC, we confirmed that speed increased by 7.32km/h and delay time reduced by 39.14sec.

• The Korean Journal of Applied Statistics
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• v.30 no.6
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• pp.931-941
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• 2017

Typical Nonparametric methods for randomized block design with replications are two methods proposed by Mack (1981) and Mack and Skillings (1980). This method is likely to cause information loss because it uses the average of repeated observations instead of each repeated observation in the processing of each block. In order to compensate for this, we proposed a test method using linear placement statistics, which is a score function applied to the joint placement method proposed by Chung and Kim (2007). Monte Carlo simulation study is adapted to compare the power with previous methods.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.264-267
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• 2005

플럭 형성 비소 오염토양에 대한 토양세척기법의 적용성 실험결과, 세척용액 100 mM과 500 mM의 농도에서 대상 토양에 대한 비소 용출량은 수산화나트륨이 염산보다 높은 효율을 보였으며, 농도 1000 mM의 경우에는 염산이 비교적 우세한 세척효율을 보였다. 토양오염공정시험법에 의한 세척후 토양내 잔류비소 농도의 경우, 염산이 수산화나트륨과 비슷하거나 다소 우세함을 알 수 있었다. 세척 대상 토양의 Cut-off size limit을 선정하여 토양세척시 생성되는 플럭을 제거하지 않고 반복 세척한 결과, 수산화나트륨의 농도 200 mM은 1000 mM에 비하여 잔류된 비소량이 비슷하거나 비교적 높았으며, 2가지 농도에 대하여 총 5회 반복 세척한 토양의 비소 농도는 토양환경보전법의 가지역 우려기준 농도인 6 mg/kg에 근접한 결과를 보였으나, 염산의 경우 총 5회 세척시 비소의 농도가 약 9 mg/kg으로 비소 잔류량이 보다 큼을 알 수 있었다. 플럭을 제거한 후 반복 세척시 수산화나트륨의 농도 1000 mM이 200 mM에 비하여 토양 세척효율이 증가하였으며, 1000 mM로 5회 세척시 잔류비소 농도가 가지역 우려기준 농도에 근접한 약 6.7 mg/kg이었고 염산을 이용하여 세척한 경우에는 3회 세척시 약 6.7 mg/kg 4, 5회 반복 세척시 각각 약 3.9, 3.3 mg/kg으로 가지역 우려기준에 적합한 농도조건이 됨을 알 수 있었다.

• Journal of the Institute of Convergence Signal Processing
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• v.13 no.3
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• pp.130-135
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• 2012

In this paper, we propose a technique to detect the size and location of the small target in images by using Gaussian kernel repeatedly. In order to detect the size and location of the small target, we find the local maximum value by applying the facet model and then use the $3{\times}3$ Gaussian kernel repeatedly. we determine the size of small target by comparing the local maximum value $D_2$ according to the number of iteration. To reduce the computational complexity, we use the Gaussian pyramid when using the kernel repeatedly. Through the experiment, we verified that the size and location of the small target is detected by the number of iterations and results show improvements from conventional methods.

• Journal of the Institute of Convergence Signal Processing
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• v.5 no.4
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• pp.271-280
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• 2004

This paper presents a new iterative image restoration algorithm with removal of boundary/object-oriented ringing, The proposed method is based on CGM(Conjugate Gradient Method) iterations with inter-wavelet shrinkage. The proposed method provides a fast restoration as much as CGM, while having adaptive do-noising and do-ringing by using wavelet shrinkage. In order to have effective do-noising and do-ringing simultaneously, the proposed method uses a space-dependent shrinkage rule. The improved performance of the proposed method over more traditional iterative image restoration algorithms such as LR(Lucy-Richardson) and CGM in do-noising and do-ringing is shown through numerical experiments.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.9
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• pp.1985-1997
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• 1997

This paper proposed a regularized iterative image restoration by using method of conjugate gradient. Compared with conventional iterative methods, method of conjugate gradient has a merit to converte toward a solution as a super-linear convergence speed. But because of those properties, there are several artifacts like ringing effects and the partial magnification of the noise in the course of restoring the images that are degraded by a defocusing blur and additive noise. So, we proposed the regularized method of conjugate gradient applying constraints. By applying the projectiong constraint and regularization parameter into that method, it is possible to suppress the magnification of the additive noise. As a experimental results, we showed the superior convergence ratio of the proposed mehtod compared with conventional iterative regularized methods.

• Magazine of the Korea Concrete Institute
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• v.3 no.3
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• pp.149-157
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• 1991

This paper concentrates on the nonlinear analysis of the reinforced concrete flexural members under cyclic loading. To develop a nonlinear material model, concrete is treated as an orthotropic nonlinear material and steel is modeled as an elasto-plastic material. The models for hysteresis behavior with stiffness degradation in compression and for crack opening and closing in tension are included. The finite element computer program for the nonlinear analysis of RC flexural members under cyclic loading is developed. The accuracy and reliabihty of the numerical procedure IS demonstrated by the FEM analysis and test results of underreinforced concrete beams.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2000.12a
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• pp.125-128
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• 2000

The conventional fractal decoding was required a vast amount computational complexity. Since every range blocks was implemented to IFS(iterated function system). In order to improve this, it has been suggested to that each range block was classified to iterated and non-iterated regions. If IFS region is contractive, then it can be performed a fast decoding. In this paper, a searched region of the domain in the encoding is limited to the range region that is similar with the domain block, and IFS region is a minimum. So, it can be performed a fast decoding by reducing the computational complexity for IFS in fractal image decoding.