• Journal of applied mathematics & informatics
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• v.29 no.1_2
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• pp.173-190
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• 2011

In this paper, we construct a new approach of affine scaling interior algorithm using the affine scaling conjugate gradient and Lanczos methods for bound constrained nonlinear optimization. We get the iterative direction by solving quadratic model via affine scaling conjugate gradient and Lanczos methods. By using the line search backtracking technique, we will find an acceptable trial step length along this direction which makes the iterate point strictly feasible and the objective function nonmonotonically decreasing. Global convergence and local superlinear convergence rate of the proposed algorithm are established under some reasonable conditions. Finally, we present some numerical results to illustrate the effectiveness of the proposed algorithm.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.11a
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• pp.102-105
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• 2017

최근 네트워크 서비스 관리의 복잡성을 줄이기 위해 새로운 네트워크 인프라가 등장하고 있다. NFV(Network Function Virtualization) 기술은 하드웨어 기반의 네트워크 장비에 가상화를 적용하여, 유연성 있는 네트워크 서비스를 제공한다. 네트워크 서비스는 Firewall, Parental Control (PC)과 같은 일련의 VNF (Virtual Network Function)로 구성된다. NFV 기술을 기존의 네트워크 환경과 통합시키는 경우 해결해야 할 난제가 존재한다. 기존 네트워크는 복잡성이 요구되며 많은 양의 트래픽을 다루어야 한다. 사용자가 요청한 네트워크 서비스의 높은 트래픽 로드로 인해 패킷 손실이 발생할 수 있다. 본 논문에서는 Zabbix 모니터링 시스템을 활용해 VNF 로드 기반의 Auto-scaling을 제안한다. 이를 통해 네트워크 서비스의 자원 효율성을 향상시키고 패킷 손실 비율을 줄일 수 있다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.11
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• pp.2304-2310
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• 2009

This paper presents WSK(wavelet shift keying) that can be improved to bit transmission rate in the digital communication. An algorithm of the conventional modulation is carried out that the scaling function and wavelet are encoded to 1(mark) and 0(space) for the input binary data, respectively. A new modulation technique that uses four carrier frequencies is proposed. Four carrier frequencies are defined as scaling function, inversed scaling function, wavelet, and inversed wavelet, which are encoded to 10, 11, 00 and 01 respectively. An algorithm of the proposed demodulation is decode to the original data using four correlation. As a results of simulation, we confirmed that the proposed method was improved to the performance at twice for the bit transmission rate.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.11
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• pp.1933-1938
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• 2008

There are the frequency shift keying(FSK), phase shift keying(PSK) and amplitude shift keying(ASK) in the conventional digital communications method. In this parer, We proposed the algorithm for wavelet shift keying system using a binary matching filter in the digital communication. Wavelet shift keying system are used to a scaling function(low frequency) and wavelet(high frequency) coefficients. The binary data is encoded by modulator which assigned the scaling function to 1(one), and wavelet to zero(0). Wavelet shift keying of the conventional method needs to a post-processing for the decoding. In this paper, wavelet shift keying signal is reconstructed by the decoder using a binary matching filter. So, it was able to the decoding without the post-processing. It was demonstrated by the experiment that the proposed algorithm is a validity.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.227-230
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• 2008

기존의 대표적인 디지털 통신방식으로 주파수 편이 변조(FSK: frequency shift keying), 위상 편이 변조(PSK: phase shift keying), 진폭 편이 변조(ASK: amplitude shift keying) 방식들이 있다. 본 논문에서는 디지털 통신에서 비트 전송률을 높이기 위하여 스케일링 함수(scaling function)와 웨이브릿(wavelet)을 이용한 2비트 스케일을 갖는 웨이브릿 편이 변조(WSK: wavelet shift keying)신호의 복원 알고리즘을 제안한다. 변조시 스케일링 함수(scaling function)와 웨이브릿(wavelet) 그리고 이 두 신호를 반전하여 2비트 스케일 즉, 00, 01, 10, 그리고 11로 변조하였다. 복조시에는 변조된 신호를 2개의 2진 정합필터에 통과시켰다. 그리고 정합필터를 거친 파형을 조합하여 4가지 신호를 복원하였다. 모의실험 결과 제안한 알고리즘이 기존의 웨이브릿 편이 변조 시스템에 비해 전송효율이 향상되었음을 알 수 있었다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.5
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• pp.982-988
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• 2012

This paper has presented the relation of scaling theory and threshold voltage of double gate(DG) MOSFET. In the case of conventional MOSFET, current and switching frequency have been analyzed based on scaling theory. To observe the possibility of application of scaling theory for threshold voltage of DGMOSFET, the change of threshold voltage has been observed and analyzed according to scaling theory. The analytical potential distribution of Poisson equation has been used, and this model has been already verified. To solve Poisson equation, charge distribution such as Gaussian function has been used. As a result, it has been observed that threshold voltage is grealty changed according to scaling factor and change rate of threshold voltages is traced for scaling of doping concentration in channel. This paper has explained for the best modified scaling theory reflected the influence of two gates as using weighting factor when scaling theory has been applied for channel length and channel thickness.

• Membrane and Water Treatment
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• v.8 no.2
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• pp.125-136
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• 2017

Reverse osmosis technology is being used on large scale for treatment of ground water, brackish water, wastewater and sea water. The most challenging issue in RO process is carbonate scaling which is directly linked with the efficiency and economy. Considering the natural phenomena of carbonate scaling different adaptations have been made to control scaling on the surface of RO membrane including acid dosage and antiscalant addition. As carbonate scaling is directly related with pH level of feed water, present study describes an experimental approach to reduce scaling on RO membrane by lowering the feed water pH by purging $CO_2$. In this comparative study four different conditions including control process (without any scale inhibitor), with dosage of antiscalant, with purging of $CO_2$ and with co addition of antiscalant and $CO_2$ in a feed stream line; it was established that $CO_2$ is a better appliance to reduce carbonate scaling on the membrane surface by reduce pH of feed stream. It was also observed that $CO_2$ and antiscalant mutually function better for scale control.

• Korean Chemical Engineering Research
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• v.60 no.2
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• pp.260-266
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• 2022

Average aggregate size in particulate suspensions is estimated with scaling theories based on fractal concept and elasticity of colloidal gel. The scaling theories are used to determine structure parameters of the aggregates, i.e., fractal dimension and power-law exponent for aggregate size reduction with shear stress using scaling behavior of elastic modulus and shear yield stress as a function of particle concentration. The structure parameters are utilized to predict aggregate size which varies with shear stress through rheological modeling. Experimentally rheological measurement is conducted for aqueous suspension of zinc oxide particles with average diameter of 110 nm. The predicted aggregate size is about 1135 nm at 1 s^-1 and 739 nm at 1000 s^-1 on the average over the particle concentrations. It has been found that the predicted aggregate size near 0.1 s^-1 agrees with that the measured one by a dynamic light scattering analyzer operated un-sheared.

• Korea-Australia Rheology Journal
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• v.13 no.4
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• pp.197-203
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• 2001

We reported on the eletrorheological (ER) properties of several semiconducting polymers including poly (p-phenylene) (PPP), poly (acene quinone) radicals (PAQRs), microencapsulated polyaniline (MPANI) and polyaniline (PANI) those we synthesized. The yield stress dependence on electric field strength for the ER fluids using these semiconducting polymers was mainly examined. The yield stress, which is an important design parameter for ER fluids, was observed to satisfy a universal scaling function, allowing that yield stress data for all the ER fluids examined in this study collapse onto a single curve for a broad range of electric field strengths. The proposed scaling function incorporates both the polarization and conductivity models.

• Bulletin of the Korean Mathematical Society
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• v.33 no.4
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• pp.639-647
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• 1996