• 한국환경과학회지
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• 제1권1호
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• pp.89-96
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• 1992

In this study , we have investigated leaching characteristics of heavy metals and alkalinity centering around steel mill slags by several extraction methods, for the purpose of risk assessment that exert influence on environment and offer of the foundation data of reuse by slags. Korean standard method, U.S.EPA Extraction Procedure, alkalinity extraction test and 9 step sequential fractionation experiment by Miller et al. were carried out for investigating teachability of steel mill slags. As a result of this experiment, heavy metals were little detected and it was considered that alkalinity does not exert a bad effect around environment in slabs with large particle size. By the result of 9 step fractionation experiment, heavy metal contents in slags were not plentiful, in addition, even comparatively plentiful contended heavy metals, for the most part, were likely to detained or bonded in silica matrix. Therefore, in case of slags with large particle size, it seems that teachability of heavy metals were next to impossible that is existed as a safety condition.

• 한국통신학회논문지
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• 제38A권9호
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• pp.792-797
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• 2013

본 논문에서는 강한 광대역정규잡음 환경에서 송신한 확산신호와 수신기에서 발생한 확산신호의 동기에 따른 2비트 비균등 양자화기의 변환손실을 (conversion loss) 분석하고, 이를 통해 변환손실이 최소인 2비트 비균등 양자화기의 출력은 ${\pm}1$, ${\pm}2$이고, 양자화 간격은 재밍 대 신호 전력비로 근사화할 수 있음을 보인다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 추계학술대회 논문집 학회본부
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• pp.419-421
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• 1994

A linear actuator using Terfenol-D rod which can accumulate displacement of the rod was fabricated. The diameter of used rod is 12[mm] and the length of it is 75[mm]. It adopts the electromagnetic units as the clamping units. Basic characteristics of the linear actuator such as displacement vs. current, velocity vs. frequency, step size vs. frequency were experimented. When the driving current is 1[A] and 100[Hz], the velocity of the actuator is about 3.5[mm/s]. We discussed the cause of step size's decrease as increasing driving frequency and the solution to the problem.

• 전기학회논문지
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• 제61권1호
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• pp.75-79
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• 2012

Maximum power point tracking(MPPT) techniques are used in photovoltaic systems to maximize the PV array output power by tracking continuously the maximum power point which depends on panels temperature and on irradiance conditions. This paper proposes a variable step size MPPT algorithm which can improve the MPPT speed and accuracy. Depending on insolation and temperature, the MPPT controller gives optimized step size. The effectiveness of the proposed system is verified thorough PSIM simulation and experiments on a 50[W] prototype. The experimental results confirm that the PV power of the improved P&O method is higher than that of the traditional P&O method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.689-692
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• 2003

In this paper, we propose an adaptive beamforming algorithm for array antenna. The proposed beamforming algorithm, based on Block LMS (Block - Least Mean Squares) algorithm, has a variable step size from coefficient update. This method shows some advantages that the convergence speed is fast and the calculation time can reduced using a block LMS algorithm from frequency domain. As the adaptive parameter approaches a stationary state, it could reduce the number of filter coefficient update with the help of various step size. In this paper we compared the efficiency of the proposed algorithm with a standard LMS algorithm which is a representative method of adaptive beamforming.

• Journal of Welding and Joining
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• 제20권1호
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• pp.55-61
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• 2002

The automobile is made up of about twenty thousand parts. Some parts are formed by pressing and combined by spot welding. Among them, steel palate of fuel tank is formed in the metal mold and bending parts are jointed by spot and seam welding. To find weldability conditions of spot welding, clearance between two welding steel plates was made and after spot welding, weldability is evaluated by means of tensile shear load, nugget size and shape. Specimen used in this study was a mild steel of 1.2mm thickness and electrode was Cu-Cr alloy of 6mm diameter. When spot welding started, the clearance of two steel plates was changed 0mm, 3mm and 5mm step by step. The fractured surface of specimen after this test was observed by Optical Microscope to measure microstructure and nugget shape. When clearance of two specimen was 3mm and 5mm, strength and nugget size was decreased and nugget shape was not clear.

• 한국응용과학기술학회지
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• 제31권3호
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• pp.492-499
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• 2014

The objectives of this study was to examine experimentally the microexplosion phenomena of single droplet W/O(water-in-oil) type emulsified fuel. Also, measured the combustion characteristics of single droplet emulsified fuel for microexplosion phenomena in atmospheric pressure condition. The larger quantity of adding water makes microexplosion phenomenon with higher intensity of sound level, because larger water droplet has better coalescence for emulsified fuel. The small quantity of adding water makes puffing with lower sound level intensity. In latter period of extinction, large size droplet of the emulsified fuel breaks down rapidly to small size droplet, and microexplosion phenomenon occurs with multi step combustion.

• Nonlinear Functional Analysis and Applications
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• 제27권2호
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• pp.381-403
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• 2022

The main goal of this research is to solve variational inequalities involving quasimonotone operators in infinite-dimensional real Hilbert spaces numerically. The main advantage of these iterative schemes is the ease with which step size rules can be designed based on an operator explanation rather than the Lipschitz constant or another line search method. The proposed iterative schemes use a monotone and non-monotone step size strategy based on mapping (operator) knowledge as a replacement for the Lipschitz constant or another line search method. The strong convergences have been demonstrated to correspond well to the proposed methods and to settle certain control specification conditions. Finally, we propose some numerical experiments to assess the effectiveness and influence of iterative methods.

• 한국음향학회지
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• 제28권7호
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• pp.640-645
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• 2009

블라인드 채널 등화기의 일종인 CMA방식의 수렴 속도는 일반적을 훈련열을 바탕으로 한 방법에 비해서 느린 경향이 있다. 또 그 수렴 속도는 정해진 스텝사이즈에 따라 정해진다. 본 논문은 기존 고정 스텝사이즈 CMA 알고리즘의 수렴 속도를 개선하기 위한 직교 정사형 망각인자를 도입하여 수렴성능이 개선된 새로운 알고리즘을 제안한다.

• 전자공학회논문지S
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• 제34S권9호
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• pp.84-90
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• 1997

We proposed a new bit-rate control algorithm to improve MPEG-2 video software encoder. Bit-rate Control plays an improtant role in picture quality of MPEG-2 encoder. To achieve better encoding performance such as controlling picture quality and using bity properly, we proposed a MPEG-2 bit-rate control algorithm using linear average Step-Size. Using a benchmark Program, we compared our algorithm with MPEG-2 Test Model 5. Our proposed algorithm showed better Bit-Rate Control with respect to used bits, picture quality.