• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제8권2호
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• pp.15-21
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• 2004

A Conjugate Gradiant (CG) method is proposed for unconstained optimization which is invariant to a nonlinear scaling of a strictly convex quadratic function. The technique has the same properties as the classical CG-method when applied to a quadratic function. The algorithm derived here is based on a logarithmic model and is compared to the standard CG method of Fletcher and Reeves [3]. Numerical results are encouraging and indicate that nonlinear scaling is promising and deserves further investigation.

• 산업기술연구
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• 제15권
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• pp.195-202
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• 1995

In this paper, we analyze the effects of scaling factors on the performance of a fuzzy controller. The quantitative relation between input and output variables of a fuzzy controller is obtained by using a quasi-linear fuzzy model. And an approximate transfer function of a fuzzy controller is derived from the comparison of fuzzy controller with the conventional PID controller. Then we analyze the effects of scaling factor using this approximate transfer function and root locus method.

• 한국정보통신학회논문지
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• 제18권1호
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• pp.57-62
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• 2014

다수의 중계기가 균등하게 분포된 무선 소거 네트워크의 용량 스케일링 법칙을 분석함으로써 인프라 구조 사용시 이득을 보인다. 가정하는 네트워크 하에서 소거 확률을 적절히 모델링함에 근거하여, 혼합 소거 네트워크에서 취득 가능한 네트워크 용량을 보인다. 보다 구체적으로, 지수 감쇠 모델 및 다항 감쇠 모델 이렇게 두 가지 물리적 모델을 사용한다. 중계기 도움이 없는 다중 홉 전송, 중계기 도움을 받는 다중 홉 전송 이렇게 두 가지 존재하는 기술을 사용하여 취득 용량을 분석한다. 유도된 용량 스케일링 법칙은 두 가지 물리적 모델 모두에 대해 노드 수 및 중계기의 수에 의존함을 확인한다.

• Journal of Power Electronics
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• 제12권1호
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• pp.164-171
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• 2012

Variable step size maximum power point trackers (MPPTs) are widely used in photovoltaic (PV) systems to extract the peak array power which depends on solar irradiation and array temperature. One essential factor which judges system dynamics and steady state performances is the scaling factor (N), which is used to update the controlling equation in the tracking algorithm to determine a new duty cycle. This paper proposes a novel stability study of variable step size incremental resistance maximum power point tracking (INR MPPT). The main contribution of this analysis appears when developing the overall small signal model of the PV system. Therefore, by using linear control theory, the boundary value of the scaling factor can be determined. The theoretical analysis and the design principle of the proposed stability analysis have been validated using MATLAB simulations, and experimentally using a fixed point digital signal processor (TMS320F2808).

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1998년도 The Third Asian Fuzzy Systems Symposium
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• pp.51-56
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• 1998

In this paper, we analyze the effects of scaling factors on the performance of a fuzzy logic controller(FLC). The quantitative relation between input and output variables of FLC is obtained by using a qualsi-linear fuzzy model, and an approximate transfer function of FLC is dervied from the comparison of it with the conventional PID controller. Then we analyze in detail the effects of scaling factor using this approximate transfer function and root locus method. Also we suggest an on-line tuning method for scaling factors which employs an sample performance function and a variable reference for tuning index.

• 한국치위생학회지
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• 제12권4호
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• pp.675-684
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• 2012

Objectives : The purpose of this study was to develop an instrument for Korean Scaling Fear (KSF)-1.1 in scaling patients. Methods : 402 sample size for scaling patients was studied in Daegu city in July and August of 2011. Mean and standard deviation was calculated in 3 dimensions(FWS: fear while scaling, DDH: distrust on dental hygienist, FAS: fear after scaling). Results : Age of 402 subjects was 36.5 years. In analyzing reliability for item-level, a range of correlation coefficient(${\alpha}$) on item-internal consistency(FWS, DDH, and FAS) was 0.58~0.88(${\alpha}$=0.90), 0.40~0.71(${\alpha}$=0.82), and 0.54~0.63(${\alpha}$=0.82), respectively. Floor(%) and ceiling(%) value on 3 dimensions were also 9.2% and 4.0%, 12.4% and 0.5%, and 17.7% and 1.2%, respectively, therefore, we found statistically high reliability for those(p<0.001). With explanatory factor analysis, this study could generate 3 dimensions(factor 1, eigenvalue 5.41, proportion 0.49; factor 2, eigenvalue 1.50, proportion 0.14; factor 3, eigenvalue 1.04, proportion 0.09) and 11 sub-scales. Also confirmatory factor analysis results showed that the KSF1.1 model was fitted very well in analysis of model fit($x^2$=112.94, df=41, p=0.000; goodness of fit index=0.95; adjusted goodness of fit index=0.92; root mean square residual=0.057). Conclusions : In conclusion, The findings of this study showed that developed reliable and valid instrument for measuring the KSF1.1 in the scaling patients.

• 천문학논총
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• 제7권1호
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• pp.51-61
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• 1992

The nonlinear stochastic behavior of chaotic inflation is characterized by the 'scaling' effect. Using a simple criterion for the appearance of scaling behavior in the ${\lambda}{\phi}^4$ inflation model, we show explicitly that in this limit the onset of the scaling regime does not require any special initial conditions and that it is independent of the self-coupling constant ${\lambda}$. Non-Gaussian statistics in adiabatic fluctuations are important only for super-horizon scales and the scaling regime does not lead to any significant statistical properties on currently observable scales. However, the scaling effect gives some cosmological consequences very different from what we expect in the naive diffusion approximation for quantum fluctuations. The classical (deterministic) treatment of the inflation field (essentially a quantum mechanical object.) becomes valid towards the end of inflation.

• 한국컴퓨터산업학회논문지
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• 제5권9호
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• pp.993-1004
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• 2004

본 논문에서는 구동토크의 제약을 갖는 4륜 2자유도 구륜이동로봇의 기구학 및 동력학 모델링과 경로추적을 다룬다. 유도된 기구학 모델을 이용하여 구륜이퐁로봇의 가제어성을 조사한다. 순간일치좌표계와 힘/토크의 전파, 뉴튼의 평형법칙을 이용하여 동려학 모델을 유도한다. 역동력학에 의해 산출된 구동토크가 한계 구동토크를 초과할 경우, time-scaling 기법을 이용하여 기준제적을 수정함으로써 구륜이동로봇이 기준경로를 추적하도록 한다. 제어기는 모델링 불확실성과 측정 잡음 등으로 인하여 발생하는 오차를 보상하도록 설계한다. 또한 본 논문에서 제시된 기법의 유효성을 입증하기 위해 모의실험을 수행하고 그 결과를 제시한다.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2006년도 학술발표회 논문집
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• pp.97-104
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• 2006

The centrifuge and 1-g shaking table tests were performed simultaneously to compare the dynamic behaviors of loose sands of same geotechnical properties. The prototype soils were 10 m thick liquefiable loose sands. The geometric scaling factors were 20 for 1-g and 40 for centrifuge tests. The excess pore pressure, surface settlement, and acceleration in the soil were measured at the same locations in the 1-g and centrifuge tests. The total excess pore pressure from development to dissipation was measured. In the centrifuge test, viscous fluid was used as the pore water to eliminate the time scaling difference between dynamic time and dissipation time. In the 1-g tests, the steady state concept was applied to determine the unit weight of the model soil, and two different time scaling factors were applied for the dynamic time and the dissipationtime. It is concluded that the 1-g tests can simulate the excess pore pressure of the prototype soil if the permeability of the model soil is small enough to prevent dissipation of excess pore pressure during shaking and the dissipation time scaling factor is properly determined.

• Journal of the korean society of oceanography
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• 제38권1호
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• pp.11-16
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• 2003

The three dimensional structure of thermohaline circulation in a D-plane is investigated using a conceptual two layer model and a scaling argument. In this simple model, the water mass formation region is excluded. The upper layer represents the oceans above the main thermocline. The lower layer represents the deep ocean below the thermocline and is much thicker than the upper layer. In each layer, geostrophy and the linear vorticity balance are assumed. The cross interfacial velocity that compensates for the deep water mass formation balances downward heat diffusion from the top. From the above relations, we can determine the thickness of the upper layer, which is the same as thermocline depth. The results we get is basically the same as that we get for an f-plane ocean or the classical thermocline theory. Mass budget using the velocity scales from the scaling argument shows that western boundary and interior transports are much larger than the net meridional transport. Therefore in the thermohaline circulation, horizontal circulation is much stronger than the vertical circulation occuring on a meridional plane.