• Bulletin of the Korean Chemical Society
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• 제30권9호
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• pp.2001-2006
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• 2009

Temperature dependence of the critical micelle concentration (CMC), $x_{CMC}$, in micellization can be described by ln $x_{CMC}$ = A + BT + C lnT + D/T, which has been derived statistical-mechanically. Here A, B, C, and D are fitting parameters. The equation fits the CMC data better than conventionally used polynomial equations of temperature. Moreover, it yields the unique(exponent) value of 2 when the CMC is expressed in a power-law form. This finding is quite significant, because it may point to the universality of the thermal behavior of CMC. Hence, in this article, the nature of the equation ln $x_{CMC}$ = A + BT + C lnT + D/T is examined from a lattice-theory point of view through the Flory-Huggins model. It is found that a linear behavior of heat capacity change of micellization is responsible for the CMC equation of temperature.

• 대한전자공학회논문지
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• 제10권6호
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• pp.45-55
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• 1973

본 논문은 한개의 터널다이오드로 구성된 시간에 무관한 비선형 회로를 논한다 부저항 소자로 구성된 비선형 회로의 해를 구하기 전에 비선형 소자의 정특성을 어떤 함수로 표시할 필요가 있다. 최소 자승법에 의해서 정특성을 표현하는 근사 다항식 커브를 구했다. 비선형 회로를 해석하기 위해서는 우선 그 회로에 관한 상태방정식이 설정되면 프레딕터·코렉터 방법에 의해서 해를 구할수 있다. 최종적으로, 비선형 회로의 안정도와 발진 조건을 논하기 위해서 limit cycle을 점철했다.

• 전기학회논문지
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• 제56권6호
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• pp.1157-1164
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• 2007

In this paper, we implement a PDA(Personal Digital Assistant)-based audiometric system in order to estimate hearing threshold by adopting both pure-tone sound and speech audiometric test system. To estimate a subject's hearing threshold in an ambulatory audiometric test environment, an efficient sound calibration scheme between a PDA and a headphone device is proposed by appling polynomial fitting algorithms in 8-banded frequency ranges.

• Journal of the Korean Statistical Society
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• 제34권3호
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• pp.209-218
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• 2005

In response surfaces analysis, we often proceed by supposing that, over a limited region of factor space, a polynomial of only first or second degree might adequately approximate the true function. To find the best subset model, all possible quadratic regressions for response surfaces can be very valuable to get optimum solutions under some reasonable experimentations. However, there is a very hard computational burden to get all possible quadratic regressions. In practice, it is sufficient to consider only hierarchical models. In this paper, we propose an algorithm to get all possible hierarchical quadratic regressions for fitting response surfaces.

• 한국공작기계학회논문집
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• 제14권3호
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• pp.54-59
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• 2005

The cylindrical object are widely used as mechanical parts in the manufacturing process. In order to handling those objects using a robot or an automated machine automatically, the pose of the object must be known. The pose can be described by two rotation angles; one angle about the x axis and the other about the y axis. In the many previous researches these angles were obtained by the computationally intensive algorithm, that is, fitting the data as a polynomial and doing pseudo inverse. So that, this method required high performance microprocessor. In this paper in order to avoid complex computation, a new method based on a genetic algorithm is proposed and analyzed through a series of simulations. This algorithm utilized the geometry of the cylindrical shape. The simulation results show that this method find the pose angles very well In most cases, but the computation time is randomly changed because the genetic algorithm is basically one of the random search method.

• 환경생물
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• 제21권4호
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• pp.384-391
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• 2003

The induction of chromosome aberrations in Hordeum vulgare germs after irradiation is studied for the dose range of 10 to 1,000 mGy. The relationship between the frequency of aberrant cells and the absorbed dose is shown to be non -linear and has a dose-independent plateau within the range of 56-467 mGy where the level of cytogenetic damage is statistically significantly distinguished from the spontaneous level. The comparison of the goodness of the experimental data fitting with mathematical models of different complexities, using the most common quantitative criteria, demonstrates the benefit of the piecewise linear model over the linear and polynomial ones in approximating the cytogenetical disturbance frequency. The results of our study support the conclusion about indirect mechanism of chromosome aberrations induced by low doses or dose rates mutagenesis.

• Journal of Astronomy and Space Sciences
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• 제15권1호
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• pp.197-208
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• 1998

Ground track manintenance maneuver simulations for the KOMPSAT spacecraft are performed for three and half years. Both longitude targeting and time targeting strate-gies are applied for in-plane maneuvers. The nominal longitude bands of maneuvers for $\pm5km$ and $\pm10km$ are applied for the longitude targeting and the 21-day maneuver time duration is used for the time targeting. Daily solar flux values for the simulation period are derived from the previous solar cycle values. Atmospheric drag formula for the KOMPSAT orbit altitude is derived from Jacchia model using polynomial and sinusoidal curve fitting. Total required delta velocity and proper time between successive maneuvers are estimated during ground track maintenance maneuver simulations.

• 충청수학회지
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• 제22권4호
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• pp.777-787
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• 2009

In this paper we investigate the upper bound on the Castelnuovo-Mumford regularity of a graded module with linear free presentation. Let M be a finitely generated graded module over a polynomial ring R with zero dimensional support. We prove that if M is generated by elements of degree $d{\geq}0$ with a linear free presentation $$\bigoplus^p{R}(-d-1)\longrightarrow^{\phi}\bigoplus^q{R}(-d){\longrightarrow}M{\longrightarrow}0$$, then the Castelnuovo-Mumford regularity of M is at most d+q-1. As an important application, we can prove vector bundle technique, which was used in [11], [13], [17] as a tool for obtaining several remarkable results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 D
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• pp.2528-2530
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• 2004

Neural network minimization problems are often conditioned and in this contribution way to handle this will be discussed. It is shown that a better conditioned minimization problem can be obtained if the problem is separated with respect to the linear parameters. This will increase the convergence speed of the minimization. One of the most powerful uses of neural networks is in function approximation(curve fitting)[1]. A main characteristic of this solution is that function (f) to be approximated is given not explicitly but implicitly through a set of input-output pairs, named as training set, that can be easily obtained from calibration data of the measurement system. In this context, the usage of Neural Network(NN) techniques for modeling the systems behavior can provide lower interpolation errors when compared with classical methods like polynomial interpolation. This paper solve of single-variable minimization using neural network.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.571-575
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• 2000

The physical properties of the spatial model, mass, stiffness and damping matrix, can be defined by a specific natural frequency, damping ratio and mode shape. These modal parameters can be determined from a set of frequency response function(FRF) measured by exciting the structure and measuring the responses at various points around the structure. In this paper, The Transfer Matrix is obtained by experimental modal analysis for the 3-story scaled building model which TMD is installed on top and the physical properties of the spatial model is determined using the residue matrix and the location of poles from FRF measurement using polynomial curve fitting methods.