• International Journal of Computer Science & Network Security
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• 제22권1호
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• pp.167-174
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• 2022

In metaheuristic algorithms such as Genetic Algorithm (GA), initial population has a significant impact as it affects the time such algorithm takes to obtain an optimal solution to the given problem. In addition, it may influence the quality of the solution obtained. In the machine learning field, feature selection is an important process to attaining a good performance model; Genetic algorithm has been utilized for this purpose by scientists. However, the characteristics of Genetic algorithm, namely random initial population generation from a vector of feature elements, may influence solution and execution time. In this paper, the use of a statistical algorithm has been introduced (Chi2) for feature relevant checks where p-values of conditional independence were considered. Features with low p-values were discarded and subject relevant subset of features to Genetic Algorithm. This is to gain a level of certainty of the fitness of features randomly selected. An ensembled-based learning model for Hepatitis has been developed for Hepatitis C stage classification. 1385 samples were used using Egyptian-dataset obtained from UCI repository. The comparative evaluation confirms decreased in execution time and an increase in model performance accuracy from 56% to 63%.

• 대한수학회지
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• 제34권3호
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• pp.623-632
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• 1997

In this paper, the nonexistence of the global solutions of semilinear wave equations with damping terms in the boundary conditions is investigated.

• Structural Engineering and Mechanics
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• 제14권3호
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• pp.263-285
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• 2002

This paper presents a numerical procedure for solving initial-value problems using the special functions which belong to a class of Rvachev's basis functions $R_{bf}$ based on algebraic and trigonometric polynomials. Because of infinite derivability of these functions, derivatives of all orders, required by differential equation of the problem and initial conditions, are used directly in the numerical procedure. The accuracy and stability of the proposed numerical procedure are proved on an example of a single degree of freedom system. Critical time step was also determined. An algorithm for solving multiple degree of freedom systems by the collocation method was developed. Numerical results obtained by $R_{bf}$ functions are compared with exact solutions and results obtained by the most commonly used numerical procedures for solving initial-value problems.

• 한국경영과학회지
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• 제23권4호
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• pp.141-149
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• 1998

One of the difficulties in using the current Boolean-based information retrieval systems is that it is hard for a user, especially a novice, to formulate an effective Boolean query. One solution to this problem is to let the system formulate a query for a user from his relevance feedback documents in this research, an intelligent query reformulation mechanism based on ID3 is proposed and the sensitivity of its retrieval effectiveness, i.e., recall, precision, and E-measure, to various input settings is analyzed. The parameters in the input settings is the number of relevant documents. Experiments conducted on the test set of Medlars revealed that the effectiveness of the proposed system is in fact sensitive to the number of the initial relevant documents. The case with two or more initial relevant documents outperformed the case with one initial relevant document with statistical significances. It is our conclusion that formulation of an effective query in the proposed system requires at least two relevant documents in its initial input set.

• 터널과지하공간
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• 제14권5호
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• pp.339-344
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• 2004

침식에 따른 횡방성 암반의 초기응력비 변화를 수치해석적으로 구하여 등방성의 경우 및 이론해와 비교한 결과 횡등방성의 영향은 크지 않아 초기지응력비가 작고 침식심도가 깊을 때만 고려하는 것이 좋을 것으로 판단되었다. 수치해석에 의한 응력과 이론적인 값의 차이는 초기 지응력비가 클수록 또 침식되는 깊이가 증가할수록 증가하였다. 또 침식 후의 초기응력비는 심도가 깊어짐에 따라 초기 응력비로부터 발산하였다. 이를 감안하여 침식에 따른 초기응력비 산정식을 제안하였다.

• 한국산업융합학회 논문집
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• 제4권4호
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• pp.427-432
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• 2001

The purpose of study is to examine the sensitivity of the rate of degradation to initial TCE concentration and iron concentration in the solution. The batch tests were executed to assess the degradation rate at varying initial conditions. First order rate constants($k_a$) were more rapid with the lower initial TCE concentration, Howere the correleation was not always linear between $k_a$ and initial TCE concentration. $k_a$ was proportionally increased as the increasing surface area. It implied that the effective reactive surface area acted as the limiting factor on the reductive dechlorination of TCE by iron.

• Smart Structures and Systems
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• 제21권4호
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• pp.469-477
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• 2018

This paper presents a numerical solution for the thick cylinders made of functionally graded materials (FGMs) with a constant Poisson's ratio and an arbitrary Young's modulus. We define two fundamental solutions which are derived from an ordinary differential equation under two particular initial boundary conditions. In addition, for the single layer case, we can define the transfer matrix N. The matrix gives a relation between the values of stress and displacement at the interior and exterior points. By using the assumed boundary condition and the transfer matrix, we can obtain the final solution. The transfer matrix method also provides an effective way for the solution of multiply layered cylinder. Finally, a lot of numerical examples are present.

• 한국가구학회지
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• 제18권4호
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• pp.282-286
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• 2007

An experiment was conducted to compare the 1% safranine solution flow depth in radial and longitudinal direction of Prunus sargentii. Longitudinal flow of safranine solution was found higher than radial flow. Body ray parenchyma was found more permeable than marginal ray parenchyma and it was about 1.3 times higher. Intercellular space conducted safranine solution more than ray parenchyma. Vessel was found to be the main avenue for liquid conduction in longitudinal direction. Different anatomical features of ray, vessel and fiber affected the penetration depth of safranine solution. Moreover initial penetration depth was found to be high and thereafter decreased gradually.

• Geomechanics and Engineering
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• 제6권1호
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• pp.47-63
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• 2014

In this paper, asymmetric drainage boundaries modeled by exponential functions which can simulate intermediate drainage from pervious to impervious boundary is proposed for the one-dimensional consolidation problem, and the solution for the new boundary conditions was derived. The new boundary conditions satisfy the initial and the steady state conditions, and the solution for the new boundary conditions can be degraded to the conventional solution by Terzaghi. Convergence study on the infinite series solution showed that only one term in the series is needed to meet the precision requirement for larger degree of consolidation, and that more terms in the series for smaller degree of consolidation. Comparisons between the present solution with those by Terzaghi and Gray are also provided.

• 제어로봇시스템학회논문지
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• 제13권7호
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• pp.683-687
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• 2007

In last decades, several linearization methods for the AOA measurements have been proposed, for example, Gauss-Newton method and Closed-Form solution. Gauss-Newton method can achieve high accuracy, but the convergence of the iterative process is not always ensured if the initial guess is not accurate enough. Closed-Form solution provides a non-iterative solution and it is less computational. It does not suffer from convergence problem, but estimation error is somewhat larger. This paper proposes a Self-Tuning Weighted Least Square AOA algorithm that is a modified version of the conventional Closed-Form solution. In order to estimate the error covariance matrix as a weight, a two-step estimation technique is used. Simulation results show that the proposed method has smaller positioning error compared to the existing methods.