• Kyungpook Mathematical Journal
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• v.61 no.2
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• pp.383-393
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• 2021

In this paper, numerical techniques are presented for solving initial value problems of fractional differential equations with variable coefficients. The method is derived by applying a Taylor vector approximation. Moreover, the operational matrix of fractional integration of a Taylor vector is provided in order to transform the continuous equations into a system of algebraic equations. Furthermore, numerical examples demonstrate that this method is applicable and accurate.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.11 no.4
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• pp.247-253
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• 2011

A sustainability of electricity supply has emerged as a critical issue for low carbon green growth in South Korea. Wind power is the fastest growing source of renewable energy. However, due to its own intermittency and volatility, the power supply generated from wind energy has variability in nature. Hence, accurate forecasting of wind speed and power plays a key role in the effective harvesting of wind energy and the integration of wind power into the current electric power grid. This paper presents a short-term wind speed prediction method based on support vector regression. Moreover, particle swarm optimization is adopted to find an optimum setting of hyper-parameters in support vector regression. An illustration is given by real-world data and the effect of model regularization by particle swarm optimization is discussed as well.

• Biomedical Science Letters
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• v.18 no.1
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• pp.29-34
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• 2012

Streptomycetes are gram-positive filamentous bacteria that are well-known for producing a vast array of bioactive compounds, including more than 70 % of commercially important antibiotics. For the research about Streptomyces sp., the protoplast and electroporation transformation method have been the general techniques for the construction of transformants. However, these techniques have low efficiency and are time-consuming. Another option is intergenic conjugation, which is used for DNA transfer using methylation-deficient E. coli as a DNA donor to avoid the methylated-DNA-dependent restriction systems of actinomycetes. This conjugation method has been widely improved and applied to many other actinomycetes. In this research, an effective transformation procedure for the construction of expression vector by using gateway system was established to avoid limit of restriction enzyme site for cloning of target gene based on transconjugation by Escherichia coli ET12567/pUZ8002 with a pSET152 integration vector.

• Journal of Positioning, Navigation, and Timing
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• v.1 no.1
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• pp.1-6
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• 2012

For a Global Positioning System (GPS) receiver, it is known that a Vector Delay Locked Loop (DLL) in which the code signals of each satellite are tracked in parallel by using navigation results shows better performance in the aspect of the tracking accuracy and the robustness than that of a Scalar DLL. However, the quantitative analysis and the logical grounds for that performance enhancement of the Vector DLL are not sufficient. This paper, therefore, proposes the structure of the GPS receiver with the Vector DLL and analyzes the performance of it. The tracking and the positioning accuracy of the Vector DLL are theoretically analyzed and confirmed by simulation results. From the simulation results, it can be seen that the tracking and positioning accuracy has been improved about 30% in case that the receiver is static and the positioning is conducted for every Pre-detection Integration Time (PIT) while C/N0 is 45 dB-Hz.

• Journal of Positioning, Navigation, and Timing
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• v.7 no.3
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• pp.155-163
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• 2018

This study examined methods to enhance navigation performance and reduce the divergence of navigation solutions that may occur in the event of global positioning system (GPS) failure by integrating the GPS/inertial navigation system (INS) with the three-dimensional (3D) magnetic vector measurements of a magnetometer. A magnetic heading aiding method that employs a magnetometer has been widely used to enhance the heading performance in low-cost GPS/INS navigation systems with insufficient observability. However, in the case of GPS failure, wrong heading information may further accelerate the divergence of the navigation solution. In this study, a method of integrating the 3D magnetic vector measurements of a magnetometer is proposed as a countermeasure for the case where the GPS fails. As the proposed method does not require attitude information for integration unlike the existing magnetic heading aiding method, it is applicable even in case of GPS failure. In addition, the existing magnetic heading aiding method utilizes only one-dimensional information in the heading direction, whereas the proposed method uses the two-dimensional attitude information of the magnetic vector, thus improving the observability of the system. To confirm the effect of the proposed method, simulation was performed for the normal operation and failure situation of GPS. The result confirmed that the proposed method improved the accuracy of the navigation solution and reduced the divergence speed of the navigation solution in the case of GPS failure, as compared with that of the existing method.

• The Plant Pathology Journal
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• v.25 no.2
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• pp.179-183
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• 2009

To facilitate the genetic manipulation of Cladosporium phlei, a causal agent of leaf spot disease in timothy (Phleum pretense), protoplast-mediated transformation of C. phlei has been developed and the resulting transformants were characterized in this study. Hygromycin B resistance was applied as a dominant selection marker due to the sensitivity of C. phlei to this antibiotic. The transformation efficiency ranged from approximately 20-100 transformants per experiment. Southern blot analysis of stable transformants revealed that transformation occurred by way of stable integration of the vector DNA into the fungal chromosome. PCR analysis and plasmid rescuing of randomly selected transformants suggested that integration of tandem repeat copies of vector DNA was common. In addition, multiple integrations of the transforming vector at different chromosomal sites were also observed. The establishment of a transformation method for C. phlei facilitates strain improvement of this fungus and can be applied as an initial step in the molecular analysis of pigment production in this fungus.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.453-458
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• 2004

This study proposes a new two-level condensation scheme for the construction of a reduced system. In the first step, the candidate area is selected for the construction of the reduced system by energy estimation in element-level. In the second step, primary degrees of freedom are selected by sequential elimination from the candidate degrees of freedom linked to the selected elements. Numerical examples demonstrate that the proposed method saves the computational cost effectively and provides a reduced system which predicts the eigenvalues accurately. Moreover, the well-constructed reduced system can present the reliable behavior of the structure under arbitrary dynamic loads comparing to that of global system. Time integration in a reduced system can save the computing time remarkably. Through a few numerical examples, the efficiency and reliability of the proposed scheme are verified.

• Proceedings of the IEEK Conference
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• 2002.06a
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• pp.191-194
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• 2002

We analyzed radiation characteristics of dipole antenna in a lossy 9round with conducting object located above ground. Electric field integral equation is used to solve the problem. In this integral equation, GPOF(Generalized Pencil of Function) method is applied to derive the closed form of the electric field due to a current source. Surface current on a conductor is expanded with a well-known vector triangle basis function. The singular integration of a triangle patch is transformed to the non-singular integration by Duffy's method. This transformed non-singular integration is easily calculated by using one-dimensional Gaussian quadrature rule, instead of usual closed form evaluation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.8
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• pp.834-842
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• 2002

The method of moment is applied to the analysis of electromagnetic scattering from an arbitrarily-shaped conductor. The conducting surface is discretized into triangular patches using a GID tool. Surface currents on a conductor are expanded with a vector triangle basis function. By using the Duffy's method, the singular integration appeared in a triangle patch can be transformed into the non-singular integral form suitable for one dimensional Gaussian quadrature integration method. Mutual and self integration extracted singular terms are evaluated by two dimensional Gaussian quadrature techniques.

• Honam Mathematical Journal
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• v.2 no.1
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• pp.25-35
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• 1980

Vector치(値) 함수(函數)의 Vector치(値) 적분론(積分論)에는 많은 연구(硏究)가 되어 왔으나, 본(本) 논문(論文)에서는 그 가운데 Bochner 적분론(積分論)에 대(對)해서 연구(硏究)하고 Bochner 부정적분(不定積分)에 의(依)한 Vector치(値) 측도(測度)의 표현(表現)에 관(關)한 Radon-Nikodym 정리(定理)에 대(對)해서 연구(硏究)하였다.