• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.202-204
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• 2005

This paper presents the formulation for developing 2 port Frequency Dependent AC System Equivalent(FDACSE) with the instantaneous term in 5-domain and illustrates its use. This 2 port FDNE have been applied to the New Zealand AC system. The electromagnetic transient package PSCAD/EMTDC is used to assess the transient response of the 2 port (FDACSE) developed with Norton Equivalent network. The study results have indicated the robustness and accuracy of 2 port FDACSE for electromagnetic transient studies.

• Computers and Concrete
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• v.3 no.5
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• pp.357-373
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• 2006

The concepts of four parameters of nominal water-cement ratio, equivalent water-cement ratio, average paste thickness, fly ash-binder ratio were introduced. It was verified that the four parameters and the mix proportion of mortar can be transformed each other. The behaviors (strength, workability, et al.) of mortar primarily determined by the mix proportion of mortar now depend on the four parameters. The prediction models of strength and workability of mortar were built based on artificial neural networks (ANNs). The calculation models of average paste thickness and equivalent water-cement ratio of mortar can be obtained by the reversal deduction of the two prediction models, respectively. A mortar mix proportion design algorithm was proposed. The proposed mortar mix proportion design algorithm is expected to reduce the number of trial and error, save cost, laborers and time.

• MALSORI
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• no.50
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• pp.51-69
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• 2004

In this paper, we present a one-pass semi-dynamic network decoding framework that inherits both advantages of fast decoding speed from static network decoders and memory efficiency from dynamic network decoders. Our method is based on the novel language model network representation that is essentially of finite state machine (FSM). The static network derived from the language model network [1][2] is partitioned into smaller subnetworks which are static by nature or self-structured. The whole network is dynamically managed so that those subnetworks required for decoding are cached in memory. The network is near-minimized by applying the tail-sharing algorithm. Our decoder is evaluated on the 25k-word Korean broadcast news transcription task. In case of the search network itself, the network is reduced by 73.4% from the tail-sharing algorithm. Compared with the equivalent static network decoder, the semi-dynamic network decoder has increased at most 6% in decoding time while it can be flexibly adapted to the various memory configurations, giving the minimal usage of 37.6% of the complete network size.

• Journal of Power Electronics
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• v.6 no.4
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• pp.279-289
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• 2006

This paper presents a neural network based adaptive dead-time compensation strategy for an inverter fed permanent magnet synchronous motor drive. The neural network is used for identifying the dead-time compensation time (DTCT) that includes an equivalent dead-time, turn-on/off time and on-state voltage components of the voltage source inverter. In order to train the neural network, desired DTCTs for eight operating points are prepared as training data. The trained neural network can identify a desired DTCT for any operating point because it has the capability of the interpolation. The accuracy of the identified DTCT is experimentally confirmed by comparing the calculated active power with a measured one.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.1
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• pp.64-71
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• 1997

Digital communication channels are imparied by linear effects such as dispersion, ISI(intersymbol Interference), fading phenomenon etc. But, the practical channel equalization system is required to design for compensating the nonlinear distortion caused by harmonic distortion etc. This paper is a study on the performance of nonlinear channel equalization using RBF(Radial Basis Funclion) network, which has the equivalent structure to the optimal Basian filter. Expecially, the variance of RBF network is modifiedby nonlinear polynomial filters to compare the convergence characteristic of nonlinear channel equalization. Experimental results show that the modified RBF network achieves the faster convergence property than conventional RBF network. Moreover, the RBF network ofhigher order variance modified represents the better performance than that of lower order variance in the bandpass channels and second/third order polynomial channels.

• IE interfaces
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• v.10 no.3
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• pp.179-187
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• 1997

The efficiency of material flow systems in terms of optimal network flow and minimum cost flow has always been an important design and operational goal in material handling and distribution system. In this research, an attempt was made to develop a new algorithm and the model to solve a stochastic material flow network with bidirectional and uncertain flows. A stochastic material flow network with bidirectional flows can be considered from a finite set with unknown demand probabilities of each node. This problem can be formulated as a special case of a two-stage linear programming problem which can be converted into an equivalent linear program. To find the optimal solution of proposed stochastic material flow network, some terminologies and algorithms together with theories are developed based on the partitioning and subgradient techniques. A computer program applying the proposed method was developed and was applied to various problems.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2345-2347
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• 2005

In this paper, impedance characteristics of overhead medium-voltage (MV) power lines is reported for power line communication (PLC) over an MV power line network. For analysis, a two-port equivalent network model of MV power lines is derived. By applying the transmission line theory, reflection behavior and impedance of power lines are investigated. For verification, impedance of power lines is measured at a test field for an MV PLC. The results show that impedance of MV power lines is between $200{\Omega}$ and $300{\Omega}$ and converges to a half of their characteristic impedance.

• Journal of Microbiology and Biotechnology
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• v.22 no.8
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• pp.1054-1058
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• 2012

In order to predict biologically significant attributes such as function from protein sequences, searching against large databases for homologous proteins is a common practice. In particular, BLAST and HMMER are widely used in a variety of biological fields. However, sequence-homologous proteins determined by BLAST and proteins having the same domains predicted by HMMER are not always functionally equivalent, even though their sequences are aligning with high similarity. Thus, accurate assignment of functionally equivalent proteins from aligned sequences remains a challenge in bioinformatics. We have developed the FEP-BH algorithm to predict functionally equivalent proteins from protein-protein pairs identified by BLAST and from protein-domain pairs predicted by HMMER. When examined against domain classes of the Pfam-A seed database, FEP-BH showed 71.53% accuracy, whereas BLAST and HMMER were 57.72% and 36.62%, respectively. We expect that the FEP-BH algorithm will be effective in predicting functionally equivalent proteins from BLAST and HMMER outputs and will also suit biologists who want to search out functionally equivalent proteins from among sequence-homologous proteins.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.51 no.6
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• pp.255-261
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• 2002

Recently, traction motors in trains are supplied with single phase a.c. power. After this power is converted to d.c. power, it is inverted to three phase power to operate traction motors. As going through the process of the conversion, harmonic current is generated in train. The method of conventional analysis on harmonics, studied by RTRI, is modeled with equivalent circuit of ac AT-fed electric railroad system using by the distributed constant circuit. However, this circuit as two-port network model has some difference in comparison with real system. The reason why the conventional method is different from the real system is that the conventional method dose not include three conductor groups, that is catenary, rail, and feeder, and admittance between the conductors for line capacitance. Therefore, this method has a little error. This paper proposes new method to more effectively estimate Harmonic current. In this method, numerous components in electric railway are categorized and each component is defined as a four- port network model. The equivalent circuit for the entire power supply system is also described into a four-port network model with connections of these components. In order to evaluate the efficiency and the accuracy of a proposed method, it is compared with values measured in Kyung-Bu high speed line and ones calculated by the conventional method.

• Tunnel and Underground Space
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• v.8 no.4
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• pp.275-286
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• 1998

The effective permeability and the representative element volume(REV) of fracture network model were evaluated based on the parameters such as permeability tensor, principal permeability and the direction of principal permeability. The effective permeability ranges between the harmonic mean and the arithmetic mean of the local permeabilities of subdivided blocks. From the numerical experiments, which were for investigating the influence of model volume on the variation of flux for the cubic models, it was found that the variation of flux became reduced as the model volume approached REV. The variation of groundwater flux into the tunnel in the fracture network model was mainly dependent on the ratio of the tunnel length to model size rather than REV. And it was found that groundwater flux into the tunnel was not completely consistent between the fracture network model and the equivalent porous media model, especially when the ratio of the tunnel length to model size is small.