• Korean Journal of Computational Design and Engineering
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• v.18 no.6
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• pp.417-427
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• 2013

Assembly direction is used in order to confirm the generated assembly sequences in an automatic assembly sequence planning system. Moreover, assembly sequence planners can ascertain the feasibility of a sequence during simulation with assembly direction based in a CAD environment. In other words, assembly direction is essential for sequence optimizing and automatic generation. Based on the importance of assembly direction, this paper proposes a method to select the best direction for the generated assembly sequence using disassembly simulation and geometrical common area between assembled parts. Simultaneously, this idea can be applied to verify the generated assembly sequence. In this paper, the automatic selection of assembly direction and sequence correction system is designed and implemented. The developed algorithms and the implemented system are verified based on case study in the CAD environment.

• Genomics & Informatics
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• v.7 no.3
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• pp.141-147
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• 2009

Developed proteome-scale ortholog and paralog prediction methods are mainly based on sequence similarity. However, it is known that even the closest BLAST hit often does not mean the closest neighbor. For this reason, we added conserved interaction information to find orthologs. We propose a genome-scale, automated ortholog prediction method, named OrthoInterBlast. The method is based on both sequence and interaction similarity. When we applied this method to fly and yeast, 17% of the ortholog candidates were different compared with the results of Inparanoid. By adding protein-protein interaction information, proteins that have low sequence similarity still can be selected as orthologs, which can not be easily detected by sequence homology alone.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.50 no.3
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• pp.146-152
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• 2001

This paper describes an accurate fault location algorithm based on sequence current distribution factors for a double-circuit transmission system. The proposed method uses the voltage and current collected at only the local end of a single-circuit. This method is virtually independent of the fault resistance and the mutual coupling effect caused by the zero-sequence current of the adjacent parallel circuit and insensitive to the variation of source impedance. The fault distance is determined by solving the forth-order KVL(Kirchhoff's Voltage Law) based distance equation. The zero-sequence current of adjacent circuit is estimated by using a zero-sequence current distribution factor and the zero-sequence current of the self-circuit. Thousands of fault simulation by EMTP have proved the accuracy and effectiveness of the proposed algorithm.

• KIPS Transactions on Software and Data Engineering
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• v.7 no.4
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• pp.121-128
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• 2018

A Korean morphological analyzer adopts sequence-to-sequence (seq2seq) model, which can generate an output sequence of different length from an input. In general, a seq2seq based Korean morphological analyzer takes a syllable-unit based sequence as an input, and output a syllable-unit based sequence. Syllable-based morphological analysis has the advantage that unknown words can be easily handled, but has the disadvantages that morpheme-based information is ignored. In this paper, we propose a reranking model as a post-processor of seq2seq model that can improve the accuracy of morphological analysis. The seq2seq based morphological analyzer can generate K results by using a beam-search method. The reranking model exploits morpheme-unit embedding information as well as n-gram of morphemes in order to reorder K results. The experimental results show that the reranking model can improve 1.17% F1 score comparing with the original seq2seq model.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.195-196
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• 2006

Frame synchronization is an critical factor for an effective operation of OFDM (orthogonal frequency division multiplexing) based communication systems. In this paper, we present and analyze an efficient frame synchronization method based on m-sequence for OFDM-based mobile multimedia communication systems. The cyclic extension preceding OFDM frames is of decisive importance for this method. The m-sequence is added directly to cyclic extension signal in the time domain. By utilizing the autocorrelation characteristics of m-sequence, efficient frame synchronization can be achieved. And we also consider frequency offset estimation simultaneously. The proposed frame synchronization method can be applied to the OFDM-based mobile multimedia communication systems.

• The Mathematical Education
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• v.42 no.5
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• pp.707-723
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• 2003

Teaching the notion of limit of the sequence in high school mathematics needs special attention and accurate teaching methods, for it is one of the most important bases of the advanced mathematics. Therefore it is necessary for high school students to have the right understanding of the notion of limit of the sequence. In this paper, we survey several teaching methods of the notion of limit of the sequence in high school mathematics and introduce a new method using Excell program. Also through questionnaire survey we discuss and analyse students' reaction when they learn the notion of limit of the sequence. And based on that, we suggest a method that would be believed to improve the students' understanding for the notion of limit It should be also notified that questionnaire survey was performed in order to find out which method would be appropriate to teach the notion of limit of the sequence, and that the survey result was fully reflected in the guideline that suggested.

• Bioinformatics and Biosystems
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• v.1 no.1
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• pp.46-50
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• 2006

According to the advancement of experimental techniques in molecular biology, genomic and protein sequence databases are increasing in size exponentially, and mean sequence lengths are also increasing. Because the sizes of these databases become larger, it is difficult to search similar sequences in biological databases with significant homologies to a query sequence. In this paper, we present the N-gram indexing method to retrieve similar sequences fast, precisely and comparably. This method regards a protein sequence as a text written in language of 20 amino acid codes, adapts N-gram tokens of fixed-length as its indexing scheme for sequence strings. After such tokens are indexed for all the sequences in the database, sequences can be searched with information retrieval algorithms. Using this new method, we have developed a protein sequence search system named as ProSeS (PROtein Sequence Search). ProSeS is a protein sequence analysis system which provides overall analysis results such as similar sequences with significant homologies, predicted subcellular locations of the query sequence, and major keywords extracted from annotations of similar sequences. We show experimentally that the N-gram indexing approach saves the retrieval time significantly, and that it is as accurate as current popular search tool BLAST.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.6
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• pp.60-67
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• 2014

Power system fault analysis is commonly based on well-known symmetrical component method, which describes power system elements by positive, negative and zero sequence impedance. The majority of fault in transmission lines is unbalanced fault, such as line-to-ground faults, so that both positive and zero sequence impedance is required for fault analysis. When unbalanced fault occurs, zero sequence current flows through earth and ground wires in overhead transmission systems and through cable sheaths and earth in underground transmission systems. Since zero sequence current distribution between cable sheath and earth is dependent on both sheath bondings and grounding configurations, care must be taken to calculate zero sequence impedance of underground cable transmission lines. In this paper, EMTP-based sequence impedance calculation method was described and applied to 345kV cable transmission systems. Calculation results showed that detailed circuit analysis is desirable to avoid possible errors of sequence impedance calculation resulted from various configuration of cable sheath bonding and grounding in underground cable transmission systems.

• Journal of Power Electronics
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• v.19 no.2
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• pp.560-568
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• 2019

This paper studies the inherent relationship between currents and zero-sequence components. Then a precise algorithm is proposed to calculate the injected zero-sequence component to control the DC-Link neutral-point voltage balance, which can result in a more efficient and flexible neutral point voltage balance with a desirable performance. In addition, it is shown that carried-based PWM with the calculated zero-sequence component scheme can be equivalent to space-vector pulse-width modulation (SVPWM). Based on the proposed method, the optimal zero-sequence component of the feasible modulation indices is analyzed. In addition, the unbalanced load limitation of the DC-Link neutral-point voltage balance control is also revealed. Simulation and experimental results are shown to verify the validity and practicality of the proposed algorithm.

• Smart Media Journal
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• v.7 no.4
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• pp.17-23
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• 2018

We proposed a LSTM-based RNN model that can effectively perform the automatic spacing characteristics. For those long or noisy sentences which are known to be difficult to handle within Neural Network Learning, we defined a proper input data format and decoding data format, and added dropout, bidirectional multi-layer LSTM, layer normalization, and attention mechanism to improve the performance. Despite of the fact that Sejong corpus contains some spacing errors, a noise-robust learning model developed in this study with no overfitting through a dropout method helped training and returned meaningful results of Korean word spacing and its patterns. The experimental results showed that the performance of LSTM sequence-to-sequence model is 0.94 in F1-measure, which is better than the rule-based deep-learning method of GRU-CRF.