• 한국CDE학회논문집
• /
• 제18권6호
• /
• pp.417-427
• /
• 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
• /
• 제7권3호
• /
• pp.141-147
• /
• 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.

• 대한전기학회논문지:전력기술부문A
• /
• 제50권3호
• /
• pp.146-152
• /
• 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.

• 정보처리학회논문지:소프트웨어 및 데이터공학
• /
• 제7권4호
• /
• pp.121-128
• /
• 2018

Sequence-to-sequence(Seq2seq) 모델은 입력열과 출력열의 길이가 다를 경우에도 적용할 수 있는 모델로 한국어 형태소 분석에서 많이 사용되고 있다. 일반적으로 Seq2seq 모델을 이용한 한국어 형태소 분석에서는 원문을 음절 단위로 처리하고 형태소와 품사를 음절 단위로 출력한다. 음절 단위의 형태소 분석은 사전 미등록어 문제를 쉽게 처리할 수 있다는 장점이 있는 반면 형태소 단위의 사전 정보를 반영하지 못한다는 단점이 있다. 본 연구에서는 Seq2seq 모델의 후처리로 재순위화 모델을 추가하여 형태소 분석의 최종 성능을 향상시킬 수 있는 모델을 제안한다. Seq2seq 모델에 빔 서치를 적용하여 K개 형태소 분석 결과를 생성하고 이들 결과의 순위를 재조정하는 재순위화 모델을 적용한다. 재순위화 모델은 기존의 음절 단위 처리에서 반영하지 못했던 형태소 단위의 임베딩 정보와 n-gram 문맥 정보를 활용한다. 제안한 재순위화 모델은 기존 Seq2seq 모델에 비해 약 1.17%의 F1 점수가 향상되었다.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2006년도 하계종합학술대회
• /
• pp.195-196
• /
• 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.

• 한국수학교육학회지시리즈A:수학교육
• /
• 제42권5호
• /
• pp.707-723
• /
• 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
• /
• 제1권1호
• /
• pp.46-50
• /
• 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.

• 조명전기설비학회논문지
• /
• 제28권6호
• /
• pp.60-67
• /
• 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
• /
• 제19권2호
• /
• pp.560-568
• /
• 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.

• 스마트미디어저널
• /
• 제7권4호
• /
• pp.17-23
• /
• 2018

자동 띄어쓰기 특성을 효과적으로 처리할 수 있는 LSTM(Long Short-Term Memory Neural Networks) 기반의 RNN 모델을 제시하고 적용한 결과를 분석하였다. 문장이 길거나 일부 노이즈가 포함된 경우에 신경망 학습이 쉽지 않은 문제를 해결하기 위하여 입력 데이터 형식과 디코딩 데이터 형식을 정의하고, 신경망 학습에서 드롭아웃, 양방향 다층 LSTM 셀, 계층 정규화 기법, 주목 기법(attention mechanism)을 적용하여 성능을 향상시키는 방법을 제안하였다. 학습 데이터로는 세종 말뭉치 자료를 사용하였으며, 학습 데이터가 부분적으로 불완전한 띄어쓰기가 포함되어 있었음에도 불구하고, 대량의 학습 데이터를 통해 한글 띄어쓰기에 대한 패턴이 의미 있게 학습되었다. 이것은 신경망에서 드롭아웃 기법을 통해 학습 모델의 오버피팅이 되지 않도록 함으로써 노이즈에 강한 모델을 만들었기 때문이다. 실험결과로 LSTM sequence-to-sequence 모델이 재현율과 정확도를 함께 고려한 평가 점수인 F1 값이 0.94로 규칙 기반 방식과 딥러닝 GRU-CRF보다 더 높은 성능을 보였다.