• Proceedings of the KSME Conference
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• 2005.11a
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• pp.226.2-226.2
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• 2005

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.07a
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• pp.404-404
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• 2004

• Computational Structural Engineering
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• v.26 no.3
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• pp.42-46
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• 2013

• The Journal of the Korea Contents Association
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• v.8 no.7
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• pp.53-57
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• 2008

The discretized saw-tooth map with the 16-bit finite precision which is one of the 1-dimensional chaotic maps is designed, and the circuit of chaotic binary sequence generator using the discretized saw-tooth map is presented also in this brief. The real implementation of designed chaotic map is accomplished by connecting the input and output lines exactly according to the simplified Boolean functions of output variables obtained from truth table which is discretized. The random binary output sequences generated by mLFSR generator were used for the inputs of descretized saw-tooth map, and, by the descretized map, chaotic binary sequence which has more long period of 16 times minimally is generated as a results.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.7
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• pp.71-79
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• 2004

Packet-type data transmission is characterized by the continuous transmission of massive data with relatively constant rate. In such transmission, the dynamic power consumed on buses is influenced by the sequence of transmitted data. A new coding scheme called Sequence-Switch Coding (SSC) is proposed in this paper. SSC reduces the number of bus transitions in the transmission of packet-type data by changing the sending order of the data. Some simple algorithms are presented, In. The simulation results show that SSC outperforms the well-known Bus-Invert Coding with these algorithms. SSC is not a specific algerian but a method to reduce the number of bus-transitions. There could be lots of algorithms for realizing SSC. The variety of SSC algorithms provides circuit designers a wide range of trade-off between performance and circuit complexity.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.10a
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• pp.233-236
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• 2002

An efficient method was developed in this study to obtain optimal stacking sequences, thicknesses, and minimum weights of stiffened laminated composite shells under combined loading conditions and stiffener layouts using genetic algorithms (GAs) and finite element analyses. Among many parameters in designing composite laminates determining a optimal stacking sequence that may be formulated as an integer programming problem is a primary concern. Of many optimization algorithms, GAs are powerful methodology for the problem with discrete variables. In this paper the optimal stacking sequence was determined, which gives the maximum critical buckling load factor and the minimum weight as well. To solve this problem, both the finite element analysis by ABAQUS and the GA-based optimization procedure have been implemented together with an interface code. Throughout many parametric studies using this analysis tool, the influences of stiffener sizes and three different types of stiffener layouts on the stacking sequence changes were throughly investigated subjected to various combined loading conditions.

• Journal of the Korea Concrete Institute
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• v.11 no.3
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• pp.59-67
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• 1999

The mass concrete structures are generally constructed in an incremental manner by deviding the whole structures by a series of many blocks. The temperature and stress distributions of any specific block are continuously affected by the blocks placed before and after the specific block. For an accurate analysis of mass concrete structures, the sequence of all the blocks must be accordingly considered including the change of material properties with time for those blocks considered. The purpose of this study is to propose a realistic analysis method which can take into account not only the influence of the sequence, time interval and size of concrete block placement on the temperatures and stresses, but also the change of material properties with time. It is seen from this study that the conventional simplified analysis, which neglects material property changes of some blocks with time and does not consider the effect of adjacent blocks in the analysis, may yield large discrepancies in the temperature and stress distributions of mass concrete structures. This study gives a method to choose the minimum number of blocks required to obtain reasonably accurate results in analysis. The study provides a realistic method which can determine the appropriate size and time interval of block placement, and can be efficiently used in the design and construction of mass concrete structures.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07a
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• pp.853-855
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• 2005

본 논문은 Sequence Diagram을 이용한 안전등급 PLC(Safety-Grade Programmable Logic Controller) 운영 체제의 인터페이스 설계명세를 기술한다. 원자력 발전소에 사용하기 위한 안전 소프트웨어(Safety Software)의 규제 기준인 Reg. Guide는 IEEE Std 1016, IEEE Std 1016.1 의 설계명세서 작성 표준에 따라 작성하도록 요구하며, 이러한 규제기준과 기 표준을 안전등급 PLC를 위한 운영체제 소프트웨어의 설계명 세서도 만족해야 한다. 특히 운영 체제와 외부 장치들 사이의 인터페이스를 위해 실시간 특성의 표현에 장점을 갖는 Sequence Diagram을 적용함으로써 운영체제의 인터페이스에 대한 정확성, 완전성, 그리고 일관성을 향상시킬 수 있었다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.472-473
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• 2021

The frequency-hopping sequence is a type of user-specific code that has been used in various ways in military communication, Bluetooth, and ultra-wideband communications. In a practical communication environment, a frequency-hopping sequence with an alphabet and a length suitable for the number of available frequencies and transmission period is required. Therefore, the design of the frequency-hopping sequence having various parameters is a very important problem in frequency-hopping spread-spectrum communication. To this end, this paper explores a method of synthesizing a sequence of a new length through the synthesis of existing frequency-hopping sequences. As a result, it is possible to present the possibility of frequency-hopping sequences applicable to various environments of communications.

• Journal of Korea Multimedia Society
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• v.7 no.11
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• pp.1505-1514
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• 2004

Sequence matching in time-series databases is an operation that finds the data sequences whose changing patterns are similar to that of a query sequence. Typically, sequence matching hires a multi-dimensional index for its efficient processing. In order to alleviate the dimensionality curse problem of the multi-dimensional index in high-dimensional cases, the previous methods for sequence matching apply the Discrete Fourier Transform(DFT) to data sequences, and take only the first two or three DFT coefficients as organizing attributes of the multi-dimensional index. This paper first points out the problems in such simple methods taking the firs two or three coefficients, and proposes a novel solution to construct the optimal multi -dimensional index. The proposed method analyzes the characteristics of a target database, and identifies the organizing attributes having the best discrimination power based on the analysis. It also determines the optimal number of organizing attributes for efficient sequence matching by using a cost model. To show the effectiveness of the proposed method, we perform a series of experiments. The results show that the Proposed method outperforms the previous ones significantly.