• Journal of Internet Computing and Services
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• v.14 no.1
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• pp.63-69
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• 2013

Approximate Frequent pattern mining is to find approximate patterns, not exact frequent patterns with tolerable variations for more efficiency. As the size of database increases, much faster mining techniques are needed to deal with huge databases. Moreover, it is more difficult to discover exact results of mining patterns due to inherent noise or data diversity. In these cases, by mining approximate frequent patterns, more efficient mining can be performed in terms of runtime, memory usage and scalability. In this paper, we study the characteristics of an approximate mining algorithm based on probabilistic technique and run performance evaluation of the efficient approximate frequent pattern mining algorithm. Finally, we analyze the test results for more improvement.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.1
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• pp.71-77
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• 2015

Ultrasonic imprinting is a micropattern replication technology for a thermoplastic polymer surface that uses ultrasonic vibration energy; it has the advantages of a short cycle time and low energy consumption. Recently, ultrasonic imprinting has been further developed to extend its functionality: (i) selective ultrasonic imprinting using mask films and (ii) repetitive ultrasonic imprinting for composite pattern development. In this study, selective ultrasonic imprinting was combined with repetitive imprinting in order to replicate versatile micropatterns. For this purpose, a repetitive imprinting technology was further extended to utilize mask films, which enabled versatile micropatterns to be replicated using a single mold with micro-prism patterns. The replicated hybrid micropatterns were optically evaluated through laser light images, which showed that versatile optical diffusion characteristics can be obtained from the hybrid micropatterns.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.1
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• pp.51-57
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• 2014

Ultrasonic imprinting is a novel process for replicating micropatterns on thermoplastic polymer substrates with low energy consumption and short cycle time. The polymer substrate is softened by the frictional heat and repetitive deformation energy under ultrasonic excitation; thus, a number of micropatterns are replicated on the softened polymer substrate. In the present work, the effect of mold temperature on the replication characteristics of ultrasonic imprinting is investigated. The temperature change in the patterned region is measured by varying the mold temperature. Numerical simulation is then performed for investigating pattern replication characteristics under various mold temperatures. In addition, pattern replication ratio and uniformity are compared through various experimental measurements. Through the results of these comparisons, it is found that the mold temperature has a significant positive effect on the replication characteristics of ultrasonic imprinting.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.8
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• pp.758-764
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• 2015

This paper describes the pattern synthesis of array antenna which conforms to a metallic curved surface formed by the rotation of a quadratic function by using EAGA(Enhanced Adaptive Genetic Algorithm). Three rotated-type conformal surfaces are realized by changing the coefficient of the quadratic function and the pattern of each conformal array antenna is synthesized. In order to reduce the overall time of pattern synthesis, the transformed active element pattern obtained by the active element pattern of the 2-dimensional planar array using Euler angles rotation is utilized instead of the active element pattern of the 3-dimensional conformal array antenna itself. To verify validity of the proposed synthesis procedure, the synthesized patterns using EAGA are compared with those obtained by MWS.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.12
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• pp.1031-1043
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• 2015

This paper describes the pattern synthesis method of two kinds of conformal array antenna using the Enhanced Adaptive Genetic Algorithm (EAGA). One is the $1{\times}16$ conformal array antenna on a curved cylindrical metallic surface with quadratic function, and the other is the 18-element conformal arrary antenna on a metallic surface obtained by the rotation of a quadratic function curve around the axis. The active element pattern is utilized in the pattern synthesis. Especially for the case of the rotated-type conformal array antenna the transformed active element pattern obtained from the Euler's angle rotation of the active element pattern of the planar concentric array is utilized, which reduces the synthesis time a lot. To verify the validity of the proposed synthesis method the MATLAB results are compared with the MWS results. Furthermore, for the case of $1{\times}16$ conformal array antenna the measured results are compared with the MATLAB synthesized results.

• Journal of the Korean Institute of Intelligent Systems
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• v.18 no.1
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• pp.100-108
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• 2008

This paper proposes a method of adaptively generating a gait pattern of biped robot. The gait synthesis is based on human's gait pattern analysis. The proposed method can easily be applied to generate the natural and stable gait pattern of any biped robot. To analyze the human's gait pattern, sequential images of the human's gait on the sagittal plane are acquired from which the gait control values are extracted. The gait pattern of biped robot on the sagittal plane is adaptively generated by a genetic algorithm using the human's gait control values. However, galt trajectories of the biped robot on the sagittal Plane are not enough to construct the complete gait pattern because the bided robot moves on 3-dimension space. Therefore, the gait pattern on the frontal plane, generated from Zero Moment Point (ZMP), is added to the gait one acquired on the sagittal plane. Consequently, the natural and stable walking pattern for the biped robot is obtained.

• Convergence Security Journal
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• v.9 no.4
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• pp.21-27
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• 2009

In the environment of development of network bandwidth and intrusion technology there is limit to the pattern analysis of all massed packets through the existing pattern matching method by the intrusion detection system. To detect the packets efficiently when they are received fragmented, it has been presented the matching method only the pattern of packets consisting with the operation system such as Esnort. Pattern matching performance is improved through the use of NMAP, the basic mechanism od Esnort, by scanning the operation system of the same network system and appling pattern match selectively scanned information and the same operation system as the received packets. However, it can be appeared the case of disregarding the receivied packets depending on the diversity of the kind of operation systems and recognition mistake of operation system of nmap. In this paper, we present and verify the improved intrusion detection system shortening the pattern matching time by the creation of hashy table through the pattern hash of intrusion detection system independently with the users system environment .in the state of flux.

• Journal of The Geomorphological Association of Korea
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• v.19 no.4
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• pp.139-155
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• 2012

Most of previous landform classification methods using DEM compares the values between the center of the cell and the surrounding cells, which in turn, greatly depends on analysis scale. To overcome the problem of scale-dependency, a new classification scheme is developed, which is called "Geomorphons". Unlike the traditional approaches using DEM, Geomorphons is the way which compares the level with other cells against the criteria cell. As a pilot study, we classify the landforms of Pyeongchang-Gun in Korea. Then, we compare the result with the other methods such as Topographic Position Index. Through the systematic analysis, we obtain the following findings. First, Geomorphons can reduce the time for the classification of landforms because of using unsupervised classification. Second, Geomorphons is little dependent on change in the scale, which can provide a pilot tool for reconnaissance study for covering large area.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.194-196
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• 2022

When electromagnetic wave transmitted from the radar antenna hits the target, a specific type of electric field is formed according to the electrical characteristics and appearance of the target, which is called an RCS pattern. There are various commercial programs that calculate the RCS of the target and plot the RCS pattern. For the analysis of large targets such as warships or ships, a program with a high frequency analysis method, which has a faster calculation speed than the low frequency analysis method is suitable. XGTD, a high-frequency analysis program, can quickly plot a two-dimensional RCS pattern for 360 degrees of a target, but a three-dimensional RCS pattern cannot be obtained. In this paper, it is proposed that a method of plotting two-dimensional RCS patterns of a target from various angles using XGTD, generating a three-dimensional RCS pattern using this, and converting it into a three-dimensional antenna pattern file.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.4
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• pp.1581-1589
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• 2013

The aim of this study is to suggest a methodology for calculating the peak-hour ratio of passengers at urban railway stations by reflecting the characteristics of passenger demand patterns and the land use inventory of stations. To achieve this, urban railway stations in Seoul are divided into three groups by using factor analysis and cluster analysis. For each station group, we calculate five and four variables related to the passenger demand patterns and the land use inventory of stations, respectively, as well as the peak-hour ratios of passengers. Among these nine variables, average daily passengers and the location quotient (LQ) index for business services are selected as the classification criteria for station groups based on statistical tests. Using the two variables, a group allocation process is suggested to estimate the peak-hour ratio of passengers for a newly-constructed station. Evaluation results based on thirteen stations show that the proposed methodology produces lower errors than the currently-used guideline does. The results of this study contribute to establishing efficiently construction and operation plans for newly-constructed stations.