• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.2
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• pp.301-307
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• 2015

In this paper, we consider wiretap channels in the presence of an eavesdropper assuming spatially correlated MIMO(multiple-input multiple-output) channels, where we analyze a physical layer security performance of orthogonal space-time block code(OSTBC) using one-bit feedback assuming cross polarized antennas at each node. In this paper, we present a method to select a transmit-antenna group for OSTBC using one-bit feedback(O-OSTBC) and compare secrecy outage probabilities of various transmit-antenna grouping methods. Especially, we propose an efficient transmit-antenna grouping method by comparing secrecy outage probabilities of O-OSTBC and conventional OSTBC in highly correlated MIMO channels.

• Journal of Software Engineering Society
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• v.25 no.1
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• pp.1-9
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• 2012

RFID systems have been widely used in various fields such as logistics, distribution, food, security, traffic and others. A RFID middleware, one of the key components of the RFID system, perform an important role in many functions such as filtering, grouping, reporting tag data according to given user specifications and so on. However, manual test data generation is very hard because the inputs of the RFID middleware are generated according to the RFID middleware standards and complex encoding rules. To solve this problem, in this paper, we propose a black box test technique based on RFID middleware standards. Firstly, we define ten types of input conversion rules to generate new test data from existing test data based on the standard specifications. And then, using these input conversion rules, we generate various additional test data automatically. To validate the effectiveness of generated test data, we measure coverage of generated test data on actual RFID middleware. The results show that our test data achieve 78% statement coverage and 58% branch coverage in the classes of filtering and grouping, 79% statement coverage and 64% branch coverage in the classes of reporting.

• Journal of Korean Society of Transportation
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• v.22 no.4 s.75
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• pp.43-56
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• 2004

The KHCM procedure is a micro level analysis at signalized intersections requiring a lot of input variables and complex computations. The research was to investigate the possibility of simplifying the analysis procedures by using the generalized or the combined variables that less influence on the adjusted traffic volume and through-car equivalents of left or right turns. It was also tried to make lane grouping into directional flow ratio(v/s) based on a field surveys. The maximum and minimum values of each variables were compared with each other through the KHCM analysis procedures in terms of control delay. The lane grouping and the synthetical influence of a simplified method was evaluated with the scenario built in prevailing maximum and minimum conditions. The study showed that the control delay was not significantly sensitive to the selected variables and the lane grouping and their synthetical influence as well.

• Journal of KIISE
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• v.43 no.8
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• pp.883-892
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• 2016

Spectrum-based fault localization (SFL) method assigns a suspicious ratio. The statement is strongly affected by a failed test case compared to a passed test case. A failed test case assigns a suspicious ratio while a passed test case reduces some parts of assigned suspicious ratio. In the absence of a failed test case, it is impossible to localize the fault. Thus, a failed test case is very important for fault localization. However, spectrum-based fault localization has difficulty in reflecting the unique characteristics of a failed test because a failed test case and a passed test case are input at the same time to calculate a suspicious ratio. This paper supplements for this limitation and suggests a test case grouping method for more accurate fault localization. In addition, this paper suggested a filtering method considering test efficiency and verified the effectiveness by applying 65 algorithms. In 90 % of whole methods, the accuracy was improved by 13% and the effectiveness was improved by 72% based on EXAM score.

• IE interfaces
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• v.16 no.2
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• pp.211-221
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• 2003

This paper introduces a simulation study regarding the design for the installation of Color Rescheduling Storage (CRS) in an automobile factory. In the painting shop the colors of vehicles are changed frequently according to the assembly schedule. When the color of a vehicle is changed from one to another, the cleaning process of painting-gun is necessary and it generates costs. Therefore many of the automobile manufacturers equip the CRS in front of the Top Coat Booth of the painting shop. The major objective of CRS is to reduce the change over cost in the painting process by grouping vehicles having same color. In this paper the configuration of CRS and the input/output algorithms are explained. The suggested system is verified using simulation models and experiments are conducted. Finally the best alternative is suggested by sensitivity analysis and evaluation of investment feasibility.

• Journal of Korean Association for Spatial Structures
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• v.1 no.2 s.2
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• pp.59-66
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• 2001

This paper describes three modules for development of the Space Frame Integrated Design System(SFIDS). The Control Module is implemented to control the developed system. The Model Generation Module based on PATRAN user interface enables users to generate a complicated finite element model for space frame structures. The Optimum Design Module base on a branch of combinatorial optimization techniques which can realize the optimization of a structure having a large number of members designs optimum members of a space frame after evaluating analysis results. The Control Module and the Model Generation Module Is implemented by PATRAN Command Language(PCL) while C++ language is used in the Optimum Design Module. The core of the system is PATRAN database, in which the Model Generation Module creates information of a finite element model. Then, PATRAN creates Input files needed for the analysis program from the information of the finite element model in the database, and in turn, imports output results of analysis program to the database. Finally, the Optimum Design Module processes member grouping of a space frame based on the output results, and performs optimal member selection of a space frame. This process is repeated until the desired optimum structural members are obtained.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.4
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• pp.646-652
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• 2015

In this paper, the system-level performance is evaluated for the feedback scheme on the pre-coding matrix index (PMI) and channel quality indication (CQI), which are required for user selection in the multi-user MIMO system. Our analysis demonstrates that the number of users, the number of selected users, and codebook size are the key factors that govern the performance of the best companion grouping (BCG)-based user scheduling. Accordingly, we have confirmed that the probability of forming the co-scheduled user group is determined by these factors, which implies that the number of PMI's and codebook size can be dynamically determined so as to maximize the average system throughput as the number of users varies in the cell.

• Archives of design research
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• v.19 no.5 s.67
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• pp.119-128
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• 2006

The scale of visual expression has expanded from freeze frame to motion picture as media have developed. Moving pictures such as animation, movies, TV CM and GUI become formative elements whose movement is necessary compared to freeze frame as apparent movement phenomenon and unit structure such as short and scene appear. Therefore, of formative elements such as a shape, color, space, size and movement, movement is importantly distinguished in the moving image. The expression and form of image as a relationship between the signified and signifier explained by Saussure are accepted as a sign by mutual complement even though they limit the content. This makes it possible to infer that the formal feature of movement participates in the message content. To verify this, the result of moving picture visual perception experiment based on the gestalt grouping principle result shows that 70-80 percent of subjects think that 'movement' is the important grouping clue in perception. Movement affects the maintenance of the context of message content in the communication process when the meaning structure of moving picture is analyzed based on the structural feature. The identity can be maintained with if there is a movement with similar directive point even if the color and shape of people, things and background are changed. Second, the clarity of the content is elevated by a distinguished object as a figure by movement. Third, it acts as a knowledge representation which can predict similar movement process of next information processing. Forth, movement gives the content consistency even though more than two scenes have fast switch and complicated editing structure like cross-cutting. Movement becomes a clue which can make grouping information input by visual perception reaction. Also, it gives the order to the visual expression which can be used improperly by formation of structural frame of image message and has the effectiveness which elevates the clarity of signification. Moving picture has discourse with several mixed unit structures because it fundamentally contains time and the common and distinguished expression is needed by media-mix circumstances. Therefore, by the application of gestalt grouping principle to moving picture field, movement becomes the more distinguished than other formative elements and affects the formation of meaning structure. This study propose a viewpoint that develops structural formative beauty and new image expression in the media image field.

• Journal of Korea Multimedia Society
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• v.20 no.3
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• pp.465-473
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• 2017

Electrocardiogram(ECG) signal is one of the unique bio-signals of individuals and is used for personal authentication. The existing studies on personal authentication method using ECG signals show a high detection rate for a small group of candidates, but a low detection rate and increased execution time for a large group of candidates. In this paper, we propose a hierarchical algorithm that extracts fiducial points based on curvature of ECG signals as feature values for grouping candidates ​and identifies candidates using waveform-based comparisons. As a result of experiments on 74 ECG signal records of QT-DB provided by Physionet, the detection rate was about 97% at 3-heartbeat input and about 99% at 5-heartbeat input. The average execution time was 22.4 milliseconds. In conclusion, the proposed method improves the detection rate by the hierarchical personal authentication process, and also shows reduced amount of computation which is plausible in real-time personal authentication usage in the future.

• Journal of the Korea Institute of Military Science and Technology
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• v.12 no.2
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• pp.191-198
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• 2009

Some of the wargame simulators currently used in the Korean Army were developed by other countries, and do not adequately reflect the Korean Peninsula terrain and weapon systems. This implies that these war game simulators need to be calibrated with respect to the input parameters for properly assessing the effectiveness of the Korean weapon systems. In this paper, AWAM, a wargame simulator, is calibrated in terms of the time-based fighting power(FP). The FP data obtained from the Korea Combat Training Center(KCTC) are used as a reference, and the differences between the AWAM and KCTC FP data are calculated at certain points in time. Then, the Taguchi robust design method is adopted using the probabilities of hitting for the K-2 rifle as controllable input parameters. Two performance characteristics are used. One is the difference between the AWAM and KCTC FP data and the other is the score derived by grouping the difference data. For each case, optimal settings of the probabilities of hitting are determined such that the mean of each characteristic is close to 0 with its dispersion being as small as possible.