• Journal of the Institute of Electronics Engineers of Korea SP
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• v.37 no.5
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• pp.64-75
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• 2000

This paper proposes a color sample selection method that produces a uniform distribution in the display gamut plus a color reproduction method for using a uniform color sample In contrast to the conventional method, the proposed uniform color samples are selected m CIELAB, a device-independent color space, instead of RGB (red, green, and yellow) or CMY (cyan, magenta, and yellow) space, device-dependent color spaces To evaluate the performance of the proposed color samples, they were applied to color space conversion using both a regression model and neural network As a result, in the case of a color sample of the same size, the color space conversion method using the proposed samples showed a lower color difference for color conversions using either neural or regression.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.39 no.4
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• pp.455-461
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• 2002

This paper presents a new parametric log line equation of polar form for Hough transform in log-polar plane, in which it can remove the well-known unboundedness problem of Hough parameters. Bolduc's method is used to generate a log-polar image dividing the fovea and periphery from a Cartesian image. Edges of the fovea and periphery are detected by using the Sobel mask and the proposed space-variant gradient mask, and are combined in the log-polar plane. The sampled points that might constitute a log line are quite sparse in a deep peripheral region due to severe under-sampling, which is an inherent property of LPM. To cope with such under-sampling, we determine the values of cumulative cells in Hough space by using the space-variant weighting. In our experiments, the proposed method demonstrates its validity of detecting not only the lines passing through both the fovea and periphery but also the lines in a deep periphery.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.38 no.3
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• pp.24-40
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• 2001

The design and implementation of agents is an essential part of the development of immersive types of tutoring systems using virtual reality. This paper proposes several effective mechanisms for the design and implementation of agents. Unlike existing researches we focus on accommodating diversity of agents' behavior in the proposed mechanisms. First, we define the space object based on the field theory. The introduction of the field theory allows us to approach the space objects in a structural manner rather than by their classification. We can also achieve dynamic genesis and extinction of the space objects, and derivation of overall changes in spatio-temporal situations. Second, we classify the behavior of agents into composite behaviors and primitive actions in order to achieve its dynamic planning. Finally, we distribute the knowledge among agents and their associated objects according to their interrelations. By this distribution, we can handle the otherwise prohibitively large amount of knowledge related to agents' behaviors and construct a dynamic environment. By implementing a situation with agent's navigation across a composite space object, we demonstrate the effectiveness of these schemes presented above.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.5
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• pp.454-462
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• 2016

portable white space device(WSD) obeying the Korean regulations of TV white space(TVWS) can cause harmful interference to a digital TV receiver residing at the same pixel around the edge of the digital TV service coverage for the case with a changed propagation environment. In order to solve this problem, we propose a method to allocate the resource of a hybrid WSD based on TVWS geo-location DB with spectrum sensing. Using the received power of digital TV signal through the spectrum sensing, a hybrid WSD can calculate the maximum permitted EIRP based on location probability. Based on the accurate allocation method proposed in this paper, it is possible to satisfy the Korean TVWS regulations and to eliminate the harmful interference to TV receivers nearby the hybrid WSD.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.2
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• pp.381-404
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• 2022

Forest fires inflict great losses of human lives and serious damages to ecological systems. Hence, numerous fire detection methods have been proposed, one of which is fire detection based on sensors. However, these methods reveal several limitations when applied in large spaces like forests such as high cost, high level of false alarm, limited battery capacity, and other problems. In this research, we propose a novel forest fire detection method based on image processing and correlation coefficient. Firstly, two fire detection conditions are applied in RGB color space to distinguish between fire pixels and the background. Secondly, the image is converted from RGB to YCbCr color space with two fire detection conditions being applied in this color space. Finally, the correlation coefficient is used to distinguish between fires and objects with fire-like colors. Our proposed algorithm is tested and evaluated on eleven fire and non-fire videos collected from the internet and achieves up to 95.87% and 97.89% of F-score and accuracy respectively in performance evaluation.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.6
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• pp.1229-1238
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• 2023

Digital twin is a technology that creates a virtual space that replicates the real world and manages the real world efficiently by integrating the real and virtual spaces. The digital twin concept for water facilities is to effectively manage water pipes in the real world by implementing them in a virtual space and augmenting them to the interior space of the building. In the proposed method, the Unity 3D game engine is used to implement the application of digital twin technology in the interior of a building. The AR Foundation toolkit based on ARCore is used as the augmented reality technology for our Digital Twin implementation. In digital twin applications, it is essential to match the real and virtual worlds. In the proposed method, 2D image markers are used to match the real and virtual worlds. The Unity shader program is also applied to make the augmented objects visually realistic. The implementation results show that the proposed method is simple but accurate in placing water pipes in real space, and visually effective in representing water pipes on the wall.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.229-233
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• 2004

According as internet and Information-Communication technology develop with the fast speed, Electronic Catalog that is used B2B or B2C electronic commerce is important element middle who can express well special quality of corporation's goods and product most effectively from internet space. But, several problems that creation of Electronic Catalog and standard absence about application that can say as importance technology base in electronic commerce and market newcomers who is constructing each other dissimilar system and take part in electronic commercial transaction can not use Electronic Catalog information exchange and transaction are happening. So that this treatise can use Electronic Catalog document that user who define Electronic Catalog document structure that can process information of goods configurationally and takes part in transaction is defined in electronic commerce hereupon, integration style Electronic Catalog system design and embody. This system did useful information that can not get from various advantage and catalog document such as business all-in-one and interoperability in different environment that Web Services through interlock with Web Services has so that can get Web Services.

• Journal of Power Electronics
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• v.14 no.1
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• pp.92-104
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• 2014

To insure stable operation and eliminate twice torque ripple, a topology for a six phase permanent magnet synchronous generator (SP-PMSG) with a neutral point connected together was analyzed in this paper. By adopting an extended transformation matrix, the mathematic model of the space vector control was established. The voltage and torque equations were deduced while considering the third harmonic flux and inductance. In addition, the suppression third harmonic method and the closed loop control strategy were proposed. A comparison analysis indicates that the cooper loss minimum method and the current magnitude minimum method can meet different application requirements. The voltage compensation amount for each of the methods was deduced which also takes into account the third harmonic effect. A simulation and experimental result comparison validates the consistency through theoretical derivation. It can be seen that all of the two control strategies can meet the requirements of post-fault.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.163-166
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• 2005

Multilayer LTCC technology enables RF modules to be reduced dramatically by taking advantage of the three dimension flexibility. Compared to a conventional two dimensional PCB, LTCC allows higher density, reduced size, and lower cost. In this research, BPF based on LTCC for 900MHz ZigBee application was implemented which can replace SAW filter with using the material of the Dupont9599's dielectric constant 7.8. And distributed baud pass filter for 900MHz ZigBee system applications is presented. Using resonator stripline and capacitance, 2nd order band pass filter was designed. Adjusting resonator's length and capacitance is easy to tune at accurate center frequency by shifting band because ZigBee system is using narrow bandwidth, $902MHz^{\sim}928MHz$. Also resonator has no limitation in space, so reducing size is possibile. Designed filter had I.L. 2.8dB at 915MHz and attenuation at 815MHz, 1015MHz was 16dB, 15dB, respectively. Therefore, the sharpe cut-off and good insertion loss for ZigBee system application.

• Journal of the Korean Ceramic Society
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• v.44 no.3 s.298
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• pp.157-161
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• 2007

Line width under $100\;{\mu}m$ with good resolution is difficult to achieve using conventional thick-film process utilizing screen printing method. However combined with lithography technology finer line and space for miniaturization and highly integrated package is achievable. In this study, photosensitive Ag paste of optimum formulation used for thick film lithography technology was fabricated by various Ag powder, glass powder and additives. As the result, line width of $30\;{\mu}m$ with good definition and reduced mismatch during co-firing with LTCC substrate was acquired. Formulated Ag paste was used to pattern embedded fine line inductor with over 90% yield.