• Journal of The Korean Digital Architecture Interior Association
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• v.2 no.1
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• pp.9-15
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• 2002

As architectural forms tend to be large-scaled, high-storied and complicated, use of computer for processing design information has been generalized. However, CAD use in the process of developing architectural design has been neglected greatly in the educational field of architectural field due to the surging of recognition that it may limit the essential property of architectural design. It may be resulted from the limitation of CAD system, that is, it is because of tardy speed of application development for the related areas with the lack of simplicity and clarity of flexibility to be secured on the drawing and user interface. Recent CAD systems, however, overcome such a limitation, convert into object-based design from entity-based drawing, drafting and modeling for implementing design concept of architects and it connects with internet linked to superspeed information communication network and changes process and stream of architectural design. Therefore, this study deals with utility of object based CAD system with products of Autodesk Co. and consequently obtain the following conclusions. First, it expands architect's design areas by supporting cooperative design system based on model-based architectural design and internet. Second, it reduces consumption of personal and material resources and time in the process of drawing production for improving architectural design works. Third, it can reduce the frequent design changes by improving understanding of architectural space with visualization of immediate 3D information, escaping from traditional methods to deliver design information to building owner through 2D drawing or model and perspective drawing requiring much cost and time. Fourth, it keeps exactness without omission or duplication of design information and generate and renew information of all related drawings on a drawing. Fifth, it is possible to change difficult and boring architectural design work into a pleasure owing to immediate modeling and drawing of design idea. In addition, digital drawing generated by using object-based CAD system can playa role of establishing Urban Information System to be used for protecting from building in disaster and urban disasters in connection with GIS numerical map and be used for reference of all kinds of information required fro post-management of buildings. However, what is more important is that surplus time from introduction of object-based CAD system should be used for consideration to be recognized as a good space and building built as a product of this project for comfort to urban people.

• KIPS Transactions on Computer and Communication Systems
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• v.12 no.12
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• pp.347-356
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• 2023

In the recent war between Ukraine and Russia, low-orbit satellite communication played a major role, and Korea laid a foothold for low-orbit satellite communication services with the successful launch of Nuri in May 2023 and entered a full-scale civilian space age competition. In order to create an ecosystem for ICT digital transformation and data convergence in the field of low-orbit satellite communication, this paper conducts user sentiment analysis by importing posts from Reddit, one of the world's SNS, and extracts need-related sentences through need mining to identify user needs, performs topic modeling to classify topics, and prepares an action plan according to these topics. We hope that this study will be used as a policy resource for the development and innovation of new business models in the field of low-orbit satellite communication, bridging the digital information gap and solving social problems, contributing to sustainable digital transformation and enhancing soft power.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.58.2-58.2
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• 2013

Both peculiar velocities and errors in the assumed redshift-distance relation ("Alcock-Paczynski effect") generate correlations between clustering amplitude and orientation with respect to the line-of-sight. In this talk we propose a novel technique to extract the Alcock-Paczynski, geometric, distortion information from the anisotropic clustering of galaxies in 3-dimensional redshift space while minimizing non-linear clustering and peculiar velocity effects. We capitalize on the recent, large dataset from the Sloan Digital Sky Survey III (SDSS-III), which provides a large comoving sample of the universe out to high redshift. We focus our analysis on the Baryon Oscillation Spectroscopic Survey (BOSS) constant mass (CMASS) sample of 549,005 bright galaxies in the redshift range 0.43

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.11
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• pp.1860-1867
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• 2016

In this paper, first, a linearized modeling of a phase shift full-bridge converter used in chargers of electric vehicles is derived by using state-space approach and transfer functions from the duty ratio to output voltage and the inductor current are also verified. second, control systems for the output voltage and the inductor current are designed using the root locus technique. It is illustrated by experimental results that the control performance on the output variables is satisfied with the designed digital control system based on a automobile qualified 32-bit microcontroller.

• Journal of the Korean Society of Industry Convergence
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• v.18 no.3
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• pp.139-149
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• 2015

In this paper, we describe a new approach to perform real-time implementation of an robust controller for robotic manipulator based on digital signal processors in this paper. The Texas Instruments DSPs chips are used in implementing real-time adaptive control algorithms to provide enhanced motion control performance for dual-arm robotic manipulators. In the proposed scheme, adaptation laws are derived from model reference adaptive control principle based on the improved direct Lyapunov method. The proposed adaptive controller consists of an adaptive feed-forward and feedback controller and time-varying auxiliary controller elements. The proposed control scheme is simple in structure, fast in computation, and suitable for real-time control. Moreover, this scheme does not require any accurate dynamic modeling, nor values of manipulator parameters and payload. Performance of the proposed adaptive controller is illustrated by simulation and experimental results for robot manipulator consisting of dual arm with eight degrees of freedom at the joint space and cartesian space.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.38 no.6
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• pp.617-629
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• 2001

The mathematical models for the receptive field of simple cells in the human visual system have been developed in the areas of psychophysics, physiology and neuroscience. The various models used in the fields of digital image processing and computer vision include Gator complex, Gaussian derivatives and Hermite functions. In this paper, the effective widths for the models are derived based on the space-frequency uncertainty principle. The center frequency and parameters related to the models are determined in accordance with the human visual filters, and resultant bandwidths are analyzed. Furthermore, the characteristics of space and frequency for the models is analyzed and compared to the experimental data obtained from psychophysics.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.1
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• pp.570-595
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• 2017

Robust and perceptually-adaptive image watermarking algorithms have mainly targeted gray-scale images either at the modeling or embedding levels despite the widespread availability of color images. Only few of the existing algorithms are specifically designed for color images where color correlation and perception are constructively exploited. In this paper, a new perceptual and high-capacity color image watermarking solution is proposed based on the extension of Tsui et al. algorithm. The $CIEL^*a^*b^*$ space and the spatio-chromatic Fourier transform (SCFT) are combined along with a perceptual model to hide watermarks in color images where the embedding process reconciles between the conflicting requirements of digital watermarking. The perceptual model, based on an emerging color image model, exploits the non-uniform just-noticeable color difference (NUJNCD) thresholds of the $CIEL^*a^*b^*$ space. Also, spread-spectrum techniques and semi-random low-density parity check codes (SR-LDPC) are used to boost the watermark robustness and capacity. Unlike, existing color-based models, the data hiding capacity of our scheme relies on a game-theoretic model where upper bounds for watermark embedding are derived. Finally, the proposed watermarking solution outperforms existing color-based watermarking schemes in terms of robustness to standard image/color attacks, hiding capacity and imperceptibility.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.12
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• pp.1220-1230
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• 2006

In this paper, we propose a flew technique to the design and real-time control of an adaptive controller for robotic manipulator based on digital signal processors. The Texas Instruments DSPs(TMS320C80) chips are used in implementing real-time adaptive control algorithms to provide enhanced motion control performance for dual-arm robotic manipulators. In the proposed scheme, adaptation laws are derived from model reference adaptive control principle based on the improved Lyapunov second method. The proposed adaptive controller consists of an adaptive feed-forward and feedback controller and time-varying auxiliary controller elements. The proposed control scheme is simple in structure, fast in computation, and suitable for real-time control. Moreover, this scheme does not require any accurate dynamic modeling, nor values of manipulator parameters and payload. Performance of the proposed adaptive controller is illustrated by simulation and experimental results for a dual arm robot manipulator with eight joints. joint space and cartesian space.

• Korean Journal of Remote Sensing
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• v.24 no.2
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• pp.141-152
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• 2008

The 3D building modeling is one of crucial components in constructing 3D geospatial information. The existing methods for 3D building modeling depend mainly on manual photogrammetric processes, which indeed take great amount of time and efforts. In recent years, many researches on 3D building modeling using aerial LiDAR data have been actively performed to aim at overcoming the limitations of existing 3D building modeling methods. Either techniques with interpolated grid data or data fusion with digital map and images have been investigated in most of existing researches on 3D building modeling with aerial LiDAR data. The paper proposed a method of 3D building modeling with LiDAR data only. Firstly, octree-based segmentation is applied recursively to LiDAR data classified as buildings in 3D space until there are no more LiDAR points to be segmented. Once octree-based segmentation is completed, each segmented patch is thereafter merged together based on its geometric spatial characteristics. Secondly, building model components are created with merged patches. Finally, a 3D building model is generated and composed with building model components. The experimental results with real LiDAR data showed that the proposed method was capable of modeling various types of 3D buildings.

• Korean Institute of Interior Design Journal
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• no.40
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• pp.158-164
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• 2003

The rapid development of information technology has much influence on architectural design. Collaboration beyond time and space has been possible by networking the work environment and digital products. Thus, the virtual design studio on architectural design is getting more important than ever before. This research investigates a virtual design studio methodology for effective collaboration. The building design process and the communication model are studied and possible modes of design collaboration are defined. This paper proposes an internet-based Virtual Reality(VR) communication tool as well as new design methodology that we call the 'Hybrid Design Methodology'. We expect that this design methodology will dramatically increase design feedbacks, and thus results in better design alternatives. There are two issues involved in developing the collaborative virtual design studio: 1) an intuitive interface that presents collaborative relations, and 2) three-dimensional computer-mediated communication tool using sketch as a modeling method. Further research issues identified at the end of the research include developing algorithms that translate mapping images to polygons for the drafting phase in the design process.