• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1753-1756
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• 2007

In the field of 3D display, holographic displays are the only technology allowing optimal user comfort. We have developed systems based on compact projection optics, that allow advantageous new features, like large size full-color3D scenes generated at high rate on a micro-display with state of the art resolution.

• Journal of the Optical Society of Korea
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• v.20 no.1
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• pp.118-124
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• 2016

The shape and location of the cutoff shield in a projection-type headlight system were optimized by a ray-tracing technique. A shield based on a Petsval surface showed better cutoff characteristics than a flat or cylindrical shield, such as a sharp intensity gradient and less color separation at the cutoff line. Adjustment of the shield’s location between the reflector and the aspheric lens further improved its cutoff characteristics.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.11
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• pp.1054-1062
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• 2011

This study describes the time domain imaging algorithm which can be well applied to short-range UWB(ultra wideband) bistatic radar. In the imaging method of SAR technology, the frequency domain method is well applied to the areas which satisfy far-field condition. However in the near-field environment, the image quality is not good due to phase error. However back-projection method based on time domain is well applied to short-range imaging radar. Meanwhile because its processing time is very long, real time-processing is very difficult. To resolve this problem FFBP(Fast Factorized Back-Projection) was proposed. Using the raw data gathered on field we implemented back-projection and FFBP method. Then image quality and processing time were analyzed using these methods.

• ETRI Journal
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• v.37 no.2
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• pp.317-327
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• 2015

A reliable analysis of consumer preference from a large amount of purchase data acquired in real time and an accurate customer characterization technique are essential for successful direct marketing campaigns. In this study, an optimal segmentation of post office customers in Korea is performed using a subspace projection-based clustering method to generate an accurate customer characterization from a high-dimensional census dataset. Moreover, a traditional temporal mining method is extended to an algorithm using the MapReduce framework for a consumer preference analysis. The experimental results show that it is possible to use parallel mining through a MapReduce-based algorithm and that the execution time of the algorithm is faster than that of a traditional method.

• Journal of Korea Multimedia Society
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• v.8 no.12
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• pp.1572-1580
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• 2005

The common requirements for watermarking are usually invisibility, robustness, and capacity. We proposed the watermarking for 3D mesh model based on projection onto convex sets for invisibility and robustness among requirements. As such, a 3D mesh model is projected alternatively onto two convex sets until it converge a point. The robustness convex set is designed to be able to embed watermark into the distance distribution of vertices. The invisibility convex set is designed for the watermark to be invisible based on the limit range of vertex movement. The watermark can be extracted using the decision values and index that the watermark was embedded with. Experimental results verify that the watermarked mesh model has both robustness against mesh simplification, cropping, affine transformations, and vertex randomization and invisibility.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.205-210
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• 2005

A new configuration of LCD projectors for polarized stereoscopic projection having no light loss in the polarization process is suggested. In the proposed system, two polarizing filters that are employed in the conventional LCD polarized stereoscopic projection system causing additional light loss and image distortion are excluded by taking into account of polarization property of the LCD projector and image processing techniques. From some experimental results by using the Type-1 LCD projectors of NEC MT 1060R, light loss of the proposed system occurring in the polarization process is found to be zero and the resultant stereoscopic video image projected from this system is also found to be 213%, 75% and 300% brighter than those projected from the conventional Type-1 LCD projector-based, Type-2 LCD projector-based and Type-3 projector-based systems, respectively.

• Journal of Information Processing Systems
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• v.16 no.4
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• pp.774-783
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• 2020

For the issue of subsurface target localization by reverse projection, a new approach of target localization with different distances based on symmetric sub-array multiple-input multiple-output (MIMO) radar is proposed in this paper. By utilizing the particularity of structure of the two symmetric sub-arrays, the received signals are jointly reconstructed to eliminate the distance information from the steering vectors. The distance-independent direction of arrival (DOA) estimates are acquired, and the localizations of subsurface targets with different distances are realized by reverse projection. According to the localization mechanism and application characteristics of the proposed algorithm, the grid zooming method based on spatial segmentation is used to optimize the locaiton efficiency. Simulation results demonstrate the effectiveness of the proposed localization method and optimization scheme.

• Journal of information and communication convergence engineering
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• v.20 no.1
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• pp.65-72
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• 2022

With the mark of the fourth industrial revolution, the smart factory is evolving into a new future manufacturing plant. As a human-machine-interactive tool, augmented reality (AR) helps workers acquire the proficiency needed in smart factories. The valuable data displayed on the AR device must be delivered intuitively to users. Current AR applications used in smart factories lack user movement calibration, and visual fiducial markers for position correction are detected only nearby. This paper demonstrates a marker-based object detection using perspective projection to adjust augmented content while maintaining the user's original perspective with displacement. A new angle, location, and scaling values for the AR content can be calculated by comparing equivalent marker positions in two images. Two experiments were conducted to verify the implementation of the algorithm and its practicality in the smart factory. The markers were well-detected in both experiments, and the applicability in smart factories was verified by presenting appropriate displacement values for AR contents according to various movements.

• Health Policy and Management
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• v.3 no.1
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• pp.146-168
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• 1993

The study was conducted to project supply and demand of the nurses till year 2010 based on analysis of supply and demand of nurses up to year 1991. Results of the study will provide invaluable information for nurses manpower planning as well as overall health manpower planning for the 21th century. It is projected that nurses will be oversupplied based on the current prductivity which is undesirable situation if the quality of care is considered, and undersupplied based on the the medical law as well as optimal productivity. Thus, it is desirable to increase active supply of nurses. One of the ways of increasing active supply would be increasing the size of training and education. But, considering low employment rate of nurses which is about 59% better way of solving problems related to nurses shortage would be improvement in nurses' employment rate. According to simulation study done as part of this study, if nurses' employment rate goes up to 80%, there is no need for increasing the size of training to meet the demand at the level of medical law.

• Korean Journal of Logic
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• v.16 no.1
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• pp.1-15
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• 2013

Yang [12] investigated weakening-free fuzzy logics expanded by the delta connective $\Delta$, which can be interpreted as Baaz's projection and its generalizations. In this paper, we keep investigating such logics with an alternative delta connective $\Delta$, which can be regarded as a variant of the Baaz projection. The main difference is that although our new $\Delta$ satisfies many properties of Baaz projection, it can nether be interpreted as Baaz's projection itself nor its generalizations. For this, we first introduce several weakening-free fuzzy logics with the alternative connective $\Delta$. The algebraic structures corresponding to the systems are then defined, and their algebraic completeness is proved.