• Journal of the Korean Mathematical Society
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• v.47 no.4
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• pp.691-704
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• 2010

Over a ring R, let $P_R$ be a finitely generated projective right R-module. Then we define the G-injector (G-projector) if $P_R$ preservers Gorenstein injective modules (Gorenstein projective modules), the Gflator if $P_R$ preservers Gorenstein flat modules. G-injector (G-flator) and G-injector are characterized focus primarily on the cases where R is a Gorenstein ring, and under this condition we also study the relations between the injector (projector, flator) and the G-injector (G-projector, G-flator). Over any ring we also give the characteristics of G-injector (G-flator) by the Gorenstein injective (Gorenstein flat) dimensions of modules.

• Journal of Information Display
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• v.11 no.1
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• pp.28-32
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• 2010

A mini-projector prototype employing a LED light source, a nontelecentric structure, and an LCOS panel for application in the integrated 3D display was fabricated. A seamless image was obtained by tilting an array of mini-projectors. Seamless quality was created by the excellent uniformity of the projection intensity on the mini-projector's screen, which was simulated as 98.34%. Great uniformity can be realized by optimizing the design of the light source and the optics configuration, which is the key to such realization.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1331-1334
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• 2008

In this paper, we developed a novel hyperreality display called the Head Dome Projector (HDP). The HDP is a head-mounted display consisting of a dome-shaped screen with a very small radius of 40 cm, a mobile projector with ultra-wide projection lens and LED light sources. The main feature of the HDP is very wide viewing angle of 160 degrees horizontally by 120 degrees vertically comparable to the human visual field of view without head tracking and 360 degrees by 360 degrees with head tracking. According to our subjective evaluation comparing the HDP with a flat-panel display (FPD), the HDP realizes hyperreality 2.5 points higher than that realized by an FPD in the case of ${\pm}5$ level evaluation for HD motion images.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.3034-3036
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• 2000

Recently the use of Laser Projector is ascending world-widely to make the best effiencies out of the various events & commercials. To produce fixed image through Laser projector, at least 24 times/sec of iteration is required. In this view, its performance is much influenced by coordinates extraction method for high-speed controlling. This paper basically introduces the way of inputting coordinates by extraction directly from outline rather than indicating size and directions of image's outline coordinates which used by renowned US company 'L' and etc.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2705-2707
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• 2000

The branch of the laser imaging has implemented 3D graphics, color graphics and video images after it drew a simple image by development the salvo's X-Y scanner in 1960 year. Now it is used as the multimedia show of an event and an advertisement. The latest issue of laserist is the ability to generate laser images with the same ease and speed associated with traditional computer graphics. All laser projector used in the interior of a countris was imported from other country. The most important component of the laser projector is the speed and the accuracy of a actuator and the software which actuates the controller on computer. In this paper we developed the controller with a universal joint and the PC based user interface software in order to implement the laser image of two dimension, and will prepare the base of beginning the home laser projector

• Journal of Institute of Control, Robotics and Systems
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• v.3 no.6
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• pp.613-618
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• 1997

In this paper, we designed a line CCD camera for a flying image, which is composed of a line CCD sensor(2048 cells) and a rotating mirror, and investigated its optical properties. We also made the 3-D image from the flying image which is made of 2-D image being juxtaposed to 1-D images obtained by the camera, and performed the calibration to acquire high precision 3-D data. As a result, we obtained the 3-D measurement system using the slit type of laser projector is available to measure the high precision shape of objects.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.10
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• pp.141-147
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• 2003

This paper represents an absolute positioning system using a light navigation path for mobile robot. The absolute positioning system is composed of the projector unit which generates a laser beam using laser diode and mobile robot with the optical detector which has some optical sensors. The projector unit is fixed over the navigating plane of mobile robot to generate the light navigation path, and the optical detector located upper part of mobile robot detects the generated laser beam from the projector. The navigation of mobile robot is controlled by the micro-processor which compares the detected present position from the detector with the previously programmed navigation path. And experimental results show that our sensor system can be used for the absolute positioning system of the mobile robot.

• Transactions of the Society of Information Storage Systems
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• v.10 no.2
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• pp.55-60
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• 2014

Laser projector has many advantages of high brightness, high resolution and small size, but the huge drawback of image degradation called speckle which generated by coherence of laser and roughness of surface interrupts their general use. There are many methods to reduce speckle pattern, but they need effective optical systems to realize display to the far field with huge volume. We designed speckle reduction element by using microlens with controlled curvature to reduce spatial coherence. Vibration element was also applied to reduce temporal coherence which considered response time of eye. Designed element was fabricated by simple reflow method and imprinting method. From the results, the fabricated element performed 48.33% of speckle reduction efficiency and 41.29% of optical efficiency with a single doublet lens.

• International Journal of Contents
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• v.12 no.2
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• pp.1-5
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• 2016

Extensible 3D (X3D) is the ISO standard for defining 3D interactive web- and broadcast-based 3D content integrated with multimedia. With the advent of this integration of interactive 3D graphics into the web, users can easily produce 3D scenes within web contents. Even though there are diverse texture nodes in X3D, projective textures are not provided. We enable X3D to provide SingularProjectiveTexture and MultiProjectiveTexture nodes by materializing independent nodes of projector nodes for a singular projector and multi-projector. Our approach takes the creation of an independent projective texture node instead of Kamburelis's method, which requires inconvenient and duplicated specifications of two nodes, ImageTexture and Texture Coordinate.

• Journal of KIISE:Software and Applications
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• v.37 no.1
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• pp.29-38
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• 2010

We propose an interactive projection technique to display details of a large image in a high resolution and brightness by tracking a portable projector. A closed-loop based tracking method is presented to update the projected image while a user changes the position of the detail area by moving the portable projector. A marker is embedded in the large image to indicate the position to be occupied by the detail image projected by the portable projector. The marker is extracted in sequential images acquired by a camera attached to the portable projector. The marker position in the large display image is updated under a constraint that the center positions of marker and camera frame coincide in every camera frame. The image and projective transformation for warping are calculated using the marker position and shape in the camera frame. The marker's four corner points are determined by a four-step segmentation process which consists of camera image preprocessing based on HSI, edge extraction by Hough transformation, quadrangle test, and cross-ratio test. The interactive projection system implemented by the proposed method performs at about 24fps. In the user study, the overall feedback about the system usability was very high.