Abstract: A hydrogen storage system is disclosed and includes a storage unit including a plurality of unit storage containers, in which metal hydride materials are respectively provided in an interior thereof and which are connected to each other in parallel, and a thermal fluid line defining a thermal fluid passage, which passes via the plurality of unit storage containers continuously and through which a thermal fluid flows for heating or cooling the unit storage containers, thereby enhancing a storage performance and an efficiency of the hydrogen.

Abstract: Provided is a cognitive experiment method for change in periphery region image quality for parameter determination of a foveated hologram. According to an embodiment, a cognitive experiment method for determining foveated image parameters includes: generating a foveated image which includes a foveal region and a periphery region while reducing image quality regarding the periphery region; displaying the generated foveated image; receiving an input of a response to image quality of the periphery region from a subject; and collecting information regarding appropriate image quality of the periphery region, based on the response inputted by the subject. Accordingly, in applying a foveated hologram generation algorithm for real-time reproduction, various parameters such as a boundary between a foveal region image and a periphery region image in a foveated hologram, and a degree of quality degradation of the periphery region image may be appropriately determined through a cognitive experiment.

Abstract: Provided is a holographic optical element printing method using a tunable focus lens and a rotating mirror. According to an embodiment, a holographic printer includes: a first optical engine and a second optical engine configured to adjust a phase of an incident collimated beam and emit the collimated beam; and a first reduction optical system and a second reduction optical system configured to reduce the beam emitted from the first optical engine and the second optical engine and to allow the beam to enter a holographic material, wherein each of the first optical engine and the second optical engine includes: a rotating mirror configured to reflect while adjusting the phase of the incident collimated beam through rotation; and a tunable focus lens configured to refract while adjusting the phase of the incident collimated beam reflected from the rotating mirror through focus tuning.

Abstract: A hydrogen storage device includes a storage container having an accommodation space in an interior thereof, a first metal hydride material provided in the interior of the storage container and that stores hydrogen, and a second metal hydride material provided in the interior of the storage container and that stores the hydrogen at a pressure that is different from that of the first metal hydride material. An advantageous effect of restraining an excessive rise of a pressure of the storage container and enhancing safety and reliability may be obtained.

Abstract: Provided is a hologram image normalization method for a holographic printer. In a holographic printing method according to an embodiment, generating, encoding, and normalizing for the (n+1)-th hogel are performed in parallel with loading and recording of a normalized hologram for the n-th hogel, and moving and waiting for the (n+1)-th hogel. Accordingly, a global maximum value and a global minimum value for normalization may be calculated as approximate estimation values, and a hologram generation process and a printing process may be performed in parallel, so that a total printing time may be minimized and memory usage may be optimized when holographic printing is performed.

Abstract: Disclosed are a method and apparatus for reusing wastewater. The method for reusing wastewater disclosed herein includes: generating a mixed wastewater by mixing multiple types of wastewater (S20); performing a first purification by passing the mixed wastewater through a flocculation-sedimentation unit (S40); performing a second purification by passing an effluent of the flocculation-sedimentation unit through a membrane bioreactor (MBR) (S60); performing a third purification by passing an effluent of the MBR through a reverse-osmosis membrane unit (S80); and reusing an effluent of the reverse-osmosis membrane unit as cooling water or industrial water (S100).

Abstract: Provided is an uncopyable hologram QR code, According to an embodiment of the present disclosure, a 3D code generation method divides a 2D code having specific information recorded thereon into a plurality of sub 2D codes, and generatES a 3D code by coupling at least one of the divided sub 2D codes at a different depth. Accordingly, a QR code is recorded on a hologram recording medium as a hologram, and is displayed and scanned, so that it is impossible to easily duplicate the QR code unlike an existing 2D QR code.

Abstract: Provided is a Maxwellian view display which uses a space-time multiplexing scheme and widens a field of view, thereby having a degree of freedom within a set area instead of a fixed position while maintaining the advantage of the existing Maxwellian view, in which a clear image can be observed irrespective of the difference in individual ability for focal point adjustment since the focal point does not need to be adjusted. According to an embodiment of the present invention, a display includes: a light source unit for changing the position of a point light source according to time; a first lens for converting the light emitted from the light source unit to be parallel; an image generating unit for generating an image using the parallel light incident from the first lens; and a second lens for focusing the image generated by the image generating unit.

Abstract: Provided are a holographic printing device and method using multiple optical heads. The holographic printing device according to an embodiment of the present invention comprises: a fringe pattern generation unit which generates a holographic fringe pattern, and segments the generated fringe pattern into hogels; a multiplexing unit which groups the hogels, segmented by the fringe pattern generation unit, according to area; and a plurality of optical heads which respectively receive the grouped hogels and print the respective hogels in the corresponding areas of a holographic medium. Accordingly, several hogels can be printed on the holographic medium at a time using the multiple optical heads, thus reducing holographic printing time so that even large screen holograms can be printed at high speed.

Abstract: Provided is a method for inserting a copyright information indication as a means for protecting the copyright of LF content which can be played back as multi-viewpoint images, wherein the copyright information indication is only inserted in images of a specific viewpoint. A method for generating multi-viewpoint images according to an embodiment of the present invention includes the steps of: generating multi-viewpoint images; inserting a specific information indication in images of a specific viewpoint among the generated multi-viewpoint images; and storing the multi-viewpoint images in which the specific information indication has been inserted. Accordingly, the copyright of LF content, which are expensive multi-viewpoint images, can be protected by inserting the copyright information indication only in the images of the specific viewpoint.

Abstract: Provided are a method and an apparatus for printing a hologram by using a mask. The hologram printing method according to an embodiment generates a hologram fringe pattern, splits the hologram fringe pattern on a hogel basis, generates the split hogels, masks a part of the generated hogel, and prints the masked hogel on a hologram medium. Accordingly, an empty space which occurs between hogels when a hologram is printed is prevented from being generated by using a mask, so that a fill factor can be effectively enhanced, and eventually, image quality of a hologram can be enhanced.

Abstract: Provided is a method in which, when configuring an HUD that produces a holographic image at a distance using a holographic optical element (HOE), an HOE capable of correcting aberrations generated by a projection optical system is manufactured and used to improve the quality of an HUD image. A method for manufacturing an HOE for HUD according to an embodiment of the present invention comprises the steps of: measuring aberrations generated by an optical system that projects an image of a display device; recording the measured aberrations in a master HOE; reproducing an aberrated wavefront of the optical system by playing the master HOE on a display plane on which the image of the display device is expressed; and causing an interference of the reproduced aberrated wavefront and a spherical wavefront irradiated from the HUD image plane on which the image of the display device is created, and recording the interference in the HOE.

Abstract: Provided is a technology for implementing an AR optical waveguide display capable of showing a hologram image by means of a small and simple system configuration by using an HOE. A holographic display according to an embodiment of the present invention comprises: a light source module for emitting a beam; an optical waveguide through which the emitted beam is incident and propagated; a plurality of holographic optical elements (HOES) for propagating the beam incident to the optical waveguide inside the optical waveguide while totally reflecting the beam; and a modulator for reproducing a holographic image through the progressing beam and propagating the beam to the inside of the optical waveguide while totally reflecting the beam. Accordingly, it is possible to implement, as a small and simple system, an optical waveguide display showing an AR hologram by using an optical waveguide and an HOE.

Abstract: Provided is a hologram printing method and apparatus using a hologram medium light efficiency map. A hologram printing method according to an embodiment emits a laser to a hologram medium, acquires an image by photographing light diffracted from the hologram medium, generates a light efficiency map of the hologram medium from the acquired image, and records hogels on the hologram medium by referring to the generated light efficiency maps of the hologram medium. Accordingly, light efficiency is measured on each hogel area, and hologram printing is performed by adjusting an intensity of a laser of each wavelength according to a hogel, so that uniformity of luminance and color of a hologram printing result can be enhanced.

Abstract: Provided is a Maxwellian view display which uses a space-time multiplexing scheme and widens a field of view, thereby having a degree of freedom within a set area instead of a fixed position while maintaining the advantage of the existing Maxwellian view, in which a clear image can be observed irrespective of the difference in individual ability for focal point adjustment since the focal point does not need to be adjusted. According to an embodiment of the present invention, a display includes: a light source unit for changing the position of a point light source according to time; a first lens for converting the light emitted from the light source unit to be parallel; an image generating unit for generating an image using the parallel light incident from the first lens; and a second lens for focusing the image generated by the image generating unit.

Abstract: A method for inserting information into a 3D structure and recognizing information in a non-destructive method is provided. A 3D printing method according to an exemplary embodiment of the present invention includes: generating a tag having specific information recorded thereon to be inserted into a 3D structure, and printing the tag on the inside of the 3D structure while printing the 3D structure. Accordingly, since the tag having information recorded thereon is printed on the inside of the 3D structure when the 3D structure is printed by a 3D printer, it is impossible to forge/falsify information.

Abstract: Provided are a system and a method for displaying content in association with a position of a projector. A method for displaying an image, according to one embodiment of the present invention, comprises identifying a position of an image output device, generating a partial image from a full image on the basis of the position of the image output device, and outputting the generated partial image by means of the image output device. As a result, since the image projected from the image output device changes in association with the position of the image output device, a more realistic AR/VR may be provided.

Abstract: A laser light source shutter system includes a light source, a variable focus optical element to transmit a beam emitted from the light source, a pinhole located on an optical path through which the beam travels from the variable focus optical element, and a controller to control a transmission and blocking of the beam by controlling a focal length of the variable focus optical element to be equal to a distance between the variable focus optical element and the pinhole or to be equal to other distances different from the distance. Therefore, a laser light source shutter free from vibration can be realized electronically with a low cost and a high light-blocking rate using a variable focus optical element such as a variable focus lens and a variable focus mirror.

Abstract: A laser light source shutter system includes a light source, a variable focus optical element to transmit a beam emitted from the light source, a pinhole located on an optical path through which the beam travels from the variable focus optical element, and a controller to control a transmission and blocking of the beam by controlling a focal length of the variable focus optical element to be equal to a distance between the variable focus optical element and the pinhole or to be equal to other distances different from the distance. Therefore, a laser light source shutter free from vibration can be realized electronically with a low cost and a high light-blocking rate using a variable focus optical element such as a variable focus lens and a variable focus mirror.

Abstract: A method for inserting information into a 3D structure and recognizing information in a non-destructive method is provided. A 3D printing method according to an exemplary embodiment of the present invention includes: generating a tag having specific information recorded thereon to be inserted into a 3D structure, and printing the tag on the inside of the 3D structure while printing the 3D structure. Accordingly, since the tag having information recorded thereon is printed on the inside of the 3D structure when the 3D structure is printed by a 3D printer, it is impossible to forge/falsify information.