• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.601-605
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• 2009

We have proposed a measurement system for measuring a whole shape of an object easily. The proposed system consists of a camera and a cylinder whose inside is coated by a mirror layer. A target object is placed inside the cylinder and an image is captured by the camera from right above. The captured image includes sets of points that are observed from multiple viewpoints: one is observed directly, and others are observed via the mirror. Therefore, the whole shape of the object can be measured using stereo vision in a single shot. This paper shows that a prototype of the proposed system was implemented and an actual object was measured using the prototype. A method based on a pattern matching which uses a value of SSD (Sum of Squared Difference), and a method based on DP (Dynamic Programming) are employed to identify a set of corresponding points in warped captured images.

• Korean Journal of Optics and Photonics
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• v.4 no.3
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• pp.252-259
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• 1993

A holosymmetric four-mirror system with unit magnification is designed for use in the micro-lithography using a deep ultraviolet wavelength of $0.248 {\mu}m$(KrF excimer laser line). In the holosymmetric system all orders of coma and distortion are zero. By applying this principle to the 4-spherical mirror system, we have obtained only one exact solution for the unit magnification holosymmetric four-spherical mirror system with all zero third order aberrations. For correction of the residual higher order aberrations of the system, aspherization is introduced keeping the holosymmetric properties. We have obtained near diffraction-limited performance for the wavelength of 0.248 pm within N.A. of 0.33 and image field diameter of 7.6 mm.

• Korean Journal of Oriental Medicine
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• v.17 no.2
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• pp.115-120
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• 2011

Objectives : The purpose of this study is to develop an apparatus which can take a facial image by self-operated capturing technique. The user can obtain one's facial image immediately after adjusting facial tilt and focusing distance. The system has been designed for classifying Sasang typology based on facial image. Methods : The system is composed of a Webcam, one-way glass mirror and mini LCD. The Webcam takes a facial image which is displayed on the mini LCD. Then the user can see and adjust to the right position in the real time through the image mirror-reflected from the mini LCD. The optical sensor is used to estimate the proper focusing distance. To verify the performance of the system, 11 characteristic points on the facial image are used and compared with high performance DSLR camera(D700) by applying the coefficient of variance and Bland-Altman Plot. Results : The developed system and D700 show enough agreement with the small coefficient of variance to analyse constitutional types with a facial im mage. However, the result of Bland-Altman plot shows that the width parameters have distortions owing to short focusing distance. Conclusions : The system is expected to be utilized on u-healthcare services for home environment after improving the distortion in the width parameters.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.920-925
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• 2001

A study on the topology optimization of a multi-spectral camera for space-use is presented. A multi-spectral camera for space-use experiences degradation of optical image in the space, which can not be detected on the optical test bench on the earth. An optical surface deformation of a primary mirror, which is a principal component of the camera system, under the self-weight loading is an important factor affecting the optical performance of the whole camera system. In this study, topology optimization of the primary mirror of the camera is presented. Total mass of the primary mirror is given as a constraint to the optimization problem. The sensitivities of the objective function and constraint are calculated by direct differentiation method. Optimization procedure is carried out by an optimality criterion method using the sensitivities of the objective function and the constraint. As a preliminary example, topology optimization considering a self-weight loading is treated. For practical use, the polishing pressure is included as a loading in the topology optimization of the primary mirror. Results of the optimized design topology for the primary mirror with varying mass ratios are presented.

• Clinics in Shoulder and Elbow
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• v.9 no.1
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• pp.68-72
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• 2006

Purpose: To demonstrate arthroscopically the presence of bilateral shoulder "mirror lesions" due to overhead work. Materials and Methods: A cross-sectional study was performed in a historical cohort of 10 male tire plant workers who underwent MRI studies of both shoulders. Bilateral intraarticular shoulder pathology was diagnosed by magnetic resonance imaging and confirmed by arthroscopy. "Mirror lesions" were defined as similar pathology between an individual patient's two shoulders. Results: We report on ten patients who had bilateral "mirror lesions." The most common mirror lesions were tears of the rotator cuff. Most patients (7 of 10) had more than one mirror lesion in their shoulders. There were two bilateral full thickness tears involving the supraspinatus and infraspinatus, four bilateral partial thickness supraspinatus tears, six bilateral partial or upper corner lesion complete subscapularis tears, and one bilateral complete supraspinatus tear. Conclusion: Occupational overhead work with simultaneous use of both arms is associated with bilateral shoulder lesions verified by arthroscopy. By demonstrating the work-related bilateral shoulder involvement, this study suggests an etiopathogenesis for these lesions and provides rational for developing worksite prevention strategies.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.6
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• pp.4108-4114
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• 2015

An image acquisition by using an optical mirror is called as a catadioptric method. The catadioptric imaging method is generally used for acquisition of 360-degree all directional visual information in an image. An exemplar omnidirectional optical mirror is the bowl-shaped hyperbolic mirror. In this paper, a single camera omnidirectional stereo imaging method is studied with an additional concave lens. It is possible to obtain 3 dimensional coordinates of environmental objects from the omnidirectional stereo image by matching the stereo image having different view points. The omnidirectional stereo imaging system in this paper is cost-effective and relatively easy for correspondence matching because of consistent camera intrinsic parameters in the stereo image. The parameters of the imaging system are extracted through 3-step calibration and the performance for 3-dimensional coordinates reconstruction is verified through experiments in this paper. Measurable range of the proposed imaging system is also presented by depth-resolution analysis.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.6
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• pp.121-127
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• 2022

Smart mirror is an IoT device that attaches a display and an embedded computer to the mirror and provides various information to the useer along with the mirror function. This paper went beyond the form of dealing with smart mirrors only stand alone device the provide information to users, and constructed a network in which smart mirrors are connected, and proposed and implemented a CoMirror system that allows users to talk and share information with other smart mirror users. The CoMirror system has a structure in which several CoMirror clients are connected on one CoMirror server. The CoMirror client consists of Raspberry Pi, a mirror film, a touch pad, a display device, an web camera, etc. The server has functions such as face learning and recognition, user management, a relay role for exchanging messages between clients, and setting up for video call. Users can communicate with other CoMirror users via the server, such as text, image, and audio messages, as well as 1:1 video call.

• Journal of the Korea Fashion and Costume Design Association
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• v.13 no.1
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• pp.99-112
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• 2011

The purpose of this research is to study India's traditional embroidery method, Mirror Work, and to evaluate the examples of contemporary costumes as well as the applications of art to clothing that have been influenced by this technique, in order to expand its usage for creation of a new fashion image. Research in the literature and application of works related to Mirror Work have demonstrated: First of all, as a traditional embroidery method that represents the folk art of India, Mirror Work displays unique methods used in different regions and the way that various methods and materials were combined by the use of mirrors, beads, and $appliqu{\acute{e}}$. Secondly, it was found that the presentation of Mirror Work in the $pr{\hat{e}}t$-a-porte collection is based on a traditional embroidery method using both developed materials and adapted methods to express traditional reproducibility, geometric simplicity, and aesthetic characteristics of complex decorations. Thirdly, new plasticity for art to wear clothing can be created through various methods aside from embroidery, for example by a technique of wrapping crochet laces and tapes around the mirror for decorative purposes. Based on these results it can be inferred that, from the perspective of multiple forms for decorations, Mirror Work shares multiple forms of personal aesthetic goals through the mirror's unique quality for expression and enhanced images of artistic decorative art. Also, the introduction of traditional materials and methods for today's folk art and traditional costumes can be the subject of unique aesthetic characteristics based on different perspectives of the recreation of tradition. Finally, it can further create a new plasticity within the globalization phenomena.

• Korean Journal of Optics and Photonics
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• v.3 no.2
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• pp.77-85
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• 1992

The design of a flat-field XUV spectrograph is optimized for a high throughput, aberration-corrected spectral image in the wavelength region of 50-300 $\AA$ The varied-line spacing (VLS) concave grating theory for an XUV spectrograph with a toroidal mirror in front of an entrance slit is derived. Since the derived theory includes the arbitrary shaped source, it is able to correct the limit of the simple optimization theory which considers only a point source at the center of the entrance slit. The reflection matrix at the toroidal mirror and the diffraction matrix at VLS grating are derived and compared with those of a holographic grating. The absolute energy efficiency of a flat-field spectrograph is calculated by considering the reflectivities of the toroidal mirror and the Au coated concave grating and the grating efficiency. The alignment sensitivity of the toroidal mirror and the concave grating is investigated, and the method to achieve the best imaging of XUV spectrum is discussed. The calculated resolving power of the flat-field XUV spectrograph is more than 4000 in the aberration-corrected wavelength range. The focused spot size at the dispersion plane is less than $20\mu \textrm m\times \mu \textrm m$at the wavelength 100$\AA$ It is shown that a high throughput characteristic can also be achieved through a careful adjustment of alignment parameters.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.2
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• pp.135-140
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• 2012

The mirror neuron system in the cerebrum, which are handled by visual information-based imitative learning. When we observe the observer's range of mirror neuron system, we can assume intention of performance through progress of neural activation as specific range, in include of partially hidden range. It is goal of our paper that imitative learning is applied to 3D vision-based intelligent system. We have experiment as stereo camera-based restoration about acquired 3D image our previous research Using Optical flow, unscented Kalman filter. At this point, 3D input image is sequential continuous image as including of partially hidden range. We used Hidden Markov Model to perform the intention recognition about performance as result of restoration-based hidden range. The dynamic inference function about sequential input data have compatible properties such as hand gesture recognition include of hidden range. In this paper, for proposed intention recognition, we already had a simulation about object outline and feature extraction in the previous research, we generated temporal continuous feature vector about feature extraction and when we apply to Hidden Markov Model, make a result of simulation about hand gesture classification according to intention pattern. We got the result of hand gesture classification as value of posterior probability, and proved the accuracy outstandingness through the result.