• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.4
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• pp.834-848
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• 2013

To effectively use these functions many kinds of human-phone interface are used such as touch, voice, and gesture. However, the most important touch interface cannot be used in case of hand disabled person or busy both hands. Although eye tracking is a superb human-computer interface method, it has not been applied to smartphones because of the small screen size, the frequently changing geometric position between the user's face and phone screen, and the low resolution of the frontal cameras. In this paper, a new eye tracking method is proposed to act as a smartphone user interface. To maximize eye image resolution, a zoom lens and three infrared LEDs are adopted. Our proposed method has following novelties. Firstly, appropriate camera specification and image resolution are analyzed in order to smartphone based gaze tracking method. Secondly, facial movement is allowable in case of one eye region is included in image. Thirdly, the proposed method can be operated in case of both landscape and portrait screen modes. Fourthly, only two LED reflective positions are used in order to calculate gaze position on the basis of 2D geometric relation between reflective rectangle and screen. Fifthly, a prototype mock-up design module is made in order to confirm feasibility for applying to actual smart-phone. Experimental results showed that the gaze estimation error was about 31 pixels at a screen resolution of $480{\times}800$ and the average hit ratio of a $5{\times}4$ icon grid was 94.6%.

• Journal of Korea Multimedia Society
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• v.16 no.11
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• pp.1261-1271
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• 2013

Zoom tracking involves the automatic adjustment of the focus motor in response to the zoom motor movements for the purpose of keeping an object of interest in focus, and is typically achieved by moving the zoom and focus motors in a zoom lens module so as to follow the so-called "trace curve", which shows the in-focus motor positions versus the zoom motor positions for a specific object distance. Thus, one can simply implement zoom tracking by following the most closest trace curve after all the trace curve data are stored in memory. However, this approach is often prohibitive in practical implementation because of its large memory requirement. Many other zoom tracking methods such as GZT, AZT and etc. have been proposed to avoid large memory requirement but with a deteriorated performance. In this paper, we propose a new zoom tracking method called 'Approximate Feedback Zoom Tracking method (AFZT)' on DM36x-based IP network camera, which does not need large memory by approximating nearby trace curves, but generates better zoom tracking accuracy than GZT or AZT by utilizing focus value as feedback information. Experiments through real implementation shows the proposed zoom tracking method improves the tracking performance and works in real-time.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.9
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• pp.33-39
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• 2012

For photovoltaic power generation need certainly decreasing module's price and increasing promote efficiency technology. Almost of solar panel is on the decrease energy efficiency since 2,000. like silicone(Si) solar panel, thin film solar panel and etc. Silicone(Si) solar panel was best efficiency in 1999. It's 24%. But after that time, It didn't pass limit of energy efficiency. That's why, nowadays being issued that using III-V compound semiconductor to high efficiency of concentrating photovoltaic system for making an alternative proposal. In Korea, making researches in allied technology with III-V compound semiconductor solar panel, condenser technology, and solar tracker. but feasibility study for concentrating photovoltaic power generation hasn't progressed yet. This thesis made a plan about CPV(Concentrating Photovoltaic)system and CPV has a higher energy efficiency than PV(Photovoltaic)system in fine climate conditions from comparing CPV with using silicone(Si) solar panel to PV's efficiency test result.

• Korean Journal of Optics and Photonics
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• v.19 no.2
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• pp.140-143
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• 2008

The integrated external cavity laser has been fabricated with a 1550 nm FP-LD, an optical filter, a micro ball lens and accurate ceramic blocks using a micro-block stacking (MBS) technique. The integrated external cavity laser module whose size is only $2.0{\times}2.1{\times}0.7\;mm^3$ has been mounted on the TO-CAN package. For the case of the 1.8% transmission filter, the single mode characteristic has been obtained with the optical power of -27.1 dBm and the SMSR of 31.7 dB.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.9
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• pp.743-749
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• 2012

In this paper, we designed and fabricated LED navigation lights which can replace the existing ones immediately and overcome disadvantages due to use of conventional lamps. To decide the best arrangement and position of a LED module, optical systems of existing navigation lights were analyzed and refracted routes of rays were simulated. The electrical and optical characteristics of the fabricated LED navigation lights were measured and analyzed with a goniophotometer. To calculate ranges of visibility, the vertical and horizontal luminous intensity distributions were evaluated in accordance with the COLREGs (convention on the international regulation for preventing collisions at Sea). From the results, the proposed LED navigation lights showed suitable characteristics for marine environment with the power consumption reduced by 90% and the maximum luminous intensity increased by 20% compared to the existing navigation lights.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.4
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• pp.448-454
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• 2015

In this paper, the band structural design that is typically in a line was arranged in a ring shape, so as to configure the high power LED lighting in such a way as to form a concentrated light distribution angle of less than 15 degrees. The parabolic aluminized reflector PAR38 that facilitates design using area and the area of the optical system to the same extent, applied a multiple light-source condenser lens optical system for the control of integration. The LED used here implemented a single linear light source using ans LED module with ans LED, flip-chip chip-scale package. The optical system was designed based on the energy star standard.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.2
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• pp.178-185
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• 2011

Optical image stabilization is a device to compensate the camera movement in the exposure time. The compensation is implemented by movable lens or image sensor that adjusts the optical path to the camera movement. Generally, the camera is moved by a handshake, thus the handshake is considered as an external disturbance. However, there are many other vibrations such as car and train vibration. In this paper, the optical image stabilization system in high frequency region is presented. Notch filter and lead compensator are designed and applied to improve the stability without changing the actuator. To verify the performance of the optical image stabilization system in high frequency region, the experiment equipment with moving object is established. It is confirmed that the opticalimage stabilization system does not diverge at the resonance frequency.

• Korean Journal of Optics and Photonics
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• v.4 no.3
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• pp.243-251
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• 1993

We have derived Gaussian bracket expressions of aplanatic and achromatic conditions and obtained the numerical solutions for each of two modules of the telephoto type telescope objective free from the Seidel first order spherical aberration, coma, and longitudinal chromatic aberration. The system which is for use in sighting a target is optimized within the resolution of eyes. The objective lens satisfying the aplanatic and achromatic condition has f/8.5 with the half field angle 0.$3^{\circ}$, and the telephoto ratio is 0.839 with the focal length of 30 cm.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.735-737
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• 2016

In this paper, we conducted a test of the 3D printer injection method and LSU (Laser Scanning Unit) feature a fusion of the polygon mirror scanning system that is the core mechanism operation for 3D printers for office laser printers SLA system. These tests ensure that the laser was operating and control well was confirmed that a certain point is output to the X-axis by means of a laser module and a polygon mirror. And confirmed after the F-theta lens is incident on the fixed laser power of the beam, and correction according to the correction beam on the mirror reflection was confirmed jineunji the focus according to the Z-axis upper plate.

• Journal of The Korean Astronomical Society
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• v.56 no.2
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• pp.169-185
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• 2023

The GMT-Consortium Large Earth Finder (G-CLEF) is the first instrument for the Giant Magellan Telescope (GMT). G-CLEF is a fiber feed, optical band echelle spectrograph that is capable of extremely precise radial velocity measurement. G-CLEF Flexure Control Camera (FCC) is included as a part in G-CLEF Front End Assembly (GCFEA), which monitors the field images focused on a fiber mirror to control the flexure and the focus errors within GCFEA. FCC consists of an optical bench on which five optical components are installed. The order of the optical train is: a collimator, neutral density filters, a focus analyzer, a reimager and a detector (Andor iKon-L 936 CCD camera). The collimator consists of a triplet lens and receives the beam reflected by a fiber mirror. The neutral density filters make it possible a broad range star brightness as a target or a guide. The focus analyzer is used to measure a focus offset. The reimager focuses the beam from the collimator onto the CCD detector focal plane. The detector module includes a linear translator and a field de-rotator. We performed thermoelastic stress analysis for lenses and their mounts to confirm the physical safety of the lens materials. We also conducted the global structure analysis for various gravitational orientations to verify the image stability requirement during the operation of the telescope and the instrument. In this article, we present the opto-mechanical detailed design of G-CLEF FCC and describe the consequence of the numerical finite element analyses for the design.