• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.859-865
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• 2007

This paper presents a method to analyze the unbalance response of a high speed polygon mirror scanner motor supported by sintered bearing and flexible supporting structures by using the finite element method and the mode superposition method. The appropriate finite element equations for polygon mirror are described by rotating annular sector element using Kirchhoff plate theory and von Karman non-linear strain, and its rigid body motion is also considered. The rotating components except for the polygon mirror are modeled by Timoshenko beam element including the gyroscopic effect. The flexible supporting structures are modeled by using a 4-node tetrahedron element and 4-node shell element with rotational degrees of freedom. Finite element equations of each component of the polygon mirror scanner motor and the flexible supporting structures are consistently derived by satisfying the geometric compatibility in the internal boundary between each component. The rigid link constraints are also imposed at the interface area between sleeve and sintered bearing to describe the physical motion at this interface. A global matrix equation obtained by assembling the finite element equations of each substructure is transformed to a state-space matrix-vector equation, and both damped natural frequencies and modal damping ratios are calculated by solving the associated eigenvalue problem by using the restarted Arnoldi iteration method. Unbalance responses in time and frequency domain are performed by superposing the eigenvalues and eigenvectors from the free vibration analysis. The validity of the proposed method is verified by comparing the simulated unbalance response with the experimental results. This research also shows that the flexibility of supporting structures plays an important role in determining the unbalance response of the polygon mirror scanner motor.

• Korean Journal of Optics and Photonics
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• v.30 no.6
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• pp.230-236
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• 2019

We propose and demonstrate a searching and autoalignment method for indoor optical wireless communication, using a cost-effective retroreflective sheet and a microelectromechanical system (MEMS) mirror. We use an extremum-seeking method for a single axis and beam steering with a MEMS mirror to maintain a line of sight (LOS) with the optical link. This autoalignment method shows a receiver sensitivity of -31.87 dBm for a bit rate of 2.5 Gb/s over a 7 m communication link.

• Archives of design research
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• v.18 no.4 s.62
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• pp.147-154
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• 2005

In this paper, I am going to analyze a correlation of Jacques Lacan's Mirror Stage and the process of remediation on image media. It is because the remediation process of various digital media is letting people pass through one time of mirror stage again. Remediation for the Internet of traditional media, conflict with the virtual world and real world, identification that a virtual image changes a practical image is for it to be caused a remediation process by mutual link of various image media. The Narcissism which occurs in the relation a self with a idealized self searches a new own expression and forms a skillful mania culture. Reflexivity of active mania culture same as a Jacques Lacan's Mirror Stage is to be the possibility becoming the feature of media culture of today. However, if digital media culture generation spends extremely wasting time from the image media, these image media generations cannot grow into new future-type man. According to this, it is necessory to have a study on Visual Literacy that it is related to a Jacques Lacan's Mirror Stage.

• Bulletin of the Korean Space Science Society
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• 2008.10a
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• pp.37.1-37.1
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• 2008

Space Science and Technology Laboratory at Kyung Hee University developed an 80cm Nasmyth telescope with the joint work of Space & Astronomy, Inc. It was set up at Muju county public astronomical observatory in Jeonlabuk-Do. Nasmyth focus system was selected for the telescope to use two focal points by a rotatable tertiary mirror. Focal ratios of the telescope are f10, f5 respectively. Support of the main mirror is made with Lasalle-system. This system uses 24-points in the back side of the mirror that are all resting on small counter-weights and side support is 10-points Boll link Flexible type with 2 Lasalle type. The mount is wheel & disk type Alt-Azimuth design using DC-servo motors. External high accuracy encoder has 47,600 sine-waves/rot. These encoders are used to make real-time corrections on all gearing errors.

• Journal of Digital Convergence
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• v.14 no.4
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• pp.379-385
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• 2016

IT companies are increasingly taking interest in the automobile industry as a major industry of the future. Companies specializing in information technology, such as Google, Apple and Samsung, are actively taking part in the automobile industry and are conducting various research on connected cars. At this point in time, this study aims on understanding the concept of connected cars and the concept of mirror linking, which is one of the many methods in connecting cars. In this transitional period of connected cars, the purpose of this study is to present the method of mirror linking iPhones and to discover how this could be used in connected cars. By turning a normal car into a connected car, simply with a smartphone in hand, the ideas presented in this study will serve as an opportunity for many current automobile owners to experience the functions of connected cars of the future without shouldering additional expenses.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.4
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• pp.146-153
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• 2008

In this paper, a integrated phase-locked loop(PLL) as a clock multiphase generator for a high speed serial link is designed. The designed PLL keeps the same bandwidth and damping factor by using programmable current mirror in the whole operation frequency range. Also, the close-loop transfer function and VCO's phase-noise transfer function of the designed PLL are obtained with circuit netlists. The self impedance on board-mounted chip is calculated according to sizes and positions of decoupling capacitors. Especially, the detailed self-impedance analysis is carried out between frequency ranges represented the maximum gain in the close-loop transfer function and the maximum gain in the VCO's phase noise transfer function. We shows PLL's jitter characteristics by decoupling capacitor's sizes and positions from this result. The designed PLL has the wide operating range of 0.4GHz to 2GHz in operating voltage of 1.8V and it is designed 0.18-um CMOS process. The reference clock is 100MHz and PLL power consumption is 17.28mW in 1.2GHz.

• The Journal of Korean Medical History
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• v.33 no.1
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• pp.1-9
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• 2020

Pubescent Angelica is generally used in musculoskeletal diseases of lower extremity, itching, external contraction (外感) and furuncle, with the effect of dispelling wind, draining dampness, dispersing the external (解表) and stopping pain. The disease parts of Treasured Mirror of Eastern Medicine (東醫寶鑑) contain 121 examples of the usage of Pubescent Angelica. Cases of musculoskeletal diseases and itching are mainly in the External Bodily Elements section (外形篇), and those of external contraction and furuncle are mainly in the Miscellaneous Disorder section (雜病篇). Internal Bodily Elements section (內景篇) has 10 prescriptions that involve Pubescent Angelica, in Dreams (2), Voice (1), Uterus (4), Parasites (1), and Feces (2) chapters. Their specific symptoms are insomnia and sleep paralysis (Dreams), loss of voice due to external contraction (Voice), uterine hemorrhage (Uterus), phthisis (Parasites), and constipation and diarrhea (Feces). It is not easy for students beginning their clinical training to link the effects of Pubescent Angelica and its actual usage, especially in the area of internal medicine. By Analyzing the whole cases of Pubescent Angelica in the Treasured Mirror, we found various usages out of reach of basic knowledge of the herb. Such method can be utilized not only in developing herbal knowledge-based products, but also in improving Korean medicine education, by enhancing the occupational competency bridging basic and clinical knowledge.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.1
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• pp.47-52
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• 2004

This paper presents a CMOS optical receiver design featuring wide input dynamic range and low bit error rate suitable for FTTH application. We achieved 60dB input dynamic range for up to 100Mbps by controlling the PMOS feedback resistance of transimpedance preamplifier according to its output signal level. Auto-bias circuit is designed in current mirror configuration to minimize duty error. Circuit simulation has been performed using 2-poly, 3-metal, 0.6um CMOS process parameters. The designed receiver consumes less than 130mW at 100Mbps with 5V power supply.

• Journal of The Korean Astronomical Society
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• v.36 no.spc1
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• pp.125-133
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• 2003

New Jersey Institute of Technology (NJIT), in collaboration with the University of Hawaii (UH), is upgrading Big Bear Solar Observatory (BBSO) by replacing its principal, 65 cm aperture telescope with a modern, off-axis 1.6 m clear aperture instrument from a 1.7 m blank. The new telescope offers a significant incremental improvement in ground-based infrared and high angular resolution capabilities, and enhances our continuing program to understand photospheric magneto-convection and chromospheric dynamics. These are the drivers for what is broadly called space weather - an important problem, which impacts human technologies and life on earth. This New Solar Telescope (NST) will use the existing BBSO pedestal, pier and observatory building, which will be modified to accept the larger open telescope structure. It will be operated together with our 10 inch (for larger field-of-view vector magnetograms, Ca II K and Ha observations) and Singer-Link (full disk H$\alpha$, Ca II K and white light) synoptic telescopes. The NST optical and software control design will be similar to the existing SOLARC (UH) and the planned Advanced Technology Solar Telescope (ATST) facility led by the National Solar Observatory (NSO) - all three are off-axis designs. The NST will be available to guest observers and will continue BBSO's open data policy. The polishing of the primary will be done in partnership with the University of Arizona Mirror Lab, where their proof-of-concept for figuring 8 m pieces of 20 m nighttime telescopes will be the NST's primary mirror. We plan for the NST's first light in late 2005. This new telescope will be the largest aperture solar telescope, and the largest aperture off-axis telescope, located in one of the best observing sites. It will enable new, cutting edge science. The scientific results will be extremely important to space weather and global climate change research.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.127-130
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• 2017

The information and communication technology that is being developed recently has been greatly influencing the automobile market. In recent years, devices equipped with IT technology have been installed for the safety and convenience of the driver. It is necessary to develop a system that can link the Smartphone with the vehicle in accordance with these changes. In this paper, first of all we analyze the car connectivity services that served by the other competitors. In addition, we proposed and implemented the improved system that can support and control most of smart device application in vehicle by user's NEEDS. We also implemented the application that can restrict the applications which unsatisfied the drive regulations and designed and proposed the scenario that can apply our company's car connectivity system in future.