• Journal of the Institute of Electronics Engineers of Korea SC
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• v.47 no.1
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• pp.17-28
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• 2010

This paper presents a new automatic TFT-LCD image quality optimization system using DSP for the first time. Since conventional manual method depends on experiences of LCD module developers, it is highly labor-intensive and requires several correction steps providing large gamma correction error. The proposed system optimizes automatically gamma adjustment and power setting registers in mobile TFT-LCD driver IC to reduce gamma correction error, adjusting time, and flicker. It contains module-under-test (MUT, TFT-LCD module), PC installed with program, multimedia display tester for measuring luminance and flicker, and control board for interface between PC and TFT-LCD module. We have developed a new algorithm using 6-point programmable matching technique with reference gamma curve and applying automatic power setting sequence. Developed algorithm and program are generally applicable for most of the TFT-LCD modules. It is realized to calibrate gamma values of 1.8, 2.0, 2.2 and 3.0, and reduce flicker level. The control board is designed with DSP and FPGA, and it supports various interfaces such as RGB and CPU. Developed automatic image quality optimization system showed significantly reduced gamma adjusting time, reduced flicker, and much less average gamma error than conventional manual method. We believe that the proposed system is very useful to provide high-quality TFT-LCD and to improve developing process using optimized gamma-curve setting and automatic power setting.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.12
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• pp.1585-1591
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• 2011

In this paper, we present a new exoskeleton-type data glove that can sense the movement of the human finger and reflect the force to the finger. The data glove is designed on the basis of the skeletal structure of the human hand, and the finger module has 1 degree-of-freedom because it includes three four-bar mechanism joints in series and a wire-coupling mechanism. In addition, the transmission ratio of the finger module is maintained at 1:1.4:1 over the entire movement range, and hence, the module can perform both extension and flexion. In addition, to enable adduction/abduction motion of the human hand, a unique MCP joint is designed by using two universal joints. To validate the feasibility of the data glove, master-slave control experiments based on force-position control between the data glove and the robot hand are conducted.

• Journal of KIISE:Computing Practices and Letters
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• v.11 no.6
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• pp.514-530
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• 2005

This paper proposes a compact eAI framework for the integration of various types of applications deployed on different platforms in the Internet. The applications are connected and invoked to achieve a business goal by the coordination of the workflow system in the framework. for the construction of the framework, five sub-modules are elicited and the functions and roles of each module are defined. The elicited five sub-modules include business process modeling tool, eAI platform, business processes transform module, UDDI connection module, and workflow system. In the framework, intra and inter organizational applications can be integrated together across firewalls. In this paper, the extension of a workflow system to implement the framework is also described in detail and the usefulness of the framework is ascertained by implementing an application process within the framework. A full-fledged eAI solution can be constructed by gradually adding supplementary functions within this framework.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.1
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• pp.89-99
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• 2014

This paper presents the experimental torque disturbance analysis of a missile hatch system by spline backlash. The missile hatch system uses a spline and gear train for vertical elevation of the heavy hatch. The spline used for the rotation shaft of the hatch is generally used for automotive driving parts that transmit high amounts of power. It has an angular backlash, which results in jerks. Backlash of the hatch spline influences hatch swinging. The spline backlash and hatch swing are experimentally analyzed by measuring the hatch's rotation angle and acceleration. Hatch swing is visually observable for a short period, and it is measured by measuring the rotation angle variation and hatch acceleration. The shape of fluctuation and duration time of hatch angle variation are similar to those of torque. This shows that the hatch swing due to spline backlash generates torque disturbances.

• Journal of Biomedical Engineering Research
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• v.25 no.6
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• pp.505-510
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• 2004

In this article, we present an automated system for adjusting the 6 degree of freedom (D.O.F.) circular fixator. The system includes a scheduling software to adjust the Hexapod Circular Fixator (HCF) and an automated strut with the ability of the multiple synchronized motion and independent motion. The HCF was designed to control a 6 D.O.F. Ilizarov fixator and it's mechanism. The HCF adjustment software evaluates each value of altered length of the HCF struts to correct the complex skeletal deformity by using the X-ray data of the patient. The data of HCF adjustment software feed into the automated strut system which provides the scheduled adjustment. Then, the automated strut is synchronized by input data. Also the data of HCF adjustment software can be used to adjust HCF without automated struts. The proposed HCF system was verified by experiments.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.1
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• pp.40-48
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• 2016

Micro-vibration induced by on-board appendages that have mechanical moving parts has always been treated as an useless objective that has to be isolated, in order to comply with a high-resolution mission requirement of the observation satellite. In this study, we proposed a tuned mass damper energy harvester combined with a conventional passive vibration isolator for exhibiting dual functions of both electrical energy harvesting and micro-vibration isolation. The feasibility of the proposed dual-function complex system has been demonstrated through the comparison with numerical simulations, based on the results of basic characteristic tests, and experiments of the harvested power and micro-vibration.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.919-925
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• 2023

Modern drones are equipped with miniaturized mission equipment capable of performing various tasks such as surveillance and reconnaissance. Consequently, these mission equipment are exposed to disturbances like wind loads and motor rotations, which can lead to instability in the operation of the Electro-Optical Targeting System (EOTS). Specifically, simple step inputs for changing the line of sight in EOTS can cause abrupt changes in speed, inducing overshoot and potentially creating instability along with other disturbances. To address this, a velocity profile was designed so that the angular velocity moves in a trapezoidal shape when changing the EOTS line of sight. A Double-loop controller was designed to apply this profile as an input to the external loop receiving position feedback. The system's stability was then compared, and the velocity profile was optimized within a stable range by varying maximum speed and acceleration.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.5
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• pp.523-532
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• 2008

In this paper, we proposed a U-shaped RFID tag antenna with isotropic radiation characteristic for the stable operation of RFID system. The proposed antenna is composed of a U-shaped half wavelength dipole and a rectangular-shaped feed. In order to have good impedance matching with a tag chip, the commercial tag chip is attached to the lower center of the feed. A gain deviation characteristic of the U-shaped tag antenna can be further improved by inserting a rectangular slit in the lower center of the U-shaped antenna body. On the condition of VSWR<2, the tag antennas of two structures satisfy the Korea UHF RFID bandwidth and showed the gain deviation of less than 1.63 dB and 0.74 dB for without slit and with slit, respectively. On the condition of VSWR<5.8, the U-shaped tag antenna showed the gain deviation of less than 3.8 dB and 1.2 dB for without slit and with slit, respectively.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.1-6
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• 2006

촉감 제시 방법은 다른 사람에게 방해를 주지 않고 은밀하게 정보를 전달할 수 있는 장점이 있으며, 특히 시각 혹은 청각 장애인에게는 반드시 필요한 정보 전달의 수단이다. 또한 촉감을 이용한 정보의 전달은 시청각을 이용한 정보전달의 방법을 보완하거나 때로는 대체할 수도 있다. 본 논문에서는 웨어러블, 모바일, 또는 유비쿼터스 컴퓨팅 환경에서 사용할 수 있는 착용 가능한 진동촉감 제시 장치를 제안한다. 이 진동촉감 제시 장치는 25개의 진동모터를 $5{\times}5$의 형태로 배열하여 문자, 숫자뿐만 아니라 다양하고 복잡한 패턴을 표시할 수 있다. 코인형 진동모터 각각을 스펀지로 감싸고 푹신푹신한 재질의 패드에 세워서 배열하여 진동의 퍼짐을 최소화하고 사람의 글씨 쓰는 순서에 따라 진동모터를 순차적으로 구동시키는 새로운 추적모드를 제안하여 사용자의 문자 및 숫자 인식률을 크게 향상시켰다. 사용자 성능 평가에서는 사용자의 발등에 영문 알파벳을 표시하여 86.7%의 인식률을 얻었다. 또한 진동촉감 제시 장치를 이용하여 핸드폰에서의 발신자 정보표시를 한다거나 네비게이션 시스템에 적용할 수 있는 등의 유용한 응용분야를 제시하였다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.10
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• pp.1231-1237
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• 2004

Determination of geometric design parameters of a second-throat type annual supersonic ejector is described. Tested geometric parameters were primary nozzle area ratio, cross-sectional area of second-throat, L/D ratio of second-throat and primary flow injection angle. Varying these four geometric parameters, we build a test matrix made of 81 test conditions, and experimental apparatus was fabricated to accommodate them. For each test condition, the stagnation pressure of primary flow and the static pressure of the secondary flow were measured simultaneously along with their transition to steady operation and finally to unstarting condition. Comparing the performance curve of every case focused on starting pressure, the unstarting pressure and the minimum secondary pressure, we could derive correlations that the parameters have on the performance of the ejector and presented the optimal design method of the ejector. Additional experiments were carried out to find effects of temperature and mass flow rate of the secondary flow.