• Journal of the Korean Institute of Telematics and Electronics T
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• v.36T no.3
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• pp.41-49
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• 1999

In this paper, we design a controller using the $\mu$-synthesis method and apply it for the spring-mass system with noncollocated sensors and actuators. We assume that the values of the spring stiffness and load mass of the plant are uncertain. The plant is modeled with parametric uncertainty by using the state space equation, especially the descriptor form. The $H_\infty$ controller designed by the $\mu$-synthesis method is compared with the standard $H_\infty$ controller To compare performances of two $H_\infty$ controllers, it is assumed that both controllers were designed with same weighting functions except that the $\mu$-synthesis controller has structured uncertainties. By compared with the standard $H_\infty$ controller, we show that the designed controller has satisfactory robust performance as well as robust stability by simulations and experiments.

• The Journal of the Acoustical Society of Korea
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• v.36 no.2
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• pp.130-135
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• 2017

In this paper, we propose an interface for interactive sound experience in the virtual concert hall. The proposed interface consists of two systems, called 'virtual acoustic position' and 'virtual active listening'. To provide these systems, we applied an artificial reverberation algorithm, multi-channel source separation and head-related transfer function. The proposed interface was implemented by using Unity. The interface provides the virtual concert hall to user through Oculus Rift, one of the virtual reality headsets. Moreover, we used Leap Motion as a control device to allow a user experience the system with free-hand. And user can experience the sound of the system through headphones.

• Journal of The Korean Digital Architecture Interior Association
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• v.4 no.2
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• pp.26-34
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• 2004

Our country did not illustrate and reverse by a city planning law department construction Buddhist priest's robe dual setup the urban setting to be regulated, it came. The city planning law as the high position system of space planning mainly provides the use and a size of the land, the construction law the detail contents of site undergarment concrete location and the form back is provided and of course, regarding the structure which relates with the designation of concrete building use in him and the immediacy back. These two laws are come by a trade name complement and a function sharing role in order for the affirmative development of the city to become accomplished, being used. To necessity of District unit plan the general causal government employee all it is sympathizing, it relates it goes to extremes and with the maintenance of endurance environment and many portion with charge Sikkim also the fact that it is the criticism which relativy is negative in duty of administrative origination is fact in the people. But realization of plan hazard the execution of the public section which stands will be important, it will reach and the public section execution plan of the autonomous nine dimension for must be prepared. The next research that the individual globe plan and development actual condition actual proof and the research which it analyzes system is necessary with base, sees the general operation evaluation of Seoul District unit plan.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.2
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• pp.447-452
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• 2013

Microfluidic devices can offer precise control for a verity of tasks involving biological specimen. In this paper, we propose an integrated system consisting of a microfluidic device along with a digital holographic microscope and present three-dimensional (3D) sensing and segmentation of biological microorganisms. When the individual microorganisms are inputted into the microfluidic channel, the holographic microscope records their holograms. The holograms are computationally reconstructed in 3D using Fresnel transform and the reconstructed phase images are used to search the position of microorganisms. Optical experiments are carried out and experimental results are presented to illustrate the usefulness of the proposed system.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.4
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• pp.435-442
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• 2016

For inertial navigation systems, initial information such as position, velocity and attitude is required for navigation. Self-alignment is the process to determine initial attitude on stationary condition using inertial measurements such as accelerations and angular rates. The accuracy of self-alignment is determined by inertial sensor error. As soon as an inertial navigation system is powered on, the temperature of accelerometer rises rapidly until temperature stabilization. It causes acceleration error which is called temperature stabilizing error of accelerometer. Therefore, temperature stabilizing error degrades the alignment accuracy and also increases alignment time. This paper suggests a method to calculate azimuthal attitude using curve fitting of horizontal control angular rate in fixed-gain self-alignment. It is verified by simulation and experiment that the accuracy is improved and the alignment time is reduced using the proposed method under existence of the temperature stabilizing error.

• The Transactions of the Korean Institute of Power Electronics
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• v.11 no.2
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• pp.127-134
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• 2006

This paper describes a fully hardware realization of vector controller for the permanent magnet synchronous motor (PMSM) using high density field programmable gate mays (FPGA). In the proposed system, the vector controller including vector transformation , PI regulator, position and speed measurement, current measurement, and space vector PWM blocks is implemented in a FPGA using a VHSIC hardware description language (VHDL). The experimental results using a 1.1kW PMSM are provided to show the validity of the proposed system.

• Proceedings of the Korean Information Science Society Conference
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• 2007.06c
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• pp.217-222
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• 2007

This paper proposes a user interface, on see-through system environment which shows the images via two different cameras, that also ordinary user can control the computer systems or other various processes easily. For that, we include an AR technology to synthesize the virtual button to the image which is captured by the camera real-time. And we were looking for the hand position in the image to judge whether the figure selects the button. And the result of judgment visualizes through changing of the button color. The user can easily interact with the system by selecting the virtual button in the screen with watching the screen and moving her fingers at the air.

• Proceedings of the KIEE Conference
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• 2007.04c
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• pp.234-236
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• 2007

Even though the existing train route controlling method, using track circuits, ensures the sufficient number of operation, it still has problems such as discordance between train numbers which was planned for operating and train numbers being operated on the track, and allowing only one train entering for one route. To solve those problems, we study and develop the Smart train route controlling system which uses the real-time informations of train positions. This system enables improve the coefficient of utilization in a certain train route controlling section, and the safety level of train route controlling, but we should ensure satisfying reliability of data about tracks operated by trains. In addition, there is a need to protect accidents caused by erroneous information of train position, by reflecting changes of tracks, for example maintenance, improvement, expansion of tracks. In this paper, we describes data structure of a developed program which required to change CAD files to wiring diagrams and to generate them to data of tracks. And we show the result that the simulator, using the data structure, controls speed and route of trains without problems.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.122-127
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• 2002

A frequency-domain PES estimation and its prediction method are proposed for the tightly-coupled servo/mechanical design of high-TPI HDD system above 100 kTPI. The major two disturbance energies which are related with mechanical vibrations inside of HDD are used to predict the drive-level PES, while considering closed-loop servo dynamics. One is the torque disturbance which mainly comes from aerodynamic excitation of HSA system and the other is the displacement disturbance from disk-spindle dynamics. In order to obtain the accurate error transfer function of closed-loop servo control, the plant model is measured by accurate experiment. The measured PES is compared with predicted one in terms of frequency-domain PES spectrum and its standard variation value. It is proved that the proposed frequency-domain PES estimation/prediction method is capable of predicting drive-level PES of high-TPI hard disk drive.

• Journal of Korean Society of Steel Construction
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• v.11 no.1 s.38
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• pp.1-11
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• 1999

The aim of this study is to construct a machine vision monitoring system for an automatic visual inspection of weld joint in steel structure. An image processing algorithm for a visual weld defects detection on weld bead is developed using the intensity image. An optic system for getting four intensity images was set as a fixed camera position and four different illumination directions. The input images were thresholded and segmented after a suitable preprocessing and the features of each region were defined and calculated. The features were used in the detection and the classification of the visual weld defects. It is confirmed that the developed algorithm can detect weld defects that could not be detected by previously developed techniques. The recognized results were evaluated and compared to expert inspectors' results.