• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.10B
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• pp.648-659
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• 2005

One's identity on the Internet has been disclosed and abused without his consent. Personal information must be protected by appropriate security safeguard. An Individual should have the right to know whether his personal details have been collected and stored. This paper proposes various conceptual models for designing privacy enabling service architecture in the Internet identity management system. For the restriction of access to personal information, we introduce the owner's policy and the management policy The owner's policy should provide the user with enough information to manage easily and securely his data. To control precisely and effectively all personal information in the Identity provider, we propose the privacy management policy and the privacy authorization model.

• Proceedings of the KIEE Conference
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• 1990.07a
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• pp.433-436
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• 1990

An optimal Stabilization technique for a bilinear in duction model is introduced. This technique includes to o parts; the one is an stabilization control using Lyap unov Function which has the form of a sum of linear and quadratic function of the state variables, and the other is an optimal control using the performance index which depends on the choice of the elements of the Ly apunov matrices concerning both the state variables and the input variables. Therefore, induction motor is drived with the shorter transient time of the state variables and with the smaller overshoot of the ones, simulation results are obtained from a digital computer. Experimental ones are obtained from implementation of the optimizing controller using 8086 microprocessor kits and analog circuits are compared.

• Proceedings of the KIEE Conference
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• 1990.07a
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• pp.336-339
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• 1990

This paper discusses the application of VSCS(Variable Structure Control System) to position control of a trapezoidal type brushless DC motor. In order to simplify the overall control system and to improve the robustness, a new switching function which is composed of linear combination of only measurable state variables Sr(x) and Sr(x) is defined. The proposed new switching function is implemented using a digital signal processor(DSP). A general PWM amplifier is replaced by an ON-OFF pattern generator for the hardware simplification and digitalization. Experimental results are given to demonstrate the validity of the proposed control method.

• Proceedings of the KIEE Conference
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• 1990.07a
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• pp.341-345
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• 1990

This paper presents the three section sliding mode control algorithm based on hysteresis current control add indirect field oriented control method, and applies it to the position control of induction motor. The three section sliding trajectories are defined in such a way that the system responds following a max acceleration line, then a max speed line, and finally a max deceleration line. This control scheme solves the problem of robustness loss during the reaching phase that occurs in conventional VSC strategy, and ensures the stable sliding mode and robustness enhancement throughout an entire response. Also, the PID controller operating in parallel is adopted to eliminate the sliding mode's collapse phenomenon near the origin caused by steady state chattering phenomenon Digital simulation results confirm that the dynamic performance of the system is insensitive to parameter variations and disturbances.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.3
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• pp.150-157
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• 2002

This paper presents preliminarily an implementation of digital high-performance motion control system of Reluctance Synchronous Motor (RSM) drives with direct torque control (DTC). The system consist of stator flux observer, torque estimator, two hysteresis band controllers, an optimal switching look-up table, IGBT voltage source inverter, and TMS320F240 DSP controller made by Texas Instruments. The stator fluff observer is based on the combined voltage and current model with stator flux feedback adaptive control, and the input of the observer are the stator voltage and current of motor terminal for wide speed range. The rotor position and speed sensor used 6000 pulse/rev encoder. In order to prove rightness of the suggested control algorithm, we have some simulation and actual experimental system at $\pm$20 and $\pm$2000 rpm. The developed digitally high-performance motion control system+ are shown a good response characteristic of control results and high performance features using 1.0kW RSM which has 2.57 Ld/Lq salient ratio.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.4
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• pp.89-97
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• 2014

As the digital control technologies in automotive industry have advanced, electronic control units(ECUs) play a key-role to improve system performance. Transmission control unit(TCU) is a shifting controller for automatic transmission of which major functions are to determine the shift and manage the shifting process considering the various sensor signal on transmission and driver's commands. As with any ECU in vehicle, TCU performs complex algorithms such as shift control, diagnostic and failsafe functions. However, firmware design analysis is hardly possible by the reverse engineering due to code protection. Transmission simulator is a hardware-in-the-loop simulator which enables TCU to work in normal mode by simulating the electrical signal of TCU interface. In this research, diagnosis and failsafe algorithm implemented on commercialized TCU is analyzed by using the transmission simulator that is developed for wheel loader construction vehicle. This paper gives various experimental results on the proportional solenoid current trajectories for different operating modes, error detection criterion and limphome mode gears for all the possible cases of clutch malfunction. The derived results for conventional TCU can be applied to the development of inherent TCU algorithms and the transmission simulator can also be utilized for the test of TCU to be developed.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.7
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• pp.653-660
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• 2015

This paper describes the design of the force measuring system for an industrial robot's deburring work. The force measuring system is composed of a three-axis force sensor, a measuring device, a housing and a cover. The three-axis force sensor can detect x-direction force, y-direction force and z-direction force at the same time. The measuring device is designed using DSP(Digital Signal Processor), and have a RS-232 and a RS-485 communication port for sending force data to PC or other controller. As a result of test, the repeatability error and the non-lineality error of the three-axis force sensor are less than 0.03%, and the interference error of the sensor is less than 0.95%. It is thought that the force measuring system can be used for an industrial robot's deburring work.

• Journal of the Korean institute of surface engineering
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• v.38 no.2
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• pp.73-78
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• 2005

A real-time monitoring of ICP(inductively coupled plasma) assisted magnetron sputtering of MgO was carried out using a QMS(quadrupole mass spectrometer), an OES(optical emission spectrometer), and a digital oscilloscope with a high voltage probe and a current monitor. At the time of ICP ignition, the most distinct impurity was OH emission (308.9 nm) which was dissociated from water molecules. For reactive deposition oxygen was added to Ar and the OH emission intensity was reduced abruptly When the discharge voltage was regulated by a PID controller from 240V(metallic mode) to 120V(oxide mode), the emission intensity from Mg (285.2 nm) changed proportionally to the discharge voltage, but the intensity of Ar I(811.6 nm) was constant. At 100V of discharge voltage, Mg sputtering was almost stopped. Emissions from Ar I(420.1 nm) and Mg I were dropped down to 1/10, but Ar I(811.6 nm) didn't change. And the emission from atomic oxygen (O I, 777.3 nm) was increased to 10 times. These results are compatible with those from QMS study.

• Proceedings of the KIEE Conference
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• 2001.07e
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• pp.127-133
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• 2001

In SRM drive, the ON OFF angles of each phase switch should be accurately controlled in order to control the torque and speed stably. The accuracy of the switching angles is dependent upon the resolution of the encoder and the sampling period of the microprocessor, that are used to provide the information of the rotor position and to control the SRM power circuit, respectively. However, as the speed increases, the amount of the switching angle deviation from the preset values is also increased. Therefore, the low cost encoder suitable for the practical and stable SRM drive is proposed and the control algorithm to provide the switching signals using the simple digital logic circuit is also presented in this paper. As a result, a stable high speed SRM drive can be achieved by the high resolution switching angle control and it is verified from the experiments that the proposed encoder and logic controller can be a powerful candidate for the practical low cost SRM drive.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2577-2579
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• 2002

In this paper, we describe a CMOS DC-DC converter with a variable output voltage(8-12V @100mA) for a portable battery-operated system applications. The proposed DC-DC converter is used along with a Pulse-Frequency Modulation (PFM) method and consists of a reference circuit, a feedback resistor, a controller, and an internal oscillator. The integrated DC-DC converter with two external passive components(L.C) has been designed and fabricated on a 0.6${\mu}m$ 2-poly, 3-metal CMOS process and could be applied to the Personal Digital Assistants(PDA), Cellular Phone, Laptop Computer, etc.