• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.437-441
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• 1997

In the conventional remote monitoring system, a user in front of a computer monitor can acquire only 2 dimensional visual information in a passive way. Thus, even thoght the user finds an interesting object from the video image, helshe can hardly acquire additional information on the object such as name. 311 shape, etc. In this paper, an active monitoring system that shows additional information on the selected object is proposed. The active remote monitoring system can calculate the 3D position of the object that is selected in the video images. Then, using the 3D position of the object, other information on the object can be retrieved from the database and shown on the screen. To calculate the 3D position of the object, 2 CCD cameras that can be tilted and panned using 3 stepping motors are used. The algorithm of 3D position calculation and the result of experiments are explained.

• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.2
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• pp.184-189
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• 2013

This paper proposes a method for improving the performance of a position sensorless control system for a slotless surface permanent magnet synchronous motor (SPMSM) in a very low-speed region. In position sensorless control based on a motor model, accurate motor parameters are required because parameter errors would affect position estimation accuracy. Therefore, online parameter identification is applied in the proposed system. The error between the reference voltage and the voltage applied to the motor is also affect position estimation accuracy and stability, thus it is compensated to ensure accuracy and stability of the sensorless control system. In this study, two voltage error compensation methods are used, and the effects of the compensation methods are discussed. The performance of the proposed sensorless control method is evaluated by experimental results.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1858-1862
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• 2005

Stepping motor normally operates without feedback and may loss the synchronization. This problem can be prevented by using positional feedback. This paper introduces one method for closed loop control of stepping motor and a method for combining full-step control and micro-step control. This combination controlling apparatus can perform position control with high accuracy in a high speed, so that it will not suffer from vibration (or hunting) problem when stopping motor. Controlling apparatus contains a position counter block for detecting rotor position of stepping motor, a driving block for supplying current to windings of stepping motor, a control block for comparing output signal of position counter block with command position (desired position) and outputting current command signal based on deviation between current position and command position of rotor. To output current command signal, the control block refers to a sine wave data table. This table contains value of duty cycle of Pulse Width Modulation signal. As the second object of this paper, the process of building this data table is also presented.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.14 no.24
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• pp.123-132
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• 1991

This study deals with the experiment of perceiving visual information according to the positions of vehicle side mirrors. In the design of vehicle, the consideration of safety is very important. Therefore we consider the positions of side mirrors to use visual information effectively which is important factor to driver. This paper presents the position of side mirror to elevate the degree of visual perception for the circumstances of danger by experiments. To exhibit the circumstances of danger. 4 LED(Light Emitted Diode) art located at each side(right. left front. hack) of vehicle. A subject pushes the LED switch to see that if he perceives the circumstance of danger. To record the circumstance of randomly generated danger, computer interface card is used to control 4 LED and swithch on IBM PC/AT Experiments are divided into 2 parts. The 1st experiment present the independence of right & left side mirror. The 2nd experiment present optimal position of right & left side mirror. The vehicle used in experiment is model EL of H Co.. Statistical process of experimental data using SPSS(Statistical Package for Social Sciences)/PC package concludes that 1) the optimal position of right side mirror is 54cm forward of exist position. 2) for the left side mirror, the position of 120cm forward of exist position shows the worst degree of perception. and the optimal position does not exist in statistical meaning.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.45 no.2
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• pp.310-318
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• 1996

It is very important for a mobile robot to estimate its current position With precise information about the current position, the mobile robot can do path-planning or environmental map building successfully. In this paper, a position estimation method using one color image is presented. The mobile robot(K2A) takes an image of a corridor and searches for the door and pillar, which are the given landmarks. The color information is used to distinguish the landmarks. In order to represent the presence of the landmarks, Image Mode is defined. This method adopts Kullback information distance. If a landmark is detected, with the color information, the mobile robot identifies the vertical line of the landmark and its crossing point and an experimental navigation is performed.

• Journal of Korean society of Dental Hygiene
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• v.15 no.4
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• pp.743-750
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• 2015

Objectives: The purpose of the study is to examine the correlation and influencing factors among ethics position, self-esteem, and perception of patient medical information protection in the dental hygiene students. Methods: This is a cross sectional study using the structured questionnaire. A self-reported questionnaire was completed by 202 dental hygiene students using the stratified sampling method from September 1 to November 1, 2013. The questionnaire was modified and complemented from Ethics Position Questionnaire (EPQ). The questionnaire included EPQ, self-esteem, and perception of patient medical information protection. Data were analyzed by independent t-test, one way ANOVA, Duncan's multiple comparison analysis, Pearson's correlation analysis, and stepwise multiple regression analysis using IBM SPSS Statistics 21.0 program. Results: There was a positive correlation among all the variable including idealism position, self-esteem, and perception of patient medical information protection, The factors influencing on the perception of patient medical information protection were idealism position (${\beta}=0.271$, p<0.001) and self-esteem (${\beta}=0.248$, p<0.001). The corrected explanation power of the model was 15.1%. Conclusions: As the idealism position and self-esteem become higher, the perception of patient medical information protection gets higher. Therefore, this study suggests that it is needed to develop and vitalize implement the appropriate programs enhancing ethics consciousness, proper position, and self-esteem in the dental hygiene students receiving the education for their professionalism in the dental hygiene curricula.

• Journal of KIISE:Databases
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• v.34 no.4
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• pp.343-356
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• 2007

Due to advances in position monitoring technologies such as global positioning systems and sensor networks, recent position information of moving objects has the form of streaming data which are updated continuously and rapidly. In this paper we propose an efficient trajectory maintenance method that stores the streaming position data of moving objects in the limited size of storage space and estimates past positions based on the stored data. For this, we first propose a new concept of incremental extraction of position information. The incremental extraction means that, whenever a new position is added into the system, we incrementally re-compute the new version of past position data maintained in the system using the current version of past position data and the newly added position. Next, based on the incremental extraction, we present an overall framework that stores position information and estimates past positions in the stream environment. We then propose two polynomial-based methods, line-based and curve-based methods, as the method of estimating the past positions on the framework. We also propose three incremental extraction methods: equi-width, slope-based, and recent-emphasis extraction methods. Experimental results show that the proposed incremental extraction provides the relatively high accuracy (error rate is less than 3%) even though we maintain only a little portion (only 0.1%) of past position information. In particular, the curve-based incremental extraction provides very low error rate of 1.5% even storing 0.1% of total position data. These results indicate that our incremental extraction methods provide an efficient framework for storing the position information of moving objects and estimating the past positions in the stream environment.

• Journal of Power Electronics
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• v.5 no.1
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• pp.11-19
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• 2005

This paper describes the two control techniques to perform the sensorless vector control of a PMSM by injecting the high frequency voltage to the stator terminal. The first technique is the estimation algorithm of the initial rotor position. A PMSM possesses the saliency which produces the ellipse of the stator current when the high frequency voltage is injected into the motor terminal. The major axis angle of the current ellipse gives the rotor position information at a standstill. The second control technique is a sensorless control algorithm that injects the high frequency voltage to the stator terminal in order to estimate the rotor position and speed. The rotor position and speed for sensorless vector control is calculated by appropriate signal processing to extract the position information from the stator current at low speeds or standstill. The proposed sensorless algorithm using the double-band hysteresis controller exhibits excellent reference tracking and increased robustness. Experimental results are presented to verify the feasibility of the proposed control schemes. Speed, position estimation and vector control were carried out on the floating point processor TMS320VC33.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.11
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• pp.763-770
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• 2000

The speed and position information of the rotor are required in the speed control of SRM(Switched Reluctance Motors). This information is generally provided by shaft encoder or resolver. It is weak in the dusty, high temperature, and EMI environment. Consequntly, much attention has been given to SRM control for eliminationating the position and speed sensors. In this paper, a new estimation algorithm for the rotor position and speed for SRM drives is described. The algorithm is implemented by the sliding mode observer. The stability and robustness of the sliding observer for the parameter variations of the SRM are proved by variable structure control theory. Speed control of the SRM is accomplished by the estimated speed and position. Experiment results verify that the mode observer is able to estimate the speed and position well.

• Journal of information and communication convergence engineering
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• v.18 no.4
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• pp.260-266
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• 2020

This study presents the categorical structure for ther epresentation of a 3D human body position system in the WD stage after NP approval by the International Organization for Standardization (ISO), analyzes the needs of electronic medical record users and establishes future implementation plans for expanding its use in Korea. Research was conducted on the needs of doctors, nurses, health and medical information managers, and radiology departments, which are the main stakeholders of electronic medical records. The overall requirements for electronic medical records were derived from the results, and the requirements for each stage of use of electronic medical records were analyzed. Based on the results of the study, the study proposes plans to expand the use of the categorical structure for the representation of the 3D human body position system, and also aims to establish a standard system for health and medical terminology in Korea and contribute to the development of health and medical information standards through international standardization.