• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2005.04a
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• pp.247-250
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• 2005

In numerous occasions, there is need to reconstruct partially occluded facial image. Typical examples include the recognition of criminals whose facial images are captured by surveillance cameras- ln such cases a significant part of the face is occluded making the process of identification extremely difficult, both for automatic face recognition systems and human observers. To overcome these difficulties, we consider the application of Kernel PCA-based denoising method to partially occluded facial image in this paper.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.9 no.2
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• pp.76-82
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• 2009

A Heating, Ventilating and Air Conditioning (HVAC) system is a nonlinear multi-input multi-output (MIMO) system. This system is very difficult to control the temperature and the humidity ratio of a thermal space because of complex nonlinear characteristics. This paper proposes an adaptive fuzzy output feedback control based on observer for the nonlinear HVAC system. The nonlinear HVAC system is linearized through dynamic extension. State observers are designed for estimating state variables of the HVAC system. Fuzzy systems are employed to approximate uncertain nonlinear functions of the HVAC system with unavailable state variables. The obtained controller compares with an adaptive feedback controller. Simulation is given to demonstrate the effectiveness of our proposed adaptive fuzzy method.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1224-1227
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• 2009

When evaluating the quality of images and displays, it is important to combine the characteristics as perceived by the human visual system and measured by equipment using subjective and objective methods, respectively. In the case of objective methods, the quality of a display is measured using colorimetric or radiometric devices according to existing standards covering the color temperature, gamut size, gamma characteristic, and device characterization. Meanwhile, subjective methods assess the quality of an image using the human visual system based on a comparison with a reference or counterpart using such metrics as the sharpness, noise, contrast, saturation, and color accuracy. Objective and subjective methods are usually used together in comparison, as ultimately it is observers watching images on a display. In addition to existing objective methods, a new image quality metric is also introduced as regards the JPEG compression ratio that is reflected in the relationship between the gamut size and the color fidelity in CIELAB color space.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1105-1107
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• 2000

This paper proposes the new reduced-order extended Luenberger observer and presents the application to sensorless vector control of induction motor. The main features of the proposed observer are discussed and compared with the other observers.

• Journal of the Korea Safety Management & Science
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• v.7 no.5
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• pp.97-105
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• 2005

Achievement degree can be improved by display offering more effective process about cognitive, pattern recognition than making observers use memory, integration, and cognitive process of control. And this research is proved by several scholars' researches [4][5][7][9]. In this study, researches was conducted about cognition according to layout of object in instrument panel. To decide layout of instrument panel, Cognition value was preferentially decided about all location. And then, objects are arranged to correct position of low cognition following the inferior procedure about each location. As a result, we get conclusion that gauge location is taken in high importance order through mechanical importance degree bringing huge damage during driving forklift-truck.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.11
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• pp.928-934
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• 2002

A natural way to cope with fault tolerant control (FTC) problems is to modify the control parameters according to an online identification of the system parameters when a fault occurs. However. due to not only difficulties Inherent to the online multivariable identification in closed-loop systems, such as modeling errors, noise or the lack of excitation signals, but also long time requirement to identify the post-fault system and implemeutation of control problems during the identification process, we propose an alternative approach based on the observer-based fault detection and isolation (FDI) and model reference adaptive control (MRAC). The proposed robust fault diagnosis method is based on a bank of observers. We also propose a model reference adaptive control with changeable reference models according to the occurred faults. Simulation results of a flight control example show the validity and applicability of the proposed algorithms.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.9 no.1
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• pp.7-12
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• 1979

The author had performed the measurement of the various teeth regions on 200 cases of Full-mouth roentgenogram taken with the measurable Grid to detect the degree of alveolar bone resorption, aged from 20 to 60 years of Korean, and to verify the effective result of measurable Grid as a new device which enables the observers to determine the correct length of images on the periapical standard film. The results were obtained as follows. 1. It was found that the degrees of alveolar bone resorption were different in the various teeth regions. 2. As a whole, alvolar bone resorption of anterior teeth regions was more severe than that of posterior teeth regions. 3. Alveolar bone resorption of mandibular region was more severe than that of maxillary region. 4. In sex difference, alveolar bone resorption of male is more severe than that of female, and it was increased with aging. 5. Measurable grid can be used as an adjunct of evaluation of alveolar bone resorption and of calculating the tooth length.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.12 no.1
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• pp.115-121
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• 1982

In the study of the focal trough of panoramic radiograph, using the Moritta compony Panex-EC a series of 48 exposures were: taken with the 6-18 brass pins placed in the holes of the plastic model plate, then eveluated by 4 observers. The author analyzed the focal trough defined by the sharpness criteria and calcuated the vertical and horizontal magnification range in the corrected focal trough. The results were as follows; 1. Continuous focal trough was not defined in the anterior region using a very high degree of sharpness. 2. As degree of sharpness used in the analysis became less, focal trough was continuous in the anterior and posterior regions, symmetrized bilaterally, and the widths of the focal trough increased more in the posterior region. e. As sharpness criteria were reduced, the percentage range of image magnification increased on both vertical and horizontal magnification, and especially the percentage range of horizontal magnification was greater than that of vertical magnification.

• International Journal of Internet, Broadcasting and Communication
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• v.10 no.3
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• pp.65-72
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• 2018

The purpose of this study was to assess the intra-tester and inter-tester reliability and validity of elbow flexion range of motion using a smart phone used by the general public. Thirty-one general people participated in this study. The range of motion in active elbow flexion was measured with a goniometer and smart phone over two times by two observers. The intra-taster and inter-tester reliability were evaluated using the intraclass correlation coefficient(ICC). The validity was measured by Pearson's correlation coefficient. The intra-observer reliability was good in all measured items ICC>0.900. The inter-observer reliability was high with ICC>0.806. All correlation coefficients of android app and goniometer were greater than 0.868 and showed a significant positive correlation (p<0.01). The range of motion measurement with a smart phone showed acceptable reliability. Therefore, using a smartphone to measure the range of motion of the elbow joint could provide convenience and economic benefits.

• Journal of Korean Dental Science
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• v.10 no.2
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• pp.53-59
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• 2017

Purpose: The objective of the present article is to determine whether there are differences in vertical enlargement ratio among various sites within both jaws in a panoramic radiograph. Materials and Methods: Two hundred and seventy-threeimplant sites in panoramic radiographs were evaluated by two observers. Magnification ratios at various sites in both jaws were calculated and compared with each other. Result: The average vertical enlargement ratio in the panoramic radiograph was 1.264 and this value was larger than original ratio 1.250. Although vertical magnification ratio of maxillary molar area was higher than that of mandibular molar area, every group showed similar magnification ratio in clinical respect. Conclusion: Vertical magnification ratio of the maxillary molar area is statistically higher than that of the mandibular molar area in the panoramic radiograph, but it is clinically negligible.