• Proceedings of the KIEE Conference
• /
• 1999.11d
• /
• pp.1041-1043
• /
• 1999

In this work, a possible new PD detection technique, based on the electro-optic effect, has been proposed. A proto-type probe sensor for detection partial discharge is made by $LiNbO_3$ Pockels cell, diachroic sheet polarizer and right-angle prism. The Mach-Zehnder interferometer system is proposed by using this sensor and this system is applied to detecting high electric field. we show the characteristic of the proto-type probe sensor and the design of a proposed probe type sensor.

• Korean Journal of Digital Imaging in Medicine
• /
• v.16 no.2
• /
• pp.25-29
• /
• 2014

The full-field digital mammography (FFDM), which has been known as a digital breast imaging system, carries out more outstanding performance than the screen-film mammography in overall image quality, skin & nipple, description of pectoral muscle and expression of micro-calcification. Thus, in this thesis, I perform experiments for both the enhancement of image quality and accurate estimation of the result in question, when detecting the very tiny-sized lesions in mammography. The image of digital breast X-rays is the important diagnostic tool for detecting early breast cancer and micro calcification lesion. The experiment of how much compression rate has an effect on the result of diagnosis in the case of microcalcification lesion, with JPEG2000 40:1 compression and over 50% enlargement led to obscure or definitely unacceptable diagnostic results is performed. And in another study of assessment of PSNR degree. I recognized the importance of standardized management system in mammography, where not to mention the accurate reading of the image has the most crucial role in diagnosis

• Proceedings of the KIEE Conference
• /
• 1995.07a
• /
• pp.65-67
• /
• 1995

The squirrel cage rotors for induction motors may have several faults such as broken bars, bad spots in end ring, abnormal skew caused by improper processing. These faults have bad effect on the performance of the induction motor. This paper proposes the detecting technique of these faults by analyzing the current of the detecting electric magnet, using 2-D finite element method taking account of the rotor movement.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.6 no.2
• /
• pp.42-52
• /
• 1988

The main object of this study is to prove the effectiveness of Landsat data in detecting the stressed areas in forest by extracting these areas. And also to choose the effective bands for this type of survey and to reduce the effect of shadow in forest to improve the accuracy of classification are the other objects. In this study Landsat-5 TM data is used and image processing techniques such as spatial filtering and ratio are taken to reduce the effect of shadow and to improve the classification accuracy. As a result following conclusions are obtained. First, Landsat TM data is useful to detect the stressed areas in forest. Second, when detecting the stressed area, band 4 and 5 are the most effective. Third, spatial filtering and ratio are useful to reudce the effect of shadow and improve the classification accuracy. Especially, ratio has great effect on improving the classification accuracy between forest and other areas.

• Proceedings of the KSRS Conference
• /
• 2003.11a
• /
• pp.905-907
• /
• 2003

In this study, the correlation between the heat island effect and the vegetation in Deagu Korea was performed through using Landsat TM data. the island effect, presents high temperature on air like island, is connected with correlation between the surface temperature and the temperature on the air. In this study, surface temperature was analyzed by detecting the change of urban forestry with remote sensing using the vegetation vitality statistics reference (ratio change of the Park greens in Daegu) the heat island effect not only brings the environment pollution but also brings serious problem such as the destruction of ecosystem to city as a whole. Jeff Luvall has studied to restrain the heat island effect by making urban forestry. Even though Daegu had been the serious high temperature urban area the current temperature of Daegu has been dropped. The correlation between the heat island effect and the vegetation index was analyzed by using satellite images.

• Structural Engineering and Mechanics
• /
• v.28 no.5
• /
• pp.515-524
• /
• 2008

In this paper the effect of prestressing force on the first flexural natural frequency of beams is studied. Finite element technique is used to model the beam-tendon system, and the prestressing force is applied in the form of initial tension in the tendon. It is shown that the effect of prestressing force on the first natural frequency depends on bonded and unbonded nature of the tendon, and also on the eccentricity of tendon. For the beams with bonded tendon, the prestressing force does not have any appreciable effect on the first flexural natural frequency. However, for the beams with unbonded tendon, the first natural frequency significantly changes with the prestressing force and eccentricity of the tendon. If the eccentricity of tendon is small, then the first natural frequency decreases with the prestressing force and if the eccentricity is large, then the first flexural natural frequency increases with the prestressing force. Results of the present study clearly indicate that the first natural frequency can not be used as an easy indicator for detecting the loss of prestressing force, as has been attempted in some of the past studies.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.13 no.9
• /
• pp.786-790
• /
• 2000

This paper is concerned on the theoretical and experimental approaches of direct piezoelectric effect in the PVDF film. When a cantilever structure of PVDF film is bended by the external force, electric charges are concentrated on the electrode surface of the film due to the direct piezoelectric effect, and output voltage is induced from the terminals of the film. In this paper, a symbolic equation between the external force and the output voltage was introduced. Moreover, the theoretical output voltages were compared with the experimental results by falling balls, which were agreed well each other. This results can be useful in a warning system of abnormal pulse rate and breathing, and in detecting impact force and/or mechanical energy using bending of PVDF film.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.20 no.1
• /
• pp.88-93
• /
• 2010

In this paper, an edge detecting sensor using ultrasonic detection module is developed which will be used for areas of industrial applications such as plastic film winding system, cloth winding system, paper roll industry, etc. The developed sensor have properties that more exactly detect the edge line, that less affected by environmental noise, and that it produced more stable measurement output. The mass of the winding object is dominantly affect the dynamics of the system and it could produce undesirable result of the system such as stability of the closed-loop system and accuracy of edge-line-following-control(ELFC) objective. Also, there exist sensor noise due to the mechanical vibration or other environmental effect. These noise also degrade the efficiency of control system. In order to compensate these problems, this paper present a fuzzy PI/PID edge-line-controller, and which is designed and implemented.

• Korean Journal of Veterinary Research
• /
• v.50 no.1
• /
• pp.43-48
• /
• 2010

Animal disease surveillance system, defined as the continuous investigation of a given population to detect the occurrence of disease or infection for control purposes, has been key roles to assess the health status of an animal population and, more recently, in international trade of animal and animal products with regard to risk assessment. Especially, for a system aiming to determine whether or not a disease is present in a population sensitivity of the system should be maintained high enough not to miss an infected animal. Therefore, when planning the implementation of surveillance system a number of factors that affecting surveillance sensitivity should be taken into account. Of these parameters sample size is of important, and different approaches are used to calculate sample size, usually depending on the objective of surveillance systems. The purpose of this study was to evaluate the sensitivity of the current national serological surveillance programs for four selected bovine diseases assuming a specified sampling plan, to examine factors affecting the probability of detection, and to provide sample sizes required for achieving surveillance goal of detecting at least an infection in a given population. Our results showed that, for example, detecting low level of prevalence (0.2% for bovine tuberculosis) requires selection of all animals per typical Korean cattle farm (n = 17), and thus risk-based target surveillance for high risk groups can be an alternative strategy to increase sensitivity while not increasing overall sampling efforts. The minimum sample size required for detecting at least one positive animal was sharply increased as the disease prevalence is low. More importantly, high reliability of prevalence estimation was expected with increased sampling fraction even when zero-infected animal was identified. The effect of sample size is also discussed in terms of the maximum prevalence when zero-infected animals were identified and on the probability of failure to detect an infection. We suggest that for many serological surveillance systems, diagnostic performance of the testing method, sample size, prevalence, population size, and statistical confidence need to be considered to correctly interpret results of the system.

• Communications for Statistical Applications and Methods
• /
• v.4 no.1
• /
• pp.119-128
• /
• 1997

Added variable plot and component-plus-residual plot are very useful for studying the role of a predictor in classical regression analysis. The former is usually used to check the effect of adding a new variable to existing model. The latter has been suggested as computationally convenient substitutes for the added variable plots, however, this plot is found to be better in detecting nonlinear relationships of a new predictor. By combining these two plots dynamically, we can take advantages of two plots simultaneously. And even further, we can get some knowledge of collinearity between a new predictor and predictors already in the model, and more accurate information about the possible outliers.