• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.371-372
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• 2007

In this paper, we propose the color image enhancement method to improve the quality of color image without producing over-saturation and color contour artifacts. The proposed method has two manners, which one is the adaptive cumulative density function and the other is the luminance-based saturation extension. That is focused on a preference color processing in order to generate better image qualify than the algorithms focused on a uniform one for human vision.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.7
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• pp.1332-1340
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• 1992

A novel approach based on a nonlinear compensator is prposed to prevent 'windup', which is caused by the saturation of the acutator and the integral action of the controller. The anti-windup compensator is located between the conventional linear controller, designed neglecting the saturation, and the actuator. It was proven based on the describing function method that, if the closed loop control systems are stable assuming no saturation, then there may exist a range of compensator gain which prevents any limit-cycle. The computer simulation results show that the compensator proposed in the manuscript can eliminate the limit cycle and improve the transient response.

• The Journal of Korean Physical Therapy
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• v.27 no.4
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• pp.234-239
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• 2015

Purpose: This study is not a fragmentary study on characteristics of respiratory synergist when breathing, however it was intended to determine the effect of currently available respiratory exercise and to provide basic clinical information through investigation of oxygen demand and respiratory synergist that mobilizes for respiration during application of respiratory exercise. Methods: Experimental group I was selected from second grade of severity classification of GOLD, which has the highest percentage among patients with COPD, and experimental group II was selected from third grade of severity classification as a clinical sampling. After respiration pursing up lips and diaphragm respiration exercise were mediated together for six weeks, activity of respiratory muscles and oxygen saturation were measured and analyzed. Results: In comparison of change of respiratory synergist and oxygen saturation, activity of respiratory synergist in sternocleidomastoid muscle and scalene muscle showed a meaningful decrease in experimental group I. And, in comparison of change of respiratory synergist and oxygen saturation, activity of respiratory synergist in rectus abdominis muscle showed a meaningful increase in experimental group II. In comparison of change of respiratory synergist and oxygen saturation, activity of respiratory synergist in sternocleidomastoid muscle, scalene muscle, and rectus abdominis muscle showed a meaningful difference between experimental groups. Conclusion: Respiratory synergists work mainly as agonist of chest and upper limbs. Therefore it is very important to lower mobilization of respiratory synergist when breathing. It is considered that a multilateral approach and continued clinical research for improvement of respiratory function for patients with COPD will be needed in the future.

• Journal of Korean Biological Nursing Science
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• v.3 no.2
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• pp.35-50
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• 2001

This study was conducted for the evaluation of the effects of singing program combined with physical exercise on the physiologic changes, perception function and degree of depression. The subjects were the members of elderly women's glee club in D care center for the elderly, who have been singing for more than 6 months. 30 members were allocated to study group and 30 to control group. The singing program designed for both physical therapy and music therapy was consisted of initial physical exercise, singing art songs and classical song and the finishing physical exercise. This program was performed twice a week and about forth minutes was consumed for one session. We checked the heart rate, peripheral arterial oxygen saturation, perception function and degree of depression before and after the program. We used a pulse oxymeter to check the heart rate to oxygen saturation and a questionnaire for the evaluation of perception function and degree of depression. We need SPSS program for data analysis. The results of the investigated personnel complying with general characteristics were analyzed by frequency, two groups by t-test, data before and after the program by paired t-test, respectively. The results were as follows. 1) Heart rate after the program was significantly lower than that before program in test group(p<0.05). 2) Peripheral oxygen saturation after the program was significantly higher than that before the program(p<0.05). 3) Ability to match the right sign with a certain predetermined number was improved after the program. The frequency of wrong matching the sign with number before program was 30. But the frequency was decreased to 8 after the program. 4) Ability to calculate was improved after the program. The frequency of wrong calculation before the program was $1.10{\pm}1.94$. But the frequency after the program was decreased to $0.97{\pm}1.84$. 5) The degree of depression after the program($2.07{\pm}0.49$) was significantly lower than that before program(p<0.001). These results show that singing program combined with physical exercise improves the oxygen delivery to peripheral circulation, stability of heart function, the perception function(calculating and matching ability) and decreases the degree of depression. In conclusion, singing program combined with physical exercise can be used for the effective measure to improve the health of elderly and prevent dementia.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.5B no.3
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• pp.258-261
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• 2005

The Preisach model needs a distribution function or Everett function to simulate the hysteresis phenomena. To obtain these functions, many experimental data obtained from the first order transition curves are usually required. In this paper, a simple procedure to determine the Preisach density function using the Gaussian distribution function and genetic algorithm is proposed. The Preisach density function for the interaction field axis is known to have Gaussian distribution. To determine the density and distribution, genetic algorithm is adopted to decide the Gaussian parameters. With this method, just basic data like the initial magnetization curve or saturation curves are enough to get the agreeable density function. The results are compared with experimental data and we got good agreements comparing the simulation results with the experiment ones.

• Journal of the Korean Geotechnical Society
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• v.27 no.2
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• pp.63-72
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• 2011

The measured ground water behavior by TDR (time domain reflectometer) sensors were analyzed by the data filtering technique such as moving average method and Fourier transform, and the ground water level and unsaturated zone were tried to be determined numerically. At first, the variation of TDR data according to the saturation degree was measured by lab test, which is translated as a function of saturation degree. Then, changes of ground water level and lateral seepage in field conditions were simulated using acrylic pipe, and the measured data were analyzed to make calibration curve. Furthermore, TDR sensors were installed into the in-situ embankment to insure the field application. The saturation degree, unsaturated and dried zones were determined from the measured data.

• Journal of the Korean Magnetics Society
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• v.7 no.6
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• pp.308-313
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• 1997

The magnetoresistance (MR) and the saturation field behavior of the CoFe-Ag nano granular films as a function of the ferromagnetic underlayer and overlayer materials were investigated. The maximum MR ratio of 25.7 % and the saturation field of 2.1 kOe in the as-deposited 3000 $\AA$ $(Co_{92}Fe_8)_{31}Ag_{69}$ single alloy films at room temperature were obtained. The MR ratio and the saturation field of the 100 $\AA$ alloy film were 1.2 % and 5.2 kOe, respectively. Those of the sandwiched alloy films of 200 $\AA$ thick with the Fe under and overlayer of 100 $\AA$ were 11 % and 1.8 kOe respectively. The reduction of saturation field in the sandwiched alloy films is due to the exchange coupling between the ferromagnetic layers and the alloy layer. Among the Fe and FeNi, the more effective materials to reduce the saturation field of the sandwiched alloy films was Fe.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.05a
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• pp.333-336
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• 2001

The transient response in PDFA(Praseodymium-Doped Fiber Amplifier) is theoretically investigated. The PDFA has the spectral gain band in 1.3${\mu}{\textrm}{m}$. The transient model includes the transient buildup of the population inversion, the pump power, and the signal power and their transient variation along the fiber amplifier. The numerical analysis of transient model can predict the gain saturation, the variation of pump power and the gain as a function of the fiber length. It also shows the gain saturation and recovery effects depending on the pumping rate lead to distortion and saturation in the amplification of optical pulse. The results of numerical analysis, for the case of the Pr ion concentration of 1000ppm and the pump power of 0.5W the gain saturation is obtained 30dB at the length of 5m and the saturation time of upper level is 250 $mutextrm{s}$.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.48 no.2
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• pp.75-82
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• 1999

A compensation method of the motor parameters using zero sequence third harmonic voltage is presented for the speed sensorless vector control of the induction motor considering saturation of the flux. Generally, the air-gap flux of the saturated induction motor contains the space harmonic components rotating with the synchronous frequency of the motor. Because the EMF of the saturated induction motor contains the zero sequence harmonic voltages at the neutral point of the motor, those harmonic voltages can be used as a saturation index. In this work, the rotor flux observer is firstly designed for the speed sensorless vector control of induction motor. And a novel measurement method of the space harmonic voltage and a compensation method of th LPF(Low Pass Filter) are proposed. For compensating the non-linear variations of the magnetizing inductance depending on the saturation level of the motor, the dominant third harmonic voltage of the motor is used as a saturation function of the air-gap flux. And the variation of the stator resistance owing to the motor temperature can also be measured with the phase angle between the impressed voltage vector and the zero sequence voltage. The validity of the proposed parameter compensation scheme in the speed sensorless vector control using rotor flux observer is verified by the result of the simulations and the experiments.

• Journal of the Korean Magnetics Society
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• v.7 no.1
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• pp.31-37
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• 1997

The magnetoresistance and the saturation field behavior of the Co-Ag nano granular films as a function of the composition and the ferromagnetic underlayer and overlayermaterials were investigated. The maximum magnetoresistance of 23% and the saturation field of 2.3 kOe at room temperature were obtained in the as-deposited 3000$\AA$ $Co_{30}Ag_{70}$ single alloy films. The magnetoresistance and the saturation field of 100$\AA$ $Co_{30}Ag-{70}$ alloy film were 3.65 % and 3.0 kOe respectively. Those of the sandwiched films with 200$\AA$ Fe were 3.3 % and 1.23 kOe respectively. The saturation field of the sandwiched alloy films could be reduced by the exchange coupling between the ferromagnetic layers and the alloy layer. The effective depth of the exchange coupling was approximately 150$\AA$ in each Fe layer. Among the Fe, Co, and FeNi, the most effective materials to reduce the saturation field of the sandwiched alloy films was Fe.